Eelgrass – An update

Eelgrass on sand. Photo by Paul Kay
Eelgrass on sand. Photo by Paul Kay
Anemonia on Zostera. Photo by Keith Hiscock
Anemonia on Zostera. Photo by Keith Hiscock

Readers of this newsletter will know that the HMCG, CWT and Natural England have a depth of knowledge about eelgrass belonging to the Zostera species. Stella Turk, Pam Tompsett, Roger Covey, Tony Sutton and Kevan Cook have all written about its natural history and distribution within the Helford and other areas of Cornwall. For good basic information about eelgrass the best place to go is the HVMCA leaflet. In addition, Phil Lockley’s film “Jaws of Helford” has some beautiful sequences showing the life amongst the grass.

The devastating affects of the Labyrinthula species of slim mould which greatly reduced Zostra marina within the Helford estuary and destroyed the inter-tidal beds of Zostera noltei and Zostera angustifolia in the past are well documented by Pamela and Tony in their 2000 Report. However there is increasing evidence that the meadows of Zostera are spreading once more and the establishment of the voluntary “No Anchoring Zone” off Grebe Beach in 2000 is felt to have played an important part. Kevan Cook’s article in the Autumn edition 2008 of the HMCG newsletter painted an optimistic picture of the health of Zostera in the Helford and pointed to some evidence that the beds are re-establishing themselves.

In Kevan’s presentation in Gweek in January of this year he explained that there is the possibility that the ever present slime mould will again ravage the beds as it has periodically since the major outbreak on both sides of the Atlantic in the 1930s. In addition eelgrass is vulnerable to the effects of runoff and physical disturbance. So, though there are good reasons to feel happy with progress, there is a need to educate people about the value of eelgrass and explain what can be done to preserve the beds and encourage their growth.

At the moment there is no systematic evidence for the current extent of the beds in the Helford but Tony Sutton is planning to undertake a survey of the transects he used in the 1990s with his students at University College Falmouth. This should establish a new baseline and is certainly a really exciting development.

In addition there is a plan hatched by Abby Crosby to take the cause of Zostera preservation to a wider audience. It is planned to produce articles for the local and boating press to explain the well documented importance of eelgrass beds, to encourage good observation of the no anchor zone, and to alert boat owners to respect the eelgrass beds that exist elsewhere. We will be producing a poster that we hope to be able to display in marinas, sailing clubs, pubs etc which will give basic facts about the species and the no anchor zone. Finally a Power Point presentation will be produced that can be taken to clubs, schools and other interested groups. We want people to appreciate that they can do positive things to preserve eelgrass, wherever it is, and maintain a vital habitat for a rich variety of organisms.

Mike Langshaw, HMCG member and CWT volunteer

Extract from HVMCA newsletter No.42 Spring 2011

© Helford Voluntary Marine Conservation Area