Plankton Popsicles: Summer EcoMon Cruise

August 30, 2019

Researchers from several organizations aboard the summer EcoMon cruise work together on collaborative projects, and also collect samples for others who cannot get to sea.

Fish larvae float on the surface of a plankton sample.

Larval fish, mostly sea robins, floating on the surface of a plankton sample. Photo: NOAA Fisheries

I mentioned in one of my earlier blogs that we have several collaborating projects on the cruise. These range from ongoing programs with the University of Rhode Island and Woods Hole Oceanographic Institution to short-term sample requests.

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Frozen plankton samples from the baby bongo net collections on the summer 2019 EcoMon cruise. The sample on the left contains mostly comb jellies (ctenophores) and looks like a bag of seawater. The middle sample has a lot of small salps (pelagic tunicates); the dark spots are the stomachs of individual salps. The bags at right have many small copepods (planktonic crustaceans). Photo: NOAA Fisheries

Researchers sometimes ask us to collect physical samples, including plankton and seawater, while at sea. Getting out to sea can be expensive and time consuming, so we try to accommodate as many of these requests as possible.

 
We use a couple of different bongo nets to collect plankton. We preserve samples from our standard nets (60-cm bongo nets) so that we can identify and count all the fish larvae (ichthyoplankton), fish eggs, squid para-larvae, and zooplankton
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Plankton samples are dried so that the shells of Foraminifera (single-celled planktonic animals that have carbonate shells) can be used to reconstruct ocean temperature and carbonate chemistry in the Gulf of Maine. Photo: NOAA Fisheries

 

 

 
We are also freezing and drying samples from our net collections on this cruise for researchers from the University of Maine, Florida Fish and Wildlife Research Institute, and the University of Massachusetts Amherst for stable isotope analyses. Stable isotope analysis of elements such as carbon, nitrogen, and sulphur can help identify what fish and seabirds are eating or even reconstruct the oceanic temperatures where plankton like to live.
 

Harvey Walsh

Chief Scientist, GU1902

Aboard the NOAA Ship Gordon Gunter

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Pelagic amphipods including shrimp, krill, and fish are frozen for stable isotope analysis to compare to the diets of seabirds. Photo: NOAA Fisheries

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Last updated by Northeast Fisheries Science Center on September 03, 2019