Meet the Creatures!!!

European seas are full of a wide diversity of marine life. Many of the ESONET observatories are equipped with either still image or film cameras which can observe the sea bed and waters about them.

Detailed below are a selection of European marine animals, links to sources of further information, and explanations of how their long-term observation can help inform our understanding of marine ecosystems.

 

Jellyfish

Jellyfish are periodic visitors to the coasts of many European countries each year. They have a complex life history, and some species start their lives fixed to the seabed, before developing into the free-swimming form more familiar to holiday makers. Details of their lifecycle can be found HERE.

In recent years the numbers of jellyfish found invading coastal waters each year has increased. The reasons are probably numerous, including the removal of competing species (fish) by fishing, nutrient pollution from the coast and changes in ocean circulation.

Further notes on changing patterns in jellyfish distribution can be found HERE.

A video of a large jellyfish swimming can be seen HERE.

The long-term monitoring of jellyfish distribution could indicate significant changes in the marine environment.

 

 

Sea Anenomes

Sea Anenomes are familiar to many visitors to rocky beaches. They are, however, much misunderstood creatures. Although they look much like plants, they are in fact animals, and are related to jellyfish.

There are many other common misconceptions about these animals too. They are not as peaceful as they appear, and actively catch and eat fish, jellyfish, crabs etc. Additionally, they can fight fierce battles amongst their neighbours, as discussed HERE.

Perhaps most surprising is the fact that many species are not actually permanently attached to the seabed, the majority can move slowly to a new home if conditions become unfavorable, whereas others can detach and swim!

Further information on these interesting animals can be found HERE.

 

 

Sea Mice

Of all the creatures occasionally washed up on beaches, the Sea Mouse is one of the most unusual.

Sea Mice are not of course related to terrestrial mice - they are in fact polychaete worms (Click HERE for polychaete information.)

They appear at first sight to be covered in a brown fur, hence the name Sea Mouse, but when viewed from certain angles these hairs refract the light into oily blue and green colours, often in a fringe around the sides of the creature, as shown in this illustration.

The strange optical quality of these hairs is of interest to the optics community - discussed HERE. An image of the hairs can be seen HERE.

 

 

Redfish - Sebastes

These colourful fish often seem to live in association with European Cold Water Coral reefs.

It is one of a number of species which use the complex 3D structure of Cold Water Coral reefs as an ideal habitat to both aquire food and avoid predators. A report on these reefs and associated species can be found HERE.

Damage to such Cold Water Coral reefs by the activities of man (by fishing, for example) is ongoing and not wholly understood. The Coral Risk Assessment, Modelling and Monitoring project (CORAMM) project is one of several groups investigating potential causes of impacts on these ecosystems, and developing mitigation measures. The project website can be visited HERE.

 

 

Starfish

Starfish are not only found in coastal areas, but throughout the world ocean and at various depths.

They can often be found as individuals both on the coast and in the open ocean, but they can also be found in extremely dense swarms. A report on a study of swarming activity in the Irish Sea can be found HERE.

Random, occasional surveying of a marine area can miss the arrival and impact of such starfish swarms. During tests of the Jacobs University crawler at the BOOM observatory site (details HERE ) one such swarm was observed over a 3 day period - during which the starfish devoured all the mussels on the seabed. A large image of the crawler beset by starfish is available HERE - (Copyright Jacobs University).

 

 

 

 

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