Date:June 26, 2004
Author: Filipe Porteiro (University of the Azores) and John Horne (University of Washington)
Have you ever been 1000 miles from everywhere? We were. Last night at 21:30 UTC, Martin Dahl an instrument specialist, noticed we were getting our correction to the digital global positioning system (GPS) from a station that was 1000 nautical miles away (1 nautical mile = 1.852 kilometers). When we tried to find the location of the station using the electronic plotter we found that the vessel (location: 47o 14.8’ N, 28 o 39.2’ W) was approximately 1000 nautical miles from Portugal, Spain, France, the UK, Iceland, Greenland, and the coasts of Newfoundland and Nova Scotia in Canada. The Azores Islands were approximately 500 nautical miles to our south and that is where we are headed. We have completed sampling stations in the northern and middle sampling boxes and we were steaming toward the southern box (see where are they now).
1000 miles from almost everywhere. Click to enlarge.
Just how much sampling has been done? We were curious too, so we thought we would compile a few numbers: 13 of 18 superstations have been completed; 480 hours of acoustic measurements at 5 frequencies have been recorded (which translates to 2400 hours or 102 Gigbytes of data); among the nets - 27 codend samples from 10 Åkra midwater trawls, 12 macrozooplankton midwater trawls with 60 codend samples, and 3 Egerson midwater trawls; the zooplankton multinet has been deployed 8 times and resulted in 58 samples, and the Juday net with fine mesh has obtained 8 samples. That’s a grand total of 41 successful trawls and 156 codends that have caught a grand total of 48,322 fish! Over 1,086 plastic bags, labels, and preserving containers have been used to store fish. That number doesn’t include samples of crustaceans, zooplankton, or the 189 sightings of 1,149 marine mammals and approximately 5,000 seabirds. In addition to the wet samples, the acoustic towbody has been deployed 11 times, the Underwater Video Profiler 14 times, and there have been 13 Conductivity-Temperature-Depth profiles. All this sampling has been completed by a team of 30 scientists who have handled an average of 1,610.7 fish each.
Fish head montage. Click to enlarge.
This diverse team of people is also reflected in the diversity of our catch. By examining just part of an animal you can learn a lot about where it lives, what it eats, and how it finds a mate. Let’s look at fish heads (see figure). By the size of the eyes we can guess where a fish lives -- big eyes normally tell us that it lives in deep waters were the light is dim. But if it dwells in even deeper water, where there is no light at all, the eyes may be really reduced. The size of the mouth indicates the diet. Some fish use a lure to attract a meal. If the lure hangs from the lower jaw or is suspended from the top of the head, the fish probably captures their prey by ambush. These fish often have long fangs in the front of the jaw that are used to pierce prey and do not permit a captured fish to escape. Midwater fish that feed on gelatinous bodies such as jellyfish, have small mouths with reduced teeth. Long and pointed jaws are used to entangle the antennas of shrimp just before they are swallowed. Finding a mate in the deep waters of a vast ocean can also be a challenge. Some deep sea fish solve this problem with huge olfactory organs that are used to sense potential partners. The heads of many deep sea fishes have sensitive ridges with organs that help perceive the environment. Use the third figure to match ‘faces’ to names.
Fish names. Click to enlarge.