In December 2024, the International Union for Conservation of Nature released its most comprehensive assessment of shark, ray, and chimaera populations since its first global status report nearly two decades earlier. The findings made grim reading.
A third of all shark and ray species now qualify as threatened with extinction under IUCN Red List criteria. Overfishing remains the primary driver, compounded by bycatch, habitat loss, and climate change. For oceanic species specifically, those that range across the high seas, a study published in Nature found global abundance had declined by 71% since 1970, the result of an 18-fold increase in relative fishing pressure over the same period.
These are not abstract statistics. They describe a structural collapse of the ocean's apex predator layer that has been unfolding across the course of a single human lifetime.
Which Species Are Most at Risk?
The IUCN report identified the sharpest declines in species that were once among the ocean's most abundant sharks. The oceanic whitetip (Carcharhinus longimanus), which historical accounts describe as potentially the most numerous large shark on earth, is now listed as Critically Endangered. The scalloped and great hammerhead sharks share the same classification. The shortfin mako, the fastest shark alive, is Endangered.
A separate paper published in Science in late 2024 co-authored by NOAA Fisheries researchers found that overfishing had caused a further 50% decline in shark and ray populations globally since 1970, with the largest species declining first and most rapidly. That pattern, called "fishing down", reflects the ecological reality that big, slow-reproducing animals are simply unable to recover as quickly as they are removed.
A great hammerhead does not reach sexual maturity until it is roughly 15 years old. A giant manta ray gives birth to a single pup every three to four years. These animals cannot reproduce their way out of industrial fishing pressure.
The Ecological Cascade
The loss of apex predators from marine ecosystems does not simply leave a gap at the top of the food web, it rewrites the whole structure below. Research on systems where shark populations have collapsed has documented rapid increases in mesopredator species (rays, large bony fish), subsequent crashes in the organisms those mesopredators feed on, and wholesale shifts in reef and seagrass bed ecology.
Sharks also function as nutrient transporters. Their movement across depth gradients cycles nutrients between the deep ocean and shallower productive zones in ways that underpin primary productivity. Fewer sharks means less of this vertical exchange.
Where There Is Reason for Cautious Optimism
The 2024 IUCN report is not without hope. It explicitly acknowledges that countries with well-managed fisheries, Australia, the United States, Canada, show measurably lower biodiversity loss for sharks and rays than regions with little or no management. Australia's shark protection framework, which includes no-take zones, limits on targeted fishing for vulnerable species, and the prohibition of shark finning in Commonwealth waters, represents the kind of governance the report identifies as necessary globally.
Shark ecotourism is also a compelling economic counterargument to finning and targeted fishing. Studies consistently show that a reef shark alive and swimming is worth far more to a local economy over its lifetime than it is on a plate or in a bowl of soup. The economic case for conservation, properly framed, is increasingly difficult to argue against.
The IUCN's call to action is clear: governments, fisheries bodies, and consumers all have a role to play. The solutions are known. The question is whether they will be implemented with sufficient urgency.
What Ocean Users Can Do
For those of us who spend time in the sea, surfing, diving, fishing, swimming, advocating for shark conservation is not separate from our relationship with the ocean. It is central to it. Fewer sharks means a functionally degraded ocean. Choosing operators that follow responsible shark interaction guidelines, supporting organisations working on policy reform, and understanding the ecological value of the animals we share the water with all contribute to that larger effort.
The shark that shares your break or your dive site is not a threat to be feared. It is a sign that the ecosystem around you is still functioning.
Shark Stop exists at the intersection of ocean love and ocean safety. Our shark-bite resistant wetsuits reflect our belief that humans and sharks can share the ocean — and that informed, prepared ocean users are part of a healthier relationship with these animals. Find out more here.