G5 Doctoral dissertation (article)
So long and thanks for all the fish : fisheries erode adaptive potential (2024)
Kokoon kohdistuva kalastus heikentää kalojen adaptiivista potentiaalia
Sadler, D. (2024). So long and thanks for all the fish : fisheries erode adaptive potential [Doctoral dissertation]. University of Jyväskylä. JYU Dissertations, 777. https://urn.fi/URN:ISBN:978-952-86-0139-5
JYU authors or editors
Publication details
All authors or editors: Sadler, Daniel
eISBN: 978-952-86-0139-5
Journal or series: JYU Dissertations
eISSN: 2489-9003
Publication year: 2024
Number in series: 777
Number of pages in the book: 1 verkkoaineisto (58, 15 sivua, 5 numeroimatonta sivua)
Publisher: University of Jyväskylä
Place of Publication: Jyväskylä
Publication country: Finland
Publication language: English
Persistent website address: https://urn.fi/URN:ISBN:978-952-86-0139-5
Publication open access: Openly available
Publication channel open access: Open Access channel
Abstract
Fisheries not only deplete fish populations but are size-selective, removing the largest individuals in the population. The effects of directional selection are little known compared to bottlenecks and loss of diversity associated with overharvesting. This directional selection for body size can lead to loss of genomic and phenotypic diversity, leading to a loss of adaptive potential. To alleviate population loss, fisheries may halt harvesting to allow for population recovery. It is unknown whether a period of recovery prevents further genomic divergence and loss of adaptive potential. To address these questions, I used a model zebrafish system that had been exposed to five generations of size-selective harvesting, followed by ten generations of recovery. Two lines had experienced directional selection for either large or small body size, whilst one line was subject to random removal of individuals. I used a combination of molecular approaches and a long-term experimental study system to (1) determine the genomic change after an overharvesting event, and whether directional selection exacerbates such change, (2) whether a period of recovery prevents further genomic divergence, and (3) how directional selection interacts with exposure to thermal stress to influence physiology, life history, behaviour, genomic markers, and skin microbiota. I found that the change in genomic architecture depended on the direction of selection after harvesting and was stochastic between line replicates. Furthermore, I found that despite a recovery period, genomic architecture continues to change and genomic diversity decrease. Moreover, I found that directional selection increases susceptibility to thermal stress, decreasing fitness based on phenotypic measurements and genomic markers. I also find that a legacy of directional selection does not influence skin microbiota. Taken together, a legacy of directional selection can alter genomic architecture, and degrade adaptive potential of a population, reducing fitness of individuals. Crucially, I find that direction of selection does not matter as much as the act of selection itself, and that a balanced harvesting approach may be the optimum strategy to manage fisheries.
Keywords: Directional selection; fitness components; fisheries; multiple stressors; population genomics; size-selection; thermal stress
Keywords: fishing; fishes; fish populations; genomics; selection criteria; size; genome; temperature; doctoral dissertations
Free keywords: directional selection; fitness components; fisheries; multiple stressors; population genomics; size-selection; thermal stress
Contributing organizations
Ministry reporting: Yes
VIRTA submission year: 2024
