Seagrass-Watch Magazine Issue 47 - March 2013 | Page 41

The aim of the survey was to confirm seagrass presence in the river, its general location, and assess the best methods for a future
detailed investigation. The seagrass Zostera marina was successfully found in several locations, the largest of which was opposite the
quay on Polruan side, amongst residential moorings and downstream, adjacent to a beach replenished with dredged shellfish
material. It was this site that became the focus for future surveys.
On the 10th September 2012 the first survey was undertaken to assess the extent of the meadows using a ‘VideoRay’ Remote
Operated Vehicle (ROV) and covered an area of 150 m over five transects. A follow-up survey to assess the density and biodiversity of
the meadows was undertaken on 22nd September 2012, by a dive team of volunteer SeaSearch divers, supported by the Fowey
Harbour Commissioners. The dive team laid two 30m transects, between 4 - 6m depth, which were surveyed for both habitat and
species present. Faunal abundance was recorded using the SACFOR scale as applied within SeaSearch protocol, with 0.25m2
quadrats laid every 5m and photographed for later analysis. Species identified during the dive included the snakelocks anemone
(Anemonia viridis), daisy anemone (Cereus pedunculatus), and sand mason worms (Lanice conchilega)(7). SeaSearch observation
data forms from the second dive have been submitted. It is hoped that further analysis of video data will produce additional results in
regard to species diversity and that GIS maps will be produced from
the initial ROV survey data.
A further dive is planned once initial data has been fully assessed. All
future dives will benefit from a means of assessing contemporary
health status from the historic baseline currently being created.

Zostera marina
Zostera marina was found in several locations in Fowey estuary. In the UK, Zostera marina is the
most widely distributed seagrass and dominates sandy and muddy sediments in coastal areas of low
to moderate wave exposure. This species is a widespread and dominant species, usually
monospecific meadows. It has declines mostly in developed and populated areas in Europe and North
America. Ongoing restoration efforts since the 1940s in Europe and North America transplanted to reestablish populations of eelgrass in part of their former range from which they had been extirpated.
There has been a global decline of area covered by Zostera marina by 1.4% per year based on 126
documented changes in area that have been conducted over a 10 year period from 1990-2000.
CM

source: Short, F.T Carruthers, T.J.R., Waycott, M., Kendrick, G.A., Fourqurean, J.W Callabine, A., Kenworthy, W.J. & Dennison, W 2010. Zostera marina.
.,
.,
.C.
In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2.

References
1.Ports and Harbours of the UK, (2012). Commercial, Online: www.ports.org.uk. Last accessed 25 September 2012.
2.Fowey Harbour Commissioners, (2010). Online: www.foweyharbour.co.uk. Last accessed 18 September 2012.
3.Lostwithiel Town Council, (2012). Medieval Capital, Online: http://www.lostwithieltowncouncil.gov.uk/medieval.php. Last accessed 26 September 2012.
4.Dines, H.G., (1956). The metalliferous mining region of south-west England, volume 2. British Geological Survey, Backhurst and T
aylor Ltd, Nottingham.
5.Hoddinott, C., (2009). Environmental Management Review 2009 – 2010. Fowey Harbour Commissioners, Fowey.
6.Jenkin, A. K. H., (1966). Mines and Miners of Cornwall, XII. Around Liskeard, Marazion and Penzance, Wordens of Cornwall Ltd.
7.Naylor, P., (2011). Great British Marine Animals, 3rd Edition. Sound Diving Publications, Cornwall

EJ

MARCH 2013

41