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What Is a Scallop Dredge?

Jeremy Laukkonen
Jeremy Laukkonen

A scallop dredge is a fishing device that is capable of scraping along a seabed to capture edible mollusks. Some dredges are designed specifically for scallop fishing, though very similar devices are also used to obtain oysters, crabs and various other species that live on the ocean floor. These dredges typically are constructed from steel frames and metal mesh netting, and they are towed behind motorized fishing vessels. Fishing dredges can cause substantial damage to a seabed and result in the undesirable bycatch of species such as octopuses and starfish.

Scallops are a type of edible shellfish that are present throughout the oceans of the world. These bivalve mollusks have fan-shaped shells and are filter feeders that live on seabeds. Most scallop fishing utilizes dredges, though there are a few other methods. Long rakes were used in the past, though that method is less effective than a scallop dredge and is no longer as common. In addition to being fished for in the wild through those methods, scallops also can be farmed in a type of aquaculture.

Cooked scallops.
Cooked scallops.

The basic construction of a scallop dredge consists of a mesh net attached to a metal frame. This device is lowered to the seabed by a motorized fishing boat and then towed. The leading edge of the net is open, allowing the frame to scoop through materials present on the sea floor as the fishing vessel tows it forward. Small objects pass through the net, and any scallops on the sea floor become trapped inside. Several of these dredges are often towed at once, and large vessels can deploy 20 or more over each side.

Scallops in their shells.
Scallops in their shells.

After the net of a scallop dredge has been filled, the device can be hoisted to the surface for the contents to be processed. Many species that feed on mollusks, such as dog whelks and starfish, are caught along with the scallops and must be separated out. Other species can also be part of this bycatch because anything larger than a scallop can become trapped in a scallop dredge.

Fishing dredges often damage the seabed and catch other sea life like starfish.
Fishing dredges often damage the seabed and catch other sea life like starfish.

An alternative to fishing with a scallop dredge is hand gathering, which typically is accomplished by a diver who is equipped with an underwater breathing apparatus. This type of scallop fishing can be less destructive to the ecology of the seabed, though it is a more labor-intensive endeavor. Scallops caught in this manner tend to reach the market faster because of the extra processing that dredge-caught scallops typically undergo.

Discussion Comments


@stl156 - Scallops are a pretty versatile species, so they can be found everywhere. Interestingly enough, most of the world's scallops come from the eastern parts of Canada and the United States. Japan and China have some fisheries, too.

Unfortunately, catching scallops is getting harder because of decreasing shark populations. The same animals that sharks eat are the same things that eat scallops. Without the sharks, more scallops get eaten, and it is causing a huge problem.


Where is scallop dredging usually done? Do they live near the shore like clams, or are they found in deeper water? I am from Canada. Are scallops common anywhere here, or are they usually found in other parts of the world?

Are there any sorts of laws about scallop dredging? I know for certain types of fishing, you have to have special nets that will let out other fish. How long does it take the ocean floor to recover after the dredge equipment has gone through?


@JimmyT - I think scallops are a lot better than clams and oysters. At least in all of the scallop recipes I've had, the scallops are cooked until they are solid, so they don't have the cool, slimy texture of other shellfish.

You can get fried or breaded scallops at most seafood restaurants or buy them from your grocery store in the fish section. I don't know that I've ever bought them in the store, but my guess is that scallop marketing is like fish marketing.

If they are wild caught, it will probably be on the package, since I figure most people think the wild kind tastes better. I don't know if they do or not. On the other hand, the farmed scallops will probably also be advertised so that people who are worried about the environment will buy them instead of the wild caught type.


I don't think I have ever had a scallop before. What do they taste like, and where can you buy them? I don't particularly like clams or oysters, but I'm willing to give scallops a try.

I don't like the idea of knowing that dredging for them can be harmful to the ocean. Is there any way to know whether or not the scallops you are eating are wild or from an aquaculture? Does one kind taste better than the other?

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    • Cooked scallops.
      By: alain wacquier
      Cooked scallops.
    • Scallops in their shells.
      By: Picture Partners
      Scallops in their shells.
    • Fishing dredges often damage the seabed and catch other sea life like starfish.
      By: Giuseppe Porzani
      Fishing dredges often damage the seabed and catch other sea life like starfish.