Mission: Leg III of SEAMAP Summer Groundfish Survey
Geographic Area of Cruise: Gulf of Mexico
Date: July 11, 2019
Weather Data from the Bridge: Latitude: 28.29° N Longitude: 83.18° W Wave Height: 1-2 feet Wind Speed: 11 knots Wind Direction: 190 Visibility: 10 nm Air Temperature: 29.8°C Barometric Pressure: 1013.6 mb Sky: Few clouds
As I mentioned in my introductory post, the purpose of the SEAMAP Summer Groundfish Survey is to collect data for managing commercial fisheries in the Gulf of Mexico. However, the science involved is much more complex than counting and measuring fish varieties.
The research crew gathers data in three ways. The first way involves trawling for fish. The bulk of the work on-board focuses on trawling or dragging a 42-foot net along the bottom of the Gulf floor for 30 minutes. Then cranes haul the net and its catch, and the research team and other personnel weigh the catch. The shift team sorts the haul which involves pulling out all of the shrimp and red snapper, which are the most commercially important species, and taking random samples of the rest. Then the team counts each species in the sample and record weights and measurements in a database called FSCS (Fisheries Scientific Computer System).
SEAMAP can be used by various government, educational, and private entities. For example, in the Gulf data is used to protect the shrimp and red snapper populations. For several years, Gulf states have been closing the shrimp fishery and putting limits on the snapper catches seasonally to allow the population to reproduce and grow. The SEAMAP data helps determine the length of the season and size limits for each species.
Another method of data collection is conductivity, temperature, and depth measurements (CTD). The process involves taking readings on the surface, the bottom of Gulf floor, and at least two other points between in order to create a CTD profile of the water sampled at each trawling locations. The data becomes important in order to assess the extent of hypoxia or “dead zones” in the Gulf (see how compounded data is used to build maps of hypoxic areas of the Gulf: https://www.noaa.gov/media-release/noaa-forecasts-very-large-dead-zone-for-gulf-of-mexico). Plotting and measuring characteristics of hypoxia have become a major part of fishery research especially in the Gulf, which has the second largest area of seasonal hypoxia in the world around the Mississippi Delta area. SEAMAP data collected since the early 1980s show that the zone of hypoxia in the Gulf has been spreading, unfortunately. One recent research sample taken near Corpus Christi, TX indicated that hypoxia was occurring further south than in the past. This summer, during surveys two CTD devices are being used. The first is a large cylinder-shaped machine that travels the depth of the water for its readings. It provides a single snapshot. The second CTD is called a “Manta,” which is a multi-parameter water quality sonde (or probe). While it can be used for many kinds of water quality tests, NOAA is using it to test for hypoxia across a swath of sea while pulling the trawling net. This help determine the rate of oxygenation at a different depth in the water and across a wider field than the other CTD can provide.
Did You Know?
Algae is a major problem in the Gulf of Mexico. Hypoxia is often associated with the overgrowth of certain species of algae, which can lead to oxygen depletion when they die, sink to the bottom, and decompose. Two major outbreaks of algae contamination have occurred in the past three years. From 2017-2018, red algae, which is common in the Gulf, began washing ashore in Florida. “Red Tide” is the common name for these algae blooms, which are large concentrations of aquatic microorganisms, such as protozoans and unicellular algae. The upwelling of nutrients from the sea floor, often following massive storms, provides for the algae and triggers bloom events. The wave of hurricanes (including Irma and during this period caused the bloom. The second is more recent. Currently, beaches nearest the Mississippi Delta have been closed due to an abundance of green algae. This toxic algae bloom resulted from large amounts of nutrients, pesticides, fertilizers being released into the Bonnet Carre Spillway in Louisiana because of the record-high Mississippi River levels near Lake Pontchartrain. The spillway opening is being blamed for high mortality rates of dolphins, oysters and other aquatic life, as well as the algae blooms plaguing Louisiana and Mississippi waters.
Pulling away from Pascagoula yesterday, I knew we were headed into open waters for the next day and half as we traveled east down the coast to the Tampa Bay, FL area. I stood on the fore deck and watched Oregon II cruise past the shipyard, the old naval station, the refinery, navigation buoys, barrier islands, and returning vessels. The Gulf is a busy place. While the two major oceans that flank either side of the U.S. seem so dominant, the Gulf as the ninth largest body of water in the world and has just as much importance. As a basin linked to the Atlantic Ocean, the tidal ranges in the Gulf are extremely small due to the narrow connection with the ocean. This means that outside of major weather, the Gulf is relatively calm, which is not the case with our trip.
As we cruise into open waters, along the horizon we can see drilling platforms jutting out of the Gulf like skyscrapers or resorts lining the distant shore. Oil and gas extraction are huge in this region. Steaming alongside us are oil tankers coming up from the south and cargo ships with towering containers moving back and forth between Latin America and the US Coast. What’s in the Gulf (marine wildlife and natural resources) has geographic importance, but what comes across the Gulf has strategic value too.
The further we cruised away from Mississippi, the water became choppy. The storm clouds that delayed our departure the day before were now overhead. In the distances, rain connected the sky to sea. While the storm is predicted to move northwest, the hope is that we can avoid its intensification over the Gulf Stream as we move southeasterly.
I learned that water in the Gulf this July is much warmer than normal. As a result, locally produced tropical storms have formed over the Gulf. Typically, tropical storms (the prelude to a hurricane) form over the Atlantic closer to the Equator and move North. Sometimes they can form in isolated areas like the Gulf. Near us, an isolated tropical storm (named Barry) is pushing us toward research stations closer to the coast in order to avoid more turbulent and windy working conditions. While the research we are conducting is important, safety and security aboard the ship comes first.
Weather Data from the Bridge
Latitude: 029 23.89 N
Longitude 094 14.260 W
Barometric Pressure 1022.22mbar
Air Temperature: 69 degrees F
The isness of things is well worth studying; but it is their whyness that makes life worth living.
– William Beebe
Science and Technology Log
Today is our last day at sea and we have currently completed 53 stations!At each station we send out the CTD. CTD stands for Conductivity, Temperature and Depth. However, this device measures much more than that.During this mission we are looking at 4 parameters: temperature, conductivity, dissolved oxygen and fluorescence which can be used to measure the productivity of an area based on photosynthetic organisms.
Once the CTD is deployed, it is held at the surface for three minutes.During this time, 4,320 scans are completed!However, this data, which is used to acclimate the system, is discarded from the information that is collected for this station.
Next, the CTD is slowly lowered through the water until it is about 1 meter from the bottom.In about 30 meters of water this round trip takes about 5 minutes during which the CTD conducts 241 scans every 10 seconds for a grand total of approximately 7,230 scans collected at each station.
Our CTD scans have gathered the expected data but during the summer months the CTD has found areas of hypoxia off the coast of Louisiana and Texas.
The gloomy weather has made the last few days of the voyage tricky. Wind and rough seas have made sleeping and working difficult. Plus, I have missed my morning visits with dolphins at the bow of the ship due to the poor weather.But seeing the dark blue water and big waves has added to the adventure of the trip.
We have had some interesting catches including one that weighed over 800 pounds and was mostly jellyfish.Some of the catches are filled with heavy mud while others a very clean. Some have lots of shells or debris.I am pleasantly surprised to see that even though I notice the occasional plastic bottle floating by, there has not been much human litter included in our catches.I am constantly amazed by the diversity in each haul.There are species that we see at just about every station and there are others that we have only seen once or twice during the whole trip.
I am thrilled to have had the experience of being a NOAA Teacher at Sea and I am excited to bring what I have learned back to the classroom to share with my students.
Bonus points for the first student in each class to send me the correct answer!
These are Calico Crabs, but this little one has something growing on it?What is it?
Did you know…
That you can tell the gender of a flat fish by holding it up to the light?
Today’s Shout Out!
Kudos to all of my students who followed along, answered the challenge questions, played species BINGO, and plotted my course!You made this adventure even more enjoyable!See you soon 🙂
While our main mission aboard the NOAA Ship Oregon II is to survey and study sharks and red snapper, it is also very important to understand the environmental conditions and physical properties of the sea water in which these animals live. The CTD instrument is used to help understand many different properties within the water itself. The acronym CTD stands for Conductivity (salinity), Temperature, and Depth. Sensors also measure dissolved oxygen content and fluorescence (presence of cholorphyll).
Conductivity is a measure of how well a solution conducts electricity and it is directly related to salinity, or the salt that is within ocean water. When salinity measurements are combined with temperature readings, seawater density can be determined. This is crucial information since seawater density is a driving force for major ocean currents. The physical properties and the depth of the water is recorded continuously both on the way down to the ocean floor, and on the way back up to the surface. There is a light, and a video camera attached to the CTD to provide a look at the bottom type, as that is where the long line is deployed, and gives us a good look at the environment where our catch is made. These data can explain why certain animals gather in areas with certain bottom types or physical parameters. This can be particularly important in areas such as the hypoxic zone in the Gulf of Mexico. This is an area of low oxygen water caused by algal blooms related to runoff of chemical fertilizers from the Mississippi River drainage.
