Science for Everyone

Researching Down Under​

Post by Bailey Moritz, Scallop Research Intern

The boat is loaded and we’re reading to hop in the water!

Scallop survey dives in and around Muscle Ridge have begun! Cait and I have gotten out on a lobstermans boat several days so far and more days to come. Meeting our captain and his lobster boat at the dock at 7am, we step over bait totes and down the steep metal ramp with our scuba tanks and equipment. Ideally, 4 dives get done in a day. Once we reach the dive site, a 100m transect is laid down with cement blocks and buoys on either end. Fighting against our awkward fins and the rolling of the boat to maintain balance, we hit the water and descend on the transect, down the length of which we will record the number of scallops and crustaceans we see, We’ll also collect the scallops we encounter in collection bags to be brought topside for tissue sample processing and later shell analysis. The bags can get heavy if the site is rich in scallops, so we have to control our buoyancy accordingly.

As it may sound, the survey methods themselves are quite straightforward. Lay out a 100m transect on land and the task is rather simple. But as this has been my first experience with underwater research, I’ve learned that there are definite complications to take into consideration as you descent for a scientific dive.

Jim, the fisherman who took us diving, demonstrates how to shuck a scallop. We’ll keep the adductor muscle for sampling, which is the part people eat. 

Barnacles and seaweed often cover the top of the scallops. This one is a female, indicated by the pink, egg filled gonad.

One of the critical factors for underwater research are the limitations that come with diving. We can only stay down as long as we have sufficient air in our tanks, so the scope of data collected has to fit within that timeframe. As anyone who has gone for a swim in Maine lately can attest to, the water is not warm and since we are diving in wet suits, we eventually get too cold to stay underwater. Tides impact the depth at which each site sits, changing multiple times a day. Some days, the tide and currents are moving strongly and we can get carried off to the side of the transect or just carried right over the top without time to collect any data! The other day, we attempted to do a dive survey, but storms the night before had kicked up a lot of mud and sediment, and the bottom was just too dark and murky to see your hand in front of your face, let alone any scallops. Visibility becomes one of the biggest factors in this type of research.

Another challenge underwater is the ability to write. Fun fact; pencils can write underwater! Because of this helpful perk of the yellow No. 2, we are able to use “writing cylinders” on our wrists, which are a segment of PVC pipe with waterproof data sheets and a pencil taped on, to collect data. Since hand signals can only go so far, they also allow us to write notes to each other if there is a change in the plan or a point of confusion.

Scallop dive surveys will continue into the fall, and we’re crossing our fingers for some sunshine and good visibility going forward!

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