The
following sites are recommended as being worthy of Phase II survey, on the basis
of the combined findings of this, and previous, surveys. This work should be
carried out by experienced marine biologists with knowledge of local marine
flora and fauna and survey protocol.
The
habitat and species diversity of the Calf of Man, as well as its underwater
scenic beauty, are well known and documented (Morrow
et al., 1993)
(Mitchell and
Hextall, 1994, Sanderson et al., 1994)
. It was proposed as a voluntary Marine Nature Reserve (MNR) (Department
of Agriculture Fisheries and Forestry, 1992)
, which would have given it some protection. However, the proposal was
not implemented. The islet is uninhabited and relatively unaffected by man’s
activities, and provided this continues, it will probably sustain the rich
variety of communities it now possesses.
Recommendations:
No further Phase II survey work is necessary here from a baseline perspective.
It would be of value to periodically resurvey the sites described in 1991 and
1992 in order to ensure that any detrimental changes in its marine life are
detected at an early stage. Particular attention should be paid to the species
of conservation interest noted in (Morrow
et al., 1993)
. It would also be of scientific interest to monitor the populations of
the ross coral, Pentapora foliacea, as
it is considered vulnerable to fishing activities (including crab potting) (Bunker
and Mercer, 1988;
Edwards, 1993; Eno et
al., 1996)
, and may be declining around the Calf (M. Bates, pers. obs). These
surveys should be conducted by divers with appropriate experience in biological
survey work.
Maerl
was previously only documented at Niarbyl on the west coast, and Douglas on the
east coast (Geffen et
al., 1990)
. During this survey, it was recorded extensively around the north of the
Island (at 20 sites), forming over half of the substratum at 6 sites. It was
most abundant between the Point of Ayre and Ramsey, but also off Douglas and
Laxey on the east coast, and north of Kirk Michael on the west coast. The
presence of maerl increases the complexity of the gravel or coarse sand habitat
upon which it grows, thereby dramatically increasing the biological diversity.
However, it is considered vulnerable to fishing activities, such as scallop
dredging (Hall-Spencer, 1995). The species of maerl is most likely to be Phymatolithon
calcareum which is considered uncommon around the British Isles, and is
listed on the EC Habitats Directive Annex Vb (Connor
et al., 1997)
. Maerl beds are currently one of only six soft sediment biotope
complexes under review by the UK Marine SACs Project. This means that they are
considered to be of high conservation interest at the European level, and a
priority feature of candidate marine ‘special areas of conservation’ (SACs).
Recommendations:
Survey the north east coast of the Island, between the Point of Ayre (54° 25.07’N, 4° 21.84’W) and The Dog Mills (54° 21.11’N, 4° 22.80’W), and up to 2km offshore, to determine the extent of the
maerl beds, and fully describe the associated community. This should be
conducted by divers with appropriate experience in biological survey work. At
least 20 dives would be required to thoroughly cover this heterogeneous area of
seabed. Samples of the maerl should be collected for expert indentification.
Sublittoral
beds of the edible mussel, Mytilus edulis,
are not uncommon around the British Isles, but usually occur in deeper water,
below the limit of kelp growth (Connor
et al., 1997)
. A bed up to 50cm high was located off the Point of Ayre during this
survey, in 10-12m of water, where kelp was also observed.
Recommendations:
This site should be surveyed, possibly as a 4-6 dive extension of the survey
programme suggested above for maerl. The extent of the bed and the diversity of
the associated community should be described by divers with appropriate
experience in biological survey work.
Muddy
sands in more sheltered locations can support a variety of animal dominated
communities, but may also include seagrass (Zostera
marina or Ruppia spp.) beds. These
are uncommon in the British Isles (Connor
et al., 1997)
. Two beds have now been recorded around the Island, one previously
documented at Langness (Geffen et al., 1990), and the other recorded for this first time during
this survey near Gob ny rona in Ramsey Bay.
Recommendations:
A series of dives should be conducted around the Gob ny rona headland (54° 18.73’N, 4° 21.00’W) to locate and map the seagrass bed. Particular attention
should be paid to the west side where sheltered conditions would be most
favorable for the development of a seagrass bed. Divers of any biological
ability could conduct this work, although samples of the whole plant should be
collected for identification purposes.
Sea
caves are among the (Annex I) marine habitat types for which SACs can be
proposed (Council of the
European Communities, 1992)
, and are therefore considered of sufficient conservation interest to
warrant statutory protection. Sublittoral caves can support a rich succession of
communities as light attenuates deeper into the cave (sea caves ref XX
Bianchi?). Sea caves were located to the south of the Meayll Peninsula at the
Sugarloaf and the Anvil (54°
3.53’N, 4°
45.50’W), and also on the Gantry ledges near Ronaldsway Airport (54° 4.81’N, 4° 36.86’W).
Recommendations:
These sites should be surveyed by divers with appropriate experience in
biological survey work. Two dives per cave would be sufficient.