Ready to deploy the CTD
Calibrating the CTD
The CTD instrument itself is housed in a steel container and is surrounded by a ring of of steel tubing to protect it while deployed and from bumping against the ship or sea floor. Attached water sampling bottles can be individually triggered at various depths to collect water samples allowing scientists to analyze water at specific depths at a particular place and time. The entire structure is slowly lowered by a hydraulic winch, and is capable of making vertical profiles to depths over 500 meters. An interior computer display in the ship’s Dry Science Lab profiles the current location of the CTD and shows when the winch should stop. We have found this to be a tricky job, during large wave swells, as the boat rocks quite a bit and changes the depth by a meter or more. The operator must be very careful that the CTD doesn’t hit the ocean floor too hard which can damage the equipment.
The data collected while deployed at each station is instantly uploaded to NOAA servers for immediate use by researchers and scientists. The current data is also available the general public as well, on the NOAA website. Once safely back aboard the Oregon II, the CTD video camera is taken off and uploaded to the computer, The CTD must be washed off and the lines flushed for one minute with fresh water, as the salt water from the ocean can damage and corrode the very sensitive equipment inside. The instrument is also calibrated regularly to ensure it is working correctly throughout all legs of the long line survey.
I am having such a great time during my Teacher at Sea experience. In the 9 days aboard ship so far, we have traveled the entire coasts of Mississippi, Arkansas, Florida, South Carolina, and North Carolina. Never in my life did I think I would get an opportunity to do something like this as I’ve dreamed about it for decades, and now my dreams have come true. I’m learning so much about fishing procedures, the biology of sharks, navigational charting, and the science of collecting data for further study while back on land at the lab. I can’t wait to get home and spread the word about NOAA’s mission and how they are helping make the world a better place, and are advocating for the conservation of these beautiful animals!
Animals Seen: Sharpnose shark, Tiger Shark, Grouper, Red Drum fish, Moray Eel, Blue Line Tile fish
“The solution to pollution is dilution” was a common refrain during the midcentury as large scale factories became more common. This mindset applied to both air and water as both seemed limitless. Looking out over the Gulf of Mexico, a relatively small body of water, it’s easy to see how this logic prevailed. Even the Great Lakes, the largest body of fresh surface water in the world, accepted incalculable amounts of pollution and sewage from coastal factories, steel and wood mills, and of course major cities.
The rise of the modern technological age that took humans to the moon gave us the first glimpse of the fallacy of the “solution”. “Earthrise” is the first photo of the entire Earth taken from space, showing us how thin our protective atmosphere really is and how delicately the Blue Planet floats in the vastness of space. This is the beginning of the modern environmental movement.
To truly guide the development of national policies including those that protect air and water quality, federal agencies such as NOAA are responsible for collecting data about our atmosphere and oceans, now knowing that these ecological compartments cannot endlessly dilute the pollution we generate. What seemed to be an obvious solution has today ballooned into a number of serious problems, from acid rain and blinding smog in cities to burning rivers, mass fish die offs that wash up on Lake Michigan beaches and dying coral reefs in the oceans.
A major pollutant in the Gulf is sourced from industrial agriculture practices from as far away as Illinois and the rest of the Midwest farm belt. Fertilizer and pesticides enter local rivers that find their way to the Mississippi River which carries contaminants into the Gulf of Mexico.
We have reached the Gulf’s “Dead Zone”, yielding a few tiny catches. Station W1601 may have given the smallest catch ever—a clump of seaweed and a whole shrimp.
Hypoxia literally means “low oxygen”. When fertilizers used to grow corn and soy enter bodies of water, they likewise feed the growth of algae, which are not technically plants but they are the aquatic equivalent. But plants make oxygen, how can this lead to low oxygen? Algae and land plants only produce oxygen during the day. At night, they consume oxygen gas through respiration. They do this during the day as well, but overall produce more oxygen in the light through photosynthesis. For hundreds of millions of years, that’s been fine, but the recent addition of fertilizers and the warm Gulf waters cause an explosion of the kind of microscopic algae that are suspended in the water column and turn water bright green, or red in the case of “red tides”. These explosions are called algal blooms.
Algal blooms can cloud up water, making life hard for other photosynthetic organisms such as coral symbionts and larger seaweeds. At night, animals can suffocate without oxygen. During red tides, some algae release toxins that harm other life. When these organisms die and sink, bacteria go to work and decompose their bodies. The population of bacteria explodes, consuming the remaining oxygen at the sea floor. Animals that wander into the hypoxic zone also suffocate and die, feeding more decomposer bacteria that can survive with little to no oxygen. Thus, hypoxic areas are also called “dead zones”. The hypoxic zone is just above the sea floor, as little as a half a meter above, and oxygen levels can drop precipitously within a meter of the bottom.
NOAA scientists including those conducting the SEAMAP Summer Groundfish survey on Oregon II track the location, size and movement of the Gulf hypoxic zone using the conductivity-temperature-dissolved oxygen probe, or CTD. The CTD is sent into the water before every trawl to take a variety of measurements. Besides conductivity (a measure of ions), temperature and oxygen, the CTD also checks the salinity, clarity and amount of photosynthetic pigments in the water, which gives an idea of plankton populations. Ours uses two different sensors for conductivity, salinity, temperature and oxygen, double-checking each other. A pump pulls water through the various sensors and the measurements are sent directly to a computer in the dry lab to record these data.
The CTD is lowered to just under the surface of the water to make sure the pump is working and to flush the system. Then it is lowered to within a meter of the bottom. The CTD also has an altimeter to measure the distance from the bottom, while the ship also uses sonar to determine the water depth at each station. Water is measured continuously as the CTD is lowered and raised, creating a graph that profiles the water column. Crewmen are on deck controlling the winches according to the directions from a scientist over the radio who is monitoring the water depth and measurements in the dry lab.
The CTD also has bottles that can store water samples so oxygen can be tested a third time in the lab onboard. When we only get a few fish where the CTD recorded normal oxygen, the CTD is launched again to verify oxygen levels using all three methods. In the CTD output, oxygen is coded in green as a line on the graph and in the data tables. Most stations read in the 5-6 range, the cutoff for hypoxia is 2. We are reading less than 1 in the Dead Zone.
With storms in the path and not-so-plenty of fish in the sea, today is a slow day.
Looking out over the water, I can’t help but think how intrepid, even audacious, early mariners must have been. I know we are within a couple miles of the coast but there’s no sign of land anywhere in any direction. Even with the reassurance that satellites, radar, radios, AND trained NOAA Corps officers steering in the bridge are all keeping track of us, I still swallow a moment of panic. What kind of person decides to sail out in search of new continents when it only takes a couple hours to lose track of where you came from? And yet, the Polynesians set out thousands years ago in canoes from mainland Asia, the Aborigine ancestors managed to find Australia, and of course, Europeans sailed across the Atlantic to the Americas, whether they knew it or not. It was all possible through careful observations of the winds, waves, ocean currents, stars and other indications of direction, but I still have to think that that’s a pretty bold move when you don’t know if land lies ahead.
At least we’re not alone out here. These are some other animals that we’ll leave for the mammal survey and birders to count.
Dolphins appear around large catches for some pickings from the net.
Frigate birds, male in the upper left appear black, female below with a white breast.
Frigate bird inhabit tropical waters and are relatively uncommon in the U.S.
Brown pelican, Pelecanus occidentalis
Gulls never left the side of NOAA Ship Oregon II.
Did You Know?
The CTD also shows the layers of ocean water. Looking at the graph again for the red (salinity) and blue (temperature) lines, we can see where they cross at about 15 meters. This shows where colder, saltier water starts compared to the warm surface water that is diluted by fresh water and mixed by wind.
Warm weather and blue skies are making it easy to spend a lot of time out on deck, looking for wildlife! In addition to the lazy seagulls who keep hitching a ride on the ship’s trawling gear, we continue to spot dolphins, flying fish, and even a shark feeding frenzy!
Latitude: 28 24.13 N
Longitude: 83 57.32 W
Air temp: 27.7 C
Water temp: 31.3 C
Wind direction: light and variable
Wind speed: light and variable
Wave height: 0.3 meter
Sky: 50% cloud cover, no rain
Science and Technology Log
The organisms in each catch provide a snap shot of the marine life in one location in one moment in time. It’s interesting to see what we catch, but there are not many scientific conclusions that we can draw based on what we see in just 10 days. However, this survey has been completed twice per year (once in the summer and once in the fall) for over 35 years. It is looking at trends, or changes and patterns over time, that allows scientists to draw conclusions about the health and ecology of the Gulf of Mexico.
One of the major practical applications of this research is to prevent overfishing, the removal of too many individuals from a population causing that population to become unstable. Continued overfishing can lead to the extinction of a species because it leaves too few mature individuals to reproduce and replace those that are removed.
