Östman, Örjan
- Department of Aquatic Resources (SLU Aqua), Swedish University of Agricultural Sciences
Research article2023Peer reviewedOpen access
Size-based indicators for assessments of ecological status of coastal fish communities
Ostman, O.; Hommik, K.; Bolund, E.; Heikinheimo, O.; Olin, M.; Lejk, A. M.; Svirgsden, R.; Smolinski, S.; Olsson, J.
Abstract
Human impact does not only affect the abundances of fish, but also the age- and size-distributions. Indicators of fish age and size-structures can hence be useful tools for fisheries- and environmental management. Size-based indicators have been tested and proposed for large, homogenous marine ecosystems with high fishing mortality, but rarely for fine-scaled heterogeneous ecosystems in coastal zones. Here we analyse a suite of size indicators for coastal fish communities in the Baltic Sea, including mean and median length, 10th and 90th-percentile of the length distribution (L10, L90), mean length of the 10% largest fish (Lmax), large fish indices, size-spectra, and size-diversity. Results show good precision and accuracy of most indicators at realistic sample sizes, except for size-spectra and size-diversity, making them less suitable. Different indicators showed correlations among sites, indicating similar responses to environmental variation. Most size indicators responded positively to lower fishing pressure, especially indicators emphasizing the largest individuals in the population (e.g. L90 and Lmax), whereas eutrophication and physical disturbances had less impact. We conclude that size-based indicators aiming at describing the occurrence of larger fish, like L90 and Lmax, are useful for establishing management targets and assessing the status of coastal fish.
Keywords
Baltic Sea; body size; ecosystem-based management; indicators; length; mortality; somatic growth
Published in
ICES Journal of Marine Science
2023, volume: 80, number: 10, pages: 2478-2489
Publisher: OXFORD UNIV PRESS
SLU Authors
Bolund, Elisabeth
- Department of Aquatic Resources (SLU Aqua), Swedish University of Agricultural Sciences
- Department of Aquatic Resources (SLU Aqua), Swedish University of Agricultural Sciences
Olsson, Jens
- Department of Aquatic Resources (SLU Aqua), Swedish University of Agricultural Sciences
- Department of Aquatic Resources (SLU Aqua), Swedish University of Agricultural Sciences
Associated SLU-program
Coastal and sea areas
Global goals (SDG)
UKÄ Subject classification
Fish and Aquacultural Science
Publication identifier
- DOI: https://doi.org/10.1093/icesjms/fsad158
Permanent link to this page (URI)
https://res.slu.se/id/publ/126976