Perhaps you have heard the slogan, “Reuse, Reduce, and Recycle” this week as folks have focused on Earth Day and tried to highlight ways to “go green”. It is kind of catchy, makes sense, and underscores our personal responsibility in taking care of our natural resources. As I took a look at the wetland habitat at Duck Creek this week, I thought of this slogan in a slightly different context.
As spring has progressed we have kept some locations flooded, while other spots have begun to dry out as temperatures increase and we have started to lower the water levels. Currently, on the mud flats in the open marsh you can see partially decomposed stems and leaves beginning to dry out. If you’ve been chasing turkeys in the timber, you can see various degrees of dried out and broken down leaves. In both of these habitats, by wading out through the muck into deeper water, you can begin to see a glaze on the water’s surface. Along with the trees that have budded out in higher, dryer locations, photosynthesis has really ratcheted up under the water as well. The glaze on the water is the result of tremendous bloom of a variety of algae communities.
Now stay with me, I realize algae probably has the curb appeal of….well, algae. It is a pain in the rear trying to fish through and periodically there are stories of dogs dying from swimming through toxic blooms of blue-green algae. I realize algae doesn’t have the best reputation, but hear me out because it does serve a purpose.
Let’s think back to last fall when we were able to flood a lot of different habitats ranging from flooded timber with leaf littered floors to the open marsh with aquatic plants and annual seed producing grasses and forbs. The purpose was to make the seeds, acorns, bugs, and other plant parts available for waterfowl to forage on as they migrated through this fall and spring. Although many of the ducks have moved on, the kitchen is still open. With the transition in seasons the menu has changed along with the potential clientele.
On a microbial level while these habitats were flooded in the fall and winter the water was leaching nutrients out of all of that dead plant matter. Microbes and bacteria were also chewing away and releasing the nutrients that were once tied up in the rotting plant tissue. With the warmer temperatures algae has been given the green light to turn on and start utilizing these now released nutrients. In the spirit of Earth Day, this example of algae shows us how the duck food, duck waste, and left overs are being reduced, reused, and recycled by another component of the wetland system. This is called nutrient cycling.
The bloom of algae provides food for a different suite of critters across the wetland food web. The late migrating Shovelers that are still hanging around, love it and can sift out a decent meal by filtering through the split-pea soup. Those digging in their tackle box and hoping to land the next big lunker should also pay attention. The fat blue-gill, warmouth, crappie and bass that are so fun to catch, wouldn’t get there unless they had abundant food. Algae provides the food base for a wide range of bugs, that ultimately end up fattening up our fish. Additionally, during the larval and juvenile stage many fish species would starve if algae, zooplankton, and other tiny food items were not available.
Peering through the water column right now provides a totally different perspective that may go unseen and unthought-of from above. Within the shallow water green masses and wispy strings of algae crowd the biological broth with shoots and blades of emerald colored plants that are expanding and using the dissolved nutrients. If the habitat stays flooded in portions of the area, this growth will continue, bugs will churn, crawdads and fish will grow, and herons will be fat and happy through the summer. If water levels recede, another cycle of decomposition and nutrient release will begin allowing for more terrestrial plants to take advantage of the resources. Although algae typically doesn’t get a good wrap, it is one component of our wetlands that is vital in how these systems reuse, reduce, and recycle. While we might just celebrate Earth Day once a year, going green and using the available resources wisely is just another typical day in the marsh.