One famous example of overfishing and its consequences occurred in the late 1980’s off the Atlantic coast of Canada. Cod was a major food source and commercial industry in the provinces of Newfoundland and Labrodor. However, unregulated overfishing depleted the cod population and, between 1988 and 1992 the cod population crashed, losing more than 99% of its biomass – they were essentially gone. This destroyed the industry, putting over 40,000 people out of work. In 1992, the government finally imposed a complete ban on cod fishing in hopes that the cod population could still recover. The fishing ban is still in place today, though just last year, Canadian scientists released a report stating that there are some signs of hope!
When NOAA scientists notice overfishing occurring in US waters, they can recommend that protective regulations, or rules, are put in place to limit or even stop fishing in an area until the species has had a chance to recover.
Here are a few examples of the types of regulations that have been created in the Gulf of Mexico in response to the data from the Groundfish Survey.
Texas Shrimping Closure
To prevent overfishing of shrimp in the western Gulf of Mexico, NOAA and the Texas Department of Wildlife collaborated to implement an annual closure of state and federal waters off the coast of Texas to shrimping. This is called the “Texas Closure.”
The Texas closure runs each year from about May 15 to July 15, though the exact dates vary depending on the health of the shrimp population that year. This break allows the shrimp time to mature to an age at which they can reproduce, and to migrate out to deeper waters, which is where females spawn. It also allows the shrimp to grow to a size that is more commercially valuable.
We saw quite a few shrimp in our recent catches. Because this species is being more intensively monitored, we collected more detailed data about the individuals we caught, including the length, mass, and sex of a sample of least 200 individual shrimp (instead of a the smaller sample size of 20 that we used for most other species.)
In addition to sending out an annual notice to fisherman of the dates of the Texas Closure, NOAA also makes all of the shrimp survey data available. This can help fishermen to target the best fishing locations and work efficiently. For example, this is a plot showing the amount of brown shrimp found at various locations, created using this year’s survey data.
Red Snapper Regulation
Another species that is currently under regulation is the red snapper, which has been a popular seafood in the US since the 1840s. As fishing technology improved and recreational fishing expanded in the 1950’s, the number of red snapper captured each year increased dramatically. The shrimp industry was also expanding rapidly at this time, and juvenile red snapper were often accidentally caught and killed in shrimp trawls. As a result of these three pressures, the red snapper population began to decline dramatically.
By 1990, the spawning potential, or the number of eggs produced by the population each year, was only 2% of what it would have been naturally, without any fishing. This was far below the target spawning potential level of 26% that is necessary to sustain the species.
Limiting the number of commercial and recreational fishing licenses issued each year
Restricting the size and number of fish that a fisherman could collect on a fishing trip
Reducing the amount of time each year that fishermen could fish for red snapper
Regulating the type of fishing gear that could be used
Requiring commercial shrimp fishermen to install devices on their trawls to reduce the by-catch of juvenile red snapper
Requiring fishermen to avoid areas where red snapper spawn
Survey results in the last 5 years show that these regulations are working and that the red snapper population is growing. This is good news. However, the red snapper is not out of the woods yet. It is important to understand that, as a species with a long life span (they can live over 50 years!), it will take time for the population to regain
its normal age structure. Currently, the majority of red snapper found in the Gulf are less than 10 years old. These fish are still juveniles capable of producing only a fraction of the offspring a fully mature individual would produce. It is important to continue to closely monitor and regulate the fishing of snapper until both the number and age of individuals has been restored to a sustainable level.
We were fortunate to catch members of three different species of red snapper during my leg of the survey. I did notice that most of them were relatively small – less than 10 inches – which is consistent with the concern that the population is still disproportionately young.
As with the shrimp, we collected more detailed information about these individuals. We also removed the stomachs of a sample of snappers. As I discussed in my last blog (“What Tummies Tell Us”), scientists back on land will examine the contents of their stomachs as part of a diet study to better understand what snapper are eating. Because the invasive lionfish has a competitive relationship with red snapper, meaning that it eats many of the same foods that red snapper eat, fisheries biologists are concerned that red snapper may be forced to settle for alternative and/or reduced food sources and that this could also slow their recovery.
In addition to collecting data about the fish and other organisms we find, remember that we also use a group of instruments called a CTD to collect information about the quality of the water at each survey station. (For more about CTDs, please see my previous blog “First Day of Fishing.”)
One of the measurements the CTD takes is the amount of oxygen that is dissolved in the water. This is important because, just like you and me, fish need to take in oxygen to survive. (The difference is that you and I use our lungs to remove oxygen from the air, whereas fish use gills to remove oxygen from the water!) When dissolved oxygen concentrations in the water drop below 2 mg/L, a condition called hypoxia, most marine organisms cannot survive.
When waters become hypoxic, organisms that are able to migrate (like some fishes) will leave the area. Organisms that cannot migrate (like corals or crabs) will die from lack of oxygen. This creates large areas of ocean, called dead zones, that are devoid of typical marine life. Often anaerobic microorganisms, some of which are toxic to humans, will then grow out of control in these areas. Not only is this stressful for the marine populations, it hampers regular fishing activities, and can even pose a threat to human health.
The Gulf of Mexico is home to the largest hypoxic zone in US waters. Nitrogen-rich fertilizers and animal waste from farming activities throughout the Midwest United States all collect in the Mississippi River, which drains into the Gulf. Though nitrogen is a nutrient that organisms need in order to grow and be healthy, excess nitrogen causes an imbalance in the normal nitrogen cycle, and stimulates high levels of algae plant growth called an algal bloom. Once the algae use up the excess nitrogen, they begin to die. This causes the population of decomposers like fungi and bacteria to spike. Like most animals, these decomposers consume oxygen. Because there are more decomposers than usual, they begin to use up oxygen faster than it can be replenished.
This hypoxic zone is largest in the summer, when farming activities are at their peak. In the winter, there is less farming, and therefore less nitrogen. As the hypoxic water continues to mix with normal ocean water, the levels of oxygen begin to return to normal. (When there are tropical storms or hurricanes in the Gulf, this mixing effect is more significant, helping to reduce the impact of the hypoxia. This is often the primary cause of low-hypoxia years like 2000.) Unfortunately, the average size of the annual dead zone remains at nearly 15,000 square kilometers, three times the goal of 5,000 square kilometers.
The data collected from this year’s Groundfish Survey was used to create this map of hypoxic areas. How might this map be different if tropical storm Cindy had not occurred this summer?
The data we collect on the Groundfish survey is combined with data gathered during other NOAA missions and by other organizations, like NASA (the National Aeronautics and Space Administration) and USGS (the United States Geologic Survey). By collaborating and sharing data, scientists are able to develop a more complete and detailed understanding of hypoxia levels.
In response to the levels of hypoxia seen in the data, the federal Environmental Protection Agency (EPA) has required Midwestern states to develop and implement plans that will allow them to make greater progress in reducing the nutrient pollution that flows into the Mississippi. Specifically, the EPA wants states to do things like:
Identify areas of land that have the largest impact on pollution in the Mississippi
Set caps on how much nitrogen and other nutrients can be used in these areas
Develop new agricultural practices and technologies that will reduce the amount of these pollutants that are used or that will flow into the water
Ensure that the permitting process that states use to grant permission to use potential pollutants is effective at limiting pollutants to reasonable levels
Develop a plan for monitoring how much nutrient pollution is being released into waters
These EPA regulations were only recently implemented, so it is still unclear what, if any, impact they will have on the hypoxic zone in the Gulf. It will be interesting to keep an eye on the data from the Groundfish survey in coming years to help answer that question!
In the mean time, though, things still seem to be moving in the wrong direction. In fact, NOAA just announced that this summer’s dead zone is the largest ever recorded.
Getting a PhD in your chosen field of science is an awesome accomplishment and is necessary if your goal is to design and carry out your own research projects. However, I’ve noticed that the PhD is often presented to students as the only path into a career in science. I think this is unfortunate, since this often discourages students who know they do not want to pursue a graduate degree from entering the field.
I’ve noticed that most of the scientists I’ve met while on board the Oregon II and in the NOAA lab at Pascagoula do not hold PhDs, but are still deeply involved in field work, lab work, and data analysis every day.
I asked Andre DeBose, a senior NOAA fishery biologist and the Field Party Chief for this mission, if he feels a PhD is necessary for those interested in fishery biology. Andre agreed that a graduate degree is not necessary, but he cautioned that it is a very competitive field and that education is one way to set yourself apart – “if you have the opportunity to get an advanced degree, take the opportunity.”
However, he continued, “the MOST important thing you can do is take the opportunity to do internships, volunteering, and fellowships. Those open a lot of doors for you in the world of biology.” Andre himself holds a bachelors degree in biology, but it was his years of experience working in aquaculture and as a contractor with NOAA that were most helpful in paving the way to the permanent position he holds today. “When I graduated from college, I took a low-paying job in aquaculture, just to start learning everything I could about fish. When contract [or short-term] positions became available at the NOAA lab, I applied and tried to make myself as useful as possible. It took time and I had to be really persistent – I would literally call the lab all the time and asked if they had anything they needed help with – but when a full time position finally became available, everyone knew who I was and knew that I had the right skills for the job.”
