Fishing
When the James River Spinymussel becomes an embryo, it attaches itself to the gills of a fish. This sounds like a simple process, but in reality there are multiple variables that go into making this stage of the life cycle successful. Although there are plenty of fish species in the watersheds, there are only certain fish species (see Table 1 below) that JRSM embryos can attach to and it is difficult for them to latch onto the gills. Not only are there specific fish that they can latch onto, but the odds of them successfully finding one of these fish at the perfect moment is quite slim. The Spinymussel becomes an embryo externally, meaning they simply sit in the open water waiting for one of the proper fish to swim by. If the fish are not swimming through where the embryo is, or if the water is not moving fast enough to take the embryo to a fish, then the Spinymussel will die before even reaching adulthood. The embryos do not swim, so they cannot go to the fish, the fish have to come to them. If the correct fish species does not make contact with the embryo, then they cannot successfully attach. For an endangered species, successful reproduction is a necessity to replenish the population, and this stage of the life cycle can be very difficult for the mussels to pass.
Testing Protocol
In order to determine whether or not these fish species were present in the rivers we were testing, we had to catch them. Our fishing strategy consisted of using a large net, tied between two wooden stakes, and moving it against the flow of the river while another group member walked towards the net from upstream, encouraging the fish to swim into our net. We would then lift the net and collect any fish we caught into a bucket. At the end of the day, we would do an inspection of each fish, identifying and recording the species. Often times, we would only catch one species of fish for a designated river, rarely catching more than two different species per outing. There were multiple outings where we did not catch any fish at all, but when we did catch fish, fortunately they were often on the list above. This means that the fish to which the spinymussel embryos need to attach are present in the watersheds, making their chances of reproduction, and eventually reinstatement, a little bit higher.
