Mission: Microbial Stowaways: Exploring Shipwreck Microbiomes in the deep Gulf of Mexico
Geographic Area: Gulf of Mexico
Date: June 27, 2019
Science Log
Yesterday was a doozy of a day I think everyone on the ship would agree. One frustrating setback after another had to be overcome, but one by one each problem was solved and the day ended successfully. If you would like to read more about this expedition, it is featured on the NOAA Ocean Exploration and Research website.
The first discovery yesterday morning was that the ship’s pole-mounted ultrashort baseline tracking system (USBL) had been zapped with electricity overnight and was unusable. This piece of equipment is a key piece of a complex system. Without it we would not know precisely where the ROV was, nor could we control the sweeps of the ROV over the shipwrecks for accurate mapping. The scheduled dive time of 1330 (that’s 1:30PM!) was out of the question. There was even talk of returning to port to get new equipment. Yikes. This would cost the expedition $30,000-$40,000 for a full 24 hours of operation, and no one wanted to do this.
Max, the team’s underwater systems engineer, worked his magic, and replaced the damaged part. This required expert knowledge and some tricky maneuvers. Once this was fixed, the next step was to send a positioning beacon down to the seafloor to calibrate the signal from the ship to the ROV so that we would be able to track it precisely. Calibrating means that the ship and the ROV have to agree on where home is. The beacon is attached to three floats connected together to make a “lander”, and then 2 heavy weights are attached as well. The weights take the beacon down. The lander brings it back to the surface later. The deployment went without a hitch. However, when the lander floated to the surface, we noticed it was floating in a strange way. When we hauled it aboard, we discovered that one of the glass floats had imploded – probably due to a material defect under the intense pressure at 1200m below sea level – and all we had left of that unit was a shattered mess of yellow plastic.
The glass float inside this yellow “hard hat” imploded. It’s a good thing there are two others to bring the transponder back to the surface.
In spite of that, the calibration was complete and we could send the ROV on its mission. We loaded the experiments onto the back of the ROV, along with another lander and weights. This was the exciting moment! The crane lifted the ROV off the ship deck and swung it out over the water. But in the process, the chain holding the weights broke and, with a mighty groan from all of us watching, both of them sank into the sea. Back came the ROV for a new set of weights. Luckily nothing was damaged. By 1745 (5:30PM), 5 hours after the scheduled time, the ROV went over the side for a second time successfully. Once this was done the Chief Scientist was able to crack a smile and relax a bit.
The team works to mount a new lander on the ROV.
Launching the ROV off the back deck, loaded with experimental equipment and a lander.
The mechanical arm on the ROV retrieved a microbial experiment left on the sea floor in 2017. We watched it all on the big screen in the lab.
Now we had an hour to wait for the ROV to reach the sea floor again, and begin its mission of deploying and retrieving experiments. Inside the cabin of the ship, some of us sat mesmerized by the drifting phytoplankton on the big screen, hoping to see the giant squid that had been spotted on the last expedition. Up in the pilothouse the captain was on duty holding the ship in one spot for as long as it took for the ROV to return. Not an easy job!
Yesterday I saw what scientific exploration is really like. As someone said, “Two means one, and one means none,” meaning that when you are out at sea, you have to have a second or even a third of every critical piece of equipment because something is inevitably going to break and you will not be able to run to Walmart for a new one. Failures and setbacks are part of the game. As a NOAA Teacher at Sea, I am looking at all that goes on on the ship through the lens of a classroom teacher. Yesterday’s successes were due to clear headed thinking, perseverance, and team work by many. These are precisely the qualities I hope I can foster in my students.
I’m actually afraid of the sea. The unspeakable power, the dark depths, the mysterious uncharted territory – the sea has always held curious minds captive. I want to be someone who faces the things that scare me. And for 19 days, on a relatively tiny ship, I will be doing just that.
