Abstract
A stock–recruitment model with a temperature component was used to estimate the effect of an increase in temperature predicted by climate change projections on population persistence and distribution of twaite shad Alosa fallax. An increase of 1 and 2° C above the current mean summer (June to August) water temperature of 17·8° C was estimated to result in a three and six-fold increase in the population, respectively. Climate change is also predicted to result in an earlier commencement to their spawning migration into fresh water. The model was expanded to investigate the effect of any additional mortality that might arise from a tidal power barrage across the Severn Estuary. Turbine mortality was separated into two components: (1) juvenile (pre-maturation) on their out migration during their first year and on their first return to the river to spawn and (2) post-maturation mortality on adults on the repeat spawning component of the population. Under current conditions, decreasing pre-maturation and post-maturation survival by 8% is estimated to result in the stock becoming extinct. It is estimated that an increase in mean summer water temperature of 1° C would mean that survival pre and post-maturation would need to be reduced by c. 10% before the stock becomes extinct. Therefore, climate change is likely to be beneficial to populations of A. fallax within U.K. rivers, increasing survival and thus, population persistence.
DOI
10.1111/j.1095-8649.2010.02775.x
Publication Date
2010-11-01
Publication Title
Journal of Fish Biology
Volume
77
Issue
8
Publisher
Wiley
ISSN
1095-8649
Embargo Period
2024-11-22
First Page
1912
Last Page
1930
Recommended Citation
Aprahamian, M., Aprahamian, C., & Knights, A. (2010) 'Climate change and the green energy paradox: the consequences for twaite shad Alosa fallax from the River Severn, U.K.', Journal of Fish Biology, 77(8), pp. 1912-1930. Wiley: Available at: https://doi.org/10.1111/j.1095-8649.2010.02775.x
