Suitability of SACs for Addressing Research Needs
Chapter VIII outlined several areas of research that would contribute
to the development of management policies relevant to this biotope complex. The present
chapter has made clear that details of community composition and species abundance are
lacking for almost all the proposed SACs, Loch Duich being the best-known at present. The
table at the end of this chapter summarizes the state of knowledge of the various sites,
and lists their perceived relative importance in conservation terms.
The proposed study of sea pen population dynamics could be carried out
in Loch nam Madadh, Loch Alsh/Duich or Portland Harbour, all of which contain populations
of Virgularia mirabilis in water accessible to divers. The Scottish sites also have
the other two sea pen species. A Comparison of Portland Harbour with a Scottish locality
would be interesting, as the former is a geographically marginal population probably
experiencing a greater range of human impacts.
The effects of experimental trawling on sea pens and megafaunal
burrowers could be studied in the Sound of Arisaig, or off the Berwickshire coast if the
biotope is shown to have the extent inferred by Foster-Smith et al. (1996), although
follow-up diving observations of the trawl paths would not be possible. Whether
potentially destructive studies of this kind would be allowed within an SAC is doubtful.
The distribution of sea pens, megafaunal burrowers and other benthic biota in relation to
local inputs of organic matter (aquaculture, sewage outfalls) could be studied in any of
the relevant SACs, and should certainly form part of any routine monitoring programme in
semi-enclosed sites with restricted water circulation (eg. Strangford Loch, Loch Duich).
Studies of genetic differentiation between populations could clearly
involve SACs in which the species of interest were found. In the case of species with
highly localized distributions (eg. Funiculina quadrangularis, Pachycerianthus
multiplicatus), genetic evidence would probably confirm suspicions that isolated
populations are self-seeding, and hence susceptible to local extinction if their
environments are disrupted. The genetic population structure of other, more widespread
species (eg. Virgularia mirabilis, Callianassa subterranea) should also be
investigated, as this might well reveal hitherto unrecognized barriers to larval dispersal
created by coastal geography or hydrographic patterns. Data from studies of this kind
would therefore help to determine the likelihood of community recovery following a