Each year, winter rains and melting snows move enormous amounts of debris into streams, rivers and the Chesapeake Bay. Tons of debris, both natural and manmade, are deposited along shorelines, in shallow water areas and in channels.
Large obstructions in waterways can be a hazard to boaters and should be removed or flagged, if possible. Garbage can be a danger for wildlife and a health hazard.
However, some amount of natural debris is a critical component of healthy streams, rivers, shorelines and the Chesapeake Bay.
In streams, small pieces of driftwood are grazed upon by beetles, caddisflies, stoneflies and mayflies. Other insects use driftwood to crawl out of the water as they emerge from their larval forms into adults. In Coastal Plain streams, large woody debris provides the principal substrate for insects such as stoneflies, mayflies and dragonflies. These and other insects, in turn, are one of the most important food sources for fish, as well as amphibians, reptiles and birds.
Woody debris plays many other roles in aquatic ecosystems. Wood in streams can alter water flow, creating deep pools that are quickly inhabited by certain species of fish. In larger streams and rivers, turtles climb onto partially submerged logs to bask in the sun.
After major storms and flooding, trees, branches and leaves are stranded along the edge of a river. These huge debris piles are quickly inhabited by a variety of mammals including mice, voles and chipmunks. Rotting logs are a favorite place for many amphibians to deposit their eggs. Insect-eating birds forage on an abundance of insects and insect larvae in and on the debris.
During high flow events, huge amounts of debris can be carried downstream in larger rivers and deposited in estuaries and marshes and along shorelines. The use of woody debris by wildlife in estuaries has often been overlooked. This organic matter in shallow water areas, while unsightly to some people, provides habitat for aquatic wildlife.
Driftwood is often used as nest building material by ospreys, eagles, herons and muskrats.
Partially buried logs and trees serve as perches for birds such as herons, gulls and shorebirds.
This grounded debris may also help to stabilize eroding shorelines by trapping sediments. Decaying wood is attacked by wood-boring worms, clams and crustaceans and also serves as a nutrient-rich base on which wetland plants become rooted.
Larger submerged pieces are a valuable part of the aquatic habitat in the Chesapeake Bay. These natural physical structures provide refuge for such species as blue crabs, mud crabs and grass shrimp. Fish, such as Atlantic croaker, killifish, mummichug, anchovy and striped bass, forage for food among submerged debris while hiding from predators.
As many sport fishermen know, fallen trees in tidal creeks are excellent sites for catching perch, bass and croaker. Compared to areas without natural physical structures, both the variety and number of aquatic wildlife increases in shallow water areas with woody debris.
Although this can be a nuisance to boaters, removing all large organic matter from waterways is not physically possible. Boaters, whether in canoes, kayaks, powerboats or sailboats, must remain alert to avoid hitting submerged logs.
Those who live on the water should regularly clear debris off their shore, especially trash and man-made objects that can pose a danger to both people and animals.
Consider leaving some of the larger driftwood in the shallows and on the beach, though. This is especially important along bulk-headed shorelines, where debris left in the shallows is probably the only natural habitat available to aquatic life.
This habitat will attract a variety of wildlife. The pleasure gained from watching birds, fish and crustaceans, and the beauty they bring to one's view will probably far outweigh the aesthetics of a "clean" shoreline.