Water Framework Directive Marine Plants Task Team Tools Paper ...

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Establishing a species richness and composition index Initial data sources were based largely on the NILS and the BPS field meetings with a few other papers by prominent phycologists, comparable to the BPS field meetings. From these species lists Paul Wood, from HeriotWatt University, created a large database, which has been gradually increased to include a number of additional surveys, some of which were completed by the MPTT during summer of 2003 and 2004 in which areas of limited species records were targeted. Although the database now includes a vast and varied number of shores throughout the British Isles and Republic of Ireland there is still a slight northern bias in terms of numbers of shores, with very limited data from the Republic of Ireland. But it is hoped that over the next few years the database will increase further enabling the final macroalgal tool to be continually refined. Whilst trying to establish levels of species richness, to represent the different levels of ecological quality, possible factors known to influence the levels of species richness needed to be considered i.e. natural environmental conditions. There is a need to acknowledge the various typologies established for the purpose of the WFD and how to account for these including reference conditions for each typology. Therefore, the initial approach used in establishing the reduced species list was to analyse the effects of certain environmental factors specifically those used to categorize the typologies. The NILS (1988) provided the best information for a large area of coastline from which to assess the effect of exposure, shore type, and habitat type/number on the overall species composition of a shore. These data include not only biologically rich sites, but also ‘typical’ and ‘poor’ sites as well as representing a full range of physical habitat types and their associated biological communities. A recent study of the effects of environmental variables (Wells and Wilkinson, 2002b) showed certain factors contributed more significantly than others to the overall species richness and species composition. Exposure is known to effect algal species in the intertidal by contributing to their distribution. Sheltered shores tend to be characterised by dense covering of fucoids and generally a large abundance of species, moderately exposed shores exhibit a less abundant but mosaic distribution of
fauna and flora and exposed shores are characterised by their limited algal abundance and wide lichen zone on the upper littoral. However despite exposure appearing to contribute to the abundance and zonation patterns of algae in the intertidal there is no significant impact on the levels of species richness. Exposed shores did result in slightly lower average species richness (but not significantly different to shores of other exposure ratings), this is more likely to be due to their limited abundance and therefore harder to locate. There was also little difference in species composition between shores of varying exposure level. Shore type refers to the most dominant type of substrate present on the shore, such as rock platforms, boulders and pebbles. This can contribute quite significantly to the levels of species richness as certain substrates are more habitable than others and provide more favourable conditions for attachment. Rock ridges, outcrops and platforms were shown to have significantly higher species richness than shores consisting predominantly of boulders, pebbles and vertical rock. This is probably due to the levels of stability offered by large fixed areas of hard substrate compared with pebbles and boulders which are less stable and unable to support climax communities as effectively. The following shore types are given in order of their contribution to the level of species richness: Rock ridges/outcrops/platforms > Irregular rock and boulders > steep/vertical rock > pebbles, stones and small rocks > shingle and gravel. Subhabitat type and number have a similar effect to shore type with the presence of some subhabitats resulting in higher levels of species richness. Large, wide rockpools provide very favourable habitats by limiting the effects of desiccation providing a more tolerable environment than is experienced on open rock. The following subhabitat types are given in order of their contribution to the level of species richness: wide shallow/large/deep rockpools > basic rockpools and crevices > overhangs > caves. Equally with increasing number of subhabitat types there is a significant increase in the levels of algal species richness recorded as higher subhabitat diversity results in higher species diversity.
Page 1 and 2: Water Framework Directive Marine Pl
Page 3 and 4: dates will result in a larger speci
Page 5: Figure 2: Sites included within the
Page 9 and 10: Table 1: Field sampling sheet to re
Page 11 and 12: These different community factors c
Page 13 and 14: All datasets were tested for normal
Page 15 and 16: Table 3: Calculation of ‘deshor
Page 17 and 18: Development of a Reduced Species Li
Page 19 and 20: certain species are only present on
Page 21 and 22: Figure 11: Map of the UK and Republ
Page 23 and 24: Table 4: Species lists for each of
Page 25 and 26: Table 6: Boundaries values for RSL,
Page 27 and 28: The final metric system works on a
Page 29 and 30: Table 10: Final quality status and
Page 31 and 32: EQR Value EQR Value 1.00 0.80 0.60
Page 33 and 34: EQR Value 1.00 0.80 0.60 0.40 0.20

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