Beach and Dune - Gower - page 137

areas such as Three Cliff Bay and Caswell. The sting can be painful and persistent, but is usually relieved
byappropriatemedical treatment. Deathisextremely rare,althoughrespiratoryfailureandgangrenehave
been reported. The venom glands provide the weever fish with protection against attacks by larger pred-
atory fish.
THE STRANDLINE
Strandlines are an accumulation of debris at the high water level along the upper shore, which consists of
natural flotsam - organic debris of marine and terrestrial origin - unfortunately supplemented today by
artificial materials. Although strandlines are often short-lived, because of the way they are formed, they
areofparticularimportance,especiallyonexposedshores,wheretheycanactasprecursorstosanddunes.
The more permanent strandlines on the Gower beaches stabilise the foreshore, by enhancing the moisture
and organic content of the sand, allowing pioneering plants such as sea sandwort Honkenya peploides ,
sea rocket Cakile maritima and saltwort Salsola kali to become established. These plants in turn aid the
trapping of sand, assisting the formation of dune systems. Unfortunately Japanese knotweed Fallopia ja-
ponica has now begun a slow, but steady, colonisation of natural coastal habitats, appearing along the
strandline ofsand-dunesystems.Inruralareas,suchasGower,itisalready anextremely aggressive com-
petitor in open woodland and hedgerows as well as along the banks of watercourses, spreading by ve-
getative propagation from fragments of rhizome that are dispersed very effectively by water. The highest
densities of knotweed in Britain are in South Wales and it may have spread from Maesteg, where it was
first recorded in the wild around 1885 on a cinder tip.
Undisturbed strandlines are of importance because of their rich invertebrate communities, and the
tangled driftwood and seaweed shelters a vast number of rove beetles, kelp flies and other species in
addition to the ever-present sandhoppers. Several of the beaches also have large populations of the rare
strandlinewoodlouse Armadillidium album .Thisisacharacteristicspecies,whichoccurswheretheupper
strandline contains abundant supplies of wood and other debris that remains undisturbed throughout the
year. The animal is noticeably absent from beaches that are used by large numbers of people. The speci-
ality of the Bristol Channel shores is, however, a particularly striking ground beetle, the cream and black
Nebria complanata (Fig. 73). This sociable species shelters under driftwood during the day and emerges
topreymainlyonsandhoppersatnight.Attemptstotidyupbeachescanbehighlydamagingtothebeetle,
and strandline disturbance needs to be kept to a minimum.
Beach litter is a major problem in Gower and plastic debris is present along the strandline of all
beaches.Comparativelylittleofthisisdroppedbyvisitorstotheareaandmostofthematerialisseaborne,
some of it having travelled enormous distances. Seaborne litter is a continuing problem, particularly on
Whiteford Sands and Rhossili beach, where bottles originating from South America are regularly found.
Much of this material is not biodegradable and can be unsightly. As a consequence mechanical removal
of the strandline has been adopted during the summer months on some beaches, particularly in Port-Eyn-
on Bay, as a cost-effective way of cleaning the area. Unfortunately even this seasonal cleaning is dam-
aging to the wildlife of the strandline. Amphipods, such as the sandhopper Talitrus saltator , are particu-
larly vulnerable as only one generation reaches maturity each year. The newly hatched juveniles are not
strong enough to bury themselves in the sand to avoid desiccation and rely instead on the freshly depos-
ited strandline seaweeds, which maintain arelative humidity ofbetween 85and90percent overlowtide.
Studies have shown that the removal of strandline seaweeds, even just during the summer months, effect-
ively destroys the populations. In addition the compaction of the sand by the machine effectively kills
any animals below the surface of the beach. If it is not possible to leave the beach untouched, hazardous,
unsightly or dangerous material such as glass, plastics and sewage-related items should be removed by