Relationships between juvenile fish assemblages and the physical features of bays along the Atlantic coast of mainland Nova Scotia, with implications for coastal Marine Protected Areas

Marine Protected Area (MPA) sites are traditionally selected to protect individual species, or areas with scenic views. Selecting sites in an ecologically defensible manner reduces the arbitrariness in these decisions, and allows representative and distinctive areas to be identified and included in MPA networks. To further coastal conservation planning, this study examined coastal fish assemblages and the physical features of nearshore ecosystems to determine relationships between geophysical characteristics and biotic communities.;Twenty bays were sampled for juvenile fish along the coast of mainland Nova Scotia, from Chedabucto Bay to the Bay of Fundy. Using a beach seine, 19,505 individual fish, representing 35 unique species, were caught during two field seasons (June--October 2005, June--September 2006). Based on physiographic features and environmental variables, bays sorted into well-defined bay types. Results indicated that the fish assemblages did not relate to these bay types, nor to geographic location. There were significant correlations between fish species and substrate type, in particular sediment particle size. Species-accumulation relationships discovered that a set of small bays, equal in shoreline length to a large bay, contained more fish species (26--35) than the larger bays (14--17 species). A minimum shoreline length of 3.37 km is required within a small bay to encompass all 35 species caught in this study.;This study lays the foundation for the environmentally justifiable selection of representative coastal zone MPAs along the Atlantic coast of Nova Scotia.