Sharks and Rays

Bycatch in commercial fisheries is one of the greatest threats to shark and ray populations worldwide.

Since the 1970’s the global abundance of sharks and rays has declined by 71% with the primary threat the increase of fisheries throughout their range. It is estimated that 99.6% of sharks and rays are affected by fishing (primarily incidental capture). Declines were first seen in large species, which declined before the 1980’s, followed by declines in medium and then smaller species. Currently one-third of the worlds sharks, rays and chimaeras are threatened with extinction according to the IUCN Red List.

Risks for sharks and rays

Dead shark entangled in a fishing net

Dead shark entangled in a fishing net

The full impact of bycatch on sharks is not well understood since species specific bycatch rates are not reported in many fisheries. However, it can be expected that sharks are common components of bycatch in fisheries worldwide and that mortality rates are high for many species.

The loss of sharks has been shown to negatively impact ecosystems. For example, the loss of sharks can lead to changes in the abundance of their prey species, which can lead to a cascade of other trophic-level impacts (i.e., abundance of predators can decrease, or prey behavior can be altered, thereby releasing lower-trophic-level species from predation) in the ecosystem.

It is critical to minimize the risk of bycatch on sharks in order to develop and protect healthy oceans.

Fishery Impacts