Reuben Lasker Pulls Into the Navy Pier on 1 May 2014
NOAA Ship Reuben Lasker is “one of the most technologically advanced fisheries vessels in the world” according to the Office of Marine & Aviation Operations. In addition to studying fish and marine life populations, it is also equipped for acoustic data sampling and the gathering of oceanographic data. It can stay out to sea for up to 40 days at a time without needing to return for food or fuel replenishment.
And yet, as I’m writing this, I can’t help but think about SS Edmund Fitzgerald and RMS Titanic. They were the most advanced ships of their time too. Of course, I’m just letting my imagination get carried away. People fear the things they don’t understand. And I’m looking forward to learning as much as I can on this cruise in order to understand not just how this incredible vessel operates, but also how the ocean and atmosphere impact my life on a daily basis.
I was lucky last year to stumble across a professional development opportunity funded through the American Meteorological Society. I took two graduate level courses since then – DataStreme Atmosphere and DataStreme Ocean. Upon finishing this program I’ll earn a graduate certificate from the California University of Pennsylvania and be able to apply my new understanding of earth science directly to my classroom instruction. Already I’ve been able to incorporate fascinating information about coral reefs, the Bermuda Triangle, map reading, and weather into lessons and activities this year.
Why does a Reading Specialist need all this professional development, you might ask? In science of all things? Because nobody reads about things they’re not interested in (unless they have to). Students need to have something to connect with, to care about, in order to learn. When was the last time I, as an adult, read something I didn’t care about? Probably years.
Humans are curious by nature, and by incorporating new topics into our reading lessons over the past year, I’ve noticed that students really like learning about earth science. It’s like the mother who hides cauliflower in the lasagna – students are more motivated to read when they’re reading about something exciting and directly relevant to their lives. Thankfully, the more they read, the better they get at comprehending the nuances of the text. And then the less they need me.
A classroom
One of the most valuable aspects of this trip for me is that I’ll return with a new appreciation for earth science, current events as they relate to our food supply and environment, and marine life. I can use this experience to build exciting lessons for high school students who may use their connection to these lessons as a lifeline. The last ditch effort to find something exciting to learn before graduating with a lackluster memory of the doldrums of the high school classroom.
Teenagers are tough eggs to crack! But I like them. And I’m very grateful to the NOAA Teacher at Sea program for giving me, and other teachers, opportunities like this to show our students that there are literally thousands of directions to take after high school in regard to career and quality of life. And that high school is one of the few places where they can build the foundational knowledge necessary to get them there – for free. I want my students to pursue their passions. To get excited about learning! And the first step to doing that successfully is to expose them to as many post-secondary options and lessons about their world as we can in the short time that we spend with them. Thanks NOAA! I’m excited to start my journey.
Mission: Microbial Stowaways: Exploring Shipwreck Microbiomes in the deep Gulf of Mexico
Geographic Area: Gulf of Mexico
Date: June 24-25, 2019
Science Log
On Monday I was introduced to the R/V Point Sur in Gulfport, Mississippi. Every nook and cranny of this vessel is packed, and it took the science crew most of the day to pack it even fuller with all the equipment they need. The largest single item is the remotely operated vehicle (ROV) Odysseus which makes a large footprint on the back deck. Over it hangs an enormous pulley that will be used to lift Odysseus in and out of the water.
R/V Point Sur in port
This the ROV Odysseus waiting to be deployed on a shipwreck. It’s as eager as I am to see it operate. It looks like it is ready to jump in!
When I arrived at the port, I met Dr. Leila Hamdan, the Chief Scientist, and some of the crew. We have two Rachels on board and they are both graduate students studying microbial biomes. Over time a layer of microbes form a “biofilm” on different kinds of wood and metal. This organic layer forms on the surface of a shipwrecks, and this is what the scientists are studying. They want to know how this layer speeds up or slows down the corrosion of shipwrecks and how other organisms use this habitat.
