Current status
Sea bryum is a species of dune slacks, wet sandy ground at the edges of saltmarshes and occasionally old gravel pits. In Britain it is essentially a dune-slack species.
This species was once widely distributed around the coast of Britain. It has been recorded from approximately 35 sites on the coasts of Devon, Somerset, Glamorgan, Ceredigion (Cardiganshire), Gwynedd, Anglesey, Cheshire, Merseyside, Lancashire, Cumbria, Kyle and Carrick, Lincolnshire, Humberside, Cleveland, East Lothian, Fife, Angus, Moray and Ross. It has not been seen at over half of these sites since 1950; post-1970 records exist only for Tayside, Lothian, Sefton Coast, Gwynedd and Kent. There is also an inland record from Greater Manchester, but the plant has not been found there for over a century. There is a possibility that the distribution of sea bryum may be somewhat confused with B. mamillatum as it is difficult to distinguish between the two species. Sea bryum has a widespread, but mainly coastal, distribution in northern and central Europe, but becomes rare in the south. It was once known in Ireland. It is also recorded from Asia and southern Africa.
In Great Britain this species is provisionally classified as Vulnerable. It receives general protection under the Wildlife and Countryside Act 1981. It is also classified as Vulnerable in Europe as a whole.
Current factors causing loss or decline
Dune stabilisation and associated infilling of dune slacks in which this species grows. In some cases, dune stabilisation has been increased by coastal protection works.
Holiday developments and the associated increase in recreational pressures, for example golf course construction.
Falling water-table levels are a persistent threat to many of the dune-slack sites for this species.
Invasion of scrub, particularly associated with a decline in rabbit populations, is a potential threat at all dune sites.
Development of coarse vegetation following enrichment from dog-fouling is a significant threat at some sites.
Current action
The extant sea bryum sites on the Sefton Coast are within SSSIs and the candidate SAC. Most of the Welsh localities are SSSIs and some are NNRs.
Dune slacks have been the focus of much conservation activity in recent years. Active restoration work including turf-cutting and scrub removal has been undertaken on the Sefton Coast.
SNH has recently commissioned a survey of the Wester Ross site.
Action plan objectives and targets
Maintain populations of this species at all extant sites.
If appropriate and biologically feasible, establish further populations in the vicinity of extant colonies at three sites by 2010
Establish by 2005 ex situ stocks of this species to safeguard extant populations
Proposed actions with lead agencies
Policy and legislation
Ensure that the need to protect the geomorphology of dune systems harbouring sea bryum is recognised in relevant Shoreline Management Plans, and that the impact on threatened species is considered when assessing and/or proposing sea defence and coastal protection measures. (ACTION: DETR, EA, NE, LAs, MAFF)
Ensure that the needs of threatened dune slack species such as sea bryum are considered when assessing applications for water abstraction, or other developments, or land uses which may contribute to a lowering of the water table in dune-slack habitat. (ACTION: CCW, EA, NE, LAs, SNH)
Site safeguard and management
Ensure regular assessment of threats posed by visitors to important sand-dune sites, and implement measures (such as fencing) where necessary to ensure that these threats are minimised. (ACTION: CCW, NE, SNH)
Following a period of monitoring (as outlined under 5.5.2) assess the need to undertake habitat creation/restoration including turf-stripping, scrub removal and scrape excavation, and implement if necessary. (ACTION: CCW, NE, SNH)
Consider notifying as SSSIs sites with viable populations of sea bryum where this is consistent with selection guidelines and where it is necessary to ensure their long-term protection and appropriate management. (ACTION: CCW, NE, SNH)
Ensure that extreme caution is exercised when undertaking re-profiling of dune slacks for the creation of natterjack toad habitat in the vicinity of known sea bryum sites. (ACTION: CCW, NE, SNH)
Ensure that further dehydration of sites (eg through afforestation) does not occur. (ACTION: CCW, NE, FE, SNH)
Species management and protection
Depending on the results of 5.5.4, establish ex situ stocks of this species from material derived from British populations. (ACTION: NE, CCW, RBG Kew, SNH)
Advisory
Advise landowners and managers, and relevant agencies, of the presence and importance of sea bryum, specific management for its conservation, and any potentially damaging actions. Landowners and managers should have access to specialist advice if needed. (ACTION: CCW, NE, SNH)
Future Research and Monitoring
Compile information and resurvey sites where necessary, in order to establish an understanding of the current distribution and status of sea bryum in the UK. Surveys should also focus on sites in the vicinity of old records where dune slack restoration has taken place, so as to discover whether this species has recolonised. An assessment of threats to each extant colony should also be made. (ACTION: CCW, EHS, NE, SNH)
Compile a list of dune systems which would be worth searching for sea bryum and distribute to active bryologists, encouraging surveys of these areas. (ACTION: CCW, EHS, NE, SNH)
Undertake regular monitoring of all extant sea bryum sites and any rediscovered sites. The findings should be used to inform the action outlined under 5.2.1. (ACTION: CCW, NE, SNH)
Undertake pilot studies to develop and refine ex situ conservation techniques for this species and other threatened bryophytes (ACTION: CCW, NE, RBG Kew, SNH)
Compile information from published literature, and commission new research if necessary, to investigate the problems of falling water tables on sand dune systems including the Sefton Coast. A report should be produced identifying measures which are needed to ensure that water levels are maintained at optimal levels for the conservation of sea bryum and other dune species. The findings of the study should also be used to refine the action outlined under 5.1.2. (ACTION: EA, NE)
Communications and Publicity
Encourage bryologists to pass all records of sea bryum, including ecological information, to a national database (ACTION: CCW, NE, JNCC, SNH)
national database (ACTION: CCW, NE, JNCC, SNH)
Links with other action plans
None given.
Publication details
Originally published in: UK Biodiversity Group Tranche 2 Action Plans - Volume III: Plants and fungi (February 1999, Tranche 2, Vol III, p211)