in the
Gulf of Mexico. Increasing human populations have resulted in increased human impact on ecosystems. Human activities has resulted in an increased extinction rate of species which has caused a major decrease in biological diversity of plants and animals in our environment. These impacts include increased pressure from fisheries including reef degradation and
overfishing as well as pressure from the tourism industry which has increased over the past few years. The deterioration of coral reefs is mainly linked to human activities – 88% of reefs are threatened through various reasons as listed above, including excessive amounts of CO2 (
carbon dioxide) emissions. Oceans absorb approximately 1/3 of the CO2 produced by humans, which has detrimental effects on the marine environment. The increasing levels of CO2 in oceans change the seawater chemistry by decreasing the
pH, which is known as
ocean acidification.
Oil spills also impact marine environments, contributing to
marine pollution as a result of human activity. The
effects of oil on marine fish have been studied following major spills in the United States. Shipping is a major vector for the introduction of exotic marine species, some of which can become overabundant and transform ecosystems. Collisions with
ships can also be fatal for whales and can impact on the viability of whole populations, including the
right whale population off the east coast of the United States.
Coral reefs scuba diver surveying bleached corals.
Coral reefs are the epicenter of immense amounts of
biodiversity and are a key player in the survival of entire ecosystems. They provide various marine animals with food, protection, and shelter which keep generations of species alive. Furthermore, coral reefs are an integral part of sustaining human life through serving as a food source (i.e., fish and mollusks) as well as a marine space for
ecotourism which provides economic benefits. Also, humans are now conducting research regarding the use of corals as new potential sources for pharmaceuticals (i.e. steroids and anti-inflammatory drugs). Because of the
human impact on coral reefs, these ecosystems are becoming increasingly degraded and in need of conservation. The biggest threats include
overfishing, destructive fishing practices, sedimentation, and pollution from land-based sources. This, in conjunction with increased carbon in oceans, coral bleaching, and diseases, means that there are no pristine reefs anywhere in the world. Up to 88% of coral reefs in Southeast Asia are now threatened, with 50% of those reefs at either "high" or "very high" risk of disappearing, which directly affects the biodiversity and survival of species dependent on coral. This perpetuation of bad habits simply leads to the further decline of coral reefs and therefore perpetuates the problem. One way of stopping this cycle is by educating the local community about why the conservation of marine spaces that include coral reefs is important.
Overfishing (IUU) being prevented by a Japanese fisheries patrol.
Overfishing is one of main causes of the decrease in the ocean's wildlife population over the past years. The
Food and Agriculture Organization of the United Nation reported that the percentage of the world's fish stocks that are at biologically sustainable levels have decreased from 90% in 1974 to 65.8% in 2017. The overfishing of these large fisheries destroys the marine environment and threatens the livelihood of billions who depend on fish as protein or as a source of income for catching and selling. According to the
World Wildlife Fund, illegal, unreported, and unregulated fishing is a major factor in overfishing.
Illegal fishing is estimated to account for up to 30% of the catch for some high-value species, and the industry is estimated to be worth $36 billion per year. According to
The Hidden Nursery: How Baby Great White Sharks Are Revitalizing New York’s Marine Ecosystem, while the great white sharks baby population is increasing from New York City to the tip of Long Island, recent overfishing has started to cause the young vulnerable sharks to swim into dangerous waters off Martha Vineyard and Cape Cod where adult Great Whites are picking them off before they can mature. If Overfishing continues, we may see a population drop again soon.
Overabundance Overabundance can occur when the population of a certain species cannot be controlled naturally or by human intervention. The domination of one species can create an imbalance in an ecosystem, which can lead to the demise of other species and of the habitat. Overabundance occurs predominately among
invasive species. Overfishing can contribute to overabundance due to eliminating an ecosystem's natural predator. This disrupts the natural food chain and allows species to grow without regulation. Not only does this create overpopulation with specific species, but it also makes changes within the structure of the environments ecosystem. Once established, it is difficult to eradicate an exotic organism from an ecosystem. The
San Francisco Bay is one of the places in the world that is the most impacted by foreign and invasive species. According to the Baykeeper organization, 97 percent of the organisms in the San Francisco Bay have been compromised by the 240 invasive species that have been brought into the ecosystem. Invasive species in the bay such as the
Asian clam have changed the food web of the ecosystem by depleting populations of native species such as plankton. The Asian clam clogs pipes and obstructs the flow of water in electrical generating facilities. Their presence in the San Francisco Bay has cost the United States an estimated one billion dollars in damages. Conservation practices have been put in place in order to address these invasive species. In order to diminish the impact humans have had to the environment, countries established stronger policies and regulations, particularly within their shipping practices like ballast water discharge. These practices can allow non-native species to disperse into new environments and disrupt the already established ecosystems. == Extinct and endangered species ==