NOAA Teacher at Sea
Onboard NOAA Ship McArthur II April 20-27, 2008
Mission: Assembly of Science Team and Movement of Science Gear/Equipment Geographical Area: Coos Bay to Astoria, Oregon Date: April 21, 2008
Weather Data from the Bridge
Sunrise: 0620 Sunset: 2010
Wind: 10 kts
Seas: 4-7 ft
Science and Technology Log
With childlike anticipation and excitement I waited for the McARTHUR II to be freed from its berth and be given the freedom to sail towards the ocean world ruled by Neptune, the god of water and sea in Roman mythology. The time had finally arrived and with the captain’s decision we pulled away from the dock, turned 180O, and set “sail” due west to where the water worlds of the Columbia River and Pacific Ocean collide. After exiting the Columbia and entering the Pacific, the McARTHUR II would turn south and set a heading toward the first sampling station located about nine miles offshore due west of Cape Falcon. ETA (Estimated Time of Arrival) is early afternoon. In the meantime I enjoyed the rugged, coastal scenery of the far southwestern tip of the state of Washington on the northern shore of the Columbia River. Before long I was officially an ocean mariner. An important question was soon to be answered: How long would it take for me to obtain my sea legs?
It was time to get to work. Before reaching the first sampling site the science team met in the lounge to try on thermal survival suits to determine if they fit properly. It was cumbersome putting on the heavy red suit; I looked liked the cartoon character Gumby (but red rather than green) but it gave me a bit of peace of mind. Hopefully, that’s the last I’ll see of that suit. Next, we met on the ship’s fantail (back lower working deck of the ship). The Chief Bos’n discussed shipboard operations that are carried out on and safety issues associated with the fantail, the working section of the ship. Hardhats and a working vest are mandatory. We then learned how to operate the “A” frame that aids in deployment and retrieval of the heavy, bulky CTD platform, how to properly attach the Niskin bottles’ cables to the triggering latch at the top of the CTD, and lastly how to correctly deliver the water collected inside the Niskin bottles to a sample container for analysis in the ship’s wet lab.
From the fantail we moved to the main deck on the starboard side aft of the ship’s middle section to learn how to deploy, retrieve, and collect samples from the four types of zooplankton nets, each of which also requires recording certain kinds of data about the cast. I’ll discuss biological sampling in more detail later. Admittedly, when it was all done I was a bit overwhelmed but figured that after a station or two when I developed a rhythm and familiarity with the equipment and time scale for collecting samples, I would get the hang of it.
It was 1500 (3pm) and the McARTHUR II had rendezvoused with the first nearshore sampling site about 10 miles west of Cape Falcon (45O46’N, 124O10’W). Preparations were complete and now it was time to begin 24 hour non-stop operations. I put on rain gear and rubber boots, found some dry gloves, and adjusted my hardhat and workvest. With that, Bob Sleeth and I made our way to the “A” frame to prepare for the first CTD deployment.
My first full day at sea. We departed early morning on schedule from the Astoria dock. As expected we met rough waters where the Columbia River and Pacific Ocean meet. The day was overcast as is typical for this region of the U.S. this time of year, and cold. It snowed during the trip out to sea. Along the Columbia I was treated to the gorgeous coastal cliffs of Cape Disappointment to the north and the snow capped mountains south of Astoria. The swells subsided once the McARTHUR II reached water depths >200 feet. I’ve been out to sea for over twelve hours now and I’ve experienced no signs of sea sickness though the waters have been relatively calm. I am still earning my “sea legs” but I suppose by cruise’s end I won’t run into the hallway walls, the hallway water fountain, or my bed as often.
The overcast, gray skies ruined any chance in witnessing a marine sunset. I was still energized and excited like a kid on a “candy high” when I crawled into my lower bunk bed at 1900 (7pm). With my first shift complete I looked forward to my second shift at 0100 (1am). I figured though that I wouldn’t sleep with it being a new environment, new sounds, new smells, and the ship pitching and rolling. For the next five hours I went back and forth between sleep and semi-sleep where you’re relaxed but at the same time fully aware of the surroundings. Half past midnight I rolled out of bed, got dressed, and went to the dry lab to prepare for the 0100 to 0500 shift.
