Saw sharks are a group of cartilaginous fish distinguished by their elongated, saw-like snout, known as a rostrum. This feature, edged with sharp, tooth-like projections and sensitive barbels, helps them detect and disable prey in their often murky habitats. Unlike sawfish, which are a type of ray, saw sharks possess gill slits on the sides of their heads, similar to other shark species. They inhabit the deep waters of continental shelves in temperate, subtropical, and tropical oceans, primarily found across the Indian and Pacific Oceans.
Saw Shark Conservation Status
The conservation status of saw sharks varies among species. The family includes eight recognized species, with individual classifications on the International Union for Conservation of Nature (IUCN) Red List ranging from “Least Concern” to “Vulnerable.” The IUCN Red List assesses extinction risk based on population trends, size, and geographic range.
“Least Concern” species do not meet criteria for a threatened category, while “Vulnerable” indicates a high risk of extinction in the wild. For example, the Common Sawshark (Pristiophorus cirratus), Shortnose Sawshark (Pristiophorus nudipinnis), and Tropical Sawshark (Pristiophorus delicatus) are listed as “Least Concern.” These species benefit from stable commercial catch rates, reduced total allowable catches, or minimal fishing pressure in their deepwater habitats.
Major Threats to Saw Sharks
Saw shark populations face several threats, with commercial fishing activities being a primary concern. Bycatch is a major issue, where saw sharks are unintentionally caught in fishing gear targeting other species. Their toothed rostrums are particularly prone to entanglement in nets like bottom trawls, gillnets, and longlines, which operate in their benthic (bottom-dwelling) habitats. This incidental capture often leads to injury or mortality, contributing to population declines even in species not directly targeted.
Habitat degradation and loss also threaten saw sharks. While many species inhabit deeper waters, coastal development, pollution, and climate change can indirectly impact their ecosystems. Ocean acidification and rising temperatures, for example, can affect prey availability or alter habitat conditions. Although direct targeted fishing for saw sharks is less common than bycatch, some species may be retained for their meat or rostra, adding to fishing pressure in certain regions.
Conservation Efforts Underway
Various initiatives are being implemented globally to protect saw sharks and mitigate the threats they face. International agreements, such as CITES, list some saw shark species, regulating their international trade to prevent overexploitation. National laws in specific regions also provide protection, often alongside broader fisheries management plans.
Fisheries management strategies aim to reduce bycatch. These efforts include modifying fishing gear to prevent entanglement, implementing time and area closures to protect sensitive habitats or breeding grounds, and promoting sustainable fishing practices. Research and monitoring programs gather data on saw shark populations, distribution, and biology. This information helps understand their ecological needs and informs conservation strategies.
Protecting saw shark habitats, such as marine protected areas (MPAs), is another conservation measure. MPAs delineate ocean zones where human activities, particularly fishing, are restricted to allow marine life to recover. While some saw sharks are wide-ranging, MPAs can safeguard their habitats and provide refuge from fishing pressure. Raising public awareness about saw sharks and their conservation challenges also helps garner support for protective measures and encourages responsible ocean stewardship.