Help Save Our Rays

Rays and skates are the most diverse of the cartilaginous fishes. There are around 600 species worldwide. These range from the gigantic manta rays, with a 'wingspan' of over six meters, right down to skates the size of a person's hand. Though they vary greatly in size and body form, a common characteristic of rays and skates is that they all have a flattened body with broad pectoral fins that form a body 'disc'.

Rays are found throughout the oceans, from the tropics to the cold waters around the Arctic and Antarctica.

They are also found at all depths, from the intertidal zone down to the deep sea. While most rays live in the sea, a few also live in fresh water; some up to thousands of kilometers inland in South America. Their wide distribution and diversity means that rays have an important role in almost all marine ecosystems, with each species having its own distinctive niche. Almost all rays feed on prey living close to, on, or just underneath the bottom. They act somewhat like the vacuum cleaners of the ocean. This means that the animals that feed on them live on the bottom as well. Rays feed mainly on invertebrates and small vertebrates, with prey ranging from quite large fish down to tiny crustaceans. All known rays are carnivorous, and as a group they are high in the food web.

Because rays are at the top of ocean food webs they have few predators themselves. Their low natural death rate has allowed them to adopt a life history strategy focussed on producing a few, large young. Compared to most bony fish, rays are long- lived, slow-growing, and are late to mature. Unfortunately, this strategy makes rays highly vulnerable to human-made pressures such as fishing, habitat degradation and pollution.

Rays are a common catch within many fisheries, both inshore and offshore. Although rays are targeted in fisheries elsewhere in the world, they are largely caught accidentally, as a bycatch of commercial and recreational fisheries targeting other species. Most fishing pressure occurs in waters over the continental shelves, putting the species living in this area at risk. Deep-sea rays are even more at risk to fishing pressures than coastal and pelagic species, as the low productivity of the deep-sea floor means that many of the species found there grow extremely slowly and have a low reproductive rate.

As a consequence, many of these species are naturally rare.

Many species are found in only a small area, while others may live only in specific habitats over a wider area. Fisheries in the deep-sea are still being commercially developed, and rays will increasingly be caught as bycatch in these areas. Unfortunately, the low reproductive rate of these rays means that species can be heavily reduced, even to extinction, before the targeted bony fish species shows a significant decline in catch.

Habitat modification and pollution are also major issues for some inshore species. Estuarine and coastal areas are suffering increasing alteration through development, restriction of river flows, land reclamation and other pressures. The young of many inshore species spend their first few months or years in high productivity 'nursery' areas. Often these nursery areas are located in estuaries or shallow mangrove-fringed ecosystems where there is plenty of food and protection from larger predators. The destruction of these nursery areas can result in a permanent reduction in the local ray population.

Rays are present in most marine ecosystems worldwide, and have a vital role in maintaining the health and function of these ecosystems. Their ecological niche has been little-studied when compared to sharks, but their diversity, abundance and worldwide distribution are evidence of their success. The challenge for marine science now is to ensure these rays are protected, so they do not quietly disappear before we can fully understand just how important they are.

Help Save Our Rays

Rays are found throughout the oceans, from the tropics to the cold waters around the Arctic and Antarctica.

Want to
Help Save Our Rays?

As a consequence, many of these species are naturally rare.

Join the Revolution

Help Save Our Rays

Rays are found throughout the oceans, from the tropics to the cold waters around the Arctic and Antarctica.

Want to Help Save Our Rays?

As a consequence, many of these species are naturally rare.

Join the Revolution

Want to
Help Save Our Rays?