Jenny Hartigan: Tucker Trawl: Collecting Sea Life! July 24, 2017

NOAA Teacher at Sea

Jenny Hartigan

Aboard NOAA Ship R/V Fulmar

July 21 – July 28, 2017

 

Mission:  Applied California Current Ecosystem Studies: Bird, mammal, zooplankton, and water column survey


Geographic Area:
North-central California

 

Date: July 24

 

Weather Data from the Bridge:

Latitude: 37.8591° N,

Longitude: 122.4853° W

Time: 0700

Sky: overcast, foggy

Visibility:   less than 1 nautical mile

Wind Direction: NW

Wind speed: 10-20 knots

Sea wave height: 2-4 feet

NW Swell 7-9 feet at 8 seconds

Air Temperature: 52 degrees F

Wind Chill: 34 degrees F

Rainfall: 0mm

 

 

Scientific Log:

On Sunday we encountered heavy fog as soon as we headed out to sea, so the captain sounded the foghorn every 2 minutes. The scientists Jaime, Ryan and Kirsten deployed the Tucker Trawl. It consists of a large net with 3 codends. A codend looks like a small cup that attaches to the end of the net. Each codend collects sea life at a different depth. The Tucker Trawl is always deployed at the edge of the continental shelf. The shelf is about 200 meters below sea level. The goal is to take organism samples from the pelagic (non-coastal or open) ocean. 400 meters of cable are deployed along with the net, so you can see that it goes deep in the ocean!

IMG_2519

The scientists deploying the Tucker Trawl.

Using the Tucker Trawl requires a whole team of people. 3 scientists deploy the net, and the captain operates the winch and A Frame so the net doesn’t hit the deck during the process. The NOAA Corpsman drives the boat so as to maintain alignment and speed. One scientist keeps an eve on the angle of the cable, and communicates with the driver to maintain the proper angle by adjusting speed. After recovering the net, all three samples must be rinsed into a bottle. Too much water pressure can mangle the specimens, so we use a gentle rinse. The bottle is then labeled and treated with fixative to preserve the samples. Then it is stored to later be sent to a lab for identification. I have learned that taking these samples requires a lot of communication, to maintain fidelity to a testable process, utilize equipment wisely, and to ensure safety of all personnel.

2017-07-26 09.16.36

A view from above as the Tucker Trawl goes out to sea.

 

Each offshore transect has one Tucker Trawl site. After that we move to another site and take Hoop net, CTD, Niskin, water, phytoplankton samples. I will explain these later. Sampling all of these sites provides data for the scientists to investigate the entire ecosystem. They collect plankton (producers) from shallow and deep water, observe marine mammals and birds (predators) on the surface, and sample the environmental conditions such as ocean temperature, salinity, nutrients, and ocean acidification indicators. These studies inform decisions for managing a sustainable environment for both sea life and humans.

2017-07-25 11.39.15

Two scientists collecting sea life from the Tucker Trawl.

 

Personal

I want to tell you about the galley. This is the kitchen where we store and prepare our food. We have an oven, stove, microwave, sink and two refrigerators, but everything is compact due to limited space. All of the cabinets and the fridge have latches on them to keep food from flying around when the seas are rough. I have to remind myself to latch the fridge each time I open it. I don’t want to be the person who created a giant smoothie in the kitchen!

 

We eat our meals at the table, which then converts to a bed for sleeping. Every little bit of space is used efficiently here.

 

Did you know?

An albatross is part of the tube-nose family of birds. One of its features is having a tube nose above the nares. Nares are the openings to the nostrils. The birds also have openings at the end of the tubes. This adaptation gives it a keen sense of smell. We saw black-footed albatross, which nests in the Hawaiian Islands, and flies long distances across the ocean to find food in the productive waters of Cordell Bank and Greater Farallones National Marine Sanctuaries. So this albatross has been traveling at sea for a long distance!

 

Animals Seen Today

We spotted a CA sea lion cavorting in the wake of the ship. It looked like it was having so much fun as it leaped and twisted above the waves.

 

I love hearing from you. Keep those comments coming!

Dana Chu: May 17, 2016

NOAA Teacher at Sea
Dana Chu
On Board NOAA Ship Bell M. Shimada
May 13 – 22, 2016

Mission: Applied California Current Ecosystem Studies (ACCESS) is a working partnership between Cordell Bank National Marine Sanctuary, Greater Farallones National Marine Sanctuary, and Point Blue Conservation Science to survey the oceanographic conditions that influence and drive the availability of prey species (i.e., krill) to predators (i.e., marine mammals and sea birds).

