Torbay Rmcz, Devon Physical Features Surveyed
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Torbay rMCZ, Devon Seasearch Site Surveys 2012 This report summarises the results of surveys carried out in the recommended MCZ by Seasearch divers during 2012. The aim of the surveys was to add detail of the habitats and species found within the area to support the designation process. Particular attention was paid to the Habitat and Species FOCI identified in the Ecological Guidance on the designation of MCZs. Surveys were carried out at a number of sites in all parts of the rMCZ. 1 2 4 3 5 Sites Surveyed 1 Babbacombe 2 Hope’s Cove CW 3 Orestone 6 7 4 Thatcher Gut 8 9 5 Fairy Cove 6 Elberry Cove 7 Fishcombe Cove 8 Brixham Breakwater 10 11 9 Shoalstone Beach 12 10 Cod Rock 11 Sharpham Bay 12 St Mary’s Bay Physical features Surveyed The main features of the area surveyed by Seasearch in 2012 were eelgrass beds (Hopes Cove (2), Thatcher Gut (4), Elberry Cove (6), Fishcombe Cove (7) and Brixham Breakwater Beach (8)), infralittoral rocky reefs (Babbacombe (1), Fairy Cove (5), Shoalstone (9) and St Marys Bay (12)), circalittoral rocky reefs (Orestone (3), Cod Rock (10) and Sharpham Bay (11)) and a variety of sediments from gravel to sandy mud (most sites). All of the sites are already within the Torbay SAC, but a number had not been previously surveyed and the records of eelgrass beds at Hope’s Cove and Thatcher Gut are new, is arCWe the circalittoral rocky reef in Sharpham Bay. CW Features of the Marine Life and Habitats Eeelgrass Beds (Sites 2,4,6,7,8) Eelgrass, Zostera marina, is one of the very few flowering plants underwater and, unlike seaweeds, has a system of roots which can help to bind soft sediments and create a complex habitat in what would otherwise be a relatively un-diverse environment. Seagrass beds are found in shallow, relatively clear, waters where there is limited wave action, but may be tidal currents. Torbay has a number of eelgrass beds, some of which have been previously surveyed. The two beds shown here at Hope’s Cove (Site 2) and Thatcher Gut (Site 4) are both newly identified. Seagrass beds can be damaged by indiscriminant anchoring within them, by extensive potting and by trawling for scallops. Hope’s Cove Eeelgrass Bed CWo Damage to the eelgrass was seen at Hope’s Cove, with uprooted plants present (below). Whilst it not possible to say whether or not the damage was natural on not, there Thatcher Gut Eeelgrass Bed was a yacht anchored in the bed at the time of our visit CWe and cuttle pots were also set close to the edge of the bed. A variety of anemones, worms, molluscs and small fishes were recorded within the eelgrass beds. Most notable was a short snouted seahorse Hippocampus hippocampus at Hope’s Cove (which was unfortunately not photographed. A selection of other species are shown below. JL RR Above: Greater Pipefish, Syngnathus acus Below: Sea Hare, Aplysia punctata RR CW Above left: Eyelash worm, Myxicola infundibulum Above right: Polycera sea slug MR Below right: hermit crab JL Cuttlefish, Sepia officinalis CW Cuttlefish come inshore to breed in the spring and, at the time of our survey in May, there were pairs of adults observed (below) and bunches of cuttlefish eggs commonly seen attached to the seagrass fronds at Hope’s Cove (right). At the same time there were pots set just outside the seagrass bed to catch the breeding population. This practice not only removes breeding adults but eggs are often laid on the pots themselves and lost when the pots are raised. MR Cuttlefish breed and are commonly recorded from other sites around Torbay, including Babbacombe and Thatcher’s Gut CWo (below) Infralittoral Rock (Sites 1,5,9,12) Seaweed dominated (infralittoral) rock was surveyed at four, widely spaced, coastal sites, Babbacombe, Fairy Cove, Shoalstone and St Mary’s Bay. The presence of a CWe seaweed specialist in the survey team resulted in records of 44 species of seaweeds at Babbacombe and 28 species at Shoalstone. These included a number of non- native species, Sargassum muticum, Heterosiphonica japionica and Antithamnionella ternifolia. CW Cuttlefish and eggs were also present at Babbacombe in May, as were the cuttlefish pots spread out across the bay to catch the breeding population. Other species of note included trumpet anemones, Aiptasia mutabilis, at Shoalstone. This is a nationally scarce southern species, which can be locally abundant on shallow rocky reefs. In July at St Mary’s Bay there were many large edible CWe crabs mating. All of the infralittoral rocky sites were subject to human impacts including potting, mooring, recreational angling and diving. There was considerable litter present underwater, especially at Babbacombe. This included beer cans, cigarette packets and angling line. At Fairy Cove the litter was fishing related and included old pots, rope and rubber. Circalittoral Rock (Sites 3, 10, 11) Rocky reefs with small red seaweeds and animal turfs were recorded at Orestone, Cod Rock and Sharpham Bay. Of these sites Orestone and Cod Rock had been recorded previously, but the reef in Sharpham Bay, south of Berry Head was previously un-recorded. This site contains low-lying silted reefs at a depth of between 6m and 9m below chart datum. The reefs were up to 2m high in places and covered in a ‘turf’ of short red seaweeds, bryozoans, feathery hydroids and sponges. Notable species were anglerfish, Lophius piscatorius (priority species), and a nationally scarce sea slug, Okenia elegans CWo (right). Sublittoral sands, gravel and mud Torbay contains a wide variety of underwater sediments. Those recorded in this survey included coarse sediments (mixes of sand, gravel, pebbles and cobbles), both infralittoral (Thatcher Gut, Shoalstone) and circalittoral (Orestone), sands (Babbacombe, Stoalstone), muddy sand (Babbacombe, Hope’s Cove, Brixham Breakwater, Sharpham Bay) and sandy mud (Hope’s Cove). Generally the muddy sand and mud sites exhibit the widest variety of mobile and burrowing animals. Typical species are RA the mud runner crab, Goneplax rhomboides (right) and the burrowing anemone Cerianthus lloydii (lower right). An inhabitant of fine sand was the masked crab, Corystes CWo cassivelaunus (below). SS JL JL The conservation objectives for the rMCZ are in most Human Impacts cases to maintain in a favourable condition. This survey adds records of Ostrea edulis and Hippocampus Torbay is an area which has high levels of human activity, hippocampus to existing listed priority species. both recreational and commercial. The activities which we Only in the case of the seagrass beds and subtidal mud is consider are most likely to be having an adverse impact on the objective to recover to a favourable condition. At marine life and habitats are trawling, potting and mooring present there are few concrete proposals to achieve this within sensitive seagrass and subtidal mud habitats. and we suggest that the seagrass beds should be subject The majority of other surface-based activities do not have to limitations on mooring and potting in addition to a any impact on seabed habitats and species, except around complete ban on trawling if they are to achieve the Berry Head where seasonal limitations to protect bird conservation objective of recovery. populations are proposed. The rMCZ proposal casts doubt on the presence of subtidal mud within the area. Whilst there is a grey area Benefits of Protection between the definitions of mud, muddy sand and sandy mud we believe that the muddy sand, at least just The great majority of the rMCZ already lies within a Special outside the seagrass bed at Hope’s Cove (pictures above), Area of Conservation and the proposal only includes those should also be protected from the same activities. features which are not already listed, and thus theoretically The seasonal capture of breeding cuttlefish at a number protected, by that designation. Thus many of the rock of sites within the bay is not addressed by the rMCZ features, both infralittoral and circalittoral, are not proposed proposals. This is unlikely to be a sustainable fishery in for any protection within the rMCZ. However, we have the long term because of how it is undertaken, and the identified an additional area of circalittoral rock in this opportunity should be taken to maintain this population survey which should be included. as well as the other features. This report has been written by Chris Wood based on Seasearch Survey records made by Lin Baldock, Dominic Flint, James Lucey, Nick Owen, Martin Pratt, Mary Restell, Roy Restell, Lynda Rose, Trudy Russell, Sally Sharrock, Jean-Luc Solandt, Chris Webb and Chris Wood, and Observation records made by David Dooley and Sally Sharrock. Photos by James Lucey, Mary Restell, Roy Restell and Chris Wood. Seasearch would like to thank the volunteer divers for their records and also Rick Parker and Tony Hoile for taking us to the sites. Report published by Marine Conservation Society for Seasearch www.seasearch.org.uk Technical Appendix Current proposal The features proposed for designation are: This Appendix contains more detailed information Broad Scale Habitats and Habitat FOCI: subtidal mud, about the surveys undertaken and records made. It intertidal coarse sediment, mixed sediment, mud, sands includes: and muddy sand, low and moderate energy intertidal - dive details rock, intertidal under-boulder communities, Honeycomb - map of Hope’s Cove seagrass bed worm reefs and seagrass bed. The objective is to - habitat sketches maintain in favourable condition except for subtidal mud - biotope list and seagrass beds where it is to recover to favourable - species list condition. Species FOCI: Long snouted seahorse Hippocampus The data has been entered into the Marine Recorder guttulatus (but not H.