More Than Half of Reef Sharks and Rays at Risk of Extinction, According to New Research
Michelle Milliken
Coral reefs are essential, due to the livelihoods they support and the habitat they provide for countless marine animals. However, these important ocean fixtures face a myriad of threats, primarily climate change, land-based pollution, and unsustainable fishing practices. A new study finds these threats are impacting the survival prospects of dozens of species of sharks and rays, as well.
Researchers at Simon Fraser University in British Columbia recently set out to determine the status of 134 species of sharks and rays that live among reefs. Using the International Union for Conservation of Nature (IUCN) Red List, they found that 59% were threatened with extinction.
Samantha Sherman, the study's lead author and post-doctoral research fellow at Simon Fraser, says, "It was a bit surprising just how high the threat level is for these species. Many species that we thought of as common are declining at alarming rates and becoming more difficult to find in some places."
Their findings, published in the journal Nature Communications, showed that in addition to 59% of the species studied being either vulnerable, endangered, or critically endangered, 13% were also classified as near threatened.
The team says the main reason behind the risk to these populations is overfishing, but climate change and habitat degradation are also contributing. The researchers found that larger-bodied sharks are among those most at risk, as well as those that live across the waters of several nations with different management policies and in the waters of countries with more fishing and less governance surrounding it.
To address the declines among shark and ray species, the team says more local protections, broader fisheries management, and well-implemented marine protected areas are needed. They suggest that countries could also work together to have consistent management of species that overlap all their jurisdictions.
Nick Dulvy, study co-author and Canada Research Chair in Marine Biodiversity and Conservation, says, "Protective measures for sharks have only begun to show up recently. As these species have late maturity and long lives, the effects of these protections may not be seen for decades. This is why we need to implement management immediately to conserve these species and secure a future for coral reefs."
In addition to the habitat coral reefs provide for the species studied in this research, the National Oceanic and Atmospheric Administration says roughly half a billion people rely on coral reefs for food and for their livelihoods. The reefs also protect coastlines from storms and erosion, provide habitat for economically important fish species, are hotspots for marine biodiversity, and are even a source of new medications.
