Wildlife of Studland Bay
Undulate Ray © K Maidment
Seagrasses are the only truly marine flowering plants and they form a unique meadow habitat in shallow water. The species at Studland is the common eelgrass, Zostera marina. The underground stems (rhizomes) and roots of the seagrass help bind together and stabilise the seabed sediment, reducing rates of erosion - potentially important in a site like Studland. It is nationally scarce in Britain and is of international importance.
The plants provide food for wildlfowl, such as brent goose and wigeon, and the meadows shelter a wide range of fish and invertebrates. Seagrass meadows act as a nursery ground for commercially important fish and shellfish such as bass, sea bream, plaice, sole, cuttlefish and spider crabs by offering plentiful food and shelter at this vulnerable time of their life. Some pipefish species are almost totally restricted to seagrass meadows and the spiny seahorse is strongly associated with this habitat.
Globally, seagrass meadows are under threat. A recent study reported that 58% of the world's seagrass meadows are declining, with 110km2 of seagrass disappearing every year since 1980 - the main causes being direct loss from coastal development and dredging and indirect impacts of declining water quality. Other impacts include boating, fishing and natural impacts such as storms and disease.
More information at www.projectseagrass.org
Seagrass meadow © Christine Roberts
Seahorse © J Hatcher
Despite first appearances, seahorses are fish. Like their relatives, the pipefish, they have jaws fused into a narrow tube and use bellow-like cheeks to suck in small prey. It is thought that seahorses first evolved their upright posture as an adaptation to living in seagrass meadows, taking advantage of the vertical stems for shelter and camouflage.
Two species of seahorse are found in the UK, the spiny seahorse, Hippocampus guttulatus, and the short-snouted seahorse, Hippocampus hippocampus. Although both species have been found to be breeding in Studland Bay, the spiny seahorse is the one most associated with seagrass and therefore most likely to be found.
In 2008 both British seahorses were added to a list of protected species under the Wildlife & Countryside Act (1981).
Find more information about the spiny seahorse at http://jncc.defra.gov.uk/page-5658
Spiny Seahorse © Peter Tinsley
Undulate rays are identified by their swirly patterning composed of dark wavy bands bordered by white spots. They live in relatively shallow water, most commonly between 10 and 30m depth and in the UK are at the northern limit of their range. The distribution of undulate ray eggcases found on beaches suggests there is a spawning area in the vicinity of Studland Bay. Juvenile undulate rays, measuring around 10cm long, have been recorded in Studland Bay, using it as a nursery area where they can feed up on small crustaceans, sea snails and fish in the relative safety of the seagrass meadow.
The Undulate Ray is a Prohibited Species in commercial fisheries and is listed as Endangered on the IUCN red list. The species would benefit from the protection of crucial egg laying and nursery grounds.
Find out more at www.sharktrust.org/en/undulate_ray
Undulate Ray © Peter Tinsley
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