Search results for "Gillnetting"
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Age is not just a number—Mathematical model suggests senescence affects how fish populations respond to different fishing regimes
2021
Abstract Senescence is often described as an age‐dependent increase in natural mortality (known as actuarial senescence) and an age‐dependent decrease in fecundity (known as reproductive senescence), and its role in nature is still poorly understood. Based on empirical estimates of reproductive and actuarial senescence, we used mathematical simulations to explore how senescence affects the population dynamics of Coregonus albula, a small, schooling salmonid fish. Using an empirically based eco‐evolutionary model, we investigated how the presence or absence of senescence affects the eco‐evolutionary dynamics of a fish population during pristine, intensive harvest, and recovery phases. Our si…
Density and biomass of smelt (Osmerus eperlanus) in five Finnish lakes
2005
Abstract Hydro-acoustic stock assessment and exploratory sampling with small mesh-sized trawls and seines have sometimes suggested that the importance of smelt (Osmerus eperlanus) in pelagic fish communities might be greater than sampling from commercial fishery and gillnetting indicate. We studied the proportion of smelt in the total fish density (fish ha−1) and biomass (kg ha−1) of pelagic fish with echo sounding and trawling in five southern boreal lakes. Fish density varied between 460 and 2000 fish ha−1 in the study lakes. Smelt and vendace (Coregonus albula) accounted for more than 95% of the exploratory trawl-catches. The total fish biomass in the study areas varied between 3 and 13 …