NOAA Teacher at Sea
Onboard NOAA Ship McArthur II April 20-27, 2008
Mission: Assembly of Science Team and Movement of Science Gear/Equipment Geographical Area: Coos Bay to Astoria, Oregon Date: April 20, 2008
Science and Technology Log
The start of the cruise has been delayed one day due to the rough, unpredictable, and potentially dangerous waters where the mighty eastward flowing Columbia River and its massive volume of freshwater collides head on with the cold, salty water of the vast Pacific Ocean. Where this water slugfest happens, sands bars shift repeatedly this way and that way as the pushing and shoving between the massive volumes of sea and freshwater continues without interruption. At low tide the sand bars are easily seen; they are numerous and of great area and irregular in shape.
On account of the delay, most of the day was spent making sure instruments worked properly and non-instrument equipment was organized to maximize efficiency. Perhaps though more importantly, the delay gave the eleven science team members— most of them complete strangers to one another—extra time to get to know one another. This is important because all of us will be shipboard for eight days confined to quaint sleeping quarters, working, eating, relaxing, playing, and interacting with each other. There’s no escaping once the ship moves away from the dock and goes out to sea. It also gave science team members time to get to know the ship’s crew, who themselves play a key role in the overall success of the mission.
Communication is a two-way street. From the science team perspective we have to communicate with each other and also with the crew in order to be productive and minimize mistakes. Ocean science truly is an interdisciplinary endeavor that relies on the talents and work ethic of the people involved. This brings me to my next topic. Science is a uniquely human pursuit; good science relies on people. Modern scientific inquiry is all about assembling the best minds and talent possible into a highly productive team. It’s not just about brains though. Personalities and people skills matter too. In fact, they matter a lot. They can make or break a scientific mission. All it takes is an individual with a 60-grit sandpaper personality to upset the ebb and flow of human group dynamics.
Ocean science is all about teamwork!
In a few hours I’ll see how such dynamics work out on this cruise with this assemblage of people, the youngest being an undergraduate science major and the oldest a retired Silicon Valley engineer. Four of the eleven science team members (myself included) have never been at sea. We don’t know what to expect or, for that matter, think about with respect to what lies ahead this next full week.
After lunch we met as a group with the NOAA Corps officers and reviewed the ship’s rules and regulations. We then had a science team meeting whereby the cruise’s Chief Scientist, Dr. Steven Rumrill, gave a brief overview of the cruise’s scientific mission, discussed shipboard operations, the cruise’s plans and objectives, and the itinerary and the logistics associated with sample collection and data acquisition.
In summary, the science team will measure a number of salient water quality parameters (see my log April 19, 2008) and collect samples of marine invertebrates (boneless organisms) along the Oregon Continental Shelf (OCS) at varying depths and distances from the coast over the period of 20-27 April 2008. This time of year was chosen because it precedes the development of an upwelling/hypoxia event that is anticipated to develop later in the summer of 2008. (The oceanographic terms upwelling and hypoxia will be discussed later in this log.) Water and biological sampling will continue non-stop for 24hrs per day, every day of the cruise except the last day when preparations are made for eventual docking.
Each work shift is four hours in length and is followed by an eight hour rest & relaxation (R&R) period. My assigned shift mate is Bob Sleeth and the team leader Ali Helms, a research cruise veteran who works full-time under Chief Scientist Steve Rumrill at South Slough National Estuarine Research Reserve (SSNERR). Ali will work the CTD controls in the dry lab while Bob and I will collect water samples from the CTD Niskin bottles and also zooplankton and phytoplankton using specially designed nets deployed starboard (right side of ship) to various depths and eventually retrieved after a certain length of time. Our daily shift schedule is from 0100 to 0500 (1am to 5am) and 1300 to 1700 (1pm to 5pm) with an eight hour R&R period in between each shift. Once started operations will continue on a 24-hour basis without interruption unless for inclement weather or seas.
The map to the right shows the major geographical regions where sampling will occur along the continental shelf of Oregon between Astoria (46O10’N, 123O50’W) and Cape Blanco (42O51’N, 124O41’W). At each sampling site biological (phytoplankton and zooplankton) samples will be collected at varying depths using special collection nets of varying mesh and design.
The operating area for this cruise is the nearshore region of the Oregon Continental Shelf (OCS), between Astoria (Cape Falcon 45o46’N, 124o40’W) and Cape Blanco (42o51’N, 124o41’W) at sites or stations ranging from 3 to 55 miles off the coast. Multiple sampling stations are scheduled along the Newport Hydrographic (NH) Line (maroon line), the Umpqua Estuary Line (green line), the Coos Bay Line (blue line), and the Coquille Estuary Line (orange line). The number of sampling stations is indicated by the number adjacent each colored line. Sampling also will take place at multiple sites (26 total) south of the Columbia River-Pacific Ocean interface and north of the NH Line as indicated by the purple circle on the map at right. Weather permitting, in total there are 59 sites where chemical and biological characterization of the water column will be carried out.