Now, Andre tries to help others navigate the tricky career path into marine biology. In addition to his responsibilities as a biologist, he is also the Outreach and Education Coordinator for the NOAA lab, which allows him to mentors all of interns (and Teachers at Sea like me!) and to talk with students at schools in the community.
If you’re interested in pursuing a career in marine biology, it’s never to early to start looking for some of those volunteer opportunities! There are lots of scientists out there like Andre who are excited to share their knowledge and experience.
Did You Know?
In the Gulf of Mexico, each state has the authority to regulate the waters that are within about 9 miles of the coast. (This includes making rules about fishing.) Beyond that, the federal government, with the help of federal agencies like NOAA, make the rules!
Questions to Consider:
Research: This article discussed the political side of the Snapper situation. Research other news articles about this issue to ensure that you have a balanced perspective.
Weather Data from the Bridge: I am now back in Longmont, Colorado
Latitude: 40 08.07 N
Longitude: 105 08.56 W
Air temp: 31.1 C
Science and Technology Log
One of the major questions I had before my Teacher at Sea voyage was how the level of oxygen in the water will affect the species we collect. Typically, in the summer, a dead zone forms in the Gulf of Mexico spreading out from the mouth of the Mississippi river. You can see an image of the dead zone from 2011 below.
Phytoplankton, or microscopic marine algae, are the base of the marine food web. There are two main classes, diatoms and dinoflagellates, which are both photosynthetic and typically live towards the top of the water column. We did not sample plankton on our leg of the cruise, but if you want to learn more you can check out this site: https://oceanservice.noaa.gov/facts/phyto.html. In the summer, phytoplankton and algae can build up due to excess nutrients in the water that are running off from urban areas, agriculture and industry. Much of our sampling was near the mouth of the Mississippi River, which is a significant source of excess nutrients. The extra nitrogen and phosphorus in the runoff cause the excess growth of photosynthetic organisms which leads to a buildup of zooplankton (heterotrophic plankton). Once the phytoplankton and zooplankton die and sink to the bottom they are decomposed by oxygen consuming bacteria which deplete the oxygen in the water column. According to NOAA, hypoxia in aquatic systems refers to an area where the dissolved oxygen concentration is below 2 mg/L. At this point, most organisms become physiologically stressed and cannot survive.
Tropical Storm Cindy, which kicked up just as I was arriving in Galveston, brought significant freshwater into the gulf and mixed that water around so we did not see as many low oxygen readings as expected. While I was talking with Andre about hypoxia when we were on the ship, he used the analogy of stirring a bowl of soup. There is a cool layer on top, but as you stir the top layer and mix it with the lower layers, the whole bowl cools. Similarly, the oxygen rich freshwater from the storm is mixed around with the existing water, reducing the areas of low oxygen. You can see in the map below that we had fewer hypoxic areas than in 2011.
We used the CTD to obtain oxygen readings in the water column at each station. In the visuals below you can see a CTD indicating high oxygen levels and a CTD indicating lower, hypoxic, oxygen levels. The low oxygen CTD was from leg one of the survey. It corresponds with the red area in the hypoxia map above.
Personal Log and Reflections
When I arrived back on land I still felt the rocking of the Oregon II. It took two to three days before I felt stable again. As friends and family ask about my experience, I find it hard to put into words. I am so grateful to the NOAA Teacher at Sea program for giving me this incredible experience and especially thankful to Science Field Party Chief Andre Debose and my day shift science team members, Tyler, David and Sarah, for teaching me so much, being patient and making my experience one that I will never forget.
The ocean is so vast and we have explored so little of it, but now, I have a strong understanding of how a large scale marine survey is conducted. Being an active participant in fisheries research was definitely out of my comfort zone. The experience helped stretch me and my learning and has giving me great insight to bring back to share with my students and school community. The map below shows our journey over the two weeks I was on the ship traveling along the Texas, Louisiana, Mississippi and Florida coasts.
My experience on Oregon II has also re-engaged me with the ocean. As a child, I spent time each summer on an island off the coast of Maine and even got to go fishing with my Dad and his lobsterman buddies. But for the last 20 years or so, my exposure to the ocean has been limited to just a few visits. My curiosity for the marine world has been reignited; I look forward to bringing more fisheries science and insight into my classroom.
I mentioned in a previous blog that our shrimp data was sent daily to SEAMAP and made available to fisheries managers and shrimpers to allow them to make the best decisions about when to re-open the shrimp season. According to Texas Parks and Wildlife (TPWD), the commercial shrimp season for both the state and federal waters re-opened just after sunset on July 15, 2017. TPWD said, “The opening date is based on an evaluation of the biological, social and economic impact to maximize the benefits to the industry and the public.” It is satisfying to know that I was part of the “biological evaluation” to which they refer.
Finally, I took some video while out at sea and now with more bandwidth and time, I’ve been able to process some of that video to shed additional light on how fisheries research is conducted. I’ve added two videos. The first one shows the process of conducting a bottom trawl and the second one show the fish sorting and measuring process. Enjoy!
Did You Know?
You can use the following sites to help you make smart sustainable seafood choices:
Monterey Bay Aquarium (http://www.seafoodwatch.org). There is also a free app you can put on your phone so you can do a quick look up when you are at a restaurant, the grocery or a fish market.
The largest Gulf of Mexico dead zone recorded was in 2002, encompassing 8,497 square miles. The smallest recorded dead zone measured 15 square miles in 1988. The average size of the dead zone from 2010-2015 was about 5,500 square miles, nearly three times the 1,900 square mile goal set by the Hypoxia Task Force in 2001 and reaffirmed in 2008.
Thank you to the Dawson sixth graders (now seventh graders!) for your great questions. I look forward to speaking with you all when school starts in a few weeks.
What is at the bottom of the low oxygen part of the ocean? (Allison)
There is a lot of accumulated dead organic matter that is decomposed by oxygen consuming bacteria.
What do you find in the dead zone? Do less animals live there? (Leeham, Mae, Shane, Alfie, Bennett)
Typically, trawls are smaller and the diversity of organisms decreases in the low oxygen areas. Often you will find resilient organisms like croaker. There is a lot of research looking at which organisms can live in dead zones and how these organisms compensate for the low levels of oxygen.
Is there any way to fix the dead zone? What can we do about the dead zone? (Isaac, Owen, Ava)
It is estimated that seventy percent of the excess nitrogen and phosphorus that runs off into the Gulf of Mexico comes from industrial agriculture. Reducing the amount of fertilizer used to grow our food would help decrease the extent of the dead zone area. Perhaps one of you will come up with a way to feed our communities in a more sustainable way or a technology that can remove these excess nutrients before the water reaches the Gulf.
Mission: I am back home in Amboy, IL, now so my mission is getting back to a “normal” schedule and getting my land legs back!
Weather: Partly sunny, 82 degrees
Date: June 25, 2014
Science and Technology:
Hypoxia or low oxygen levels in the water is my final topic. The “dead zone” may seem like it does not relate to me being home, but in reality it really does.
This “dead zone” is affected by many things such as the oceanographic conditions, but a major cause is excessive nutrient pollution from agriculture and waste water. Being from a rural agricultural area I wonder how much of what we are doing here in the north affects the ocean waters far away?
So how does this all start? The nitrogen and phosphorus that flows into the water fuels the growth of algae, later when the algae dies and decays, it sinks to the bottom. At the bottom the bacteria will devour the dissolved oxygen from the water. With little or no oxygen the organisms living there must either move, if they can, or they will die.
Where does this nitrogen and phosphorus come from? Most of this can be found in fertilizers from agriculture, golf courses and suburban lawns, discharges from sewage treatment plants, and even from erosion of soil full of nutrients. Since past spring was very rainy and there were floods near the Mississippi River much of this was taken from the soil into the water. The flood waters then drained back into the river and into the gulf carrying many of these nutrients.
How do we know this is happening and that it is getting worse? On the NOAA Ship Oregon II and other ships there are daily checks of the water oxygen levels. Tests similar to these have been conducted for many years. The results are compared and they show that changes in the oxygen levels are happening and not for the better.
While on the ship the scientist performed these tests using the CTD. Water taken from the CTD is handled very carefully so no oxygen is added by accident. As chemicals are added, you can see the changes where the oxygen in the water bonds to the chemicals. The results of these tests are compared to the results collected by the computer. Having both tests generate similar results show more proof of the oxygen levels.
I noticed that when the ship was closer to land, the oxygen levels would be lower and Lead Scientist Kim Johnson said as the ship traveled closer to the mouth of the Mississippi River, the levels would drop even more. (I plan on watching the results as they are posted.)
Can anything be done to stop this? Some scientist say one of the solutions would be to use fewer fertilizers another would be to maybe watch when the chemicals were added, so there would be less runoff.
Of course checking septic systems and sewage treatment plants to be sure they are up to code and working correctly would help. These solutions sound simple, but maybe people do not even realize what happens up north and how it really does affect what is going on at the bottom of the ocean.
