The Future of NOAA’s Long-Running Sea Scallop Survey 

New England/Mid Atlantic — The NOAA sea scallop survey has been providing data on population status since 1979. Over that time, the stock has recovered from very low levels to a population large enough to support one of the nation’s most valuable single-species fisheries. The status of the population isn’t the only thing that’s changed. Increasingly sophisticated ways to track sea scallop populations have come along. We have adapted and diversified our survey methods to take advantage of them.

Adding Survey Capacity
While we started with one vessel surveying the entire area with a dredge. The area is now divided among our science center and several partners, including the sea scallop industry. They use both dredges and optical (photographic) instruments deployed from research and commercial scallop vessels. All these data are used for stock assessments and for quota setting.

This year, for the first time, our science center’s survey covered Georges Bank and adjacent waters using:

-A dredge
-A towed camera–and–sensor system called HabCam
-Our newest sampling device—a Tethys-class long-range autonomous underwater vehicle nicknamed “Stella”

These were deployed off three different vessels: a university-owned research ship, a commercial sea scallop vessel, and a NOAA research vessel.

Stella, the Long-Range Autonomous Underwater Vehicle

The most recent addition to our survey capacity is Stella, our long-range autonomous underwater vehicle. It carries the same imaging package as our towed sampling system, the HabCam, but can be programmed to operate without human supervision.

Stella is being developed with partners at the Woods Hole Oceanographic Institution, and was designed by the Monterey Bay Aquarium Research Institute. It is owned and operated by the Woods Hole Oceanographic Institution, equipped with WHOI-designed stereo imaging camera payloads.

“Stella was developed for surveying inside the new wind energy development areas,” said Peter Chase, who is in charge of our center’s resource surveys. “It’s one way to capture data to replace towed HabCam sampling in those areas.”

Large vessels similar to those currently used for our dredge surveys will likely not operate among the multiple turbines planned within wind energy areas. “Our focus now is on testing deployments and operations of the Stella from different platforms before formally incorporating it into our regular survey,” said Chase. “We are also gathering more information on how long Stella’s batteries last under different conditions. That’s important for any fully autonomous operations. Ideally we’d be able to release Stella from shore for a round trip to a survey area.”

Stella has the same capacity for sampling as HabCam but travels more slowly. “It has a number of advantages,” said Dvora Hart, our lead sea scallop assessment scientist. “We can deploy it untended while other operations continue, and we have so far used it to further investigate areas of particular interest. For example, if the dredge encounters high densities of sea scallops, Stella can rework the area, taking photographs that can confirm what’s on the bottom as well as how efficient the dredge is at capturing what’s in its path.”

After this year’s successes with the Stella and deployments from a variety of vessels, Chase said the survey will likely continue to use multiple vessels.

“We will be better positioned to consistently complete the survey. We can use a commercial vessel to do all the dredging and the research vessels to deploy the camera systems. The commercial vessel has a sister ship and we have two options for research vessels,” said Chase. In recent years, research vessels have encountered operational issues that led to reduced or canceled surveys.

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Wayne Creed

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