Causes of Marine Life Extinction
Animal and plant life has thrived on Earth for thousands of years, encompassing both terrestrial and marine species. Marine life can be defined as the diverse range of plants, animals, and other organisms that inhabit aquatic environments such as oceans and seas. This includes plankton, algae, seagrasses, coastal mangroves, various species of fish, seals, dolphins, sea turtles, whales, sharks, otters, and countless other living beings.
The extinction of numerous terrestrial and marine species can be attributed to several factors. Here are some of the primary contributors to the decline in marine life:
Climate Change
Climate change stands out as one of the most significant threats to marine ecosystems. The phenomenon of global warming has altered the Earth’s climate patterns, resulting in increased temperatures, melting glaciers, and rising sea levels. This temperature rise not only causes coral bleaching but also threatens the survival of coral reefs, which serve as crucial habitats and food sources for numerous marine organisms.
Overfishing
Overfishing is a critical factor in the depletion of marine life. This practice refers to catching fish at a rate that exceeds their reproductive capacity, leading to a decline in populations such as the Atlantic bluefin tuna and grouper. Consequently, overfishing jeopardizes these species and also disrupts the breeding of other fish, such as sardines. This decline can have detrimental effects on the socio-economic well-being of coastal communities that rely on fishing for their livelihoods.
Marine Pollution
Marine pollution represents another major cause of marine life extinction. This type of pollution, which contaminates ocean and sea waters, can originate from land-based sources such as littering on beaches that is subsequently washed into the ocean during high tides. Additionally, pollution can result from activities at sea, including oil spills from ships. These contaminants pose severe risks, leading to toxicity in marine organisms, resulting in death and reduced population numbers.
Illegal Fishing and Trade
Illegal fishing for commercial purposes, targeting the meat and eggs of marine animals, is a significant driver of marine life extinction. Notable examples include the poaching of sea turtles in Costa Rica, shark fishing in the Galapagos Islands, and the illegal capture of crabs in Russia—all of which involve species that are critically endangered.
Endangered Marine Species
A multitude of marine species has faced extinction, either already lost thousands of years ago or declining in recent times. A number of marine organisms are currently at risk of extinction, including:
- The dugong (sea cow).
- Bluefin tuna.
- Coral reefs.
- Gray whales.
- Krill.
- Leatherback sea turtles.
- Manatees.
- The steller’s sea cow.
- Hector’s dolphin.
- Napoleon wrasse.
- Mediterranean monk seals.
- Chinook salmon.
- Gharial crocodiles.
- Vaquita.
- Southern sea otters.