What is the "Benthos"?

The benthos refers collectively to all aquatic organisms which live on, in, or near the bottom (substratum) of water bodies. This includes organisms inhabiting both running and standing waters, and also applies to organisms from both saltwater and freshwater habitats.

The term "phytobenthos" is used when referring to the primary producers (i.e., various algae and aquatic plants), whereas "zoobenthos" is applied in reference to all consumers (i.e., benthic animals, and protozoa). "Benthic microflora" (bacteria, fungi, and many protozoa) constitute the decomposer community, and are involved in the recycling of essential nutrients.

The benthos may be further subdivided on the basis of size. Large benthic animals (those readily visible without the use of a microscope) are collectively referred to as macrozoobenthos or macroinvertebrates. Representatives include clams, snails, worms, amphipods, crayfish, and the larvae of many aquatic insects (e.g., dragonflies, mayflies, stoneflies, caddisflies, chironomid midges, and black flies.) Microscopes are essential to discern members of the microbenthos, e.g. nematodes, ostracods.

The benthic macroinvertebrates consume algae, coarse particulate matter (such as fallen leaves) with its associated fungi and bacteria, fine suspended organic matter, and prey organisms. Macroinvertebrates are part of the food supply for many fishes and other vertebrates of lakes and streams.

Thus, the benthos encompasses a huge array of life with many phyla involved. They inhabit such disparate habitats as the small aquaria formed in the bottom of pitcher plant leaves, to the bottom inhabitants of the Mississippi River, the Great Lakes, and the oceans.

Members of the North American Benthological Society are scientists mainly interested in freshwater biology. These habitats include rivers, streams, temporary streams, lakes, reservoirs, wetlands, and bogs. Benthologists study the life histories, population ecology, and systematics of the benthos. They elucidate the community ecology of the benthos and freshwater ecosystems and work for their conservation. In the area of applied research, benthologists develop pollution monitoring methods and impact assessment techniques. They study pest organisms, such as black flies, zebra mussels (a biofouling organism), and nuisance algae to develop strategies for reducing the health or economic impacts of the pests. Because many of the benthos are important as fish food, their study is important to fisheries management.

Most NABS members are associated with educational institutions as faculty, students or staff. Others are employed by government agencies where they use their benthic knowledge for impact assessment, pollution control, and resource conservation. Some benthologists are employed in industry, typically environmental consulting firms. They may be concerned with biofouling by benthic organisms, environmental monitoring for permitting/licensing of facilities, mitigation of impacts, and many varied tasks.

Many members conduct research pertaining to freshwater zoobenthos (especially aquatic insects and molluscs), but membership is open to all. Studies of phytobenthos are essential to understanding benthic communities, and the processes in marine benthic communities provide important parallels to those occurring in freshwater. All persons interested in benthic organisms are encouraged to join and to participate in the society's activities.