I was able to join in and help put together microbial recruitment experiment towers, or MREs for short. Each tower is a PVC pipe fitted with samples of wood, both oak and pine, and some metal samples. Each of these pipes fits loosely inside a second pipe, and then each set is roped together and attached to a float. Each tower is rigged in such a way that it will sink to the sea floor vertically, and then the outer pipe will rise to expose the inner tower and the sample plugs. After four months, the MREs will be retrieved, and the scientists will be studying what kinds of microbes grew on the samples. Their experiments add to our understanding of how shipwrecks act as a habitat for corals and other organisms
Here we are putting together one of the MREs which will be sent to the ocean floor near one of the shipwrecks.
Finally, at the end of the day we had to quickly load the last of the gear on the ship before a huge container ship of bananas arrived to dock in our space. We set up a “fire line” to hand the last of the gear into the ship as fast as possible. We could see the huge Chiquita banana ship heading our way. The port was already stacked four high with Chiquita banana shipping containers and more bananas were coming! Who is eating so many bananas?!
As the newbie member of the crew, I was allowed to stay on board as the crew moved the ship from the large loading dock to the smaller pier on the other side of the port. This meant I got a taste of the ocean breezes that are going to help keep us cool once we leave land. I saw pelicans glide low over the water as I stood on the deck and imagined all the new and amazing things I am about to see and do.
Day 2
If you’ve never been to Mississippi in the summer, I can tell you it is HOT and HUMID. It’s hard to imagine until you try to actually do something in it. If you were an egg, you would definitely fry on the sidewalk. Despite the heat, all over the ship crew and scientists are working, bolting things together, greasing mechanical parts, putting last minute touches on their experimental equipment, organizing the lab and working at laptops. To mitigate the heat and humidity outside, the air-conditioning runs on high inside the ship. This helps to keep the humidity from damaging the equipment, as well as to keep the crew happy. So it is actually COLD in here!
In addition to all this activity, a group of high school students visited the ship. They are participating in The Ocean Science and Technology Camp to learn about marine science careers and they will be tracking our progress from shore. Each of our many talented scientists shared a bit about their research and their roles in the ship. I will share more about that in another blog. We are scheduled to leave tonight at 1930 hrs, that’s 7:30PM for most of us! Stay with me, it’s going to be awesome!
Rachel explains how core samples are taken to summer camp students.
Last night I fell asleep, twice, at the lab bench in between trawls, since I am still adjusting to being on the night shift. We worked from 9:00 P.M. to 6:30 A.M. After the shift I had a nice hot shower and slept a solid 9 hours from 7:00 AM to 4:00 PM. Hopefully, I will be less drowsy tonight!
Upon waking, I went to the galley and grabbed some Raisin Bran and coffee and took it up to the flying bridge to hang out with Ornithologist Brian Hoover. Our current location is in the middle of the Channel Islands, an area I know something about because my friend Evan Morrison, mentioned in my first blog, helps with the Channel Islands Swimming Association, and I would like to swim between these islands one day. Lauren Valentino, Flora Cordoleani, Ily Iglesias and I congregated on the flying bridge and decided we should exercise. We joined Flora in her squat challenge (80 squats on this particular day), followed by 5 minutes of planking and a bit of erging. Half of female members of the fish sorting team are avid rock climbers. They did lots of pull-ups using the rock ring climbing training holds that are installed there.
It felt nice and warm when the ship stopped for deployment of the Conductivity, Temperature and Depth (CTD) Rosette, and it got chilly again as the wind picked up when the ship started moving again. We saw a few whale spouts in the distance and at 5:30 P.M. we went down to the galley for a delicious meal of steak and mashed potatoes. I am beginning to really appreciate how nice this whole experience has been in terms of amenities. The NOAA Reuben Lasker first set launch in 2014 and is a state of the art fisheries vessel with a sophisticated acoustics lab, fish lab, dynamic positioning system, CTD, etc., but is ALSO equipped with creature comforts including a movie lounge, an ice cream cooler loaded with ice cream sandwiches, snickers, fruit pops, you name it, and my personal favorite – a coffee bar where all coffee is freshly ground, an espresso machine, and all varieties of milk and creamers, including Reese’s cup whipped cream. The mattress in my stateroom bunk is quite comfortable and the shower gets hot within seconds! I doubt it can get much better than this for a research experience at sea?