Geographic area of cruise: Greater Farallones, Cordell Bank, and Monterey Bay National Marine Sanctuaries

Date: Tuesday, May 17, 2016

Weather Data from the Bridge
Clear skies, light winds at 0600 increased to 18 knots at 0900, 6-8 feet swells

Science and Technology Log

Ahoy from the Bell Shimada! Today, I will explain three of the tools that are deployed from the side deck to obtain samples of the water and the ocean’s prey species.

First off we have the Harmful Algal Bloom Net, also known as the HAB Net, which is basically a 10-inch opening with a 39-inch fine mesh netting attached to a closed end canister. The HAB net is deployed manually by hand to the depth of 30 feet three consecutive times to obtain a water sample. The top fourth of the water collected is decanted and the remaining water (approximately 80ml) is transferred to a bottle which is then sealed and labeled with the location (latitude, longitude), date, time, vertical or horizontal position, and any particular comments. The samples will eventually be mailed off to California Department of Health Services lab for analysis for harmful toxins from algae that can affect shellfish consumers.

Next we have the hoop net, which is pretty much similar in design to the HAB net, except for a larger opening diameter of 3 feet (think hula hoop) and a net length of nine feet. The net tapers off into a closed container with open slits on the sides to allow for water drainage. The purpose of the hoop net to collect organisms that are found at the various depth levels of the deployment. The hoop net is attached to a cable held by the winch. The hoop net is lowered at a specific angle which when calculated with the speed of the vessel equates to a certain depth. The survey crew reports the wire angle sighting throughout the deployment.

Every time the hoop net is brought back up there is a sense of anticipation at what we will find once the canister is open. Coloring is a good indicator. Purple usually indicates a high concentration of doliolids, while a darker color may indicate a significant amount of krill. Phytoplankton usually have a brownish coloring. Many of the hoop net collections from today and yesterday include doliolids and colonial salps, neither are very nutrient dense. Yesterday we also found pyrosomes, which are transparent organisms that resemble a sea cucumber with little bumps and soft thorns along their body. The smallest pyrosome we came upon was two and a half inches with the largest over six inches long. A few small fish of less than one inch in length also showed up sporadically in these collections as well.

The Scientific team is looking for the presence of krill in the samples obtained. The Euphausia pacifica is one of the many species of krill found in these waters. Many tiny krill were found in the various hoop net deployments. On the last hoop net deployment for today and yesterday, larger sized krill of approximately 1 inch) were found. This is good news because krill is the dominant food source for marine mammals such as whales. Ideally it would be even better if the larger krill appeared more frequently in the hoop net samples.

Finally, we have the Tucker Trawl, which is the largest and most complex of the three nets discussed in today’s post. The Tucker Trawl consists of three separate nets, one for sampling at each depth: the top, middle, and bottom of the water column. Like the hoop net, the tucker trawl nets also have a canister with open slits along the side covered with mesh to allow water to drain. All three nets are mounted on the same frame attached to a wire cable held by the winch. As the Tucker Trawl is towed only one net is open at a time for a specific length of time. The net is closed by dropping a weight down along the tow. Once the weight reaches the net opening, it triggers the net to shut and sends a vibration signal up the cable line back to the surface which can be felt by the scientist holding the cable. The net is then towed at the next depth for ten minutes. Once the last net tow has been completed, the Tucker Trawl is brought back up to surface. Similar to the hoop net, the survey tech reads the wire angle throughout the deployment to determine the angle the cable needs to be at in order for the net to reach a certain depth. This is where all the Geometry comes in handy!

As mentioned already, with three nets, the Tucker Trawl yields three separate collections of the nutrients found within the top, middle and bottom of the water column. Once the nets are retrieved, each collection container is poured into a different bucket or tub, and then into a sieve before making it into a collection bottle. If there is a large quantity collected, a subsample is used to fill up a maximum of two bottles before the remainder is discarded back into the ocean. Once the samples are processed, an outside label is attached to the bottle and an interior label is dropped inside the bottle, formalin is added to preserve the sample organisms collected so that they can be analyzed later back in the lab.

Personal Log

It is so good to finally get my sea legs! I am glad I can be of use and actively participate. Cooperative teamwork is essential to getting everything to flow smoothly and on time. The Bell Shimada’s deck crew and NOAA team work hand in hand with the scientists to deploy and retrieve the various instruments and devices.

In the past two days I am getting a lot of hands on experience with deploying the HAB net to assisting with processing samples from the HOOP Net and Tucker Trawl. It’s always exciting to see what we might have collected. I can’t wait to see what the rest of the week may bring. I wonder what interesting finds we will get with the midnight Tucker Trawl samples.

