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Marine Nature Reserve (marine + nature_reserve)
Selected AbstractsThe distribution and prevalence of sponges in relation to environmental gradients within a temperate sea lough: vertical cliff surfacesDIVERSITY AND DISTRIBUTIONS, Issue 6 2000James J. Bell Abstract. The prevalence and distribution of sponges was surveyed on vertical cliff surfaces at Lough Hyne Marine Nature Reserve, Co. Cork, Ireland. The number of sponge species was recorded at 6-metre depth intervals at four sites within Lough Hyne, and at one site on the adjacent Atlantic coastline to examine differences in abundance and zonation patterns. Sites ranged from an exposed turbulent regime to sheltered, sedimented environments. Individual species showed different distributions and prevalence between sites and with increasing depth. Greatest differences were observed between the most- and least-disturbed sites. Distinct sponge zonation patterns were evident at all sites sampled. Twenty-five species were considered dominant at all five sites with the remaining 48 species considered rare. Only four of the 25 most-dominant species occurred at the site experiencing the most turbulent flow conditions, whereas 12 species were found at the site of unidirectional fast flow. At sites of moderate to slight water movement and high sedimentation, between 18 and 24 of the most dominant species were present. Encrusting forms constituted high proportions of sponge communities at all five sites sampled (although consisting of different species). At sites of turbulent and unidirectional fast flow massive forms also dominated whereas at the least turbulent sites, where sedimentation was high, arborescent sponges were abundant. Few species showed exclusive distribution to a single depth and site, but there was some degree of correlation between species distributions and abiotic factors such as sedimentation rate and flow regimes. Sponge distributions and densities are discussed with respect to the suitability of species' morphologies to particular environments, intra-specific and inter-specific competition and physiological adaptations that enable them to survive in different habitats. [source] The distribution and prevalence of sponges in relation to environmental gradients within a temperate sea lough: inclined cliff surfacesDIVERSITY AND DISTRIBUTIONS, Issue 6 2000James J. Bell Abstract. Sponge communities on inclined cliff surfaces (40°) at Lough Hyne Marine Nature Reserve, Co. Cork, Ireland were sampled at five sites (four inside the lough and one on the adjacent Atlantic coast). Each site varied in sedimentation rate and flow regime. Sites ranged from turbulent (with negligible sedimentation) to very low flow (< 3 cm,1) and highly sedimented regimes. Sponge species showed variation between sites and depth. The greatest difference in sponge communities was observed between the most turbulent and most sedimented sites. The distinct zonation patterns, present at all sites, were most pronounced at the highly sedimented sites. Encrusting forms constituted a high proportion of the sponges at all sites. However encrusting species found at the turbulent site were different to those at the sedimented sites. Arborescent species were common, mainly at the sedimented sites within Lough Hyne. Distributions of sponge species are considered with respect to morphological adaptation, competition and physiological adaptation. The distributions of sponge species on inclined surfaces are also compared with those on vertical cliff faces. [source] Sponge morphological diversity: a qualitative predictor of species diversity?AQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 2 2001James J. Bell Abstract 1.,To the non-specialist, problems are often associated with the quantification of sponge species diversity, as colour, shape and size can be highly variable within a single species. These variables can lead to an under-estimation of the contribution of sponges to the biodiversity of the benthos especially during biological surveys. 2.,Sponge species diversity (Shannon H, values), richness (mean number of species) and morphological diversity (Shannon H, values) were sampled at six sites (6 m depth intervals) on vertical (90°) and inclined surfaces (45°) experiencing different flow regimes at Lough Hyne Marine Nature Reserve (Ireland). Morphological diversity was sampled independently of species diversity. The time taken for the collection of both species and morphological diversity was recorded. 3.,Morphological diversity was positively correlated with both sponge species diversity (r2=0.87, p<0.05) and sponge species richness (r2=0.70, p<0.05). Linear regression was found to be significant for both the relationships (p<0.05 for each F -value). A sigmoidal relationship (r2=0.97, p<0.05) was found between morphological and species richness which proved to be significant (F -value 40.67, p<0.05). Separate Bray,Curtis dendrograms and correspondence analysis of morphological and species community compositions at the six sites showed very similar clustering and four major clusters were identified. 4.,The results of the present study indicate that sampling of sponge morphological diversity, rather than sponge species diversity and richness may be used as a qualitative estimate of sponge species diversity. Sampling of morphological diversity is much less time consuming, both in the field and laboratory, than collecting species diversity data and no specialist knowledge is required. Consideration is given to the use of such relationships in biological surveys and bio-monitoring. Copyright © 2001 John Wiley & Sons, Ltd. [source] Government perspective, statutory protection and the direction of future research and co-operation in the context of the marine environmentAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 1 2002T.W. Eggeling Abstract 1.The Falkland Islands Government is proud of the successful development of its commercial fishery and sees no reason why it should not continue to be managed in a responsible and sustainable way. However, it recognizes that the fishery is vulnerable to over-fishing, changes in the migration patterns of the principal commercial species and the health of world markets. 2.To widen its economic base, the Falkland Islands Government is seeking to promote farm diversification and eco-tourism, to further develop its commercial fishery, and to encourage offshore oil exploration and development in areas under its jurisdiction. 3.It recognizes the value and importance of its wildlife populations and habitats but sees no reason why economic development and environmental protection should be mutually exclusive, provided that suitable measures are adopted to control development and protect the environment, a precautionary approach is applied, all potential risks to the environment are carefully assessed and remedial measures taken to avoid or minimize any adverse impacts. Extensive new legislation has already been enacted, baseline survey work undertaken and further environmental research commissioned. 4.The Government accepts that additional wildlife habitats and populations need to be afforded environmental protection through designation as National Nature Reserves (NNR) and Marine Nature Reserves (MNR) and thereafter managed effectively. It recognizes that much more environmental research needs to be carried out and, to that end, is willing to seek expert guidance on the future direction of that research, to co-operate with other governments or organisations in the carrying out of that research and to contribute financially to further environmental research in and around the Falkland Islands. Copyright © 2002 John Wiley & Sons, Ltd. [source] | ||||||||||