Population Effect on Marine Life

Population Effect on Marine Life

Oceans and marine life have been an integral part of human existence since time immemorial. All kinds of human activity directly impact marine life and its health. From food and medicine to providing job opportunities to humans, we depend on it for our survival. There are almost 3 billion people in the world who live within 200 km of a coastline. This figure might double in the next few years. In simple terms, it means that the economic and technological development of human beings is threatening marine ecosystems. A report from the World Wildlife Fund (WWF) has found that there has been a 50% decrease in marine life populations between 1970 and 2012. We have pushed oceans to their limits and any change in their ecosystems means it’s harder for marine life to survive and flourish. Overfishing has been a global problem for some time now and according to the WWF report, populations of tuna and mackerel have declined by 75%, while the Bluefin tuna is almost extinct in the Pacific.

The Pacific Ocean is a great case study if one wants to look at the impact of the human population on marine life. Owing to fewer regulations in Asia, activities such as “shark finning” are impacting the shark population in the Pacific Ocean. The shark fins are removed while its body is thrown back into the waters. Shark-fin soup fans don’t know that if we continue to fish the way we are doing right now, in 10 years, 25% of the shark species could be extinct. Experts estimate that 80% of all trash that is found in the seas comes from land. A Great Pacific Garbage Patch has been formed in the North Pacific Gyre, an area that’s largely free of ocean currents. Millions of tons of plastic are swirling around collected in a space that’s twice the size of Texas.

The ratio of plastic to plankton in the water here is 46:1, which means that fish are feeding on tiny pellets of plastic that they assume is food. With 250,000 metric tons of plastic in the oceans, another concern is that small fish are harmed, which in turn harm the bigger fish that feed on them. Plastic suffocation has been taking too many lives in the waters already. A quarter of the entire marine life lives on coral reefs and much depends on it. The loss of coral reefs will impact humans directly. As our population grows more than 7 billion, marine life has come under intense pressure as 15% of animal protein consumed by humans is fish. We end up overharvesting to meet the growing demand for seafood. As our numbers grow, our production of waste also grows and that means further pollution of marine life. A 2009 UN assessment of the state of commercial fisheries around the world found that most (almost 80 percent) of fish stocks are either fully exploited or overexploited, and there’s a need for precautionary management. The population of all large predatory fish is on the decline overall.

Out of 21 marine species that we know have been driven to extinction in the last 300 years, 16 of them belong to the period after 1972. As tuna and mackerel are popular among humans, there has been a 74% drop in their populations. Another recent study by University of British Columbia researchers found that the predatory fish biomass in the oceans is down by two-thirds in the last 100 years, and this decline is getting faster, with 54% of it happening in the last 40 years. When we disrupt or break the marine food chain, we not only harm marine life, we also harm ourselves. The rapid economic development of many coastal areas around the world has been negative for the health of marine life. The human race is suffering already because of climate change but what we fail to take note of is that these disasters have affected marine life strongly too. As WWF International Head Marco Lambertini said, "Human activity has severely damaged the ocean by catching fish faster than they can reproduce while also destroying their nurseries." As we participate in climate change activities, oceans and marine life bear the brunt of it. The waters absorb more heat and carbon dioxide, which means warmer and more acidic oceans. Marine life has to either adapt or die. In the 20th century, we witnessed that nearly half of the world’s wetlands vanished, along with 50% of all mangroves. Island countries are suffering the most as they see a rise in sea levels and pollution of the waters.

Tourism also affects marine life negatively owing to unsustainable coastal development. Deforestation and damming rivers lead to further deterioration of marine life. From using pesticides and chemicals in coastal areas to throwing all waste in the seas, our growing population is making our oceans and seas uninhabitable. As we can see, some of the damage that’s already been done cannot be reversed. But not all of it. We can still control the damage and even help some species rebound. It is imperative to improve fishing practices, protect marine habitat and work on reversing climate change if we want lasting results.

We all need to work together to control population growth and find sustainable ways to depend on marine life for survival. In many countries, coastal zone managers are appointed to search for integrated, multidisciplinary approaches to resource management. An internationally-accepted approach, known as the Integrated coastal management (ICM), helps policymakers in including population figures when researching on threats and opportunities facing coastal areas. This method is based on the United States’ 1972 Coastal Zone Management Act.

Many countries are also using something called Marine Protected Areas (MPAs) to rope off certain sections to let marine wildlife recover. The Endangered Species Act has been not just been saving whales, turtles, and sea otters from extinction, but it has also helped in increasing their population. Countries like the US, which are world players, play a crucial role in reversing the negative effects of the human population on marine life. We depend on marine life for our survival and we must keep it healthy and thriving.