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

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Establishing a species richness and composition index<br />

Initial data sources were based largely on the NILS and the BPS field meetings with a<br />

few other papers by prominent phycologists, comparable to the BPS field meetings.<br />

From these species lists Paul Wood, from Heriot­Watt University, created a large<br />

database, which has been gradually increased to include a number of additional<br />

surveys, some of which were completed by the MPTT during summer of 2003 and<br />

2004 in which areas of limited species records were targeted. Although the database<br />

now includes a vast and varied number of shores throughout the British Isles and<br />

Republic of Ireland there is still a slight northern bias in terms of numbers of shores,<br />

with very limited data from the Republic of Ireland. But it is hoped that over the next<br />

few years the database will increase further enabling the final macroalgal tool to be<br />

continually refined.<br />

Whilst trying to establish levels of species richness, to represent the different levels of<br />

ecological quality, possible factors known to influence the levels of species richness<br />

needed to be considered i.e. natural environmental conditions. There is a need to<br />

acknowledge the various typologies established for the purpose of the WFD and how<br />

to account for these including reference conditions for each typology. Therefore, the<br />

initial approach used in establishing the reduced species list was to analyse the effects<br />

of certain environmental factors specifically those used to categorize the typologies.<br />

The NILS (1988) provided the best information for a large area of coastline from<br />

which to assess the effect of exposure, shore type, and habitat type/number on the<br />

overall species composition of a shore. These data include not only biologically rich<br />

sites, but also ‘typical’ and ‘poor’ sites as well as representing a full range of physical<br />

habitat types and their associated biological communities.<br />

A recent study of the effects of environmental variables (Wells and Wilkinson, 2002b)<br />

showed certain factors contributed more significantly than others to the overall<br />

species richness and species composition. Exposure is known to effect algal species in<br />

the intertidal by contributing to their distribution. Sheltered shores tend to be<br />

characterised by dense covering of fucoids and generally a large abundance of<br />

species, moderately exposed shores exhibit a less abundant but mosaic distribution of

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