Evaluation of Southern Hawkes Bay Coast

SUMMARY 1) The use of presence/absence data is a valid method for comparing communities from hard shore marine environments where the biota is relatively sessile. It is an extensively used method in botanical surveys and its use should be extended into the marine environment. 2) Blackhead had the highest species richness and the widest range of species diversity, suggesting a diversity of habitats. Kairakau also appears to be of relatively high value (in terms of richness and diversity). On the other hand. the diversity values suggest that Paoanui is of relatively low ecological value. It should be clearly noted, however, that the differences between transects and sites are minor and that preferred site selection should probably not rest on the criteria of species richness, species diversity, or species evenness. 3) Almost all correlations between transects were highly significant. Also, the correlation coefficients between transects within sites tended to be greater than those between transects between sites. Thus, transects within sites tended to be more similar to each other than they were to transects from other sites. Overall, the frequency of occurrence data led to consistent answers and an ability to recognise within group similarities. A high degree of similarity between sites was found. 4) No useful conclusion could be drawn from attempting to group individual quadrats. A useful alternative would be to attempt to discover associations between the species present. When all sites were considered (considering only Blackhead and Aramoana would not have provided enough contrast in the available data) only two of the 'New Habitat' types of Creswell & Warren (1991) exhibited any degree of agreement based on their associated biota. However, the mixing of New Habitats that was observed assisted in making re-assignments of these New Habitat types to a revised set of CMRU habitats. Once this was done then it was possible to see a degree of CMRU habitat fidelity in relation to their associated biota. Of all the habitats suggested it was concluded that four appeared to have a relatively distinct biota. These were the Upper Intertidal.