Finally, after nearly a week at sea, the science team aboard the NOAA ship Bell M. Shimada this summer have started hearing the calls of “Fishing, fishing, fishing!” from the bridge. This little phrase sets off the exploratory trawling and subsequent processing that allows us to research hake populations off the US West Coast. And while some scientists go to the bridge to make sure the area is clear of mammals and help lead the trawl, two decks down, the wet lab churns into action, preparing for that exciting moment when the net makes it back on deck.
This leg, the wet lab, is led by Amanda Vitale. She and the other wet lab assists have used the time leading up to the trawls to refine their roles within the laboratory. Flurries of meetings happen in the ship lounge, where Julia Clemons (Fisheries Engineering and Acoustic Technologies (FEAT) team lead) delineates an entire flowchart worth of tasks for the team so operations after a tow will be efficient and smooth. There’s operating the conveyor belt and hopper, weighing several kilos worth of fish, identifying any number of bycatch species, and, of course individually sampling each fish for a bevy of biological information.
Caption: Julia Clemons (NOAA Fisheries, floor) leads a wet lab team meeting to develop station workflow in the Shimada Lounge. Additionally pictured: Bryant Srioudom (NOAA IN FISH intern), Melina Shak (Caelum), Amanda Vitale (A.I.S., Inc.). Credit: Maddie Reifsteck
Not long after this meeting, the flow is put to the test – a successful trawl concludes. This year, the survey is using pocket nets attached to the outside of the Aleutian Wing Trawl (AWT) net to test for net selectivity – basically a measure of how well the regular net is capturing smaller hake (usually Age-1 and young-of-the-year). These have to be emptied first before anything in the net’s codend can be processed.
For small trawls, the codend is emptied into a collapsible tote, where wet lab assists use shovels to sort and divide up the catch into a myriad of baskets and totes. Larger trawls, however, get dumped into a hopper, and then are sorted out as they move along a conveyor belt. This is where all the cool bycatch organisms are found!
Caption: Ana Olsen (volunteer) looks toward the hopper as Pacific hake come down the conveyor belt. Credit: Maddie Reifsteck
So far, we’ve seen three different species of squid, a couple boccaccio, hundreds of myctophids, a few salps, and even some other commercially relevant species like Pacific herring and northern sardine. Several pictures of these you may see soon, or have already seen, in my survey creature feature photos on the NOAA West Coast Fisheries Instagram page.
Caption: A small (5 cm!) Abraliopsis felis squid that was pulled up with a trawl during leg 1 of the Pacific Hake research survey. Credit: Maddie Reifsteck
And while, of course, the science team appreciates and gets excited for hake to come aboard, everyone also has additional animals they hope to see! Amanda, for instance, is holding out to see either a viperfish or a Mola mola onboard (especially if we could keep it alive and return it to the sea!). Bryant, an Inclusive NOAA Fisheries intern, would be particularly excited to see and ID a cool squid. Melina wants to see a couple of different rockfish species. She actually was involved in coding the routes for the rockfish in the CLAMS software (Catch Logger for Acoustic Midwater Surveys - originally developed by the Alaska Fisheries Science Center) that the wet lab uses to track and log all the biological data taken after a trawl.
Once all of the other fish and invertebrates are sorted out, the team can now focus on the most important species of the survey – the hake! All of these fish are separated into roughly equal-weight baskets. Most of these fish are first sexed and then have their fork lengths taken. This gives an idea of the age composition of the catch, as hake grow continuously as they get older. One basket, however, is pulled aside for enhanced sampling. Under this protocol, each fish is weighed, sexed, assessed for maturity, has their fork length taken, their otoliths (ear bones) removed, and -depending on the fish- their stomach and/or stomach contents removed and fixed for analysis back on land. This suite of parameters ultimately helps us understand hake biology and ecology much more thoroughly – including things like how they grow, exactly how old they are, where certain ages of hake prefer to aggregate, what they eat at depth, and whether or not they’re breeding at certain locations.
After this regular round of sampling is complete, the wet lab assists also pull aside certain fishes for special research projects. This leg, the lab is also collecting hake to support Bryant’s intern project on hake feeding ecology, a project that will analyze what chemical tracers hake express in certain areas and why, and also a blood sampling project that hopes to look at hake growth hormones and how to isolate them from blood products.
Ultimately, it’s a lot of work from start to finish to process a catch in the wet lab, but this group makes it look like it’s the most fun you could have on a given evening. They’ve got music playing. They pass fish between them with an enviable efficiency, an infectious excitement, and genuine curiosity about the organisms they encounter. And when the sun finally sets over the stern, the entire wet lab team gets to commemorate all their hard work with a picture in their rain gear in front of the setting sun.
Caption: The wet lab team poses for a sunset photo in front of the A-frame on the stern of the Bell M Shimada. Credit: Steve de Blois (NOAA Fisheries)
About the author: Maddie Reifsteck is a volunteer with the Fisheries Resource Analysis and Monitoring Division of the Northwest Fisheries Science Center. She is a former Hollings Scholar and a recent graduate of Eckerd College, pursuing a career in marine science.
