Plankton are microscopic plants and animals that float freely in the upper surface waters of all the oceans in the world. Microscopic plants, known as phytoplankton, absorb light and produce oxygen just like our trees and plants. Phytoplankton are the food source, or primary producer, at the start of all marine food webs.

Bycatch refers to any fish or marine animals that have been unintentionally caught while fishing for other species. Sometimes this catch is used or sold, but often the bycatch is thrown back overboard.

Crustaceans are a group of clawed animals with exoskeletons and many legs. The term crustacean includes lobsters, crabs and shrimp (shrimp are sometimes known as prawns).

Discarding is the practice of returning unwanted fish to the sea. The returned fish, then called discards, are put back for a number of reasons including if the fish are too small or if the law states that fishermen have caught too many fish on this trip.

An ecolabel provides environmental information on an independently-tested product. The MSC ecolabel is used on menus and packaging to show that the seafood you're eating comes from a certified sustainable source and is fully traceable.

An ecosystem includes all plants and animals living in a particular habitat and interacting with each other.

If an animal or plant is endangered then it is seriously at risk of becoming extinct.

Fish are cold-blooded animals that live in water and breathe using gills.

The general term fishery can have a number of different meanings and is sometimes quite confusing! Fishery can mean the community of fishermen catching the fish, the geographical area that the fishing is taking place or the actual fish species in the water itself.

A fish species is a group of fish that have similar characteristics to each other and can produce young together. For example, haddock is a species of fish as all haddock have very similar features and breed to produce young haddock.