Sharks and rays have biological characteristics and an ecological role which suggests they could be particularly vulnerable to fishing pressure as they include some of the latest maturing and slowest reproducing of all vertebrates, resulting in very low population growth rates with little capacity to recover from overfishing and other threats such as pollution or habitat destruction  All elasmobranchs are predators and must exist at the top of the food chain. Their abundance is therefore relatively small compared to groups situated in lower trophic levels.

As a group, elasmobranchs present an array of challenges for fisheries management and conservation.  Life–history characteristics make sharks a fragile resource, and more susceptible to overfishing than most teleost (bony) fishes. The high mobility of many species, sometimes involving transboundary migrations, incorporates another level of complexity to their assessment and highlights the need for proper knowledge about stock delimitation and dynamics if adequate management is to be implemented. Elasmobranch fisheries assessment is complicated further because of a general lack of baseline information about their fisheries throughout the world.

Skates and rays are species of fish, closely related to sharks that are dorso-ventrally flattened. This gives them an added advantage to be able to glide along the sea-floor. Rays and skates are very similar in appearance however, there are differences. Rays give birth to live pups (viviparous) whilst skates produce egg cases (oviparous) that are distinctive to the species. Skates have a tail that is stockier and does not have a stinging spine. Rays have a thinner tail and sometimes have a stinging spine. 

Skates and Rays bury themselves under sand on the sea-floor to protect themselves from predators. There are two breathing holes called spiracles located near their eyes which allow them to breath when covered in sand. The presence of these spiracles means that rays have the ability to rest on the sea-floor whereas most other sharks must keep swimming to keep water moving across their gills or else they will not be able to breath. Their mouth is on the underside of their body which enables them to feed on benthic animals.

In reference to anatomical structures, skates have a prominent dorsal fin, while rays have a reduced or no dorsal fin at all. Skates also have more flesh in their tails with no spines compared to rays with thin, whip-like tails and a stinging barb. The barb and the poison they carry serve as a protection for the ray from intruders or predators. Skates have no barbs but rely on the projection formations that stick out like thorns on their backs for their protection.

Rays are often in the shape of a kite with a smooth tail while skates have a more round or triangle shape with small fins in the tail. In terms of comparison in size, rays are considered larger than skates. Teeth are also another category of difference between the two. Skates have small teeth while rays have plate-like teeth that are used for crushing food.