Toxins present in the food web
Bacillus thuringiensis kills the larvae of certain flies and mosquitoes. The main targets for this Bt are the larval stages of mosquitoes, black flies, and fungus gnats; it does not kill larval stages of "higher" flies such as the house fly, stable fly, or blow flies.

Microcystis, can pass through the gut of grass carp unharmed, and pick up nutrients while in the gut. Thus, in some cases, blue-green algae blooms have been exacerbated by grass carp. Also, Microcystis has been shown to produce more toxins in the presence of grass carp. Grass carp, which have natural defenses to their toxins, sometimes can contain enough algal toxins in their systems that they become hazardous to eat.

Ecosystem’s evasive species
The Burmese python has its origins in Southeast Asia and was introduced in Everglades in 1979. Perhaps no other invasive species has attracted as much media attention at Burmese pythons in Florida, particularly after spectacular photographs and eyewitness accounts of struggles between native alligators and these snakes were released. Burmese pythons have voracious appetites and have been found to eat animals ranging in size from wrens to white-tailed deer. A study by Michael Dorcas of Davidson College found some mammals populations have dropped 90 percent in areas populated by the pythons. They share the top of the food chain in the Everglades with alligators and prey on 39 endangered species and 41 additional rare species. They continue to be sold as pets; around 6,000 pythons were imported into Miami from 2003 to 2005. They are removed immediately from Everglades National Park; as of 2007, national park staff report extracting a total of 600 pythons. Another 300 were captured in 2008 alone. As of 2012, it's estimated 30,000 are living in South Florida in 2012.
The Common Myna has its origins in Southeast Asia and was introduced in 1983 in Everglades. Common Mynas are prohibited from being imported into the U.S. Like Monk Parakeets, they also live in large communal nests, and are frequently seen near shopping malls where their nests are made in parking lot light poles. They have been reported to attack native purple martins (Progne subis) and in wilderness areas they inhabit next boxes intended for native birds to use or tree cavities, competing with native birds for space. Common Mynas can harbor diseases such as avian malaria that can be spread to native bird populations.
The Black rat was introduced once with the arrival of European settlers in 16th century. Black rats were possibly the first introduced mammals to Florida, followed by pigs. There are a few feral rat species in South Florida, including Norway rats (Rattus norvegicus), but black rats are considerably more populous than any other species of rat. All exotic rats compete with native mice and rodents for food and shelter, but the black rat is noted for significantly affecting the endangered Key Largo woodrat (Neotoma floridana smalli).

Ecosystem’s endangered species
The Florida panther is an endangered subspecies of cougar (Puma concolor) that lives in forests and swamps of southern Florida in the United States. The Florida panther has been protected from legal hunting since 1958, and in 1967 it was listed as endangered by the U.S. Fish and Wildlife Service; it was added to the state's endangered species list in 1973. It continues to be one of the most intensively and expensively protected felines, mostly because there are so few left. In the 1970s, there were an estimated 20 Florida panthers in the wild, and their numbers have increased to an estimated 100 to 160 as of 2012.
The Red-cockaded Woodpecker has been the focus of conservation efforts even before the passing of the Endangered Species Act in 1970. Due to the high importance of nesting habitat on the woodpecker's reproduction, much management has been dedicated to create ideal and more numerous nesting sites. Nesting clusters have been spared from forestry activity to preserve old-growth, large diameter trees. The nesting sites themselves have also been managed to make them more appealing. The use of controlled burning has been used to reduce deciduous growth around nesting colonies. The red-cockaded woodpecker has been shown to prefer nesting sites with less deciduous growth. The use of controlled burning must be exercised with caution due to the highly flammable resin barriers formed by the woodpecker. In an effort to increase the Red-cockaded Woodpecker population, states such as Texas, Louisiana, and Georgia's wildlife management are creating artificial cavities in Longleaf Pine trees. There are two methods in which wildlife management officers use to insert cavities in long leaf pines. The most respected and latest approach is to carve out a nesting cavity in the tree and insert a man-made nest. The older and less used approach is to drill a cavity into the tree in hopes that the birds will settle there and nest. In addition to the creation of new cavities, methods for protecting existing cavities are also used. The most common technique employed is a restrictor plate. The plate prevents other species from enlarging or changing the shape of the cavity entrance. These restrictor plates must be carefully monitored, however, to ensure that no hindrance is given to the woodpecker. Adjustments must also be made as the tree grows.