Lesson Learned: Neatness and accuracy are imperative when labeling samples! Pre-planning and preparing labels ahead of time helps streamline the process once the samples are in hand.

Word of the Day:        Thermocline – This is the depth range where the temperature of the water drops steeply. The region above the thermocline has nutrient depleted waters and while the region below has nutrient rich waters.

 

Talia Romito: Second Day at Sea, July 25, 2012

NOAA Teacher at Sea
Talia Romito
Onboard R/V Fulmar
July 24– July 29, 2012

Mission: Ecosystem Survey
Geographic area of cruise: Cordell Bank and Gulf of the Farallones National Marine Sanctuaries
Date: July 25, 2012

Location Data:
Latitude: 37 53.55 W
Longitude: 123 5.7 N

Weather Data From Bridge:
Air Temperature 12.2 C (54 F)
Wind Speed 15 knots/ 17 mph
Wind Direction: From the South West
Surface Water Temperature: 13 C (55.4 F)

Science and Technology Log

Wednesday July 25, 2012

Up Early!

I woke up at 6 AM to the sounds of the people scurrying around to get ready for departure.  The Captain, Erik, and Mate, Dave were preparing the boat while the rest of us were getting breakfast and loading gear.  We welcomed four people onto the boat to complete the team for the day.

Me on the left in my Rubber Fashion Statement

Me on the left in my Rubber Fashion Statement

Today we are completing both the Offshore and Nearshore Line 6 transects.  It is going to be a long day for me with eight stations along the transect for deploying different instruments for gathering data.  I’ll tell you more about that a little later.  The scientists and crew decided to start at the West end of Offshore Line 6.  It took about two hours to get out there so while the crew was in the Wheelhouse the rest of us were able to settle in for little cat naps.  It felt so good to be able to get a little more sleep before the work began.

Gear Up and Get to Work!

With ten minutes until “go” time, the team started to get ready for the long day ahead.  Everyone had on many layers of clothes with a protective waterproof outer layer.  I put on my black rubber boots, yellow rubber overalls, and bright orange float coat (jacket with built-in floatation).  I looked like a bumble bee who ran into an orange flower.  It was definitely one of my better fashion statements.  I think everyone should wear rubber clothes in bright colors, just kidding :P.

Conductivity - Temperature - Depth CTD

Conductivity – Temperature – Depth – CTD

The boat stopped and then Kaitlin and I got to work on the back deck.  At each station we deployed at least two pieces of equipment.  The first is the CTD which means Conductivity, Temperature, and Depth.  This machine is so cool. It gathers information about a bunch of different things.  It has four different types of sensors.  They include percentage of dissolved oxygen, turbidity (amount of particulates in the water), fluorometer for chlorophyll A (the intensity and wavelength of a certain spectrum of light), and a conductivity/ temperature meter in order to calculate salinity.

The second piece of equipment is the Hoop Net.  The name is pretty intuitive, but I’ll describe it to you anyway.  There is a large steel hoop that is 1 meter in diameter on one end.  The net connects to it and gradually gets smaller to the cod end at the collection bucket which is 4.5 centimeters in diameter.

Hoop Net on the winch

Hoop Net

The net is 3.5 meters long from hoop to where it connects to the collection bucket and the mesh is 333 microns.  The bucket has screens that allows water and phytoplankton to escape.  The purpose of the hoop is to collect zooplankton.  The samples we collect to go the Institute of Ocean Sciences in Canada to be processed after the cruise is over.

The third piece of equipment is the Tucker Trawl.  We deploy it once each day near the Shelf Break in order to collect krill.  This net is huge and heavy.  This net allows the scientists to get samples at different depths within the water column.  The Tucker Trawl has three separate nets; top, middle, and bottom.  They deploy it with the bottom net open and then close the bottom and open the middle and top nets in order as the net raises.  They let out  400 meters of cable in order to be at a depth of 200 meters below the surface to start and raise the net from there stopping twice to open the next two nets.  The scientists watch the eco-sounder (sophisticated fish finder) and determine at what depth they would like to open the next two nets.  Please watch the video to get a clear picture of what is going on and how awesome it is.

The Funny Part!