Game Plan and Trawling Line: Point Sal line with five 15 minute hauls.
I am familiar with the sorting protocol now. The catch is dropped from the net into the bucket by members of the deck crew and survey tech, with the oversight of Keith Sakuma, Chief Scientist and NOAA Operations Officer Keith Hanson. The bucket is immediately placed in the fish lab and this is when the fish sorting team starts our work.
Dropping the catch from the Cobb Trawl net into the bucket.
A volume of fish just placed on a sorting tray. This catch has a lot of anchovies, krill, and California smoothtongues.
Separating the krill from the myctophids, Northern anchovies, and California smoothtongues.
Team Red Hats sorting fish. NOAA’s Keith Hanson in the rear left side.
SORTING AND COUNTINGMETHOD
We start by carefully picking through a 2000 mL or 5000 mL volume of the harvest, depending on Keith Sakuma’s initial assessment of the species density and volume in the bucket. The first volume of catch to be sorted is evenly dispersed onto four white sorting trays arrayed on the main lab bench. Once you have a pile of the catch on your tray, you start to separate them into piles of different types of organisms, such as Northern anchovies, ctenophores, krill, salps, pyrosomes, Californian smoothtongues, squid, rockfish, myctophids, and young of year (YOY) fish. I prefer to use my hands for sorting while others use forceps. Once sorted, we count the number of individuals for each species. If we have difficulty identifying an animal that we have not yet seen, we ask Keith Sakuma or a more experienced team member to help with identification. YOY fish, some in larval form, are particularly difficult for me.
Once sorted and counted, we verbally call out the common name and number of organisms to Keith Sakuma who manually records the data in a 3-ring binder for the lab hard-copy. For smaller organisms, such as krill or salps, or in hauls with a high number of any particular species, it would be quite tedious to pick out and count each individual in the total haul. This is why we start with a small subsample volume or 0.5, 2 or 5L, count the individuals in that small volume, establish the ratio for the number of individuals in that volume, and then extrapolate and calculate by the total volume of the haul. For example, if we counted 97 pyrosomes in the initial 5L sort, and we collected a total of 1000L, then we can say that there are 19,400 pyrosomes in the haul.
Chief Scientist Keith Sakuma recording the data from a haul during sorting.
Once 20 individuals of each species have been called out, we no longer have to count that species since the ratio for this catch has already been established and to expedite sorting the rest of the volume. Following sorting, the length of the twenty representatives of each species is measured using electronic calipers and the values populate on an Excel spreadsheet. After measuring, specimens requested by various research institutes including Scripps Institution of Oceanography, Moss Landing, and Monterey Bay Aquarium Research Institute (MBARI) are collected, labelled and frozen.
Flora Cordoleani keeping track of which specimens are to be preserved for various research groups.
Keith Sakuma bagging specimens to send to collaborators.
Creature(s) feature: Salps and Pyrosomes.
Salps What are these strange gelatinous organisms in our catch that look like little puddles of clear jelly with a red, green, yellow, and brown digestive organ in the center? They are goopy, small and slippery making them difficult to pick up by hand. They float on the sea surface and are ubiquitous in our hauls BUT NOBODY KNOWS ABOUT THEM.
These creatures are called salps and belong to the subphylum Tunicata. Tunicates have a notochord in their early stage of life which makes them members of the phylum Chordata, to which humans also belong. Having a transparent body is a way escape being preyed upon.
A group of salps. This species is dime to quarter sized and this number of salps occupies a volume of ~10-15 ml once placed in a beaker.
Salp digestive organs.
Salps are planktonic tunicates That can be found as individual salps or in long chains called blastozooids. The salps shown in the photo below were individuals and were notable in most of our hauls. Individual salps in this pile are dime to quarter sized and occupy a volume of ~10-15 ml. We measured the volume of salps in every haul.
