When we hear the word reef, we often imagine beautiful and diverse tropical coral reefs. But there are actually several other types of reef that exist in temperate and cold waters, which are home to numerous marine species. In the UK, these include rocky reefs that provide a habitat for algae, marine invertebrates and fish. The biodiversity of species can vary widely depending on the environmental conditions surrounding the reef and rock type it has developed on. Biogenic reefs are formed by large populations of a living species, with the most well known being the tropical coral reef. In the UK biogenic reefs can be formed by species including mussels and several types of worms (Ross and Serpulid worms).
Just 200 meters off my local coastline (North Norfolk) is the largest known chalk reef in European waters. The Cromer Shoal chalk reef extent was only discovered in 2010 when divers mapped its 20 mile length. As well as chalk that creates outcrops 3m high offshore, it has areas of rock, exposed peat and clay. It is home to wide diversity of marine species, from the small (30 species of nudibranchs (sea slugs) ) to the large (porpoises and dolphins). A new species of purple ‘hymedesmia’ sponge was even discovered in 2011 by Dr Claire Goodwin! The reef also provides a home for juvenile fish including Whiting, Dover and Sole.
At the moment, trawling is banned on the reef to minimise the damage to the reef and seabed. Lobster and crab pots are allowed and lost equipment relating to this is often found on the reef, though it tends to cause only minimal damage. Cromer Shoal chalk reefs are currently being considered for the next round of proposed Marine Conservation Zones to increase and ensure future protection of this unique environment.
To learn more and support the designation of Cromer Shoal chalk reef as a Marine conservation Zone please see The Norfolk Wildlife Trust’s website.
The Wildlife Trust website
Images: Rob Spray and George Styole
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