Ah, spring! Singing birds, peeping frogs, mud. What exactly is “mud”? Not too runny, but not too solid, either. As with pornography, we know it when we see it. Children are drawn to it and know instinctively how to differentiate among mud for pies, mud for structures, and mud for stomping. Although mud may or may not have been necessary for the origin of life (there are opinions on both sides), it has been intrinsically connected to and has supported life ever since. In deep ocean structures, there is a feedback loop between the mud and the microorganisms that dwell there: when the organisms die, their skeletons drift to the bottom to enhance the mud, which then provides scaffolding and recycled nutrients for future generations of microorganisms. Because the Chesapeake Bay is so shallow (~20’ deep on average), this kind of nutrient cycling from top to bottom to top is fast and efficient. The downside to mixing by tide and wind is that pollutants also easily disperse to all layers of water and mud.
Mud supports life of all sizes, from the innumerable bacteria inhabiting the hot springs and mud pots of Yellowstone to hippopotamuses who need mud to keep cool. Middle-size creatures like wasps, swallows, and beaver use mud for home construction and maintenance. Frogs overwinter in mud left behind at the vernal pools where they hatched. Our beloved blue crabs will hunker down in mud for protection when they are peeling. We can infer the universal importance of mud just by noting the number of animals with “mud” as part of their common name: mud turtle, mud skipper, mud crab, mud puppy, mud hen, mud bug.
Because intertidal mudflats are, to use a technical term, squishy, they are a key habitat for shorebirds. Birds can nest and forage without threat of becoming prey to larger, heavier animals. And what might they find as they poke through the mud? Flatworms, round worms, snails, tiny shrimp, tiny crabs, bivalves, brittlestars, anemones, beetles, and whelks. These feed on phytoplankton, zooplankton, and each other. Obligate carnivores, whelks are among the top predators of mudflats, drilling through shells with their dagger-shaped toothlets to reach the soft tissue inside.
In conclusion, the next time you find yourself slogging through mud, consider skipping instead. As Buddhists say, “No mud, no lotus.”
(Apologies to mud botanists for overlooking plant life that is also intrinsic to mud ecology.)
by Sue Hauser
Maryland Master Naturalist