While on the topic of salps, I will tell you about a cool 1 inch long salp parasite I found on my sorting tray (see image below). Keith Sakuma explained that it was a deep sea amphipod called Phronima which is a parasitoid that takes up residence inside of a salp’s body, eats the salp’s organs, and then lays its eggs inside of the salp. The King-of-the-salmon, Trachipterus altivelis, (which we are also catching) uses its protrusible jaw to get inside of the salp just to eat this amphipod!
Phronima amphipod – lives and reproduced in salp after eating the salp’s organs. King-of-the-salmon fish use their protrusible jaws to eat the amphipod.
King-of-the-salmon, Trachipterus altivelis
King-of-the-salmon, Trachipterus altivelis, who preys upon phronima living inside of salp, with jaw protruded.
A large haul full of salps.
Another type of salp we keep catching is Thetys vagina, a large solitary species of nektonic salp that feeds on plankton, such as diatoms, and is an important carbon sink in the ocean. Thetys has an external surface, or test, that is covered with bumps and ridges, as seen in the photo below.
Thetys vagina, the twin-sailed salp.
The internal filtering organ of Thetys vagina.
Kristin Saksa examining a larger Thetys vagina, or the twin-sailed salp. The dark colored tentacles are downward facing. This is the siphon where water enters the sac-filled body.
PyrosomesPyrosoma atlanticum are another type of planktonic tunicate which are very numerous in most of our hauls. Pyrosomes look like bumpy pink hollow tubes with openings on both ends. They are rigid in structure and easy to pick up by hand, whereas salps are goopy and difficult to pick up by hand. We have collected some pyrosomes that are 13 inches long, while most are in the 4-6 inch range. The small pyrosomes look like clear Tic Tacs, but they do not taste as such.
Pyrosoma atlanticum, with an ~6 inch specimen on the left and small pyrosomes on the right.
How can pyrosomes be so ubiquitous just 20 miles or so off of the Central California Coast, but I have never seen one that has floated up on the beach or while swimming?
Pyrosoma atlanticum are also planktonic tunicates, but are colonial organisms made up of many zooids held together by a gelatinous structure called the tunic. One end of the tube is wide open and filters the water for zooplankton and phytoplankton, while the other end is tighter and resembles a diaphragm or sphincter. The pyrosomes we harvested appeared in diverse array of pinks and purples. Pyrosomes are believed to harbor intracellular bioluminescent bacteria. Pyrosomes are drifting organisms that swim by beating cilia lining the branchial basket to propel the animals through the water and create a current for filter feeding.
Pyrosoma atlanticum assorted by color.
Moss Landing Graduate Student Kristin Saksa excited about the large haul of Pyrosoma atlanticum.
I departed Chattanooga, TN, for San Francisco, CA, on May 28th to participate as a NOAA Teacher at Sea on Leg 2 of NOAA’s Juvenile Rockfish Recruitment and Ecosystem Assessment Survey. My job as a Teacher at Sea will be to share my experience and knowledge acquired over the next 10 days working alongside NOAA scientists with MY AUDIENCE. Who is my audience? You! I hope that you all can be my students! You, my McCallie students and colleagues, my friends, my swimming community and my family members. My intention here is to explain in layman’s terms what I learned, and especially, what I thought was cool.
After tapas in North Beach with my San Francisco friends Cathy Delneo and Evan Morrison, they dropped me off at Pier 15 to sleep in my stateroom on the NOAA Ship Reuben Lasker. I felt rocking even while docked in the San Francisco Bay, but I slept great and am happy to report that my CVS brand “less drowsy” Dramamine tablets seem to be working as I am prone to motion sickness. This morning Evan and I got to explore the ship and take a bunch of photos of The City from the top deck of the ship, called the Flying Bridge. I imagine I will be spending many hours up here over the next 10 days!
Karah and Evan on the Flying Bridge the morning of departure.
