Flood Pulse: Wetland Health Check-Up
Wetlands are cool because they are both wet and dry. During the dry season or during a drought, terrestrial species can be found using these areas. On the flip side, when the rains come down and the floods come up, these low lying areas become accessible to aquatic critters. In between these two extremes there are species that can handle a little bit of water, but can also hack having their feet dry for some time. It is this exchange between wet and dry conditions and all of the different species that find niches here or there, that make wetlands so productive...and in my book, so cool.
I’ve discussed before that one of our Duck Creek renovation goals is to reconnect historic drainages when possible. During flood events several spillways and low water crossings will help facilitate this. Well, in the last month Mother Nature reconnected the whole basin, spillways or not, during this historic flood event. Over the last two weeks we’ve gone out and have taken a look to see what kind of critters are out and about and utilizing these connected habitats.
It has been pretty cool to see the number and diversity of species that we’ve caught so far. We’ve caught a variety of sunfish (Warmouth, Green Sunfish, Orange-spotted Sunfish, Longear Sunfish, Red-Spotted Sunfish, and Red-eared Sunfish). Not surprisingly we’ve also caught quite a few predators, such as Spotted Gar and Bowfin. Additionally, we’ve been able to capture quite a few unique species that are of conservation of concern (Lake Chubsucker, Starhead Topminnow, Dollar Sunfish, Bantam Sunfish, Weed Shiner, Pugnose Minnow) and one state endangered species (Taillight Shiner). Now, to most people these probably appear to be just bait minnows, but they are in fact important and add to Mingo Basin’s diversity and complexity. I'll go further into this in a minute.
Fish aren’t the only critters we’ve been able to catch. There have been quite a few amphibians as well. Along with the bumper crop of tadpoles we’ve caught three different species of salamanders. Central Newts, which have bright orange bellies with black flecks, have been captured. We have caught another species of conservation concern, the Mole Salamander, in both their larval and adult form. (You might remember another post earlier this year where I talked about these guys.) Another cool surprise that we’ve caught has been several Lesser Sirens. These salamanders spend most of their time in the muddy depths of the swamp and are seldom seen. They are unique because of their external gills and they lack hind legs (scroll through the pictures to see one).
Several snakes both terrestrial and aquatic have been either caught or seen within the flooded areas as well (Black Rat Snake, Western Cottonmouths, Broad-banded Water Snakes, Ribbon Snake). Also Mississippi Mud Turtles have found their way into our nets.
Here again we’ve been catching terrestrial and aquatic species. When we first started sampling we were catching a lot of earthworms as they were trying to find some oxygen elsewhere. Unfortunately for them, many probably wound up in the belly of a bowfin or some other hungry fish. Representing the aquatic communities, Hellgrammites (dobsonfly larvae) and crayfish, have also been carefully sifted out of our nets.
Diversity and its role
So why am I so excited about these non-game species? Well, for one, catching a bunch of critters (whether they are game or non-game) is a heck of a lot better than catching nothing. Secondly, finding a diversity of species in a natural system is like taking a pulse check and feeling a healthy heart-beat. The interactions between plants, animals, soils, and water within wetlands are intricate and complex. When species start dropping out and diversity declines, the system becomes weakened and not as resilient to large disturbances. In a way you could think of it like this: variety is not only the spice of life, but in wetland systems, it is also the glue that binds it all together.
So even though Crappie or Mallards might be main reason you come to Duck Creek, it is the overall number of different species, including "bait minnows", that allow the food webs to be connected, keep nutrient cycles churning, and allow Duck Creek's wetlands stay healthy ... even when the area is under water by several feet. The more we understand these interactions and the role that large events play, the better we can manage these conditions in the future.