Given the prominence of feeding activity, and the sheer volume of supplemental food dispensed into the environment, it is worthy to examine the impacts of feeding on nature and to improve one’s understanding of the proper care and responsibilities that come with feeding wild birds.

Aquatic biodiversity is the rich and wonderful variety of plants and animals—from crayfish to catfish, from mussels to mayflies, from tadpoles to trout—that live in watery habitats. It is the number of different native species, or species richness.

Biodiversity is declining globally at rates unprecedented in human history. Aquatic fauna in the United States are especially threatened; freshwater species are disappearing at a rate two to five times faster than native land animals. Causes of this decline include habitat loss and fragmentation, channelization of streams, dams, aquatic invasive species, pollution, and warming water temperatures. Humans actions to reduce the loss of aquatic biodiversity include preventing further habitat loss, restoring degraded habitats, stopping the introduction and spread of invasive species, and reducing pollutants and erosion.

Natural aquatic habitats include ponds, lakes, rivers, streams, springs, estuaries, bays, and various types of wetlands. Some of these habitats are shallow and others deep, some are cold-water and others warm-water, some are freshwater and others saltwater, and some have high oxygen levels and others little oxygen.

Nearly 300 species of mussels inhabit freshwater rivers, streams, and lakes in the United States. This is the richest diversity of mussels found in the world and an extraordinary natural heritage that needs protection. Because of the lustrous, pearl-like interior of the shells, some of these pearly mussels have important commercial value in the cultured pearl and jewelry industry.

Freshwater habitats throughout the United States harbor the richest diversity of crayfish in the world. These aquatic animals serve as important links in the food web, indicators of water quality, and a food source for humans. Crayfish are threatened by habitat loss, pollution, and invasive species. This publication describes crayfish biology and ecology as well as threats to crayfish populations.

Fish are cold-blooded animals with a backbone, gills for breathing underwater, and paired fins for swimming. They live underwater and are dependent on water for dissolved oxygen, support, food, and shelter. North America has the most diverse temperate freshwater fish fauna in the world, but nearly 20 percent of those native freshwater fish species are imperiled, meaning that they are endangered, threatened, or of special concern. Fish are an important part of the food web, key indicators of water quality and ecosystem health, and a source of food and recreation for humans.

This publication provides descriptions of some of the major freshwater fish families in North America, such as minnows, perch, and sunfish. Each description includes information about species diversity, distribution, ecology, and roles in commercial and sport fishing.

About 8,900 species of amphibians (frogs, salamanders, and caecilians) are found world-wide. Of these, 116 species are frogs that inhabit the United States. The greatest diversity of amphibians occurs in the Southeastern United States. Frogs can be found in both aquatic and terrestrial habitats, from deep water to tall trees. They are adapted to local environments in coloration, body structure, and behavior.

Of the more than 800 species of salamanders found worldwide, more than 230 live in North America. Over 40 percent of these are considered to be at risk.

This publication describes turtles, including their structure and appearance, life cycle, ecology, distribution, and diversity. It describes major threats to turtles, including habitat loss, collection for the pet trade and food markets, invasive species, and urbanization.

Six hundred fifty different species of snails are widely distributed across the streams, rivers, and lakes of North America. There are unique species associated with every type of aquatic habitat from the Canadian Arctic to the Everglades of Florida.

In North America, there are more than 8,600 species of insects associated with freshwater environments during some part of their lives. Just about anywhere you go on the planet, there is some kind of insect that will live in almost any place that stays wet for a week or so. Aquatic insects are important food for fish and waterfowl. They also play important roles in keeping freshwater ecosystems functioning properly. This article describes the biology and ecology of aquatic insects, the major groups of aquatic insects found in freshwater habitats, and how to observe them.