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!

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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.

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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.

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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!

4 Replies to “Jenny Hartigan: Tucker Trawl: Collecting Sea Life! July 24, 2017”

  1. Hi Jenny, its Ryan (one of the scientists on board R/V Fulmar). Great job relaying the message and providing detail. Keep up the great work and I look forward to reading more of what you write.

  2. Hello Ms. Hartigan! This seems so cool! The other day we were in the Marin headlands and found a Harbor Porpoise that had washed up dead on the shore. It’s front was all mauled and there were animal tracks around it. The people from the Marine Mammal center came and brought it to the post mortem lab and did an autopsy. One group from the camp I was doing that week happened to be going to the center that day, and they asked about the porpoise and the people said that it had been scavenged by a raccoon. Hope you’re having a great summer!

    From Maggie

  3. Hi Maggie, Great to hear from you! I’d like to hear more about your camp. Come visit me at Lincoln and tell me about it. One of the scientists on the boat told me he used to examine dolphin carcasses. too.

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