Is fish biomass controlled by abiotic or biotic factors? Results of long- term monitoring in a large eutrophic lake
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Kuupäev
2020
Kättesaadavus
Ajakirja pealkiri
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Kirjastaja
Elsevier
Abstrakt
Relationships between biomass and ecological factors including trophic interactions were examined to understand the dynamics of six fish species in Lake Võrtsjärv, a large shallow eutrophic lake located in Estonia
(north-eastern Europe). The database contained initially 31 predictive variables that were monitored in situ
for nearly forty years. The strongest predictive variables were selected by three parallel approaches: single correlation (Pearson), a multivariate method (Co-inertia analyses), and a machine learning algorithm (Random Forests), followed by a Generalized Least Squares model to determine meaningful relationships with fish biomass.
Models with both additive and interactive effects were constructed. The results revealed that the indicators of degraded ecological conditions (high cyanobacteria biomass and their proportion in total phytoplankton, high summer temperature, high nutrient concentration) were negatively correlated to fish biomass. Benthic
macroinvertebrates and other biotic predictors (biomass of specific fish prey and predators) were also important
contributors to fish biomass dynamics. Together, abiotic and biotic factors explained 40–60% of the variance of
fish biomass, depending of the species. Our findings suggest that both abiotic and biotic factors control fish biomass changes in this eutrophic lake.
This research was funded by Estonian Research Council grants (PSG 32), institutional research funding IUT 21-2 of the Estonian Ministry of Education and Research and by European Union Regional Development Fund program DoRa+ and ASTRA. The authors are thankful to Dr. Külli Kangur (Estonian University of Life Sciences) for participating in the sampling effort of benthic macroinvertebrates.
This research was funded by Estonian Research Council grants (PSG 32), institutional research funding IUT 21-2 of the Estonian Ministry of Education and Research and by European Union Regional Development Fund program DoRa+ and ASTRA. The authors are thankful to Dr. Külli Kangur (Estonian University of Life Sciences) for participating in the sampling effort of benthic macroinvertebrates.
Kirjeldus
Märksõnad
shallow lake, food webs, Cyanobacteria, macroinvertebrates, pike, pikeperch, articles