Seagrass-Watch Magazine Issue 47 - March 2013 | Page 40
England
Cornwall
discovery
Article by Emily Jenkinson
Photography by Emily Jenkinson
& Clare Marshall
England
EJ
After centuries of shipping traffic and maintenance dredging, seagrass and its diverse faunal
assemblage were found to persevere in Fowey estuary.
The Fowey River is situated in Cornwall, south west England; over 33 km from its source on Bodmin Moor to the mouth of the estuary
at Fowey(1), the tidal limit of the estuary approximately 8 km up river at Lostwithiel. Fowey is a deep water harbour that is a very
important exporting port on the south west peninsula, being the largest in tonnage terms. It is also in the top twelve ports for non-oil
product exports in the United Kingdom(2), and accommodates over 7000 visiting craft through the summer season with up to 1500
resident craft. Cargoes through the port include: the export of copper, tin and china clay; the import of coal, timber, limestone; and
general cargo such as coal was unloaded at Berrills Wharf as late as the 1960s (1), and Lostwithiel in the 13th century was a key stannery
town for the county’s mining industry(3). This historical and
contemporary commercial interest has necessitated a maintenance
of deep water channels because sediment accretion in the lower
harbour from mining activity further upstream since the late 16th
century has silted up the intertidal regions of the river (4).
Maintenance dredging in the lower harbour in the early part of the
20th century gave access to the berths upstream by larger vessels,
allowing china clay to be shipped regularly through the port. Regular
dredging continues with support of annual hydrographic surveys (5),
however due to historic heavy metal contamination(6) sediment
removal is minimised(5).
It is in areas which were possibly previously dredged that Cornwall
Wildlife Trust and Fowey Harbour Commissioners have carried out a
preliminary survey and assessment of the Fowey Estuary seagrass
meadows (early October 2011).
Snakelocks anemone (Anemonia viridis)
in Zostera meadow, Fowey Estuary
Anemonia viridis
CM
Snakelocks anemone (Anemonia viridis) has long flexuous tentacles which are a grey-brown or bright green in colour. The green
variety has purple tips to the tentacles. The tentacles rarely withdraw into the col