Bongos, Barnacles and Boyle’s Law

May 29, 2019

Today marks one week into the voyage of the Henry B. Bigelow Spring Ecosystem Monitoring Survey, also known as EcoMon, and we have covered a lot of ground, literally, since our last update.  Now we have completed 60 stations as we move onto Georges Bank for the northern portion of our survey.  Aided by very good weather, we’ve been able to make good progress, and the sampling has proceeded smoothly with no stations missed from our truncated cruise plan.

Our plankton catches have been light, unencumbered by any algae blooms, thankfully unlike our plankton tows from last fall which were often dominated by dense blooms of a diatom, Thalassiosira mala, that coated our nets with a green mesh-plugging slime!

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Scanning electron micrograph of the diatom Thalassiosira mala that bloomed off the coast of Southern New England in the fall of 2018. Photo credit: Dr. Lucie Maranda, URI/GSO

Fish larvae from the Mid-Atlantic Bight and Southern New England waters have been sparse.  We have a student on board, Quentin Nichols, who has been retrieving fish larvae from one of the bongo plankton nets, but has met with only modest success from the tows he has examined in the southern part of the survey.

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Quentin Nichols from the NEFSC’s Narragansett Lab at his microscope aboard the FSV Henry B. Bigelow. Photo credit: NOAA Fisheries/Jerry Prezioso

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A flatfish larva collected from the bongo plankton sampler by Quentin Nichols. Photo credit: NOAA Fisheries/Quentin Nichols

Sometimes we do encounter rather unusual “planktonic” finds.  One tow had two colonies of gooseneck barnacles which had attached themselves to two fragments of buoyant plastic that were scooped up by our bongo nets.  It was ironic to find pieces of plastic, one of today’s greatest threats to the ocean ecosystem, providing a habitat for some organisms.

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Gooseneck barnacles collected from the bongo nets. Photo credit: NOAA Fisheries/Jerry Prezioso

Ecosystem monitoring cruises from the Oceans and Climate Branch of the Northeast Fisheries Science Center collaborate with other institutions to conduct joint research while underway.  In addition, there is often an outreach component, usually in the form of a NOAA Teacher-at-Sea candidate who will sail with us to assist in deploying gear and recording data.  In our case a teacher wasn’t available to join us, but we do have representation from some young students in the form of hand-decorated Styrofoam cups.

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Tamara Holzwarth-Davis from the NEFSC’s Woods Hole Laboratory holds a mesh bag full of Styrofoam cups from 4th graders at Springbrook Elementary School. Photo credit: NOAA Fisheries/Jerry Prezioso

Fourth graders from the Springbrook Elementary School in Westerly, Rhode Island, have given us 60 of these cups to take out to sea.  Placed in a mesh bag and attached to our Niskin bottle rosette, they will provide an excellent

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Anthony Johnson and Jonathan Harvey retrieve the Niskin bottle rosette sampler with attached yellow mesh bag full of Styrofoam cups. Photo credit: NOAA Fisheries/Jerry Prezioso

demonstration of Boyle’s Law for the students as they shrink from repeated submersion with the sampling array as it’s lowered to the sea floor to collect water samples and hydrographic data.  These cups, now already a fraction of their original size, will be returned to the students after we disembark on June 6 as mementos of their class’s sea-pressure project!

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Cruise track of the HB 1902 EcoMon Survey as of the morning of May 29, 2019. Photo credit: NOAA Fisheries/Jerry Prezioso

Now with one week left to this survey we are planning a route that will take us across Georges Bank and through the Gulf of Maine, sampling as many stations as we can reach in the time remaining.  What has been unusual compared to surveys at other times of the year is that the weather has been consistently good, and is forecast to remain so for the near future, which certainly makes planning a lot easier!
Jerry Prezioso
Chief Scientist
HB 1902 Spring Ecosystem Monitoring Survey