Dive collection of marine seafood is a low impact method that has a minimum impact on seabed habitats. The seabed is not damaged in any way and the only species being affected is the target species. Diving itself can be dangerous however, depths that can be worked are limited to 30m due to human physiology and practicality. Diver collection of shellfish on a commercial basis is controlled by strict governmental legislation from the Health and Safety Executive. If you are purchasing diver-collected seafood you should always check that suppliers meet these guidelines for their own safety.
Although this is a low impact method of capture there still can be an issue with over exploitation if un regulated. Divers most often collect high value seafood such as scallops, razor clams, lobsters and crawfish.
There is particular concern that diver collection of crawfish (spiny lobster) can be a particularly efficient way of targetting this slow moving species. There is evidence that diver collection in the 1960's and 70's s was a contributor to the collapse in crawfish
stocks in Uk waters, although increased use of tangle netting which can be deployed safely at much deeper depths was also undoubtedly to blame.