FIRST TEST FOR NEW POND KETTLES

Last summer, we were fortunate to get funding to replace the kettles in ponds 12 and 13. The kettle is the concrete structure at the low point of the pond. As a pond drains, the fish gather in the kettle where they can be netted out. The previous kettles were at the end of their life and had become a safety issue due to the crumbling concrete. I found that out the hard way one day when I went for an unexpected swim. Contractors got to work last summer removing the old kettles and installing the new ones. Former hatchery manager, Doug Aloisi helped design a new style that is much different than the ones we currently use. The new design creates an area of low current velocity for the fish to rest in prior to harvest. Our current kettles lack that “quiet” water, meaning fish must swim against the current coming through the kettle or risk being pinned against the screen. Another benefit of the new design is the increased screen surface area. This will lower current velocities going through the screen and reduce chances of algae and vegetation plugging the screen. Finally, the kettles have a dual drain design that will help us draw down the pond to the perfect level. We can open the first drain and sleep easy at night knowing the pond will be ready for harvest in the morning without constant monitoring or return trips to the hatchery in the evening to shut pond drains. Pond 12 work was completed this spring and will get its first test with a crop of yellow perch. We’re excited to see how these new kettles work and hopefully they help us produce more and healthier fish for years to come! By: Nick Bloomfield

Concrete kettle in a hatchery filled pond with an excavator on the road. Photo: Nick Bloomfield/USFWS.