Meeting the Science Team
The first science team member I met was Kelly Goodwin, Ph.D., an environmental molecular biologist from NOAA National Marine Fisheries Service (NMFS), Southwest Fisheries Science Center (SWFSC) La Jolla, and NOAA Atlantic Oceanographic and Meteorological Laboratory. Kelly is here along with Associate Researcher Lauren Valentino to collect environmental DNA (eDNA) from water collected at three depths (5 meters, the chlorophyll maximum, and 100 meters) during deployment of the Conductivity, Temperature and Depth (CTD) Rosette. There will be more about these marine scientists and the cool biotechnology they will be employing to come in a future post!
Next, I met my stateroom bunkmate Flora Cordoleani, Ph.D., of NOAA NMFS, SWFSC,Fisheries Ecology Division (FED). Her research lab at the University of California Davis focuses on the management of the endangered king salmon in the Central California Valley. I will definitely interview her for a future blog!
Meet the rest of the team: Doctoral student Ilysa (Ily) Iglesias, NMFS SWFSC FED/ University of California Santa Cruz (UCSC), works in John Field’s Lab. Ily will be analyzing the myctophids (one of the most abundant mesopelagic fish groups) collected on this survey and elucidating their role in the trophic cascade. She was on the cruise last year as well and I can already tell is psyched about this opportunity and wants to teach everyone.
John Field, Ph.D., was on the previous leg of the cruise and is the Principal Investigator for this project while Keith Sakuma, of NMFS SWFSC FED, is the Chief Scientist and has been working on this survey for 30 years as of this cruise!
Kristin Saksa of NMFS SWFSC FED/ Moss Landing Marine Lab (MLML) and Kaila Pearson, NMFS SWFSC FED, of Scripps, who are both working on master’s degrees in marine science.
Jarrod Santora, Ph.D., an ecologist from NMFS SWFSC FED/UCSC, will be on the day shift. Brian Hoover, Ph.D., an ornithologist who works for the Farallon Institute for Advanced Ecosystem Research (FIAER), will be observing birds and marine mammals on the day shift.
Keith Hanson is a NOAA Corps Officer representing NMFS SWFSC FED and is also a valuable member of the science team.
Night shift fish sorting crew. From left: Karah Nazor, Ph.D., Flora Cordoleani, Ph.D., Kristin Saksa, Keith Sakuma, Keith Hanson, Kaila Pearson, and Ilysa Iglesias.
After a welcome aboard orientation and safety briefing given by NOAA Corps Officer David Wang, we enjoyed a delicious reuben sandwich in the galley (cafeteria) of the Reuben Lasker. Meals are served at 7 AM, 11 AM and 5 PM. Since I will be on night shift I can request to have meals put aside for me to eat whenever I want. Below is a typical menu. The food is superb! See a menu from one of our last days below.
Menu for my last day.
After a noon departure the engineers spent a couple of hours testing the dynamic positioning system just north of the Bay Bridge. This system takes inputs from ocean conditions such as the tide, wind, waves and swell and uses the propulsion and thrusting instruments on board to maintain a fixed position on the global positioning system (GPS). Most of the night shift science crew used this opportunity to nap since we had to stay up all night!
Kaila Pearson woke me up just in time as we exited San Francisco Bay to take in the spectacular view of passing under the Golden Gate Bridge. It was a gorgeous sunny day in San Francisco and I felt super grateful to be a part of this research team, excited to get to know the team of amazing (mostly) female scientists I had just met, and ready to start fishing! It was fun to get to serve as a impromptu San Francisco tour guide as we departed the Bay, since I am quite familiar with this landscape. This body of water was my first open water swimming playground when I used to live in San Francisco during my postdoc at UCSF and was a member of the South End Rowing Club.
Our departure from the San Francisco Bay. Photo taken on the flying bridge. From Left: Kaila Pearson, Flora Cordoleani, Ph.D., Lauren Valentino, and Ilysa Iglesia with Teacher at Sea Karah Nazor, Ph.D., in front.
