Methods for studying coastal bivalves in a changing world : A review and implications for management

Abstract

Anthropogenic activities such as pollution, CO2 emission, and overfishing, are among leading reasons for global environmental change and negative impacts on the marine environment including loss of biodiversity. Marine bivalves are an example of species that suffers from such consequences while they have high value in both aquaculture and marine ecosystems. With the existence of many threats including overharvesting, invasive species, parasites, and diseases, coastal bivalves such as flat oysters (Ostrea edulis) and blue mussels (Mytilus spp) are in many places endangered. The existing knowledge gaps in the historic and current distribution, however, makes quantifying the effects of these threats difficult and conservation management challenging. With the global dispersal of the invasive Pacific oyster (Crassostrea gigas) which is perceived as a threat to many coastal ecosystems, it has become even more important to increase our knowledge of native species to be able to devise successful management strategies and safeguard their future existence.There are, for instance, no standardized protocols for designing and performing mapping and monitoring surveys of coastal bivalves in Scandinavia. To start filling these gaps a literature review was conducted to get an overview of field techniques used in surveys of coastal bivalves and evaluate which method is suitable for different study aims.