| Cetacean populations may change in size and distribution over time and information on spatial and temporal variation in cetacean abundance is needed to understand the population dynamics. Besides for scientific interest, the population ecology data are essential as well to determine both whether management actions are necessary and the effectiveness of any actions that are in place. Such information must be interpreted in the light of other information relative to population structure, on direct (e.g. incidental capture in fishing gear) and indirect (e.g. pollution) anthropogenic effects. In this respect the acquisition of data on population status is particularly important in the process of designating specially protected areas (e.g. Special Area for Conservation-SAC or Marine Protected Area-MPA). For many species the key role of protected areas will be to preserve critical habitat. Defining and prioritising the protection of critical habitats becomes rather complex because the cetacean distribution and activity varies with season and between years. It is impossible to detect changes in most cetacean populations with current levels of financial investment, effort, survey technology and survey design. For instance the last two North Sea surveys for cetaceans had an interval of 11 years (SCANS, 2008) and do not give information on short-term changes in population size and neither do they provide information on fine- scale distribution. This project will investigate a complementary approach to gain a more complete picture regarding the spatial and temporary distribution of cetaceans at specific sites, by studying key cetacean species using both systematic and (cost-effective) opportunistic methods. |
