The common whelk is the largest sea snail found in UK seas, though you're more likely to find the dry balls of empty whelk egg capsules washed up in strandlines.

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.

Arrowhead is an aquatic plant of shallow water and slow-moving waterways. In bloom over summer, it displays small, white flowers, but it is the arrow-shaped leaves that are most distinctive.

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!

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.

The Broad-bodied chaser is a common dragonfly that can be seen in summer around ponds and lakes, and even in gardens. It lives up to its name: its flattened body gives it a fat, broad look.