Saturday, October 24th is World Fish Migration Day, a one-day global celebration of migratory fish and open rivers. Every day is a good one to celebrate and advocate for connected rivers, and as spring runs of migratory fish are making their way up river it is a particularly good time.
Many species of fish migrate between freshwater and salt water as a key part of their life-cycle. Some fish, such as well-known species of salmon, spawn in freshwater and then migrate out to the ocean where they grow to be adults, returning to rivers to spawn. Still others do just the opposite, like the American eel, living their adult lives in freshwater and returning to the open ocean to spawn. Their paths are as diverse as the fish themselves. West coast Chinook salmon have been tagged traveling as much as 3,500 miles, while some east coast river herring are content to travel a few miles upstream to a freshwater pond for spawning.
It isn’t only the ocean-going fish that need to move. Fish that live the entirety of their lives in freshwater also move between different types of habitat throughout their lives, accessing tributaries, the floodplain, and the main channel. These fish are persistent in their efforts. Brook trout at one study site in western Massachusetts have been recorded repeatedly attempting a 2-foot leap into a metal culvert in order to access a small side tributary protected from larger fish in the main channel.
We don’t make it easy on the fish to get where they are going. On most rivers dams stand in their way, blocking access to upstream habitat and creating challenges navigating downstream. Levees separate channels from nursery floodplains. Roads-stream crossings disrupt habitat connectivity even at the small scale.
Without access to vital habitat, fish populations decline. We need to support efforts to reconnect and keep connected rivers through removing unnecessary dams, reconnecting floodplains, managing our water use, and managing hydropower for sustainable rivers. And that is what World Fish Migration Day is all about.
Celebrate connected and healthy rivers with us. Keep an eye on our social media. Find a World Fish Migration Day event close to join at http://www.worldfishmigrationday.com/.