Native oysters are a staple of our seas and our plates - but our love of their taste has lead to a sharp decline all around the UK.

This gentle giant is the largest shark in UK seas, reaching up to 12m in length. There's no need to fear them though, they only eat plankton!

Sometimes called 'Marsh samphire', wild common glasswort is often gathered and eaten. It grows on saltmarshes and beaches, sometimes forming big, green, fleshy carpets.

One of the most bizarre fish to find on the rocky shore, the clingfish appears an assortment of different animals stuck together!

These colourful little fish are a delight for snorkellers or shallow water divers to photograph, rarely being scared off by their presence!

The moon jelly is the most common jellyfish in UK seas, often washing up on our beaches. No need to worry though - it doesn't sting humans.

Water-cress has become so popular as a salad addition that it is now cultivated on a wide scale. In the wild, it grows in shallow, fast-flowing streams and is an indicator of clean water.

The silverfish is so-named for its fish-like way of moving and its silvery scales. It can be found in the damp corners of the house, such as the kitchen or bathroom. Infestations can cause serious…