Fishing for shellfish, like scallops, has traditionally been done by using a shellfish dredge. Shellfish dredge technology has remained relatively unchanged for many decades. A shellfish dredge traditionally consists of a metal towing mechanism connected to a bag. The towing mechanism runs along the ocean floor and the shellfish, which rest on the ocean floor, are captured in the bag. The bag is similar in shape to a purse and has a deep-scooped ocean-floor side that runs along the ocean floor, a pocket side that creates the pocket space for the shellfish to lie and a side panel connecting the ocean-floor side to the pocket side. The bag has a scooped metal chain on the top perimeter of the ocean-floor side, which is supposed to apply additional pressure to the ocean floor, keeping the bag in constant and full contact with the ocean floor. However, in practice, only the endpoints of the scooped chain, where the bag is attached to the towing mechanism, come in full contact with the ocean floor. These portions often become worn out quickly and the entire chain needs to be replaced. The remaining portion of the chain does not get worn out and remains in better condition, but still needs to be replaced due to the worn out endpoints.
The worn out endpoint sections of the scooped chain also correspond to the sections of the bag that are actually catching a large majority of the shellfish. The region where the bag and chain connect to the towing mechanism creates a triangular shape and comes to a peak at the points of attachment. During use, shellfish are predominantly collected in these peak regions of the bag, with the remaining bag being primarily empty. The entire center region is not in constant and full contact with the ocean floor because it does not have the additional pressure created by the peaks and the towing mechanism and thus is not capturing all the shellfish. The current method of configuring a shellfish dredge is only capturing in the bag a small percentage of the shellfish capable of being caught.
The opening of the bag, the capture area, represents the area where the shellfish enter and is traditionally shaped like a semi-circle. The top edges of the circle, the end peaks, are connected to the towing mechanism.
In recent years, the environmental impact of shellfish dredging has come under more scrutiny. Environmental regulations address the need to keep protected sea-animals from inadvertently getting caught in the shellfish dredge bag. These regulations often require additional chains and netting to be placed on the bag. Additionally, due to the desire to preserve the ocean bottom, there is an environmental advantage in decreasing the bottom time, the amount of time that a dredge spends on the ocean floor. At the same time, there is an economic and consumer need to preserve or increase the shellfish yields.