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Escalating pressures caused by the combined effects of population growth, demographic shifts, economic development and global climate change pose unprecedented threats to sandy beach ecosystems worldwide. Conservation of beaches as functional ecosystems and protection of their unique biodiversity requires management interventions that not only mitigate threats to physical properties of sandy shores, but also include ecological dimensions. Yet, beach management remains overwhelmingly focused on engineering interventions. Here we summarise the key outcomes of several workshops, held during the 2006 Sandy Beach Ecology Symposium in Vigo, Spain, that addressed issues of climate change, beach management and sampling methodology. Because efficient communication between managers and ecologists is critical, we summarise the salient features of sandy beaches as functional ecosystems in 50 ‘key statements’; these provide a succinct synopsis of the main structural and functional characteristics of these highly dynamic systems. Key outcomes of the workshops include a set of recommendations on designs and methods for sampling the benthic infaunal communities of beaches, the identification of the main ecological effects caused by direct and indirect human interventions, the predicted consequence of climate change for beach ecosystems, and priority areas for future research.

Sandy beaches line most of the world's oceans and are highly valued by society: more people use sandy beaches than any other type of shore. While the economic and social values of beaches are generally regarded as paramount, sandy shores also have special ecological features and contain a distinctive biodiversity that is generally not recognized. These unique ecosystems are facing escalating anthropogenic pressures, chiefly from rapacious coastal development, direct human uses — mainly associated with recreation — and rising sea levels. Beaches are increasingly becoming trapped in a ‘coastal squeeze’ between burgeoning human populations from the land and the effects of global climate change from the sea. Society's interventions (e.g. shoreline armouring, beach nourishment) to combat changes in beach environments, such as erosion and shoreline retreat, can result in severe ecological impacts and loss of biodiversity at local scales, but are predicted also to have cumulative large‐scale consequences worldwide. Because of the scale of this problem, the continued existence of beaches as functional ecosystems is likely to depend on direct conservation efforts. Conservation, in turn, will have to increasingly draw on a consolidated body of ecological theory for these ecosystems. Although this body of theory has yet to be fully developed, we identify here a number of critical research directions that are required to progress coastal management and conservation of sandy beach ecosystems.

Talitrus saltator biology, population dynamics, and reproduction were studied more or less simultaneously at three sand beaches: Lavos, on the western coast of Portugal; Collelungo, on the Italian coast of the Thyrrenian Sea; and Zouara, on the northern coast of Tunisia. The species exhibited a consistent pattern of aggregated distribution. Densities were higher at Lavos than at Collelungo and Zouara. Reproduction took place from early March to late September at Lavos and Collelungo, and from late February to early November at Zouara. The average sex ratio was favourable to males at Lavos and Collelungo, and to females at Zouara. Based on data from Lavos, the population abundance was positively correlated with temperature, while the percentage of juveniles in the population was positively correlated with temperature and sediment moisture. Adult individuals from the Atlantic population were larger than the Mediterranean ones, while newborn individuals from the Mediterranean were slightly larger than Atlantic ones. Life span was estimated at 7-11 months at Lavos, 6-9 months at Collelungo, and 6-8 months at Zouara. Cohorts born at the beginning of the reproductive period tend to have shorter lives than the ones born later in the season, with longer life spans occurring in cohorts that crossed the winter to breed in the next year. The minimum period necessary for sexual differentiation after birth was estimated at AE4 weeks at Lavos, AE3 weeks at Collelungo, and AE4.5 weeks at Zouara, for males, and AE6 weeks at Lavos, and AE5 weeks at Collelungo and Zouara, for females. The period necessary for female's sexual maturation after being born was estimated at AE10 weeks at Lavos, and AE8 weeks at Collelungo and Zouara. At the studied sites, T. saltator appeared as semiannual species, with iteroparous females appearing to produce at least two broods per year, and exhibited a bivoltine life cycle. Growth production (P) was estimated at 0.74 g m ÿ2 yr ÿ1 ashfree dry weight (AFDW; 17.7 kJ m ÿ2 yr ÿ1 ) at Lavos, 0.12 g m ÿ2 yr ÿ1 AFDW (2.8 kJ m ÿ2 yr ÿ1 ) at Collelungo, and 0.61 g m ÿ2 yr ÿ1 AFDW (14.3 kJ m ÿ2 yr ÿ1 ) at Zouara. Elimination production (E) was estimated at 1.40 g m ÿ2 yr ÿ1 AFDW (33.5 kJ m ÿ2 yr ÿ1 ) at Lavos, 0.20 g m ÿ2 yr ÿ1 AFDW (4.8 kJ m ÿ2 yr ÿ1 ) at Collelungo, and 1.11 g m ÿ2 yr ÿ1 AFDW (26.6 kJ m ÿ2 yr ÿ1 ) at Zouara. The average annual biomass ð B BÞ (standing stock) was estimated at 0.13 g m ÿ2 at Lavos, 0.014 g m ÿ2 at Collelungo, and 0.084 g m ÿ2 at Zouara, resulting in P= B B ratios of 5.7 at Lavos, 8.2 at Collelungo, and 7.3 at Zouara, and E= B B ratios of 10.8 at Lavos, 14.4 at Collelungo, and 13.1 at Zouara. The present results, combined with information from literature, revealed a geographic variation in T. saltator populations with regard to their morphological characteristics, growth rates, life spans, and life cycles.

