The usual, and the oddities

Since transiting the Cape Cod Canal on Thursday, the Pisces has continued its remarkable rate of progress in Southern New England waters. As of 6 p.m. Saturday night (November 15) we are outside of New York harbor and working our way further south towards the New Jersey coast. Tows in these inshore waters have had large amounts of phytoplankton, and catches of salps and ribbed jellyfish have been in several of our plankton tows. We also had ribbed jellyfish in one of our most recent shallow water mid-water trawls, along with a couple of juvenile butterfish and a few larval menhaden. Some earlier mid-water trawls had squid and lanternfish.

cruise trsacvk as of Nov.15 at 6 p.m.

Pisces cruise track as of 6 p.m. November 15, 2014. Image courtesy of NOAA Shiptracker website.

two juvenile butterfish and a menhaden larva

Two juvenile butterfish and a menhaden larva captured in a recent tow of the Shallow Water Midwater Trawl. Photo by Jerry Prezioso, NEFSC/NOAA

We have been striving to catch our fish with as little trauma as possible for oxygen consumption measurements, but have had difficulty keeping most of them alive. We have gotten good data from “Lumpy” the lumpfish, who is still on board and doing well, from some sand eels and a paper nautilus. Our latest tenant of the respirometer is a lookdown, a shiny silvery fish which is not only about the size of a half dollar, but resembles one as well! We had hoped to make measurements on butterfish, but have not had any success in keeping them alive long enough to place them in the respirometers.

lookdown fish in respirometer

A lookdown fish, swimming against a mild current in the flow-through respirometer. Photo by Jerry Prezioso, NEFSC/NOAA

cod-end aquarium

A codend aquarium for the midwater trawl, made by Chris Taylor and the scientists and crew aboard Pisces, will help keep fish alive during tows. Photo by Jerry Prezioso, NEFSC/NOAA

To address this issue the scientists and crew worked together yesterday to come up with a tub that is placed inside the codend of the trawl to provide a soft landing place of undisturbed water at the back of the net for at least some of the fish that are scooped up, and also to keep them submerged in water while the net is being dragged up the trawlway and onto the deck.   We think that if we can address these issues of capture trauma we may have a better chance of getting some candidates for the respirometers. So far we’ve only caught a few squid and lantern fish in the tub. The squid were alive and well, but the lanternfish were not. The lanternfish did however appear to be in much better shape than ones we have caught just using the trawl alone, so we feel we are making some improvements. Now we just need a good catch of butterfish to give our design a real test!

We are continuing to catch a few oddities, such as a balloon squid, so named for its round shape, and also some Phronima, the latin name for a small amphipod that feeds on salps and then lives inside the clear salp body, swimming it around like a little barrel-shaped house. This thumb-sized crustacean is reputed to have been the inspiration for the appearance of the alien creature in the series of Alien movies!

balloon squid

A balloon squid captured in the Shallow Water Midwater trawl. Photo by Dan Vendettuoli, NEFSC/NOAA

a Phronimna amphipod

A Phronima amphipod, captured in the Shallow Water Midwater trawl. Photo by Dan Vendettuoli, NEFSC/NOAA

Jerry Prezioso
Chief Scientist
PC1405 NE Pelagic-EcoMon Survey

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