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. Already, a number of industries have been economically impacted by species loss.
Atlantic cod in the waters off of Newfoundland formed the basis of the local economy since the 15 th century — until overfishing the cod destroyed the livelihoods of local fishermen. Extinction is hard to see.
Past generations would regard what we see as natural today as terribly damaged, and what we see as damaged today, our children will view as natural. Wooddell believes the most important thing one can do is to put pressure on Congress and elected leaders to create land management, pollution and other sustainable policies that will protect biodiversity and the environment.
A tortoise shell mirror Photo: Housing Works. Correction: This post was updated on April 3, to remove a sentence about cownose rays devastating scallop populations off of North Carolina. It turns out that other studies have challenged those findings. The Trump administration has put forth new rules that will significantly weaken the Endangered Species Act. What happened when something like the Dodo went extinct? When I think about extinction, I always wonder what would have happened if the dinosaurs had not become extinct.
I am late to the discussion about keystone species but since I have learned about the roles of these key animals to specific environments around the world I have tried and failed to see homo sapiens as a keystone species but rather I see us more like the ungulates, which when left unchecked by a corresponding predator, such as the wolf in the Yellow Stone Park scenario, would decimate any environment we occupy.
We are overpopulating, over consuming, over producing items that are harmful to the entire world such as plastics and what will keep us in check? Who will be our wolves? If humans disappeared from the earth, just suddenly vanished, I think the earth and all her flora and fauna would recover quickly.
Our intelligence should curb our avarice, but I fear we are too shortsighted and too quick to rationalize away the science which spells out the looming disaster brought on my our ignorance and greed. Endangered species are important. Fisheries management, however, has been outpaced by our population growth, causing global fisheries to collapse under the unsustainable pressure. A assessment found that 80 percent of global fish stocks are either overly and fully exploited or have collapsed.
Though a catch reduction of percent is needed to make global fisheries sustainable, the demand for fish is expected to increase by 35 million tons by Of greatest concern is the western Atlantic bluefin tuna that spawns in the Gulf of Mexico and has declined by more than 80 percent since due to overharvesting.
Prized as a sushi fish around the world, it has become more valuable as it has become rare. The large, warm-blooded bluefin tuna is a common, upscale sushi menu item and has been severely overfished. The Atlantic bluefin, like so many other ocean species, is threatened by humans' ravenous appetites: Demand far exceeds sustainable fishing levels.
Loggerhead sea turtle : More than half the world's 7. Among them is the loggerhead sea turtle, which was listed as a federally threatened species in owing to destruction of its beach nesting habitat, harassment while nesting, overharvesting of its eggs, and bycatch death via commercial fishing gear. Ninety-five percent of the U. Thanks to careful management, the species' population increased 24 percent from to , but under intense pressure from development and recreational beach use, it declined dramatically thereafter, raising concerns it should be uplisted to endangered status.
The population has increased in recent years, but is still highly vulnerable to nesting habitat destruction and disruption. Just 42, nesting attempts were made on Florida beaches in Sandplain gerardia : As the human population has increased, it has consumed remote landscapes with houses and other structures. The natural disturbances caused by fire, flood, drought and storm patterns, are suppressed despite playing essential roles in ecosystem health. In conflict with the permanence of human development, these disturbances create an ever-changing blend of meadow and forest, young and mature vegetation patterns.
By controlling, limiting and often stopping these essential natural processes, we have changed ecosystems across America, eliminating habitat for rare and endangered species that depend on open habitats.
In New England and the Atlantic coast, brush fires once thinned out dense pine forests and created a constantly moving mosaic of grasslands and prairies. The fires have been suppressed to protect human structures, causing open habitats to be permanently replaced by forest and brush.
This nearly caused the extinction of the sandplain gerardia, a coastal plant in the snapdragon family. Lange's metalmark butterfly : Many endangered species are endemics, meaning they naturally have very small ranges and populations sizes, and usually require very particular soil, vegetation or climate conditions to survive. Human Influences on the Temperate Rainforest. The Effects of Animal Overpopulation. Impacts of Genetic Engineering on Biodiversity. How to Conserve Plants and Animals.
Endangered Species in the European Deciduous Forest. Why Are Jaguars Endangered Animals? Tasmanian Devil Facts for Kids. Loss of Individuality Due to Genetic Engineering. What Eats or Kills a Tasmanian Devil? Disease is much more common, and much more deadly, among inbred groups. Inbred species do not have the genetic variation to develop resistance to the disease. For this reason, fewer offspring of inbred groups survive to maturity.
