Sunday, June 24, 2018

Green Lake National Fish Hatchery - Feed, Clean, Repeat...

First of all, apologies for the delay since our last blog post. After our long journey from Texas to Maine and almost daily blogging for two months we both sort of just burned out on blogging. But, we're back!!


We arrived at the Green Lake National Fish Hatchery back on May 11th. This hatchery is devoted to the restoration of the endangered Atlantic Salmon to their river habitats in the Northeastern United States.

Image result for atlantic salmon

Atlantic Salmon have an interesting life cycle in that their eggs are laid in freshwater rivers, where they hatch and the fry/parr/smolts spend 2-3 years before heading out into the Atlantic Ocean. Once in the ocean they migrate to the North Atlantic where they spend 1-3 years feeding and growing into adult fish. Mature fish migrate back to their home rivers, swim upstream to traditional spawning areas, and lay/fertilize eggs. Unlike Pacific Salmon they do not die after spawning, and some individuals are able to return to the ocean to repeat the process. Due to predation and other factors it is believed that fish seldom spawn more than twice.

The entire life cycle is represented at the hatchery. The eggs hatch in February, so we were too late for that, but we did arrive to find 56 fiberglass tanks full of 1" long salmon. At this life stage they are fed nearly constantly with a combination of automatic feeders and hand feeding.


All of those black spots you see in the front tank are Atlantic Salmon. There were about 15,000 fish in each tank!

The food that they eat at this age looks like dust. The biologists constantly monitor the weight of the fish and adjust feeding rates, food size, water flow and temperature, etc. to keep the tanks healthy.


We were shown how to hand-feed the fish on our very first day. The hand-feeding is done hourly to supplement the automatic feeders and make sure food is distributed throughout the tank. The automatic feeders drop food in one spot and that favors the fish that congregate there. The hand feeding broadcasts food into different areas.


The food is oily and smelly, and we found that if we didn't wear a latex gloves our "feeding hand" would smell like fish food for the rest of the day. So you see a lot of "one-glove" wearing folks at the hatchery!


You can see that both Teri and I are have long-sleeved shirts on under our official volunteer T-shirts. Between the 50-something degree water circulating throughout the hatchery and the cool outdoor air temperatures the hatchery building stays pretty cool, especially first thing in the morning!

We've found the small staff (5 employees) to be friendly and easy to work with. Stay tuned for more from the Green Lake National Fish Hatchery and the coast of Maine. 

Mark