Abstract
The accelerating spread of exotic species is currently one of the most serious environmental threats worldwide. Spreading species may become invasive and can have far-reaching negative ecological and genetic effects on native ecosystems, as well as severe economic consequences. The Pacific oyster (Crassostrea gigas) is an invasive species that first occurred in large numbers in Sweden in 2007. Negative consequences of the invasion in Sweden are emerging and management of the oyster populations need to be initiated. Knowledge of spreading ways is of critical importance for development of effective management strategies but at present such information is lacking for Pacific oysters in Sweden. My approach to describing and quantifying the dynamic processes affecting the Pacific oysters? colonization and spreading ability along the Swedish west coast involves four main steps. First analysis of yearly recruitment success and population impact of the recruitment using length-frequency data will be performed (Aim 1). Second I will determine the origin and recruitment ways along the Swedish west coast of the species (Aim 2). Third I will define available oyster habitats in Sweden (Aim 3) and finally I will combine these results with a spreading model to predict future development of the Pacific oyster populations in Sweden (Aim 4). Together the results from these four subprojects will provide invaluable knowledge and practical tools for management of established oyster populations.
Sweden