Maybe our Amboy Marsh is the beginning, a place where the water can be filtered.
Here is a map showing the levels of oxygen in the water.
I have been home now for four days. My land legs are back and I only feel dizzy when closing my eyes while washing my hair in the shower. I want to thank everyone for reading my blogs, I hope you enjoyed my adventure and learned something new.
As I look through my pictures, memories of the sixteen days I spent at sea flood my mind. I look at the safety precautions that were taken to make sure everyone on the ship stayed safe. The drills, the posting of where everyone was to go and what they were suppose to do in case of an emergency, and the sign stating how many days the ship had gone without a problem. I always felt safe, everyone was very careful and followed rules to ensure the safety of everyone….just like we do at school!
I also think about how what seemed like a tiny space became my home away from home. Everything you need to survive on a mere 178 ft ship! Two showers for everyone to share, three heads (toilets) and one washing machine and one dryer. I thought it would be impossible, but it just proved my husband’s theory that we have too much in our home!
I want to tell you how thankful I am that NOAA has this wonderful program and allowed me to participate. I know many teachers applied for this and I am honored that I was selected. Thank you to the scientists aboard the ship: Kim, for EVERYTHING, the Night Shift: Taniya, Andre, Lee, Chrissy, and Rebeca for all of their guidance and help.
The deck crew: Chris, Chuck and Mike-thanks for your support and for making the night go by so quickly! Master Dave Nelson and ALL the members of his crew for their help in explaining everything and the tours on the ship!
This survey opened my eyes to what is happening under the water and how fragile life in the deep blue sea really is. It confirmed my thinking that we (the human race) need to look closely at what we are doing everyday and how it affects others. I plan on following the NOAA Ship Oregon II during the rest of the summer groundfish survey and during the fall groundfish survey. I want to see how the oxygen level changes, how the data collected affects the shrimp season, and follow the members of the ship!
I cannot wait to share with my students and with anyone that will listen! Would I do this again? YES, I would go back to sea in a minute if I had the chance!
The Oregon II carries an instrument called a CTD (Conductivity, Temperature, Depth) that is lowered into the ocean by a crane. On the bottom of the CTD are sensors that detect and relay information back to a computer onboard the Oregon II. On top of the sensors are Niskin (gray) bottles that are manually opened before the CTD is lowered into the water, and are tripped by the Watchleader (closing and trapping water inside) when it reaches the desired depth. Data from the CTD is sent to the ship where it is recorded and stored. After the CTD is back on board, the water from the Niskin bottles is used to check the amount of dissolved oxygen. This data is then combined with numerous stations/stops and used to create a real time map of the dissolved oxygen levels in the Gulf of Mexico.
One of the missions of the SEAMAP cruise is to measure the amount of dissolved oxygen (DO) in the Gulf of Mexico. Dissolved oxygen is the amount of oxygen that is present in the water and is available for marine life. When the dissolved oxygen content drops below 2mg/L, the water is considered to be hypoxic and the area may be called a dead zone. Basically, what this means is that marine life cannot survive because they do not have enough oxygen.
If you can imagine living at the top of Mt. Everest without an oxygen tank, that is what living in hypoxia would be like to a fish. While the majority of organisms cannot survive in a dead zone, those organisms that do survive have been found to have permanent changes in their reproductive systems, such as smaller ovaries and fewer eggs in female fish. Dead zones in the Gulf of Mexico are due to runoff from Nitrates and Phosphates that come from fertilizers, detergents and human/animal waste. Because of hypoxia, phosphate detergents have been banned in the Great Lakes and you may even notice that some of your household detergents say “phosphate free”.
Overall I’m pretty exhausted both mentally and physically. While I have taught my Environmental Students about some of the things I am doing, it’s my first time putting these into practice myself. Although I am grateful for the experience, it is a bit much to take it all in and I feel slightly overwhelmed. Luckily, I will have the chance to perform these tasks over and over before the Oregon II returns to shore. And more importantly, I am working with an amazing team of scientists who are happy to answer all of my questions and walk me through procedures multiple times.
I’m slowly adjusting to being in a different time zone, but am definitely feeling the time change. I am on the night shift which means I start work at midnight and finish at noon. This is unusual for me since I like to be in bed by ten every night. On the bright side, my night shift means I get to beat the heat during the middle of the day when the temperatures are in the eighties.
Yesterday we had an emergency abandon ship drill where we had to don survival suits. You put them on as though you were getting into a sleeping bag. This meant a lot of rolling around on the floor for me, but I like to think I entertained the crew while I was doing it. My dad thinks I look like Sebastian from the Little Mermaid in my suit, but I’m confident that I will be a warm lobster until rescue arrives in the unlikely event I have to abandon ship.
Did You Know?
Male seahorses, not female seahorses, carry fertilized eggs and give birth to their young. They will also eat any of their offspring that don’t swim away quickly enough. It pays to be a female seahorse!
NOAA Teacher at Sea Chris Peters Onboard NOAA Ship Oregon II July 10 – 19, 2013
Mission: SEAMAP Summer Groundfish Survey Geographic Area of Cruise: Gulf of Mexico, leaving from Pascagoula, MS Date: July 13, 2013
Weather and Location: Time: 23:24 Greenwich Mean Time (7:24 p.m. in Rockville, MD)
Speed (knots): 9.30
Water temperature: 28.90 degrees Celsius
Salinity (PSU = Practical Salinity Units): 35.38
Air temperature: 31.20 degrees Celsius
Relative Humidity: 65%
Wind Speed (knots): 8.92
Barometric Pressure (mb): 1013.34
Depth (m) = 19.20
Science and Technology Log
In my introduction I explained that SEAMAP is a state, federal, and university program. In fact, there is a managing unit called the SEAMAP– Gulf Subcommittee of the Gulf States Marine Fisheries Commission’s Technical Coordinating Committee who manages the activities and operations, including collecting samples and interpreting data, of the Gulf participants, including the Mississippi Laboratory of NOAA and the states of Louisiana, Mississippi,Texas, Alabama, and Florida, as well as certain universities. Parts of the program include bottom trawls, CTD deployment, and Bongo and Neuston tows. The bottom trawls involve towing nets at randomly selected spots for ten to thirty minutes. The sea life caught in the nets, normally shrimp and other animals that live at the bottom of the Gulf, are sorted, identified and measured. All of the data is recorded and helps to determine where the fish and shrimp are, and how much exists in the Gulf. Because the NOAA Laboratory and the states have worked so well together on this project, most of the trawls were completed on earlier legs of the trip and on the state boats. We have had opportunities, though, to observe and identify some of the fish from an earlier leg that had been put on ice. We’ll come back to that process a bit later.
The first twenty-four hours underway were spent heading to our first station, off the southwest coast of Florida. We have spent much of our time on this leg of the trip completing plankton collections. My students should remember that plankton includes small and microscopic (too small to see with only your eyes) organisms. The organisms may be animals, plants and plant-like organisms, or bacteria. The plankton found in the water can tell what the animal population looks like, or will look like if the conditions of the water do not change too much. Plankton is also a source of food for certain animals, so looking at plankton can give us information about whether enough of a food source is present for those animals. The purpose of the Bongo and Neuston tows is to collect plankton. Before we do those tows at each station, however, we deploy the CTD to collect some important information.
CTD stands for Conductivity, Temperature, and Depth. The machine collects data in those areas, as well as other data. The conductivity data tells how much salt (salinity) is in the water because the amount of salt affects how well the water will conduct (allow to pass through) electricity. The CTD also measures the oxygen content of the water. Remember learning about algae bloom in the Chesapeake Bay, and how the algae sucks up all of the oxygen, leaving the plants and animals in the area to die? When a body of water has an unhealthy level of oxygen, it is called hypoxic. Scientists are worried about the same kind of thing happening in the Gulf of Mexico, so determining the oxygen content in the water provides important information. In the stations we have tested so far, the oxygen content has been healthy. However, we have been far from land and much closer to where the Atlantic Ocean meets the Gulf. To learn more about hypoxia in the Gulf of Mexico, visit NOAA’s hypoxia page. Don’t forget to click on the links at the bottom that will take you to descriptions of the problems and causes of hypoxia in the Gulf.
After bringing the CTD back onto the deck, it is time to start a Neuston tow. The Neuston net is very fine, and attaches to a one meter by two meter frame at the top. The net gets narrower, and attaches to a “cod end”, a plastic cylinder with screened openings, at the bottom. This is hoisted out of the boat and into the water by a crane. It takes several people to launch the Neuston, as the frame is heavy, and it can be hard to manage in the wind.
The Neuston is pulled through the water, with about a foot above the surface, and the rest below. The purpose is to collect plankton on or near the surface of the water. Since sargassum, or seaweed, often floats on the surface of the water, sometimes the Neuston collects a lot of that. We continue to tow the net for ten minutes, and then retrieve it into the boat, again using the crane. While we did not do trawls and pull in large fish, we did see different kinds of baby fish at almost every station.
