First off, let me introduce myself. I'm Pam, I've been a GMRI intern for the last 5 months or so and have been lucky enough to be part of the salmon team here. It's been a great experience and I've definitely learned a lot!
There's a couple of salmon-related projects going on at GMRI, I've been involved with work studying Atlantic salmon migration in the Gulf of Maine. In the Gulf of Maine, salmon begin their migration when they enter the marine environment. This initial migration phase occurs as they move through the Gulf of Maine to the coast of Nova Scotia by Halifax (they then continue all the way up to Greenland). However, we don't know where in the Gulf of Maine the salmon are moving through, how they're finding their way through or how the variability in the Gulf of Maine physical environment (currents and temperatures) affects them. I've spent the last several months trying to address these questions using what's known as "individual-based modeling" (IBM).
IBMs let us simulate individual fish. We can give the fish different sets of rules to define their behavior. This is neat because it lets us experiment with different orientation methods to see what methods might be plausible and lets us simulate the path an individual fish follows through the Gulf of Maine. Then by using physical conditions from different years, we can see how these paths change due to differences in temperatures and currents.
This figure shows simulated tracks for fish- each red line is a different fish. For this figure, the fish were instructed to swim in the direction the current was flowing.