Benthic macroinvertebrates are small aquatic organisms that live in the bottom of rivers and streams.They can be found attached to rocks, plants, sticks, or can dig into the sediments. Clams, snails, crayfish and dragonfly larvae are just a few examples of macroinvertebrates . Generally speaking, a diverse macroinvertebrate community indicates a healthy aquatic ecosystem. Given an ecosystem of a certain size and with a certain amount of resources, both habitat and resources will be shared among a diverse group of species. This is because each species is adapted to a certain range of resource requirements and habitat conditions.
Different macroinvertebrate species have varying degrees of pollution tolerance. As the ecosystem becomes compromised, the environmental conditions may change that give one or more species competitive advantages. These species become dominant and outcompete the others. In most cases, pollution tolerant species will thrive. In a badly polluted ecosystem , pollution tolerant species may be the only ones that can survive, thus negatively affecting the diversity of the system.
Chemical testing only reflects water quality at the moment the test is performed. By studying macroinvertebrate communities and measuring their diversity, abundances and composition, a long-term picture of water quality can be developed. Macroinvertebrate studies are also well suited to citizen science efforts and the New Jersey Center for Water Science and Technology is able to provide training for volunteers. A macroinvertebrate study can be an effective community engagement tool and empower volunteers to take a more active role in habitat conservation.