Night 1 of Cobb Trawl and Fish Sorting
We arrived at our first trawl line, Monterey Bay, around 11:00 P.M. My job as part of the night crew is to participate in marine mammal watches before and during fishing, and then to sort, count and measure the different species of animals collected, as well as bag and freeze specimens for various research organizations. The fishing method used on this survey is a modified Cobb midwater trawl. The net is deployed to fish at 30 meters depth and has a 9.5 mm codend liner (mesh at the end of the net where the fish gather). Trawl operations commence just after dusk and conclude just before dawn, with the goal of conducting up to 5 trawls per night. The duration of fishing at target depth before “haul back” of the net can be either 5 minutes or 15 minutes. Five minute trawls are used in areas of high abundance of gelatinous organisms such as jellyfish in order to reduce the size of the catch (e.g., fishing the additional 10 minutes would result in catches large enough to damage the net).
From left, Keith Hanson, NOAA Operations Officer, and Chief Scientist Keith Sakuma, help release the catch from the first haul of the survey.
At first glance, it appeared the catch consisted mostly of Northern anchovies.
UCSC graduate student Ilysa Iglesias examines the first sort of the first haul, with the organisms arranged by species.
There are two marine mammal watches per trawl: the inside watch and the outside watch. The inside watch goes to starboard side of the bridge 30 minutes prior to reaching the planned trawl station. If any marine mammals such as sea lions, seals, dolphins or whales are spotted within one nautical mile of the planned trawl station, then the ship must move. This protocol is employed for mitigating interaction with protected marine species.
If the inside watch does not see any marine mammals, then trawl operations can begin. This is when the outside mammal watch takes over and looks for marine mammals during net deployment, trawling, and haul in. The outside watch is conducted one floor above the fishing deck, and the person must wear foul weather gear, a life vest, and a helmet. This is summer, but it is the Pacific, and it is COLD out there. If a marine mammal is spotted by the outside watch then the trawl net must immediately be reeled in.
I spotted a school of dolphins in Monterey Bay during haul back and reported the sighting via radio to the bridge officers and recorded my observations in the lab on the provided data sheet in the lab.
The duration of the entire fishing operation from net deployment, dropping the two “doors” (large metal plates weighing 900 pounds each) used to spread the net mouth open, fishing, haul in, properly wrapping the net on the winch, and finally, dispensing the harvested fish into the collection buckets, takes between 45 minutes to an hour and a half, depending on conditions.
Our first catch consisted primarily of Northern anchovies (Engraulis mordax) and California market squid, Doryteuthis (Loligo) opalescens. Ily was excited by the presence of a few plainfin midshipman, Porichthys notatus, and showed us their beautiful pattern of large photophores located on their ventral surface. These fish are quite hardy and survive the trawling procedure, so as soon as we saw one in the bucket, we placed it in a bowl of sea water for release after obtaining its length. Photophores are glandular organs that appear on deep sea or mesopelagic fish and are used for attracting prey or for confusing and distracting predators.
Northern anchovies, Engraulis mordax,, are one of the most abundant species we catch.
Photophores on ventral surface of Plainfin midshipman, Porichthys notatus.
Mesopelagic depths start around 200 meters, a depth at where 99% of the sunlight can no longer penetrate, and extend down to 1000 meters below the ocean surface. Above the mesopelagic zone is the epipelagic zone where sunlight reaches from the ocean surface down to 200 meters and, in California, corresponds to the ocean above the continental shelf.
In this survey, we will conduct trawls at 30 meters, which is technically the epipelagic zone, so why do we catch deep sea creatures? Many deep sea creatures participate in a daily vertical migration where they swim up into the upper layer of the ocean at night as that area is relatively rich in phytoplanktonic organisms. Phytoplankton are the sun-powered primary producers of the food chain, single-celled photosynthetic organisms, which also provide the majority of the oxygen we breath.