Loss of genetic variation can occur naturally. Cheetah s are a threatened species native to Africa and Asia. These big cat s have very little genetic variation. Biologist s say that during the last ice age , cheetahs went through a long period of inbreeding. As a result, there are very few genetic differences between cheetahs. They cannot adapt to changes in the environment as quickly as other animals, and fewer cheetahs survive to maturity.
Cheetahs are also much more difficult to breed in captivity than other big cats, such as lions. Human activity can also lead to a loss of genetic variation. Overhunt ing and overfish ing have reduced the populations of many animals.
Reduced population means there are fewer breeding pairs. A breeding pair is made up of two mature members of the species that are not closely related and can produce healthy offspring. With fewer breeding pairs, genetic variation shrinks. Monoculture , the agricultural method of growing a single crop , can also reduce genetic variation.
Modern agribusiness relies on monocultures. Almost all potatoes cultivate d, sold, and consumed, for instance, are from a single species, the Russet Burbank. Potatoes, native to the Andes Mountains of South America, have dozens of natural varieties.
The genetic variation of wild potatoes allows them to adapt to climate change and disease. For Russet Burbanks, however, farmers must use fertilizer s and pesticides to ensure healthy crops because the plant has almost no genetic variation. Plant breeders often go back to wild varieties to collect genes that will help cultivated plants resist pests and drought, and adapt to climate change. However, climate change is also threatening wild varieties.
That means domesticated plants may lose an important source of traits that help them overcome new threats. The Red List has seven levels of conservation: least concern, near threatened, vulnerable, endangered, critically endangered, extinct in the wild, and extinct. Each category represents a different threat level. Species that are not threatened by extinction are placed within the first two categories—least concern and near-threatened.
Those that are most threatened are placed within the next three categories, known as the threatened categories —vulnerable, endangered, and critically endangered.
Those species that are extinct in some form are placed within the last two categories—extinct in the wild and extinct.
Classifying a species as endangered has to do with its range and habitat, as well as its actual population. For this reason, a species can be of least concern in one area and endangered in another. The gray whale, for instance, has a healthy population in the eastern Pacific Ocean, along the coast of North and South America. The population in the western Pacific, however, is critically endangered. Least Concern Least concern is the lowest level of conservation.
A species of least concern is one that has a widespread and abundant population. Human beings are a species of least concern, along with most domestic animal s, such as dogs and cats.
Many wild animals, such as pigeons and houseflies, are also classified as least concern. Near Threatened A near threatened species is one that is likely to qualify for a threatened category in the near future. Many species of violet s, native to tropical jungle s in South America and Africa, are near threatened, for instance. They have healthy populations, but their rain forest habitat is disappearing at a fast pace.
People are cutting down huge areas of rain forest for development and timber. Many violet species are likely to become threatened. Vulnerable Species The definitions of the three threatened categories vulnerable, endangered, and critically endangered are based on five criteria: population reduction rate, geographic range, population size, population restrictions, and probability of extinction.
Threatened categories have different threshold s for these criteria. As the population and range of the species decreases, the species becomes more threatened. This decline is measured over 10 years or three generations of the species, whichever is longer. A generation is the period of time between the birth of an animal and the time it is able to reproduce. Mice are able to reproduce when they are about one month old.
Mouse populations are mostly tracked over year periods. An elephant's generation lasts about 15 years. So, elephant populations are measured over year periods. A species is vulnerable if its population has declined at least 50 percent and the cause of the decline is known.
Habitat loss is the leading known cause of population decline. A species is also classified as vulnerable if its population has declined at least 30 percent and the cause of the decline is not known. A new, unknown virus, for example, could kill hundreds or even thousands of individuals before being identified. An area of occupancy is where a specific population of that species resides. This area is often a breeding or nesting site in a species range.
The species is also vulnerable if that population declines by at least 10 percent within 10 years or three generations, whichever is longer. A species is vulnerable if it is restricted to less than 1, mature individuals or an area of occupancy of less than 20 square kilometers 8 square miles. These formulas calculate the chances a species can survive, without human protection, in the wild.
Vulnerable Species: Ethiopian Banana Frog The Ethiopian banana frog Afrixalus enseticola is a small frog native to high- altitude areas of southern Ethiopia. It is a vulnerable species because its area of occupancy is less than 2, square kilometers square miles. The extent and quality of its forest habitat are in decline. Threats to this habitat include forest clearance, mostly for housing and agriculture.
Vulnerable Species: Snaggletooth Shark The snaggletooth shark Hemipristis elongatus is found in the tropical , coastal waters of the Indian and Pacific Oceans.
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