Imagine being able to know exactly how many fish you could catch in the future without negatively impacting predatory fish stocks and prey. ecosystem.
All this may be possible thanks to a very specific model of gastric emptying, developed and described in a doctoral dissertation recently defended by Senior Research Fellow at DTU Aqua Niels Gerner Andersen.
“The model tells us how much prey is being eaten by predatory fish, which allows us to more accurately calculate the impact of specific fisheries management on the species composition of our fish shoals.” It can affect entire ecosystems through secondary effects on food: a chain,” explains Niels Gerner Andersen. he continues:
“The principles of predator-fish-eaten calculations are based on information about the amount and composition of prey fish in the predator stomach collected in a way that is representative of the predator school. All these snapshots of the stomach contents are We use a model of gastric emptying rate to translate it into an average rate of how much a predatory fish eats over a long period of time.”
Niels Gerner Andersen, in addition to using gastric emptying data from laboratory experiments on predatory fish at Hirtshals, Denmark, used rules of both physical, chemical, and biological processes to establish the model. and it is the end result of many years. ‘ jobs.
Never-before-seen model
This model represents the continuous gastric contents of predatory fish, i.e. the rate of gastric emptying of both the total amount in the stomach and the individual prey, irrespective of previous history, which means the moment the predatory fish ingested the individual prey. increase. This has never been achieved before, and fishery biologists will be able to more accurately calculate how many of a particular species can be caught without creating imbalances in the ecosystem in question. I mean. The model also allows researchers to better assess ways to restore balance in ecosystems with too many fish of one species.
Extensive experiments and generalized models
Niels Gerner Andersen, in collaboration with his colleagues, conducted large-scale experiments with many predatory fish and their prey. The results of these experiments, along with the development of theoretical models, meant that researchers were able to create models for general use. We only need to know some characteristics of the predator and prey fish we want to investigate. It is a model that is easy to use for predatory fish and prey fish.
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For more information on this model, see Niels Gerner Andersen’s full PhD thesis at the following link: https://orbit.dtu.dk/files/297871063/The_dynamics_of_gastric_evacuation_in_predatory_fish_Doctoral_thesis_Niels_Gerner_Andersen.pdf
Original: New method can determine how much predatory fish eat, contributing to more sustainable fisheries
Than: Technical University of Denmark
