Throughout the 20th century, marine life is being threatened at an increasing rate. Fish harvesting off coastal waters has dropped at a startling rate due to a variety of human activities that result in habitat loss, unsustainable fishing and water pollution. Despite the U.S. having strong fishery laws, of the 267 major fish stocks, roughly 17% are not being fished sustainably. Not only that, according to the U.N Food and Agriculture Organization, 85 percent of global fish stocks are "overexploited, depleted or recovering from depletion." Many scientists, such as Daniel Pauly of the University of British Columbia, have estimated that the total fish catch for the planet peaked back in the mid-1980s, and has been declining ever since. If there is no action taken against the decline of marine life, what will the oceans ecosystem look like in 50 years, if there even is one?
Most scientists studying this issue agree that the three primary causes of the crisis are plastic pollution, anthropogenic climate disruption, and overfishing. But several, like Dr. Simon Boxall, an associate professor of oceanography with the University of Southampton, blames overfishing more than the others. "The big problem is that we are overfishing," Boxall said. Gathering as many fish as possible may seem like a profitable practice, but overfishing has major consequences. The results not only affect the balance of life in the oceans, but also the social and economic well-being of the communities who depend on fish for their way of life. Millions of people rely on fish as their protein, and people act as if the sea has a limitless amount. However, over the past 50 years the increase of impulsive fishing practices has pushed countless fish stocks to the edge. “More than 85 percent of the world's fisheries have been pushed to or beyond their biological limits and are in need of strict management plans to restore them,” (Overfishing).
One of the main problems of overfishing is the easy and open access nature fisheries have. Not only that, fisheries have poor management. Present regulations and rules aren’t strong enough to limit fishing capacity, and traceability is too difficult to manage. Another key dimension to this crisis is illegal, and unreported fishing. This illegal practice accounts for an estimated 20-50% of the world’s catch. Illegal fishing rates are so high due to the booming pay stub, “The costs of illegal fishing are significant, with the value of pirate fish products estimated at between $10-23.5 billion annually,” (Overfishing). Many fishers are aware of the need to safeguard the marine environment and fish populations, but illegal fishing and other problems still exist.
Since modern industrial fishing became global, populations of all large predator fish in the oceans have gone down by 90 percent in the past 50 years, according to a shocking paper by scientists with Dalhousie University in Halifax, Canada, published in Nature in 2003. Scientists report that 90 percent of large fish, such as swordfish and tuna, have been taken from the ocean through fishing. “Several important commercial fish populations have declined to the point where their survival as a species is threatened. Target fishing of top predators, such as tuna and groupers, is changing marine communities, which lead to an abundance of smaller marine species, such as sardines and anchovies,” (Overfishing). Many people do not realize that once certain species start decline, the whole balance of the ocean becomes disrupt. Although overfishing plays a key dimension on why fish population is plummeting, there is evidence that shows the oceans have suffered at the hands of mankind more hundreds of years.
Pollution comes in many forms. Recent studies show that degradation has accelerated immensely in the past three hundred years as runoff from farms, industrial discharge, and coastal cities has increased. Many ocean pollutants are released into the environment far upstream from coastlines. The most common man-made pollutants that reach the ocean include herbicides, chemical fertilizers, pesticides, plastics, oil, sewage, detergents, and other solids. “These excess nutrients can spawn massive blooms of algae that rob the water of oxygen, leaving areas where little or no marine life can exist,” (Marine Pollution 2010). Scientists have counted close to 400 such dead zones around the world. Solid waste like soda/beer can plastic ties, bags, foam, and other forms of waste dumped into the ocean at sea are frequently consumed by marine life. Species like sea turtles, fish, marine mammals, and birds mistake most solid waste for food. Solid waste dumping can result in many fatal attacks, mostly due to suffocating. “High concentrations of plastic material, particularly plastic bags, have been found blocking the breathing passages and stomachs of many marine species, including whales, dolphins, seals, puffins, and turtles,” (Marine Pollution 2010). Although pollution is dumped into our oceans in a physical form, there are other forms of pollution that people cannot physically see.
Pollution is not always physical. The increased presence of loud or sharp sounds from ships, oil rigs, and sonar devices disrupt the communication, migration, hunting, and reproduction patterns of many marine animals, particularly marine mammals like dolphins and whales. “Spin-off technologies from the cold war—sonar, satellite data and the Global Positioning System (GPS)—have led to an unprecedented decline in fish stocks worldwide, according to a study led by researchers at the University of British Columbia (UBC) in Vancouver, Canada,” (Trivedi). With these military technologies, fishermen now have the ability to locate schools of fish in the sea as if they were searching for the closest grocery store in an unfamiliar town. This technology has also made it possible for fishermen to guide their nets around sea mountains, drop them into the deep abyss, and navigate almost every obstacle in the ocean as if it was a computer game at home. GPS, sonar, and satellite data seems to be profitable and trouble-free technology, but in reality, it is extremely dangerous and leading fish to be depleted one by one. Even though mankind has played a major role in the decline of fish, there are problems bigger than we can control.
Climate change places a larger effect on our oceans ecosystems than most people know. Increased water temperature leads to less oxygen for aquatic organisms, increased acidity, and calcification that results in the entire marine food chain being altered. Recently, a new study in the journal Global Change Biology found that warming ocean temperature could stunt the growth of fish by as much as 30 percent. As Nexus Media explains, “fish are cold-blooded animals and therefore cannot regulate their own body temperatures. So as oceans heat up, a fish’s metabolism accelerates to cope with the rising temperatures and they need more oxygen to sustain their body functions. But fish gills do not grow at the same pace as the rest of their body, resulting in a decline of oxygen supply and in growth,” (Yale 2017). Studies found that for every one degree Celsius of ocean warming, active fish such as tuna can shrink up to 30 percent, while more sluggish fish would only shrink up to 18 percent. In long-term, the decline of fish size could reduce commercial fish harvest by up to 3.4 million tons for each degree of warming.
The world must do more to sustainably manage fishing if we’re to address increasing global demand for protein in the coming decades. If the situation doesn’t improve, millions of people may no longer be able to afford fish by 2050 according to a new report from WWF Germany. “More than 3 billion people get at least 20% of their animal protein from fish. On top of that, roughly 500 million people depend on the fishing industry for work and a pay check,” (World Wildlife Fund 2017). There are ways the reverse the downward trend, we need to consume more wisely, produce better, and preserve the ocean. If this trend continues to spiral, we may lose even more of the oceans population, “A new report on the health of the ocean finds that the marine vertebrate population has declined by 49 percent between 1970 and 2012,” (World Wildlife Fund 2017).