The capelin is a species of pelagic fish which lives in the North Atlantic ocean around Iceland. The stock is both economically and ecologically important to the region. These fish migrate hundreds of kilometers to feed and spawn, and their migration routes vary from year to year. Using an interacting particle model paired with environmental information about temperature and currents, we were able to reproduce and predict three spawning migrations. I will describe our model and present scaling laws which we propose in order to preserve the global dynamics while varying the number of particles used in the simulation. I will then discuss my current work on formal derivations of corresponding macroscopic PDEs.