Previously I mentioned the oceanographic terms upwelling. So what is upwelling? A short definition is that upwelling is a vertical water circulation pattern in which deep, cold and typically nutrient- rich seawater moves upward to the ocean surface. Upwelling occurs in a number of places around the world on the western side of continents. It is caused either by strong, consistent winds blowing parallel to the shore as is the case on the Oregon coast in the summer months, or by deep, cold ocean currents smashing into the continental landmass and having no where to go but up as is the case in the southern hemisphere off southern Chile (South America) and Namibia (southwestern Africa). During summer in the northeastern Pacific, a clockwise rotating, high-pressure air system is positioned off the Washington-Oregon coast. Strong northerly winds blow south parallel to the Washington-Oregon coasts pushing the surface water towards the equator. At the southernmost region of the high pressure air system the water is pushed out to sea, away from the Oregon coast. As the surface water is pushed south toward the equator, deep, cold water from below upwells and thereby replaces the warmer, less dense surface water displaced to the south by winds of the high-pressure air system.
Hypoxia describes seawater that is low in dissolved oxygen gas (DO). Generally, the accepted concentration value for waters deemed hypoxic is less than (<) 1.5mg O2/L seawater. Marine organisms vary in their oxygen demand. The more active and larger swimming marine organisms such as tuna and mackerel typically require more oxygen per body weight in order to generate the metabolic activity necessary to supply their dense muscles with the requisite energy to slice through the water oftentimes counter to the current. So an active fish that moves into hypoxic waters decreases its chance of survival.
As expected I didn’t sleep well last night, the first night on the ship. It wasn’t because of the ship’s movement either. It hardly moved as the Columbia River was calm with the wind blowing weakly. It’s a given that more often than not I sleep poorly in a new environment whether it’s a hotel, my in-laws home, or camping. Even if dead tired at best I’ll catnap for 1.5 hour intervals at the most, if lucky.
I was assigned to share living-sleeping quarters with three other science team members. The cabin contained two bunk bed units (top and bottom) separated by a wall, two small desks in the corners, ample storage space below each lower bunk bed and all along three of the four walls of the room, a (very) small lavatory with a hot/cold water shower and toilet, and a sink with hot/cold water to freshen up in the morning or before bed. In spite of the room’s relatively small size (~12ft x ~12ft), the storage capacity was more than enough to accommodate the personal gear of four people for simple, Spartan living. Every square inch of wall space was utilized for storage or some other useful, practical function. Basically, no space was wasted. Wall hooks were everywhere to hang jackets. Each bed had its own reading light, a full-length curtain for privacy (relatively speaking), and a side bumper so that when the ship rolled one didn’t roll out of bed onto the floor. Overall, it was a good example of efficient use of space for simple, practical, but productive living.
The mission delay provided more time for me to talk to and get to know members of science team, particularly my assigned shift mate Bob Sleeth, a retired Silicon Valley electronics engineer. After a hearty breakfast we spent Sunday morning exploring the quiet Astoria waterfront. Bob and a friend sailed in a 35 foot yacht from San Diego to French Polynesia in the South Pacific, spending a year sailing to and from the small islands that constitute the vast archipelago of beautiful islands including Bora Bora and Tahiti.
After lunch I spent a considerable amount of time studying the wrestling match between the ebb and flow of the high and low tides of the Columbia River. Salt water vs. fresh water. Bob gave me a few pointers on how wave structure gives a clue about the subtle changes in wind direction and speed at the water’s surface. This led to a lengthy conversation about how the nameless but intrepid mariners of ancient times, the Vikings, and those of the Age of Maritime Discovery of the European Renaissance (Ferdinand Magellan, Christopher Columbus, James Cook and many more) used their observational powers to chart the vast oceans without the aid of longitudinal coordinates. For example, the appearance of a certain bird over water, marine organism, or the change in surface water color or texture possibly meant that land or an island, yet unseen over the curvature of the earth’s surface, lay just below the horizon.
Throughout the day a number of cargo ships loaded with goods made their way slowly into port. That led to a discussion about how a seemingly small decrease in water volume translates into cargo ships having to shed weight else they run aground. Early tomorrow morning we start the mission and head out to the intimidating, deep waters of the Pacific Ocean.