The Bongo contains two 61 centimeter, circular, sturdy plastic frames, to which fine nets are attached. These nets also narrow to a small area, to which cod ends are attached. The Bongos are lowered off the port side by using the J frame. The bongos are towed from the surface to the bottom, but no deeper than 200 meters. The bongo also has the flowmeters on it to calculate how much water passes through the net. The sample is used to estimate the populations, number, and location of animals in parts of the Gulf. The Bongo also has instruments attached to it that measure temperature, salinity (salt), and depth. In addition, the bongos have flowmeters attached to calculate how much water passes through the nets.
These are complicated tools, and some of the instruments are electronic. If the instruments are not working correctly, the scientists and engineers must have a back-up plan. In fact, at one station, the Bongo instruments were not giving accurate readings when the head of the watch (the scientist in charge) looked at the readings from inside. The back-up plan was for the deckhands to use less accurate depth finding instruments when lowering the Bongo. This can sometimes present a problem because if the instruments are off, and the Bongo drags on the bottom, a lot of mud can end up in the sample. Fortunately, a little troubleshooting, in the form of tightening some connections, solved the problem. Sometimes it’s easy to forget to check the obvious!
Once the Neuston and Bongo are up, we can detach the cod ends, and get to work preserving the plankton samples. The plankton from the Neuston, and from each of the Bongo cod ends, are preserved and stored separately. The Neuston and right Bongo plankton are rinsed through a very fine sieve with a chemical solution that is mostly ethanol, and then poured through a funnel into a jar, which is finally filled with the ethanol solution. The left Bongo plankton is handled similarly, but instead of being stored in ethanol, it is stored in salt water from the Gulf, and a small amount of formalin. Formalin contains a small amount of formaldehyde, and is used to preserve tissues. It is a toxic chemical that is harmful to humans, and must be handled very carefully, always using gloves. The samples are later sent to various laboratories to be sorted and counted. In addition to providing information about amount and location of different species, scientists can also use the preserved plankton to determine the age, as specific as the number of days old, and genetics of the baby sea animal. The formalin helps preserve the otoliths a LOT better, where the ethanol helps preserve the tissue and/or DNA better. The otolith is part of the inner ear of the animal and is the part that is used to determine age.
With stations normally being about three hours apart, it would seem like we should have a lot of down time. However, when there is a lot of sargassum in the Neuston, it must be rinsed to try to get the plankton out of it. This can take quite a long time. In addition, sometimes we do get small fish or other animals that need to be sorted, counted, measured and weighed.
Don’t forget to track our progress by visiting http://shiptracker.noaa.gov/shiptracker.html and choosing Oregon II. While you are there, don’t forget to check out the different types of maps available for tracking Oregon II. Look in the upper left-hand corner (Streets, Topo, Imagery, NOAA Nautical Charts, and Weather).
Settling in and enjoying the ride
The first three days of the trip had us motoring through incredibly calm waters and sunny days. Some of the veteran crew members commented that they had never seen the Gulf so calm. As we traveled further from Pascagoula, the water started getting bluer and bluer. It is hard to describe the deep blue that we sailed through and the camera just doesn’t seem to capture it. As we left the waters around Pascagoula, we saw many large ships, possible oil tankers, and quite a few oil rigs. However, once we passed them, we’ve barely seen another boat. It is something to look out from the bow of the boat and see nothing but water in every direction.
As promised, the food on board is delicious. The cooks take great pride in the food they serve, and there are always choices at every meal. We’ve had beef tenderloin, veal parmesan, omelets, fresh fruit, fresh vegetables, pasta, Mexican, chocolate custard pie, cookies, pecan pie – all homemade! The galley is also well-stocked with snacks. Meals are served on a strict schedule – about an hour and a half for each meal. However, if you know you will miss a meal, the cooks are happy to set some food aside for you, nicely wrapped in the refrigerator. Luckily for me, I have the day shift, and if I miss a meal, it is normally breakfast.
Everyone on the ship has been very encouraging and helpful. Some of the guys did a dive and brought me back some interesting shells to share with my students. The other scientists have been incredibly patient and helpful. Kim, the chief scientist, is a great teacher and is always looking for opportunities for me to learn something new, or practice something I just learned!
Did you know?
The starboard side of the ship is the right side, and the port side is the left side. Starboard comes from the old Anglo-Saxon word, “steorbord” because the steering oar was on the right side of the boat. Because of this, the ship would pull up to the dock, or port, on the left side. This would avoid damaging the steering oar.
Questions for my students:
What unit of measurement do you think we use to measure the small fish found in the Neuston and Bongo tows?
Can you think of any sea animals that use plankton as their main source of food? It is okay to research this before you answer!
Thank you for visiting my blog. I hope you will check back in a few days for an update!
NOAA Teacher at Sea Sarah Boehm Aboard NOAA Ship Oregon II June 23 – July 7, 2013
Mission: Summer Groundfish Survey Geographic area of cruise: Gulf of Mexico Date: July 5, 2013
Weather at 19:13 Air temperature: 26°C (79°F)
Wind direction: 135°
Wind speed: 18 knots
Water temp: 27°C
Latitude : 28° 44’ N
Longitude: 85° 32’ W
Science and Technology Log
Mr. Cummiskey, the other science teacher at CDCPS, asked if we saw an influence from farming along the Mississippi River in the Gulf ecosystem. At first it seems crazy that something happening over a thousand miles away can have an impact on an ecosystem as vast as the Gulf of Mexico, but it really is happening and part of our research is to monitor the effects. The first clue I had that something was changing was the color of the water. In the deep waters off Texas the water was a beautiful clear blue. As we got closer to the Mississippi delta the sea water turned a murky brown–a mix of mud brought down by the river and the phytoplankton that was thriving in the nutrient dense waters. Just like eating too much food is bad for people’s health, too many nutrients is actually bad for an ecosystem.
Each time we get to a sampling station we start by taking measurements of the water quality with the CTD (conductivity temperature and depth). From the bridge the officers control the ship to keep it in one place. Then the deck crew uses a winch and pulley system to move the heavy CTD equipment overboard and down into the water almost to the sea floor. All the way down and back up the machine is taking dozens of readings a second that are transmitted back to a computer in the dry lab.
The CTD records the depth, water temperature, the salinity (how salty the water is), and the dissolved oxygen. We are most concerned with the oxygen level because it greatly impacts the organisms living in the water. Fish and marine invertebrates breathe oxygen molecules that are mixed in with the water. Without enough dissolved oxygen in the water they will suffocate and die. Healthy levels in the Gulf of Mexico are 4 to 6 milligrams of O2 per liter of water. If there is less than 2 mg/L it is considered hypoxic, meaning there is not enough oxygen. This map uses the data we have collected this cruise to show dissolved oxygen levels in the bottom waters of the Gulf. The green and yellow colors shows the healthy areas, the orange areas are hypoxic.
Click on the map for a larger version. The map is updated as new data comes in.
See those orange areas in close to the coast of Louisiana? That is known as the Dead Zone. Runoff of fertilizer and other nutrient sources wash down rivers and out to sea where they contribute to algae blooms. When the algae dies it sinks and is decomposed, a process that uses up a lot of oxygen. Check out this video to learn more. All my 6th graders should notice similarities between this situation and the virtual pond we worked with this spring.
Not only do the oxygen levels change, but the composition of the fish trawls changed dramatically too. At station #144 we had an oxygen reading of 3 mg/L and an average sized trawl (26 kg) with a variety of species. At station #146 we had an oxygen reading of 1 mg/L (which is hypoxic) but pulled up a huge net of fish that filled 18 buckets. The total weight was 340 kg, but over 300 kg was just two species – croaker and butterfish. We were surprised by this catch and so did another oxygen reading and found while our nets started in hypoxic waters, during the 30 minute trawl we moved into better water with 3 mg/L of oxygen . At station #147 we had a very low oxygen reading of only 0.2 mg/L. Our trawl only brought up 1.7 kg, most of which were jellies and crabs with just a few little fish. There just wasn’t enough oxygen to support more life. Why was station #146 so huge? As the low oxygen waters spread out from the Mississippi River delta, critters were fleeing the hypoxia zone and moving to better water. So along the edge of the dead zone is an area with high population density; the oxygen refugees and the fish swooping in to eat them. However, not all creatures can move themselves out of the way. Creature like bivalves and gastropods (clams and snails) don’t have the capability to move much and so get caught in the annual hypoxic zone of the Gulf.
Hypoxia zones caused by nutrient runoff from fertilizer and other man-made sources do not just happen in the Gulf of Mexico. They have also been recorded in the Chesapeake Bay, Long Island Sound and at the mouths of rivers around the world. They can also happen in fresh water ponds and lakes.
The CTD is our main method of recording oxygen levels, but we need to make sure it is functioning properly. So each day we also take a water sample and use a titration method to find the amount of dissolved oxygen. Check out the colorful chemical reactions in this video.
People, like fish, need oxygen and water to survive. Out on the ship oxygen in the air is easy to come by, but fresh water is another story. We are surrounded by water of course, but cannot drink the salt water. I tracked down out Chief Engineer, Sean Pfarrer, to find out more about where all the fresh water on board comes from.
