Comparative study on the performance of marine benthic species in the face of environmental stress. Stress tolerance in native and invasive colonial ascidians. Institut für Tierphysiologie.

Gröner, Frederike (2010) Comparative study on the performance of marine benthic species in the face of environmental stress. Stress tolerance in native and invasive colonial ascidians. Institut für Tierphysiologie. (Master thesis), Westfälische Wilhelms-Universität , Münster, Germany, 76 pp.

[img] Text
Frederike_Gröner.pdf - Published Version
Restricted to Registered users only

Download (1466Kb) | Contact

Abstract

Processes mediated by humans are affecting coastal ecosystems on various occasions. Recently, climate change and bioinvasions gain more and more attention. The frequency of extreme weather events due to climate change as well as of bioinvasions due to increased ship traffic and aquaculture activities are predicted to increase. While the first will lead to pronounced short-term fluctuations in environmental variables like temperature and salinity, the second may have extensive consequences for the species composition of coastal communities and ecosystem functioning. Alterations in environmental regimes can impair well adapted native species and even favour the success of invaders in case they are generally more resistant to environmental stress. The latter should be true if the frequency of stress tolerant genotypes is increased in populations that were previously exposed to unfavourable conditions, for example during transport to new habitats. To test if enhanced stressful environmental conditions may be better tolerated by invasive species competing with natives, laboratory stress experiments were conducted with a native colonial ascidian, Diplosoma listerianum, and an invasive, Didemnum vexillum, from the Irish Sea, North Wales. Both species have a comparable ecology and occupy comparable ecological niches. Study organisms were exposed to several levels of reduced salinity (10-27 psu) and their tolerance was determined on the base of growth, survival (over weeks) and respiration rates (over days) under stress conditions. Generally, D. vexillum exhibits a greater tolerance to experimental conditions than D. listerianum expressed in higher growth and survival rates under hyposalinity. Based on these findings, it seems that the pre-selection of resistant genotypes may play an important role in determining the performance of populations in the face of environmental stress. Altered stress regimes in coastal habitats due to climate change can modify competitive hierarchies, while, according to my findings, invasive species should be the winners under most circumstances. My work emphasises the potential relevance of this so far widely underestimated interaction between two drivers of ecosystem change enhanced by human activity

Document Type: Thesis (Master thesis)
Thesis Advisors: UNSPECIFIED
Additional Information: Supervised by Prof. Dr. Rüdiger J. Paul, Prof. Dr. Martin Wahl
Keywords: Benthic Ecology; GAME; coastal ecosystem; marine benthic species
Research affiliation: OceanRep > GEOMAR > FB3 Marine Ecology > FB3-EOE-B Experimental Ecology - Benthic Ecology
Open Access Journal?: No
Projects: GAME
Date Deposited: 05 Sep 2011 08:01
Last Modified: 06 Jul 2012 15:06
URI: http://oceanrep.geomar.de/id/eprint/12081

Actions (login required)

View Item View Item

Document Downloads

More statistics for this item...