Saturday, April 17, 2010
What Makes a Healthy Wetland?
There is no one definition that describes a healthy wetland because of the vast diversity of wetland types. However, wetland health can be determined, to a degree, by simply observing and becoming familiar with what is "normal" for your wetland.
We can get very technical and talk about a wetland's structure and function, such as its water quality, soil condition, carrying capacity, surface and ground water storage, sediment retention, nutrient cycling, biomass production, reduction of erosion and purification of water. I am not an environmentalist or a scientist. I am just beginning to learn about the science myself.
What I can talk about is the observation of returning species, and the variety and depth of those species, which is telling us a great deal about the health of White's Wetlands. "Species composition" and "food web support" are terms that we could use to describe these visual observations. What I am really saying is "biodiversity" and "the food chain."
We are seeing species return, creatures that we have not seen for a number of years. The most recent arrival is the muskrat. The muskrat is a natural inhabitant of shallow wetlands, where they feed primarily on aquatic plants, such as cattails, arrowheads and duckweeds. They occasionally eat crayfish, snails, mussels, frogs, insects and slow-moving fish. We have not had muskrat in the wetlands for many years. The reasons for this could be numerous. However, the fact that the muskrat is here does mean that they are finding the food they need to sustain themselves.
This is also their breeding season, so there may be young soon. Since we do have snapping turtles, this could pose a problem later in the season, as the turtles move from their winter home, down the creek and into the pond, where they generally tend to spend their summers, basking in the open, warm water and under a hot sun. Snapping turtles have been known to take young muskrat, so they are potential predators.
We can observe the changing species composition over the spring and summer.
The creek is also populated with suckers this year, and quite an abundance of them too, which is all good because these fish are bottom feeders and do an excellent job of keeping the water clean and clear. They're Mother Nature's clean-up crew!
From songbirds and insects to the larger predators, we are seeing more and more evidence that this is truly becoming a habitat that can cope and manage, a self-sustaining ecosystem that will regulate itself internally with the vegetation and animal life required to maintain balance and biodiversity.
Quite a precious thing, really.