Call for more protection for seagrass meadows

Seagrasses - the underwater plants that act as nursery grounds for young fish - need more protection, say scientists.

Seagrass is found in shallow water around the coast of the UK

Monitoring of seagrass meadows off the North Wales coast found areas damaged by the likes of boat moorings, anchors and vehicles crossing at low tide had reduced value to the ecosystem.

Fewer species of fish were found where seagrass was degraded, according to research published in PeerJ journal.

The seagrass studied was near the village of Porthdinllaen, in Gwynedd.

Researchers at Swansea University studied areas with both high and low cover over a 28-hectare stretch of sea bed.

They also sampled fish living in the underwater meadows of flowering plants.

Plaice in seagrass

There was a three-fold reduction in the diversity of fish species and invertebrates, such as prawns, shrimp, juvenile cod and juvenile plaice, in areas of low cover, said lead researcher Dr Richard Unsworth.

He said that in the areas that had become damaged, there was "a reduction in diversity of the species and in the value of the habitat for juvenile fish".

The seagrass is in a special area of conservation, which is a strictly protected site under the European Habitats Directive.

However, despite this protection it was still being degraded, he said.

"We have a lot of legislation in the UK already to conserve a lot of marine habitats but these mechanisms do not have enough financial clout," said Dr Unsworth.

Impacts

Dr Jean-Luc Solandt of the Marine Conservation Society said the study reaffirmed that seagrass meadows are important habitats that should be protected.

"This research shows that disturbance to seagrass beds negatively impacts on ecosystems, and the capacity for these habitats to support a wealth of species.

"It is further evidence that protection measures are needed to preserve these diverse but fragile places."

Seagrasses are also found in several marine conservation zones off England.

Some marine conservation zones have already designated, with others due for consideration next year.

Conservation groups, backed by MPs, have been calling for a full network of protected zones to be created around the coastline of the UK.
From BBC -Science

Seagrasses are the only flowering plants that are able to live in seawater and able to pollinate while submerged. Seagrass often grow in large groups giving the appearance of terrestrial grassland – a kind of underwater meadow. There are four species of seagrass in the UK, two species of tasselweeds and two zostera species commonly known as eelgrass.

What is it?

The plants’ roots are anchored in mud, sand or fine gravel acting to stabilize the seabed and prevent erosion, which has the further effect of helping to stabilise and defend the wider coastline. The leaves are narrow and long, forming a three-dimensional habitat allowing a wide range of species to inhabit the area. The density of the grasses causes the water currents to slow down and allows nutrients to settle, in turn attracting wildlife.
Where is it found?

Seagrass is dependent on high levels of light for photosynthesis to grow and can therefore only be found in shallow water to a depth of around 4 metres. They are found around the coast of the UK in sheltered areas such as harbours, estuaries, lagoons and bays. ( From The Wildlife Trust)

http://www.wildlifetrusts.org/wildlife/habitats/seagrass