After the first night of work I feel confident that I can identify around 10 species of mesopelagic fish and forage organisms, the California Headlight Fish (more to come on these amazing myctophids from my interview with Ily), a juvenile East Pacific red octopus, Octopus rubescens, (alive), and ctenophores! Thanks to the Tennessee Aquarium’s Sharyl Crossly and Thom Demas, I get to culture ctenophores in my classroom.
Two large photophores in between the eyes of a Californian Headlightfish, Diaphus theta
Small octopus – Octopus rubescens.
Karah Nazor with a handful of ctenophores! These are Hormiphora – Undescribed Species.
Scientist Spotlight: Ornithologist Brian Hoover
Brian Hoover, Ph.D., an ornithologist who works for the Farallon Institute for Advanced Ecosystem Research (FIAER) in Petaluma, CA, observes birds and marine mammals on the day shift of this NOAA research cruise.
Brian Hoover, Ph.D., at his office in the San Francisco Bay
Brian Hoover, Ph.D., and Jarred Santora, Ph.D., watching for birds and marine mammals as we went underneath the Golden Gate Bridge.
Brian is from Colorado and earned his doctorate
at UC Davis in 2018. On this cruise we will be traversing through
biological hotspots that occur near islands, underwater canyons, and where
there is strong upwelling of the cold and nutrient rich deeper waters of the
California Current. Small fish feed on these nutrient rich waters, and
birds feed on these fish. Hotspots on this cruise included the Gulf of the
Farallons (just south of the Point Reyes upwelling plume) , the Channel Islands,
and Monterey Bay with its submarine canyon. Brian’s hours on the ship are from
7am to 7pm.
Brian can be found perched on the flying bridge during the day shirt with a pair of binoculars in his hand and his laptop off to his right on a table. Every time a bird or marine mammal is spotted within 300 yards of the ship to the right of the mid centerline of the bow, Brian records the species and numbers of animals observed in his database on his laptop. The objective of Brian’s work aboard the ship is to study how what is present underwater correlates with birds observed above the water. In other words, he aims to find correlations between the distribution and abundance of seabirds and marine mammals to the species and abundance of prey we collect during our night trawls and data collected from the ship’s acoustic krill surveys which collect data during the day. Brian explains that such information teaches us about what is going on with the bird’s prey base and how well the ecosystem is functioning as a whole. His observations allow him to observe shifts in the system over time and how this affects tertiary and apex predators. To find trends in these datasets, he used R software, Python, and ArcGIS mapping software to run spatial statistics and linear models.
Since 2010 Brian has been on 12 to 13 cruises and this is his third on the Reuben Lasker. Brian is excited to perhaps spot the Cooks Petrel, Pterodroma cookii, or the Short-tailed albatross, Phoebastria albatrus, which only lives in a volcano in japan. His favorite birds are the storm petrels because these birds are small and live in open ocean, only coming onshore to breed once a year. His dissertation focus was on the reproduction and behavior of the leeches storm petrol. He explains that seabirds have an incredible sense of smell which they utilize to find a mate and food. Brian was able to collect blood samples from burrowing birds for genotyping. He found that the major histocompatibility complex (MHC) molecules located on antigen-presenting cells may play a role in odor detection and mate selection in these birds. He found that males chose and avoided particular genotypes combinations and that healthier birds had more diverse MHCII complexes.
Brian is a sensory ecologist and studies how
seabirds interact with their environment through observations of their
behavior and physiology. When Ily asked Brian how do the seabirds know where
the fish are in the open ocean, he explained that birds have a sense of smell
that is as good or better than any commercial sensor that detects sulfur.
Why have some seabirds evolved to be so good at sniffing out traces of sulfur
in the ocean breeze up to 10 miles away from its source? Brian explained that
sulfur is an important part of the photosynthetic pathway for phytoplankton
(algal cells) and that when krill eat the algae, the algae releases the
chemical dimethyl sulfide (DMS). Marine plastic debris floating on the
sea surface also release DMS and provides an explanation as to why seabirds eat
plastic.
