Mike, our cephalopod expert, squeezed completely out of the catch, just stands and watches in dismay
Andrey, our invertebrate expert, before the flood
Incredible fish diversity to depths of 3,500 meters, yet inexplicably, Ricardo chooses to examine a surface dwelling pipefish
Date:25 July 2004
Author: John Galbraith (NOAA, NMFS,USA) and Åge Hųines (IMR, Norway)
The day started with a continuation of the work up of the previous days trawl catch.The trawl catches are diverse and many of the fishes are difficult to identify. It takes many hours to successfully categorize, sample and record the catch from a trawl sample. In addition to fishes, cephalopods are examined as well as benthic and pelagic invertebrates. Cephalopods are incredibly varied and pose a quite a challenge. Lumping all the rest of the invertebrates together, however, is an even more daunting task. Your subjects range between phyla, much less families. You would think this might garner respect from the ichthyologists, but the truth of the matter is that when the tow comes up these people are elbowed out of the way. In fact, if they got in the way, they would probably be trampled by fish people carrying heavy baskets. Often ichthyologists monopolize the microscopes and work spaces as well. This is simply survival of the fittest. It is a natural part of a research cruise and part of the evolutionary process. Just the other day, our invertebrate expert (in sandals) got flooded out while working on the catch. The source of the water? Fish people washing down their tables from the next room. The next day, our invertebrate expert was wearing boots. This is an example of adaptation. Adaptation to selection pressure ensures the survival of a species, or in this case a profession. Both the cephalopod expert and the benthic invertebrate expert are adapting to the selcction pressure of the ichthyologists in similar manners. They are changing shapes, keeping low profiles, blending into backgrounds, and working both before and after the fish are worked up. This is an example of convergent evolution. Clearly, the patterns and processes of the northern mid atlantic ecosystem become more apparent to us everyday.
The two major highlights of the day were a partially successful Bathysaurus dive and one of the most successful demersal trawls of the cruise. Excellent samples were taken for genetics, stable isotopes, fatty acids, and age and growth of several species. Diversity of the trawl catch was high and identification of the catch continued long into the next day. At these depths, there are many challenging species to identify. The primary method is to group the species into families, so that each scientist works on a separate group. This way comparison between similar species aids in identification. People tend to pick the groups that they are most interested in and the interest tends to be as varied as the fishes.