NOAA Teacher at Sea
Onboard NOAA Ship McArthur II April 20-27, 2008
Mission: Assembly of Science Team and Movement of Science Gear/Equipment Geographical Area: Coos Bay to Astoria, Oregon Date: April 19, 2008
Science and Technology Log
The long, winding drive along US Highway 101 from Oregon Institute of Marine Biology in Charleston to Astoria was well worth it. For the most part every turn opened to a panoramic view of the Pacific Ocean to the west. To the east, lush, verdant open meadows, some inundated with small ponds and bordered by thick coniferous forests, pleased our eyes. We stopped in Newport, OR to pick up a science team member and had lunch at a local restaurant with a microbrewery. I feasted on Kobe Chili.
After arriving at the Astoria dock (45O12’N, 124O50’W) late afternoon and loading all the gear, equipment, and supplies aboard the McARTHUR II, we spent the evening moving personal gear into our assigned shipboard cabins, setting up and troubleshooting the computer and data collection systems, organizing the ship’s wet lab, installing dissolved oxygen (DO) and chlorophyll fluorometer sensors onto the shipboard Conductivity-Temperature-Depth (CTD) platform, and calibrating the instruments in preparation for the cruise. The scientific instrumentation that will be used on the cruise is impressive and worth mentioning since in science data are only as good and believable as the tools used to collect it. The cruise’s instrument workhorse will be the CTD as it will be used at every sample site. The following physical-chemical water quality parameters will be measured continuously as the CTD descends and then ascends through the water column: conductivity, temperature, depth, dissolved oxygen (DO), and chlorophyll a fluorescence. Attached to the CTD are twelve cylindrical Niskin bottles, each with a volume capacity of 2.5 liters (0.66gal). Water collected in the Niskin bottles at various depths will be collected and taken to the ship’s wet lab where the following water quality parameters will be measured using a multi-sensor sonde or probe: salinity, pH, and turbidity. The photo below shows the CTD with Niskin bottles.
Let’s begin by talking about a CTD, which measures seawater’s conductivity (more or less the amount of dissolved ions in a given mass or volume of seawater), its temperature, and depth of the surrounding water column at the time a measurement is made. The latter two parameters are self-explanatory so let’s focus on conductivity. Seawater conducts electrical current because seawater contains dissolved ions, i.e. charged particles, either positive or negative. The major ions in seawater contributing to its conductivity are predominately sodium (Na+) and chloride (Cl–) but other ions in varying amounts, depending on location and depth, are present as well. Examples include magnesium (Mg+2), calcium (Ca+2), carbonate (CO3-2), bicarbonate (HCO3–), and sulfate (SO4-2). Other important elements found in trace or very small amounts in seawater are lithium (Li+), iodine (I–), zinc (Zn+2), iron (Fe+2 and Fe+3), and aluminum (Al+3). This list is not exhaustive by any means.
Conductivity is related to salinity. In general, the greater seawater’s conductivity, the greater its salinity. Salinity of seawater though is not constant; it depends on a number of factors, two of the more important being depth and temperature. Atmospheric gases, namely molecular nitrogen (N2), oxygen (O2), and carbon dioxide (CO2), readily dissolve in seawater, particularly so at the ocean’s surface where wave action facilitates this process. A dissolved oxygen (DO) probe (or sensor, typically the two words mean the same thing) measures the mass (or weight) of O2 dissolved in a given mass or volume of water. The units associated with a measured value then would be either mg O2(g)/kg seawater or mg O2(g)/L seawater. The symbol mg means milligrams, kg means kilograms (1kg = 1,000g = 2.2 pounds), and L means liter. Why is the denominator in the ratio either kg or L? The unit kg is a unit for mass, which does not depend on temperature. The mass (or weight) of a substance does not change simply because it gets warmer or cooler because mass measures the quantity of matter of the substance. The mass of any substance then is independent of temperature. If a book weighs one pound, it weighs one pound regardless if it’s placed in the sun or in the freezer. The unit L (liter) is a unit for volume, the value of which does depend on temperature. An object of some mass occupies a greater volume when warm than when cool.
Also attached to the CTD platform is a chlorophyll a fluorescence sensor, which measures the mass of chlorophyll (typically in micrograms, mcg or μg) per volume (typically one liter, L) seawater (overall units mcg/L). Small biological organisms called phytoplankton contain chlorophyll and hence carry out photosynthesis. Like the photosynthesis carried out by terrestrial vegetation, phytoplankton utilize the red and blue light-absorbing molecule called chlorophyll and the carbon dioxide (CO2) dissolved in seawater to produce biomass and molecular oxygen gas (O2). The famous equation for photosynthesis is:
CO2 + red and/blue light + H2O Ö biomass + O2 Photosynthesis though doesn’t work unless sufficient red and/or blue light from the sun is available at the depths phytoplankton are found. The zone in the ocean near the surface where marine photosynthesis takes place is called the photic zone.