Blow out Pants

Blow out Pants

Ok so working on the back deck has a  lot of ups and downs literally.  When Kaitlin and I are deploying or recovering the CTD and Hoop Net we are bending, stretching, working on our knees and more.  The first time I bent over to rinse down the hoop net I accidentally dropped the spray nozzle and it locked in the open position; I was sprayed with a steady stream of seawater right in the face until Kaitlin was able to turn in off.  It was definitely a cold welcome to work on the boat.  Oh yeah, I forgot to tell you we use seawater on the back deck for rinsing nets, etc.  There is a freshwater hose, but that is mainly used to clean the boat after each cruise.  The second time I got on my knees to collect a specimen from the Hoop Net I had a blow out!  My rubber pants split right down the middle.  So much for being prepared.  The Mate Dave was nice enough to let me borrow his rubber pants for the remainder of the trip.  Thanks Dave – you’re a life saver.

Camaraderie and Practical Jokers!

In between the stations and observing we all like to have a good time.  We always snack in between.  If someone gets something out then we all help ourselves to some of theirs or our own concoction.  We’re eating pretzels, chips and salsa, carrots and humus, pea pods, dried apple chips and more.

Fishing Lure

Fishing Lure

Erik had been planning to punk the scientists during this trip.  He bought a blue glittery fishing lure that looks like a centipede and waited for the most opportune moment to pull his prank.  While the scientists were getting the Tucker Trawl ready he tossed the lure into one of the nets so that it would come up with the sample.  When we pulled up the net Kaitlin and I saw it in the collection bucket and were very curious about what it was.  We called Jamie over and after a few moments realized it was a lure and looked up to see Erik and Dave laughing hysterically at us.  It was a good time all around.  At the same time the observers where coming down from the Flybridge and Jamie was able to continue the prank for at least fifteen minutes.  We all had a good laugh when the second group realized it was a lure too.

View from the Boat!

Black Footed Albatross

Black Footed Albatross

This is one of the best parts of the day!  I saw so many different animals from the boat during the day.  Here are just a few of the highlights.  A mother whale and calf pair were breaching multiple times.  Another Humpback Whale was tail slapping at least 12 times that I counted.  We saw Blue Whales too.  The seabirds were around as well.  The most common were Sooty Shearwaters, Common Murres, Pomarine Jaegers, and Black Footed Albatrosses.  All of these birds are amazing.  If you see a Common Murre adult and chick; the adult is the dad he’s the one that raises the chick.  The Jaeger has a special kind of scavenging style called Cleptoparasitism (stealing food from other birds).  I saw one chasing another bird till it dropped its food in mid-air and the Jaeger caught the fish before it hit the water.  Pretty cool right?!

On the way back to Sausalito we went right under the Golden Gate Bridge.  The weather was perfect.  The sun was setting with puffy clouds in a baby blue sky.  As my eyes drifted down towards San Francisco I was mesmerized by the view.  I could see the entire Bay.  The buildings reflected the golden glow of the sunset perfectly.  There wasn’t a whisper of fog on the water; I could see Alcatraz Island, Angel Island, and The Bay Bridge.

Richard Chewning, June 13, 2010

NOAA Teacher at Sea
Richard Chewning
Onboard NOAA Ship Oscar Dyson
June 4 – 24, 2010

NOAA Ship Oscar Dyson
Mission: Pollock Survey
Geographical area of cruise: Gulf of Alaska (Kodiak) to eastern Bering Sea (Dutch Harbor)
Date: June 13, 2010

Weather Data from the Bridge

Position: Eastern Bering Sea
Time: 1530
Latitude: N 56 15.380
Longitude: W 164 14.010
Cloud Cover: Overcast with light spray
Wind: 30 knots
Temperature: 5.4 C
Barometric Pressure: 1002.7 mbar

Science and Technology Log

Around 0940 Thursday morning we began our first summer 2010 pollock survey transect. Researchers have been conducting acoustic pollock trawl surveys since 1979 and bottom trawl surveys since the1950’s. The 31 transects in this year’s survey run roughly north south and progress from the eastern Bering Sea across to Russian waters in the western Bering Sea. The transect lines range in length from 60 to 270 nautical miles and are spaced 20 nautical miles apart. A nautical mile is slightly longer than a standard mile and is useful for navigating charts (maps used at sea). Only surveying during daylight hours, the Dyson will continue to run these transects till the beginning of August. A transect is a path (usually a straight line) during which the number of occurrences of an observable fact are counted (such as the abundance of pollock).

The beginning transect was marked by the launching of an expendable bathythermograph (XBT) probe. While the name might seem long and somewhat complicated sounding at first, the instrument and data being recorded are actually quite straightforward. Expendable refers to the fact that the probe is not recovered after being deployed. How is the data sent back to the Dyson you ask? Two long thin copper wires uncoil from the launcher and probe allowing data transfer back to the Dyson. The wires are broken by hand once the probe has reached the bottom. The rest of the story is revealed by subdividing the word ‘bathythermograph’ and defining its parts. ‘Bathy’ is a prefix that means deep or at depth. ‘Thermo’ is another prefix that refers to heat or temperature. Finally the word ‘graph’ means to draw a relationship between multiple variables (such as depth of the water and temperature). So an expendable bathythermograph is a disposable probe that profiles the temperature from the surface to the sea floor.

