Moreover, in the sunflower starfish, which also eats purple sea urchins, began dying because of a virus that was likely exacerbated by warmer waters. Without the sea otter and the sunflower starfish predators, the purple sea urchin began feasting on the kelp forests, which declined 93 percent between and A new study found that kelp forests are now also threatened by ocean heat waves.
Fish that need the kelp forests for spawning, such as sculpin, rock cod and red snapper may become vulnerable in the future as well. And Guam is covered in spiders because the birds are not there to eat them. These large species are more vulnerable because they live longer, reproduce more slowly, have small populations, and need more food and a greater habitat area. Scientists say their loss has played a role in pandemics, fires, the decline of valued species and the rise of invasive ones, the reduction of ecosystem services, and decreased carbon sequestration.
Elephants are an apex species that may go extinct in our lifetime, as a result of tourism, habitat loss and poaching for ivory.
This could dramatically change ecosystems in Africa and Asia. 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. Unfortunately, for the animals, these encounters often led to their extinction. Not used to running away from predators, they were easy prey to hungry sailors. Explorers also brought along their ship rats, pigs, and cats, which ate the eggs of flightless birds laying on the ground.
But how bad was it? What are the consequences of these extinctions? And can we identify what animals or islands are most at risk? Read More: Did inbreeding and poor health kill the mighty mammoth? First off, it is not only the animals themselves that are affected. The extinction of island animals in turn affects the plants that co-exist on these islands.
This is because many birds, mammals, and reptiles perform a vital service to the plants by eating their fruits, which contain seeds. After a while, these seeds will come out again and land somewhere else. This is how many plants move between different areas and make sure their little seeds can grow up in a good spot. If there are no animals left to spread seeds, the plants are at risk of becoming extinct themselves.
An island without animals and plants would be a lot less exciting than what the early explorers encountered. Read More: Mass extinction 66 million years ago paved the way for modern shark communities. In our research, we wanted to know just how bad the situation was for fruit-eating animals on islands across the world.
Were some animals more likely to go extinct then others? Have there been more extinctions on certain types of islands? Together with my colleagues Daniel Kissling and Emiel van Loon from the University of Amsterdam, and Dennis Hansen from the Zoological Museum of Zurich, we investigated data from 74 islands across the world.
We wanted to get the full picture, so we looked at all of the birds, mammals, and reptiles that eat fruit. We also included animals that have recently become extinct. We checked to see whether the island size and remoteness could explain differences between the numbers of extinctions that we found. Then, we compared characteristics between the animals that had gone extinct with those that survived, such as differences in their weight and whether or not they can fly.
Many large animals that eat fruit birds, tortoises, lizards, bats have gone extinct on islands. The remaining small animals cannot swallow and disperse the largest fruits and those plants are now at risk of extinction too. This has cascading effects: More elk means more pressure on aspen trees and their other food sources. Fewer elk being killed by predators means fewer carcasses for scavenging species. These ecosystem changes have a real human cost as well.
Tourism is a significant contributor to the economies of all these countries. In South Africa —the lowest of the four—it accounts for nearly 10 percent. In Namibia on the other end of the spectrum, tourism comprises almost 15 percent of its GDP. Tourism directly supports nearly 1 million jobs in these four countries.
Indirectly, the industry supports double that, including 19 percent of all jobs in Namibia, according to data from the World Travel and Tourism Council. Large fauna, including the black rhino, are a primary draw for the millions of tourists that visit these countries. Losing these animals could stem the flow of tourists, not only putting existing jobs at risk, but also potentially leaving these workers with less environmentally friendly job options.
Without reliable tourism jobs, some people turn to poaching, a dangerous but lucrative way to support their families. Just as the fate of the black rhino affects the world, the rhinos themselves are not insulated from people who may never set foot in their current or historic habitat.
Rhino horn is a purportedly powerful ingredient in traditional medicine from Malaysia to South Korea. Traditional Chinese medicine credits rhino horns with curing fevers and improving function.
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