Why Oceans

Basically, overfishing means taking too many fish out of the seas before new fish can reproduce to replace the ones that were caught. Worldwide, 90% of large predatory fish stocks are gone due to overfishing. The United Nations predicts that if current trends continue, global fish stocks may be extinct by the year 2048.

The depletion of fish stocks means a risk of losing a valuable food source that many people depend on for economic and dietary reasons. Nearly two-thirds of the world’s population relies on fish for 40% of their protein, and about 13 million people depend on fishing for all or most of their incomes.

While individuals cannot solve this global problem of overfishing without the help of international policymakers, it’s still critical to make change where we can. Our power lies in our consumption choices. Each time you use a dollar, you are voting. With each dollar spent or withheld, you support an industry or help bring one to an end.

If you must eat seafood, try to consume species that are non-threatened and sustainably farmed or harvested. If you are buying seafood, it is your responsibility to inform yourself about sustainable, low-impact options. This includes pet food, cosmetics, and supplements made from endangered or unsustainably caught marine creatures.

Today, the oceans and marine life are facing the threat of permanent alteration from a number of sources of pollution, and plastic is among the most significant. Plastic accounts for 60-80% of marine garbage, and it reaches up to 95% in high-density areas.

The reality is that every piece of plastic that has ever been made still exists in one form or another. Even when burned, it breaks down into microscopic, toxic particles. Made from oil, plastic is not a material that our planet can digest.

Recent studies have revealed that corals exposed to plastic showed discernable signs of disease 90% of the time. Plastic, a brittle material, is a magnet for bacteria, including some linked to coral diseases. In addition, plastics can block light, making corals more susceptible to a disease called black band, which leads to complete tissue degradation.

Take this: corals with plastic on them were 20 times more likely to be diseased than those that were not polluted. Unfortunately, plastic permeates our modern lifestyles but there are simple ways for individuals and communities to reduce their plastic footprint. For example, using reusable alternatives to everyday consumer goods like shopping bags, coffee cups, water bottles, utensils, straws, and more.

Many areas of the oceans are suffering from human-made habitat destruction, but coastal areas are disproportionately affected. As the global population grows, coastal land use and development increase.
With development come far-reaching impacts on coastal ecosystems and the species dependent on them. Coastal areas are home to over 90% of all marine species, but we are losing these habitats at an alarming rate.

Coastal habitats include estuaries, marshes, mangrove ecosystems, seagrass, and coral reefs. These habitats serve as nurseries, breeding grounds, feeding spots, and the destruction of these habitats inflict repercussions on dependent species.

Coastal development linked to human settlements, industry, aquaculture, or infrastructure can cause severe impacts on nearshore ecosystems. The effects of coastal development are both direct (e.g., landfilling, dredging, coral, and sand mining for construction) and indirect, such as from increased run-off and erosion of sediment and pollutants.

93% of the excess heat generated by human activities via the greenhouse effect is absorbed by the ocean, thus mitigating the increase in temperature of the atmosphere. This heat absorption causes a slight warming of the ocean which can be detected as deeply as seven hundred meters below sea level. It has now reached the deep sea in the polar regions and is spreading to all ocean basins. Considering the volume of the ocean, this represents a significant amount of heat!

However, even if greenhouse gas emissions ceased today, the effects of the increasing ocean temperature would continue for several decades.

Increasing ocean temperatures affect marine species and ecosystems, causing coral bleaching and the loss of breeding grounds for marine fishes and mammals. Ice melt and sea-level rise are two additional crucial consequences of warming seawater.

Rising ocean temperatures also affect the benefits humans derive from the ocean – threatening food security, increasing the prevalence of diseases, and causing more extreme weather events and the loss of coastal protection.

For over 200 years, the concentration of atmospheric carbon dioxide (CO2) has increased due to the burning of fossil fuels and land-use change. The ocean absorbs about 30% of CO2 released to the atmosphere, and as levels of atmospheric CO2 increase, so do the levels in the ocean.

When CO2 is absorbed by seawater, a series of chemical reactions occur, resulting in the increased concentration of hydrogen ions. This increase causes the seawater to become more acidic and causes carbonate ions to be relatively less abundant.

Carbonate ions are an essential building block of structures such as seashells and coral skeletons. Decreases in carbonate ions can make building and maintaining shells and other calcium carbonate structures difficult for calcifying organisms such as oysters, clams, sea urchins, shallow water corals, deep sea corals, and calcareous plankton.

These changes in ocean chemistry can affect the behavior of non-calcifying organisms as well. For example, certain fish’s ability to detect predators is decreased in more acidic waters. When these organisms are at risk, the entire food web may also be at risk.

Ocean acidification is affecting the entire world’s oceans, including coastal estuaries and waterways. Many economies are dependent on fish and shellfish, and people worldwide rely on food from the ocean as their primary source of protein.

The growing impact of human activities is causing a rapid loss of animal and plant biodiversity. Currently, the rate of animal extinction is 1,000 to 10,000 times higher than the natural extinction rate. According to a UN report on the state of the global environment, 25% of the world’s mammals will face extinction by 2032.

Some researchers believe that the sixth mass extinction event is already underway. In the paleontological sense, mass extinction is diagnosed when the pace of extinction is significantly higher than the pace of origination. Over the past 540 million years, five mass extinctions have occurred, during which at least 75% of all animal species were destroyed due to natural causes. However, today’s threat of extinction is caused by human-made influences, including habitat loss, overhunting, overfishing, the spread of invasive species and viruses, pollution, and the frighteningly high expansion rate of the human population.

In the oceans, the rate of biodiversity destruction is cataclysmic. There are many causes of marine species extinction and endangerment, such as habitat loss, acidification, atmospheric change, and pollution. The most dominant and influential threat, however, is overfishing. Overfishing is reported to be the greatest threat to marine biodiversity in all regions. When the population of a species is reduced, the genetic variation is reduced along with it. This compromises the species’ ability to adapt to new environmental stresses and changes.

Due to the interdependencies between species, the destruction of one can lead to the demise of others. When whole species are wiped out or remain at insignificant population levels, the stability of the entire ecosystem is under threat.