Down in the engine room there is a reverse osmosis machine that processes salt water and turns it into fresh water. The salt water is pumped into the machine under 950 psi of pressure. The pressurized water is forced through a selectively permeable membrane that lets water molecules through, but not the larger salt molecules. (My 6th graders should find this all sounding familiar) The super salty water left behind is pumped back out to sea, and the fresh water is used on board. Our sinks, showers and laundry all use fresh water. We go through about 1,000 gallons a day, which is close to the 1,200 gallon limit of the RO system (but only about half what 30 average Americans would use on land). To conserve fresh water the heads (toilets in sailor speak) flush with salt water.
Which brings me to one of my favorite science teacher topics – poop. Thirty people over the course of fifteen days generate a fair amount of waste. What happens to all that poop? Just emptying it into the water would be harmful to the marine environment, so we have a little waste water treatment system right on board. When you flush, it all goes down to the marine sanitation device where poop eating bacteria consume our waste. The waste water then passes by chlorine tablets that kill any bacteria before it gets dumped into the sea. I’ll admit I’m a little fascinated by the systems and technology that keeps our floating community operating in a rather comfortable fashion.
We completed our science work this afternoon and are now heading back to port. Check out the Ship Tracker to see where we have been.
CDCPS Science Students:
How did sailors long ago during the age of exploration deal with the drinking water problem?
What do you think we could do to lessen the hypoxia problem in the Gulf?
NOAA Teacher at Sea
Heather Haberman Onboard NOAA Ship Oregon II July 5 — 17, 2011
Mission: Groundfish Survey
Geographical Location: Northern Gulf of Mexico
Date: Tuesday, July 11, 2011
Weather Data from NOAA Ship Tracker Air Temperature: 29.5 C (85.1 F)
Water Temperature: 29.8 C (85.6 F)
Relative Humidity: 76%
Wind Speed: 2.09 knots
Preface: Scroll down the page if you would like to read my blog in chronological order. If you have any questions leave them for me at the end of the post.
Question of the Day: Are you seeing any oil rigs on your trip?
Answer: There are so many oil rigs out here in the Gulf of Mexico that I can’t recall a time when I couldn’t see one. Some are small and some are enormous. I never realized that there were so many different engineering designs for oil rigs. At night they are all lit up and it looks like a city in the sea out here. All of the bright lights do pose some problems for migrating birds especially during bad weather when the are attracted to the lights. The birds will often circle the lights to exhaustion or hit the structure so hard that it kills them.
Science and Technology Log
Topic of the Day: How do researchers determine the health of the Gulf waters?
Science and Technology log:
You wake up in the morning and you don’t feel well. What do you do? Some people may stick a thermometer in their mouth to see if they have a fever. Body temperature is a good indicator of illness or infection. If you still don’t feel well after a few days you could visit a doctor who may check your eyes, ears, throat, blood pressure, etc. Doctors can often figure out what’s making you sick by using certain tools and running tests. Researchers do the same thing with the ocean. In order to see how “healthy” the ocean is, measurements need to be taken. Can you tell which trawl was from healthy water and which was from “sick” water?
Why aren’t we seeing a lot of marine life in certain parts of the Gulf of Mexico? You don’t have to be a doctor to answer this question, but you do have to have some scientific tools to diagnose the problem.
On the Oregon II, a device called a CTD is used to take measurements such as conductivity (salinity), temperature, chlorophyll concentration, and dissolved oxygen (DO). These water quality measurements let researches know what’s happening in the water just like a doctor would look at your test results to gage your health status. Sometimes a doctor may need to do a second test just to confirm the results. NOAA’s fisheries biologists do the same thing with their water quality assessments. Winkler titrations and a hand-held Hack Dissolved Oxygen meter are used to confirm the dissolved oxygen readings from the CTD. Scientists need to make sure the data they collect is accurate and the more tests they perform the better their data will be.
When comparing data from this device to our trawl samples, it’s obvious that water with low levels of dissolved oxygen can not support much life.
Dissolved Oxygen: Marine animals need oxygen to survive just like land animals do. The main difference is that most marine animals have gills which are able to diffuse oxygen molecules from the water directly into their blood. Diffusion is the process of a molecule moving from an area of high concentration to low concentration.
Have you ever sprayed air freshener and noticed how the smell moves from where you sprayed it (high concentration) throughout the entire room (low concentration) until the smell is equally distributed throughout the room (equilibrium)? That’s how diffusion works.
It’s very important to understand that the amount of dissolved oxygen MUST be higher in the water then inside of the animal’s body or diffusion of oxygen into the blood won’t take place. This means the animals will either have to move or die. This is what’s happening in the “Dead Zone” in the Gulf of Mexico.
The reason levels of oxygen are so low in the Gulf of Mexico are due in part to human actions. The overuse of fertilizers that are high in nitrates and phosphates are one of the major problems. When it rains or floods, these extra nutrients wash off of our lawns and into storm drains which then drain into the rivers. Most of the Mississippi watershed consists of agricultural land in the breadbasket of the Midwest where a lot of fertilization takes place during the spring and summer months. All of the nutrients from the rivers in the Mississippi watershed eventually empty out into the Gulf of Mexico.
These nutrients help the aquatic plants grow, just as they helped our lawns and crops grow. Now you may be thinking “In the last blog you talked about how important aquatic plants are when it comes to oxygen production.” Indeed they do make oxygen, but as all of these plants die and sink to the bottom of the sea, bacteria feed on (decompose) their remains and use up the available oxygen in the process. More oxygen is consumed by these aerobic bacteria than was made by the plants which is why oxygen levels can get so low.
Hypoxia is the term used when dissolved oxygen is below 2 mg/l or 2 parts per million. That means for every one million molecules, only two of them are oxygen molecules. Most marine life try to avoid water that’s this low in oxygen because they will become stressed or die. The hypoxic zone in the Gulf occurs in one of the most important commercial fishery zones in the United States during the spring and summer months. Why during the spring and summer? There are a couple of answers to this question. One is because of the fertilizer runoff which I mentioned earlier. The other has to do with water temperature.
When the data collection is complete you will notice that the “dead zone” is larger than the state of New Jersey. It is bigger this year than in previous years due to the flooding that’s occurred in the Great Plains and Midwest this spring and summer.
Salinity (salt level): This measurement is extremely important to the fish that live in the ocean because each species has an optimal salinity level that it requires. Remember osmosis? Osmosis is how cells move water in or out depending upon their environment. If a fish ends up in an environment that’s too saline (salty), the water will begin to leave the cells of the fish through osmosis and they could “dehydrate”. If they are in water that’s too fresh, then their cells will start to fill with water and they could “bloat”. All of this cellular work is done by the body in order to maintain homeostasis. Homeostasis refers to the ability of a living thing to keep its body in balance with the ever-changing environment in which it lives.
Salinity also affects the levels of dissolved oxygen in the water. The saltier the water, the lower the oxygen levels will be. It also creates a problem with waters ability to “mix”.
Chlorophyll Concentrations: As the last blog mentioned, chlorophyll is a green pigment that phytoplankton and other aquatic plants have. By calculating the concentration of chlorophyll in an a region, researchers can determine how productive the area may be for fishing. Remember that zooplankton eat phytoplankton and bigger fish eat zooplankton, which are then eaten by bigger fish. A good general rule of thumb is that if the water is clear and blue then there won’t be as much living in it as green cloudy (turbid) water. Areas of hypoxia can also be predicted if the levels of chlorophyll get too high.
Now that you know some of the basics about ocean health, try to do your part.
* If you must use fertilizer, do so sparingly.
* Purchase soaps and detergents that are labeled phosphate free.
* Be sure to make sustainable choices when purchasing seafood (visit Seafood Watch)
Today I found out why fishermen do not like dolphins. A pod of dolphins were following us on a trawl and when we brought up the catch there were holes in the net. We had to dump the sample back into the sea and try again after the holes were patched. We went back to do a second trawl in the same area and the dolphins did the same thing. We decided to try to “outrun” the dolphins on our way to the next station.
The reason we can’t collect data on the trawls with net holes is because we won’t get an accurate representation of the actual number of species living in that area. In science it’s very important to make sure we collect good data.
NOAA Teacher at Sea Kimberly Lewis NOAA Ship: Oregon II July 1 -July 16 2010
Mission: SEAMAP Summer Groundfish Survey Geographical Area of Cruise: Gulf of Mexico Date: Sunday, July 13, 2010
Ecosystem Conservation and some of the people who monitor it
Weather Data from the Bridge Time: 1130 (11:30 AM) Position: Latitude = 28.57.59 N; Longitude = 94.49.73 W Present Weather: Clear Visibility: 8-10 nautical miles Wind Speed: 14.97 knots Wave Height: 4 feet Sea Water Temp: 29.1 C Air Temperature: Dry bulb = 31.4 C; Wet bulb = 27.0 C Barometric Pressure: 1013.77 mb
Science and Technology Log
“IT’S ALL CONNECTED.” Everything in an ecosystem is connected to everything else. This is a guiding principle of studying and managing ecosystems. This past spring in one of my online communities we were discussing whole ecosystem monitoring for conservation rather than the traditional ‘save one species at a time”.
