Giant jellyfish diver launches 'Jellywatch' survey

Barrel jellyfish are the largest jellyfish that appear in UK waters

A marine scientist who encountered a huge jellyfish while diving last month has encouraged people to take part in a nationwide survey of the creatures.

Lizzie Daly was pictured off the coast of Cornwall in July next to an enormous barrel jellyfish during a project documenting marine encounters.

Now, Ms Daly, Swansea University and the Marine Conservation Society have launched a "jellyfish watch" weekend.

It is hoped the survey will teach scientists more about the creatures.

• Divers 'humbled' by giant jellyfish encounter

The jellyfish come to UK waters in the early summer to feed on plentiful plankton

Jellyfish in the UK

• There are six different jellyfish which live in UK seas

• Two other creatures - the Portuguese man-of-war and the by-the-wind sailor can also be found, but are not jellyfish

• The barrel jellyfish is the largest in the UK - traditionally measuring 1m (3.3ft) in diameter

• The smallest is the mauve stinger, which measures just 10cm (4in)

• Although some have a mild sting, it is advised you do not touch any jellyfish you see

Source: Marine Conservation Society

The event, entitled the Great British Jellywatch weekend, is designed to aid the Marine Conservation Society (MCS), which carries out a survey every year to help monitor trends and understand jellyfish behaviour.

People across the UK are being asked to travel to their nearest beach to see how many jellyfish they can spot.

Dr Peter Richardson, Head of Ocean Recovery at MCS, said: "Jellyfish have been swimming in our oceans for over 500 million years - they are great opportunists, reproducing in huge numbers when conditions are right, so they can tell us a lot about the state of our seas."