Ecology and Evolution of Invasive Pacific Oysters in Response to Pathogen Infection and Rising Temperatures

• Main Author: Wendling, Carolin C
• Format: Thesis
• Language: unknown
• Published: 2014
• Subjects: Crassostrea gigas
• Online Access: https://epic.awi.de/id/eprint/34967/; https://epic.awi.de/id/eprint/34967/1/PhD_short.pdf; https://hdl.handle.net/10013/epic.43088; https://hdl.handle.net/10013/epic.43088.d001

Nature is a highly complex system that is subject to competition from several factors, which can be of physical, chemical, biotic but also anthropogenic origin. Nevertheless, we commonly consider only a few of those factors in our experiments. However, to understand the bigger picture, we have to test the synchronous effects of multiple factors. One great opportunity to do so comes from the direct interplay between bioinvasions and climate change. Bioinvasions constitute a natural experiment in evolution: when invasive species colonize new habitats they experience strong selection pressures from novel abiotic and biotic stressors. For a successful invasion, adaptation to those stressors is essential for survival. Additional threats may result from current climate change scenarios that further challenge the adaptive potential of invaders. Major threats of global change, such as emerging diseases are caused directly and indirectly by rising temperatures. A combined approach addressing direct effects of global change on host-parasite interactions of invasive species has rarely been taken. However, there is growing evidence that such multiple factors interact in complex ways. Furthermore, the way invasive species cope with novel parasites is still a black box. Using invasive Pacific oysters Crassostrea gigas and their opportunistic pathogens of the genus Vibrio as model organisms, this thesis addresses the evolution of an invasive species to novel sympatric parasites and combines this with additional challenges imposed by rising temperatures that are expected to occur in the habitat. C. gigas independently invaded and successfully colonized the Southern and the Northern area of the European Wadden Sea. The successful invasion of C. gigas‘ is mainly attributed to a lack of natural enemies and high propagule pressure. While Southern populations have occasionally been subjected to extensive mortalities resulting from a complex interaction of high temperatures, oyster genetics and parasite infections, Northern ...