How does endangered species affect the environment

A team of conservation biologists led by Dr. Matthais Leu recently studied how trends in threats leading to species endangerment have changed over time.

The study, published in Conservation Science and Practice in , found that endangered species face more threats now than ever before. The researchers recommended steps to bolster the ESA, such as more detailed analysis for listing species, increased funding, and improved collaborative efforts across public and private sectors.

It has been successful in bringing iconic animals like the bald eagle, the grizzly bear, and the gray wolf back from the brink of extinction.

Under the new rules, protections for newly-listed threatened species are determined on a case-by-case basis. Second, the changes relax the requirements under which a species can be removed from the ESA, making it easier for a species to lose protection before it has recovered to a healthy population size. This change undermines the ultimate purpose of the ESA: to recover imperiled species. Third, the new rules allow federal agencies to consider economic impacts, such losses to private companies, when deciding if a species should be listed as threatened or endangered under the Act.

Federal agencies formerly relied exclusively on scientific evidence and were prohibited from considering economic impacts in listing decisions. Now, the inclusion of economic analyses will likely lead to fewer species listings. Fourth, and perhaps most inconsistent with the relevant science, the revisions enable federal agencies to ignore climate change when formulating protections for specific species.

As a conservation law, the ESA operates to preserve ecosystem services — the benefits humans gain from healthy and functioning ecosystems — in addition to individual species. Ecosystems are complex, and the contribution of the many different species inhabiting them are crucial to ensure their continued functioning. Changes in biodiversity from the loss of rare species can alter ecosystems and the services they provide.

A team of researchers led by Dr. Laura Dee found that rare species often play crucial yet unknown roles in the ecosystems where they live. Sea otters, for instance, keep sea urchin populations in check so that kelp forests are able to grow and provide habitat for numerous fish and marine mammals.

In such cases, rare species may fill unique functional roles that directly affect the ecosystem or indirectly influence other species in that environment.

Rare species may also provide medicinal benefits that scientists have yet to discover. The value of species like rare horsetails, a plant that grows in Alaska shrub wetlands and makes nutrients in the soil available to other species, are often not well understood. Studying each individual species within an ecosystem, however, is not possible or practical. The researchers argue that losing rare species can have a much greater effect on an ecosystem than expected and may not be realized until the species is already lost.

Understanding the role of rare species in an ecosystem is even more difficult in a changing climate. Habitat destruction is the primary factor that threatens species. The second major factor causing species decline is the introduction of nonnative species. Other factors affecting species decline include hybridization, competition, disease, and other interspecific interactions.

Once a species is reduced to a remnant of its former population size and distribution, its vulnerability to catastrophic pollution events increases, frequently exceeding or replacing the factors responsible for the initial decline.

Small, isolated populations are particularly vulnerable to catastrophic loss by an acute event. However, when it comes to surviving a single disaster, widespread subpopulations of a species are far more resilient and ensure genetic survival. Hypothesizing theoretical concerns of potential factors that could affect an endangered species could predispose the scientific and political communities to jeopardizing threats.

The user of recovery plans as a data source must be aware of the bias within the data set. Through consumption and digestion, elephants disperse more seeds farther than any other animals; this fosters the growth of plants and trees that birds, bats and other animals depend upon for food and shelter.

Photo: Johnny and Rebecca. Elephants also dig water holes that all animals share, and they fertilize the soil with their rich dung, which provides food for other animals. The loss of apex species can also affect wildfires.

After rinderpest, an infectious virus, wiped out many plant-eating wildebeest and buffalo in East Africa in the late s, plants flourished.

During the dry season, this over-abundance of vegetation spurred an increase in wildfires. In the s, after rinderpest was eliminated through vaccinations, the wildebeest and buffalo returned.

The ecosystem went from shrubbery to grasslands again, decreasing the amount of combustible vegetation, and the wildfires decreased. The loss of pollinators could result in a decrease in seed and fruit production, leading ultimately to the extinction of many important plants.

Flying foxes, also known as fruit bats, are the only pollinators of some rainforest plants. They have been over-hunted in tropical forests with several species going extinct.

One study noted that plant species, including eucalyptus and agave, rely on flying foxes to reproduce; in turn, these plants were responsible for producing valuable products. Bees pollinate over , species of plants, including most of the 87 crops that humans rely on for food, such as almonds, apples and cucumbers.

Over the last 20 years in the U. The rusty-patched bumble bee, another important pollinator and the first bee species to be put on the endangered list, now only occupies one percent of its former range. Insect populations overall are declining due to climate change, habitat degradation, herbicides and pesticides.

A review of insect studies found that most monitored species had decreased by about 45 percent. And a German study found 75 percent fewer flying insects after just 27 years. As insect populations are reduced, the small animals, fish and birds that rely on them for food are being affected, and eventually the predators of fish and birds will feel the impacts as well.

One entomologist who had studied insects in the rainforest in the s returned in to find an up to fold reduction. Plankton, tiny plant and animal organisms that live in the ocean or fresh water, make up the foundation of the marine food chain.

Phytoplankton are critical to the health of oceans and the planet because they consume carbon dioxide and produce oxygen during photosynthesis. In , researchers found that phytoplankton had decreased 40 percent globally since , and attributed the decline to rising sea surface temperatures. The scientists speculated that the warming surface waters did not mix well with the cooler, deeper waters rich in nutrients that phytoplankton need.

In addition, zooplankton are very sensitive to slight changes in the amount of oxygen in the ocean, and may be unable to adapt as areas of low oxygen expand due to climate change. The quantity and quality of plankton also affects the nutrition of other creatures further up the food chain. In the Mediterranean Sea, the biomass of sardines and anchovies declined by one-third in just ten years.

Changes in plankton quality could be a result of water temperature, pollution or lack of nutrients, but scientists are not exactly sure why the plankton makeup in some places is changing. If it is due to global warming and pollution, some say the situation could worsen. A different community composition of phytoplankton could change the food web structure, but Dyhrman is not really worried about the total collapse of fisheries.

What will the architecture of that ecosystem look like in the future? More than a quarter of prescription medications contain chemicals that were discovered through plants or animals. Penicillin was derived from a fungus. One molecule from a rare marine bacterium could be the basis of a new way to treat to melanoma.

Scientists have so far identified about 1. Twenty-five percent of Western medicines are derived from the rainforest. Photo: Tristan Schmurr. Who knows what substances or capabilities some of these species might possess that could help treat diseases and make human lives easier? According to a study for the U.