The amount of chlorophyll measured by the sensor is in direct proportion to the amount of photosynthesizing phytoplankton found in seawater. Chlorophyll then can be counted so to speak by making the chlorophyll molecule in phytoplankton fluoresce, i.e. emit light. A chlorophyll fluorescence sensor (CFS) shoots a pulse of blue light into the surrounding seawater. A chlorophyll molecule absorbs the blue light which causes it to emit (give off) red light. The CFS sensor measures the red light emitted. Basically, the more red light that’s emitted means the more chlorophyll-containing phytoplankton present in the surrounding seawater at the depth where the measurement occurs.
A CO2 probe interfaced with a computer for continuous real-time data collection measures the amount of gaseous CO2 (in milligrams, mg) dissolved in a given volume of water (typically one liter). Measuring CO2 in seawater is done to gauge the extent of CO2 gas the ocean “cleans” or “scrubs” (not the television show) from the atmosphere. The world’s oceans are huge CO2 sinks because they absorb enormous amounts of gaseous CO2 from the atmosphere annually, a good amount of which is converted into biomass by the photosynthetic activity of phytoplankton.
The “unused” dissolved CO2 forms carbonic acid, H2CO3, which in turn drops the seawater pH, thereby eventually making seawater more acidic. This added acidity (drop in pH) is countered or buffered by the ocean’s natural basic pH, resulting in essentially no net change in pH. But this buffering capacity has limits. If the buffering capacity is exceeded by the addition of too much CO2 in a given time period or the reduction in phytoplankton photosynthesis, then the net result is a drop in pH, making the seawater more acidic. This change in seawater chemistry, in turn, can have deleterious effects on the biology of marine organisms, especially those organisms that live and reproduce in a limited pH range.
One marine organism that is expected to succumb to the predicted net acidification of the oceans over the next decade or so, if not sooner, is the pelagic snail (see photo below). The term pelagic means open so a pelagic snail is found in the open ocean away from the coast.
Why is the pelagic snail threatened? Acidification of the ocean increases the solubility of calcium carbonate (CaCO3), the major constituent of the shells of marine organisms. Solubility is a chemistry term that relates the amount of substance (CaCO3) dissolved in a liquid, in this instance seawater. Essentially a drop in pH (acidification) increases the amount of calcium carbonate in the exoskeleton or shells of marine organisms dissolved, thereby producing thinner shells. Ultimately the shell becomes too thin and any major wave action will break the shell and the organism dies. To show this process, place an egg in a glass of vinegar overnight. The egg shell’s chemical composition is CaCO3. Vinegar is acidic. Over time the shell becomes progressively thinner. Eventually the egg shell dissolves away completely if the egg remains in the vinegar long enough. The yolk inside the egg then is no longer protected by the shell.
I awoke Saturday morning to the music of song birds and a slight drizzle. I couldn’t identify which type of song bird but it didn’t matter; it was a good start to what would be a great day. Early Saturday morning we packed the scientific gear and sensitive equipment/instruments for the seven-hour vehicular transport along US Highway 101 to Astoria, Oregon (45O12’N, 124O50’W), where the NOAA research ship and crew of the McARTHUR II (see photo left) were docked and awaiting our arrival. The south-north drive along US Highway 101 is long and winding but is replete with breathtaking scenery at every turn. It’s highly recommended when visiting Oregon.
The seven-hour drive in the minivan from Coos Bay to Astoria was a good chance to interact with and talk to some of the other science team members, all of whom I had never met nor talked to previous to today. We all would be shipboard with each other for nine straight days. I had better get to know them and get an idea what makes them tick. I’m sure they thought the same.
In addition, over the past year or so I have developed a keen interest in how ships work and as I came to find out during the seven-hour drive so too did a fellow science team member, Bob Sleeth, who sat adjacent to me during the drive to Astoria. The NOAA crew was most welcoming and eager to talk about their ship. Bob and I were treated to an immensely educational tour of the McARTHUR’s navigational systems capabilities from Ensign Andrew Colegrove, a NOAA junior officer who obviously is passionate about both his job and maritime history; he also has a wealth and breadth of knowledge about the practical, engineering ins-andouts of modern ship technology and operational systems. I lost track of time but I’m sure the personal tour lasted more than two hours.