Spatial pa tterns of nematode community structure from two geographically spaced intermediate, microtidal beaches (i.e. Mediterranean and Baltic) were investigated. Differences in the nematode assemblages were found to be significantly different and related to the morphodynamic characteristics of the studied zones (upper beach, swash/breaker and subtidal). Highest nematode densities and species diversities were recorded on the coarse-grained, more physically controlled, Italian beach in contrast to the more chemically controlled Polish beach. This is in contrast to the worldwide pa tterns of macrofaunal communities. As demonstrated by higher taxonomic distinctness measurements, upper beaches were found to harbour species from both the marine and terrestrial ecosystem and are considered to be impo rtant ecotones between these adjacent systems. The swash/breaker zones are characterised by the loss of distinctive species caused by the high water percolation in these zones. The concept of parallel ecological communities 'isocommunities' is only supported for the upper beach zones.KEYWORDS: free-living nematodes, diversity, taxonomic relatedness, isocommunities, sandy beach morphodynamics, Mediterranean, Baltic CHAPTER III: Nematodes from wave-dominated sandy beaches 45 INTRODUCTIONSandy beaches are examples of simple ecosystems, driven principally by the interacting physical forces of waves, tides and sediment movements. Wave dominance varies from total on sandy, tide-less shores, decreasing as other processes, especially tides, increase their influence on the shore face topography.Microtidal (wave-dominated) sandy beaches represent widely fluctuating environments which have been classified into three distinctive types (reflective, intermediate and dissipative) according to the modal breaker height, modal wave period and sediment fall velocity, which are all combined in the dimensionless fall velocity or Dean's parameter (S2) (Sho rt 1999).These sandy sediments offer a considerable range and diversity of biotic habitats: horizontally, the sub-aerial (dunes and upper beach), the inte rt idal (swash zone/shoreline) and the subtidal (surfzone and near-shore) while vertically there are pelagic, benthic and interstitial environments. As the beach is the dynamic inte rface between the terrestrial and marine ecosystem several biotic and abiotic gradients characterize this interface.Due to these steep gradients (e.g. in oxygen, temperature, organic material, etc.) and the sediment heterogeneity, zones with specific physico-chemical properties can develop, harbouring, as a consequence, a different benthic fauna (Wieser el al. 1974). Most of the faunal research on sandy beaches has been concentrated mainly on macrofauna (>1 mm) (McLachlan and Jaramillo 1995 and references therein) and more recently also birds (e.g. Cornelius el al. 2001). In contrast, sandy beach meiofauna (all metazoans between 1 mm and 38 pm) have received considerably less a ttention notwithstanding their high diversity (even at taxon level) and de...

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Tourism has long been considered as a 'clean industry' with almost no negative effects on the environment. This study demonstrated, in two different coastal systems (Mediterranean and Baltic), that tourism related activities are particularly affecting the sandy beach meio- and nematofauna in the upper beach zone, the specific ecotone in which many meiofauna species from both the marine and the terrestrial environment congregate. Tourist upper beaches are characterized by a lower % total organic matter (%TOM), lower densities, lower diversities (absence of Insecta, Harpacticoida, Oligochaeta, terrestrial nematodes and marine Ironidae nematodes) and higher community stress compared to nearby non-tourist locations. The %TOM was found to be the single most important factor for the observed differences in meiofauna assemblage structure at tourist versus non-tourist beaches in both the Mediterranean and the Baltic region. The free-living nematode assemblages from tourist upper zones depart significantly from expectations based on random selections from the regional nematode species pool. Furthermore upper zone assemblages are characterised by a low species diversity consisting of taxonomically closely related nematode species with r-strategist features. Generally, faunal differences between tourist and non-tourist beaches are decreasing towards the lower beach zones.