XBT probe and launcher

The XBT is a very helpful tool that enables the scientists onboard the Dyson to gather temperature data while on the move. Being able to capture this data without slowing down and stopping is a big time saver. Bringing a ship to a stop on the water takes much more time than stopping a car on the highway, and deploying a reusable instrument to the bottom and back takes even more time, manpower, and resources. Temperature data allows fish biologists to better understand how water temperature and the abundance of pollock and their food supply are related.

Darin deploying XBT

Later that afternoon, we also performed our first Tucker trawl. The Tucker trawl is a cleverly designed system of three nets that allows for three discrete (separate) samples during a single deployment. The Tucker trawl is designed to catch the zooplankton (animal-like plankton) that pollock eat such as euphausiids. This net allows researchers to study the differences of zooplankton distribution at various layers in the water.

Deploying the Tucker trawl

Tucker trawl messenger

To catch these small organisms, the net needs to a have very small openings. In fact, the openings in the net are only half a millimeter in width or roughly 1/3 the thickness of a dime! The three nets are attached to a metal frame mounted on metal skis that resembles a backwards dog sled. These skis allow the sled to slide along the seafloor and avoid snagging any obstructions. The Tucker trawl is initially deployed with one net open. The first net is closed and the next net is opened using a heavy brass messenger sent down the wire connecting the Tucker trawl to the Dyson. The messenger is attached to the wire cable at the surface and allowed to slide down the cable to the net being towed in the water. The impact of the messenger triggers a spring in a latch that closes one net and opens another net. The second net is closed and the third net is opened in the same fashion. Samples are taken at the surface, at the bottom, and evenly from the seafloor all the way to the surface. Attached to the sled are sensors to record temperature and depth, the flow of water passing through the net, and the time the net spends on the bottom. The catch is collected at the end of the net in a removable cod end jar. Any jellyfish are removed from the catch, identified, and measured. The remaining zooplankton is weighed, and a small subsample is saved and preserved for later identification.

Richard sending messenger down to the Tucker trawl

Euphausiid

Hyperiid amphipod

Personal Log

At sea, a person can easily lose track of time and even forget the day of the week as work aboard the Oscar Dyson continues uninterrupted seven days a week. I was reminded that today was Saturday by a special meal served by the galley. Rick and Floyd prepared a delicious dinner of real Alaskan king crab, prime rib, baked potatoes, vegetables, and fresh baked bread. This was a real treat (along with the cookies and cream ice cream, always a fan favorite) for the crew. There was plenty to go around, and all were well satisfied.

This was actually not my first encounter with king crab on this cruise. The day before, we had the unprecedented surprise of catching a red king crab with the Tucker trawl during the bottom net deployment. To the best of the knowledge of all the scientists onboard, this had never happened before. You might remember that the Tucker trawl is designed to catch zooplankton, which are typically small in size. This unlucky crab was so large she didn’t even fit in the cod end collection jar at the end of the net. In the end the crab was lucky as we opted to release her after recording her weight and species as we already had enough crab in the freezer for dinner the following night!

Richard holding red king crab

Dinner! Lucky for her, the crab Richard’s holding was released back to the sea!

Leisure Activities

Time spent not working onboard the Dyson can be considered among a person’s most precious possessions. Working long hours, the NOAA Corps officers, visiting scientists, and crew aboard the Dyson usually only have a few hours of time before starting their next scheduled watch or shift. Sleeping is often the first order of business on a person’s to do list. Whether you take only a short nap or can sleep for several blissful hours, time in one’s rack (bed) is essential for a productive, happy, and safe crew. Often one’s sleep schedule will necessitate missing a meal but the rest gained seems well worth the trade off. A very nice service offered by the galley is making and setting aside a plate for those crew members missing a meal if requested.

Other down time activities include reading, listening to music, and working out. The Dyson also has an impressive movie collection (including many recent titles not yet released on DVD) that is administered by the Department of the Navy. New titles are added monthly. The Dyson has a very comfortable lounge for watching movies that also includes a wide selection of magazines and books. Keeping connected with the outside world is also very important while at sea. With relative reliability, people can access the internet to answer emails, pay bills online, and surf the web for news and can call friends and family back home using the satellite phone.