A few months ago I received a text from a local fisherman who had been to Alamo Lake and saw something unusual floating in the lake. He sent me a picture and at the time it looked like a polystyrene structure with some kind of plants on it.
He asked me if I knew what it was, and I didn’t. But I found out. I obtained information courtesy of Pam Kostka, Operations Project Manager for the Los Angeles District of the US Army Corps of Engineers.
Ms. Kosta sent out a post titled “Alamo Lake Newsletter Summer 2022” in which she identified what had been done at Alamo Lake that had caused many anglers and boaters to ask questions about what they had seen there.
“A floating wetland was installed in April 2022 in the creek across the lake from the Cholla boat launch to provide wildlife habitat and provide a new fishing attraction (GPS location: 34.26155N, -113.58618W).
Floating wetlands will provide a number of benefits to the lake and provide an interesting site to stop and check while boating.
The wetland was created from a floating piece of moss with holes spaced around the top for planting. Before anchoring the floating wetland in its permanent location, the holes were filled with a mixture of peat and potting soil, then the plants were added.
All plants are native to Arizona. Plants include spike rush, gold rush, gold rush, three-square bulrush, yerba mansa, arrowhead, broadleaf cattail, and grassy arrowhead.
As the plants grow, their root systems hang down in the water, eventually creating a fairly dense root mat.
The hanging roots will become covered in biofilm, a sticky secretion produced by microbes, which will collect nearby algae and zooplankton forming a community of periphyton. Periphyton is the base of most aquatic food webs and will entice aquatic insects to come for a snack, which in turn will attract fish.
Above water, flowering plants will attract pollinators, providing a resting place for birds and a home for other semi-aquatic creatures.
Plants and the periphyton community on plant roots will also have the ability to absorb excess nutrients from water. Removing excess nutrients from the water will help reduce the size and/or frequency of harmful algal blooms on the lake.
The Army Corps is seeking public comment on the island. “Have you fished in the floating swamps? What did you catch? Do you like or dislike the installation of the floating wetland? Have you noticed a problem with the floating wetland? Please let us know! Email us at AlamoDamSPL@usace.army.mil,” the agency wrote.
There’s a lot of technical information in Kostka’s report, but the bottom line is that it looks like the floating wetlands will be an area that should attract game fish to the lake.
If you’re going fishing at the Alamo, you might want to give it a try!
