Sockeye salmons (Oncorhynchus nerka), adults migrating up the Adams River to spawn. B.C. Canada

New DNA sampling techniques have just established a benchmark for fisheries science — the ability to determine the species type and abundance of migrating fish just by sampling water in a river.  The genetic bread crumbs that fish leave behind just by passing through a section of stream now are able to be used to gauge the size of migration runs and even the presence of different species moving with them.

Read more: http://www.flyfisherman.com/news/edna-bread-crumbs-track-migrating-fish/#ixzz4gId6wGmu