David Riddle, July 25, 2006

NOAA Teacher at Sea
David Riddle
Onboard NOAA Ship Albatross IV
July 13 – 28, 2006

Mission: Sea scallop survey
Geographical Area: New England
Date: July 25, 2006

Science and Technology Log 

Science-wise, catches of scallops have been variable. Sometimes we’ve hauled in huge numbers; other times almost none.  We’re still sorting and counting and measuring fish from every catch, and as we move back northward, a little east of our starting point now, the fish species have begun to change.  We’ve even caught a few lobsters.

I’ve been trained to do several different jobs so far.  I’ve monitored the computer station while collecting the CTD data, determining salinity by lowering the device over the side that measures conductivity, temperature, and density within 5-10 meters of the bottom.  I’ve also helped download the data from the inclinometer, which results in a graph showing the angle of the dredge relative to the bottom during the tow.

I’ve learned the procedures for measuring and collecting additional data on little skates. They’re the fish that look like stingrays.  We measure, length, width, weight, and determine degree of sexual maturity.

Now I’m doing the starfish count, every third tow.  My job is to collect a random bucket full of the by-catch (the leftovers) after everything else countable has been removed, then sort, count, and weigh the starfish according to species.  Sometimes the whole catch is mostly starfish, so there’s plenty to keep me busy.

Sightings:  This afternoon I saw the dorsal fins of two ocean sunfish (Mola mola). I would have assumed they were sharks, since all that was visible was the fin, but the fishermen said you could tell by the shape of the fin and the way it moved through the water. The Peterson Guide to Atlantic Coast Fishes says they’re among the largest of the marine bony fishes.  (Whale sharks and basking sharks are larger, but sharks have cartilage instead of bony skeletons.) Sunfishes can be as large as 3 meters long and 3.3 meters tall, and they may weigh over two tons.

Personal Log 

Several days have passed since my last log entry.  I’ve been making some hand-written notes, but they’re mostly about our encounter with the fringes of Tropical Storm Beryl and my re-encounter with seasickness.  Everyone has been very understanding, and I’ve appreciated it. I’m feeling back to normal now.

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