I’m seeing it now in the Gulf of Mexico. Obviously, the ocean environment is connected to human activities – the BP-Deepwater Horizon oil spill makes that abundantly clear. But there are also countless natural connections, and much less obvious human impacts, that must be understood and assessed if the Gulf ecosystem is to be protected. Commercial fish and shrimp stocks can only be sustained through a careful understanding of the human impact and natural connections in the Gulf.
That’s why we identify and count every organism we bring up in a trawl. Sometimes we get 50 or more different species in one catch, and we don’t just count the commercially important ones like red snapper and shrimp. We count the catfish, eel, sea stars, sea squirts and even jellyfish we haul in. Why? Because even though these organisms might seem “unimportant” to us, they might be important to the red snapper and shrimp. They also might be important to the organisms the red snapper and shrimp depend on. And even if they’re not directly important, studying them might tell us important things about the health of the Gulf.
Bruce and I are learning a lot about this from the incredibly knowledgeable marine biologists in the science party. Brittany Palm is a Research Fishery Biologist from NOAA’s Southeast Fishery Science Center (SEFSC) in Pascagoula, MS, and leader of the day watch on this leg of the Oregon II’s Summer Groundfish Survey. Brittany is working on her M.S. on a fish called croaker, Micropogonias undulatus, studying its stomach contents to better understand its position in the food web. Croaker is not an economically important species, but it lives in the same shallow sea floor habitat as shrimp so shrimpers end up hauling in a huge amount of croaker as bycatch. So, when the shrimping industry declined in 2003-2004, the croaker population exploded. Since croaker are closely associated with shrimp habitat and the shrimp fishery, we might gain important insights by studying croaker population and understanding what they eat, and what eats them.
Alonzo Hamilton is another NOAA Fishery Biologist from the SEFSC. Alonzo explained that there’s a lot to be learned by looking at the whole ecosystem, not just the 23 commercial species that are managed in the Gulf. For example, many of the crabs we commonly catch in our trawls are in the genus Portunas, known as “swimming crabs.”
Portunas species normally live on the sea floor, but when severe hypoxia sets in, Portunas crabs can be found at the surface, trying to escape the more severe oxygen depletion that typically takes place at the bottom of the water column.
Sean Lucey and Geoff Schook are Research Fishery Biologists from NOAA’s Northeast Fishery Science Center in Woods Hole, Massachusetts. They are working on the Oregon II right now to support the SEFSC because of huge manpower effort demanded by the oil spill. The NEFSC has been conducting their groundfish survey annually since 1963, making it the longest-running study of its kind. Originally the survey only looked at groundfish population, but as our understanding of ecosystem dynamics increased over time, more and more factors were analyzed. Now NEFSC looks at sex, age, stomach contents and many other species besides groundfish to obtain a more complete picture of the food web and the abiotic factors that affect groundfish. NEFSC even measures primary production in the marine ecosystem as one tool to estimate the potential biomass of groundfish and other species at higher trophic levels.
Andre DeBose is a NOAA Fishery Biologist from the SEFSC and the Field Party Chief for the Summer Groundfish Survey. In addition to leading the science team on the Oregon II, Andre is conducting research on Rough Scad, Trachurus lathami, an important food species for red snapper and important bait fish for red snapper fisherman. By gaining a better understanding of the relationship between Red Snapper and its prey we can better understand, and better manage, the ecosystem as a whole.
There’s a lot of information to be learned beyond just counting fish. By taking a wide look at the marine environment we can better understand how the whole ecosystem functions. This enables us not only to be more informed in setting sustainable catch levels, but also enables us to identify and respond to things that contribute to hypoxia and other problems that degrade habitat and reduce populations. It’s all connected.
Everyone in the scientific party has been working very hard to gather data. A 12 hour shift can be long at times, and other times fly by. Today Andre told us we will start cleaning up Thursday morning. It doesn’t seem possible that my 17 days with the Oregon II will soon be over. Part of me is excited to get back home to see my family and sleep in a bed that isn’t affected by the Gulf waves. The other part of me is sad due to the fact I will not longer be working with some remarkable people and worked with ongoing scientific research. It is very hard work, but very exciting to see what goes on at sea. I am sure I will call on some of them in the future for collaboration.
Chef Walter made some great meals over the past few days. Crab cakes, roasted buffalo, chicken curry, and quail, not to mention those great breakfasts. Based on my first two days of sea not able to keep anything down and not wanting to eat, I thought for sure I would go back to Ohio 15 pounds lighter. But the sea sickness wore off and I am enjoying food and adjusting to boat life.
NOAA Teacher at Sea Mechelle Shoemake Onboard NOAA Ship Oregon II June 19 – 30, 2010
Mission: SEAMAP Groundfish Survey Geographical Area of Cruise: Northwestern Gulf of Mexico Date: Tuesday, June 29, 2010
Weather Data from the Bridge Time: 0000 hours (12:00pm) Position: Latitude = 28.45.067 N; Longitude = 091.35.189 W Present Weather: cloudy Visibility: 6 nautical miles Wind Speed: 8 knots Wave Height: 4-6 foot swells Sea Water Temp: 29.8 degrees Celsius Air Temperature: Dry bulb = 27.3 degrees Celsius; Wet bulb = 26.2 degrees Celsius
Science and Technology Log
The Groundfish Survey’s purpose is to find out what species are here in the Gulf how many, and their size, sex, and maturity status. On average the trawl produces at least 20-40 different species on each tow. The type of trawl used on the Oregon II is the Bottom Otter Trawl. The deck hands put the net out, it trawls for around 30 minutes, and it is then pulled back in by the deck hands. The catch is then placed in basket where it is weighed and then separated by species Each species is then individually weighed, measured, and sexed.
We caught a nice red snapper that will be sent back to the lab for testing. It will also be determined if the oil spill had any effect on the fish, shrimp, crabs, and other species we caught. We also took some more water samples using the CTD to determine how much oil is in the water. We We used the Neuston net and the Bongo nets to gather plankton, which is also being collected for testing. The Neuston gathers plankton on the surface while the Bongo nets gather plankton all the way from the bottom of the gulf to the surface. This plankton is then placed inglass jars with a preservative Twenty-four hours later the plankton is transferred to a lesser preservative. The initial set sample is too strong for long storage. The plankton samples are then sent to Poland to a specialized plankton lab. In this lab, the plankton is identified to the family level. It is then sent back to the NOAA labs where it is identified to the species level. It was amazing to see all the little critters in the jar. There were so many of them.
Later in the day, we did another trawl….the catch of the day. Well it was a tire! It did have two little critters living in it, though. They were both identified and weighed and then frozen and packaged for the lab. The speculated reason for the trawl producing so few specis what’s called hypoxia. Hypoxia is the depletion of the oxygen in the water. If there is no oxygen,the fish and many other species cannot live. You can read more about hypoxia at http://www.ncddc.gov.
To the right is a frog fish that we found living in the tire. It has a trick to catch its food. The tentacle on the top of the head acts as a lure to attracts its prey. When a smaller fish comes by to eat what it thinks is food at the end of the frog fish’s lure…..well it gets caught and the frog fish eats the little fish. This frog fish still had its dinner in its mouth.
To the left is a picture of the last trawl that my shift made. You can see that this catch was full of shrimp and little crabs. We had to turn back towards Texas due to Tropical Storm Alex, which is forecasted by NOAA’s National Weather Service to become a hurricane by tomorrow. It’s too dangerous for the ship to be out in weather like that.
Well, I can say that this has definitely been an adventure of a lifetime. I have enjoyed my voyage with all of my new NOAA friends. They have taught me a lot. As I am writing this, we are sailing back to port in Galveston, TX. As I said earlier, we had to cut our trip short due to Tropical Storm Alex. Believe me, I know he is out there. Our ship is rolling with the waves. I had a quick lesson in securing my belongings. You never know what you might encounter when you go to sea. Thanks to NOAA for giving me this opportunity.
This cruise’s mission is two fold: 1) stock assessment of fish and invertebrates and 2) mapping of the hypoxia zone. To assess the fish and invertebrate stock, a 40-foot bottom trawl net collects bottom samples from designated sites. The samples are gathered, identified, measured and weighed by the scientists on board the ship. Data collected is eventually used to set bag limits for fish and shrimp. To measure the hypoxic zone, equipment is deployed from the ship at specific sites. Dissolved oxygen level is collected. This data is used to map the Gulf of Mexico’s hypoxic zone.
I arrived onboard the OREGON II on July 4th eager to set sail. However, we have been delayed because the auxiliary emergency generator onboard will not start. Once the generator functions properly, we will be able to set sail.
My position title is watch stander and am told training for my position is “on the job”. I am scheduled on the day shift which is 12:00 to 24:00. I look forward to fulfilling my duties as a watch stander to better understand how the samples are collected and processed.