I have a tutorial about ecosystem model: length-based models. To be honest, I do not completely understand about this kind of tutorial. Nevertheless, it gives me insight into what will happen if we fish only small fish, only medium fish or only large fish or even if we fish all of them and figure it out what will the best alternative to having such a sustain fishing pressure???
I am questioning and wondering myself, what is the best practice should be taken???
Well, this tutorial we pointed out by assuming several terms. First, the process in the ecosystem is like food web system where there are prey and predator. By thinking small fish is eaten by medium fish, and big fish eat medium fish. Afterward, we are ignoring other environmental factors such as temperature changing, pH changing, so on and so forth.
Nevertheless, this assumption is good enough to help us to understand how’s the process is going relate to management or what kind of solution or policy should be taken.
We used a spectrum calculator (http://184.108.40.206/SSC/) and easily we can find out what happen if we only catch small, medium or large fish.