Each individual invertebrate is a highly complex, specialized animal. For example, some insects transform from egg to larva, then to pupa, and finally emerge as a terrestrial winged adult. Changes to the environment can disrupt basic interactions of invertebrate species, thereby affecting other organisms in the food chain. Disruptions of natural food cycles may cause drastic changes in the community structure and ecological web of life. Eventually even humans are affected by changes to food webs and destruction of beneficial habitat for wildlife.
Most invertebrates can survive extreme natural events like severe storms, blizzards, and flooding.
Their populations have been damaged because of siltation, point and nonpoint source pollution, and outright habitat destruction. Today, our museum collections of invertebrates are often old and worn out, and there are few trained taxonomists to renew archival materials. This section is organized by general articles on invertebrates and followed by terrestrial and aquatic case studies. The authors drew on original data, often unpublished, and therefore, although some of the studies may appear outdated, this does not detract from the usefulness of the examples. Basic research on the taxonomy and ecology of species and communities is urgently needed as groundwork for future status and trend assessments.