Monday 29 May 2017

The ocean is facing an ocean full of threats!

Oceans are extremely pristine. The oceans are essentially one of the biggest resources for life on earth, but at the same time, one of the biggest dumping grounds. Globally, more than three billion people depend on our oceans and coastal ecosystems for their livelihood. One would think that humans would be more respectful to the ocean, considering that it's a vital source of nutrition for these people. Our gorgeous oceans and their inhabitants are often taken for granted.  Our ocean generates 80% of the oxygen we need but the carbon levels in the oceans are at an all-time high. Unfortunately oceans are faced with several far-reaching threats. People sometimes wrongly view the ocean as bottomless and a convenient dumping ground, it’s seen as an inexhaustible supply of food, a useful transport route, immune to all the impacts from people and thus too vast to be affected by humans’ impact but these careless actions have detrimentally affected marine ecosystems. Natural disasters result in temporary destruction of habitat. However, human impacts are more consistent and severe.

The ocean has been irreversibly damaged as a result of these human-induced impacts and unprecedented environmental changes have occurred. The world's oceans are significantly affected by human activities — and few ocean areas remain untouched. Sadly, humans will continue to inflict harm on the ocean, both through day-to-day activity and episodic events like major oil spills. Moreover, scientists have begun to realize these devastating effects on the oceans. As a result of not properly protecting the ocean, over-fishing, by catch, pollution, and other issues have become major threats to the health of our oceans. We have disrupted marine ecosystems everywhere and have driven countless species towards extinction. Thus not only are the marine habitats and species being threatened, it but also our own health, way of life, and security. Even though global fish populations provide a critical source of food for millions of people around the world, they are rapidly declining. Plastic and toxic waste also end up in oceans. Because there’s less than two per cent of our oceans set aside as marine reserves, it has become way too easy to exploit their natural resources. Even though 71% of our beautiful planet is covered by oceans, they are still severely neglected, which, in turn, is harming the innumerable creatures that live in them, and polluting one of our largest resources.

Here’s a look at the most prominent and extensive threats:

Overfishing & Destructive Fishing
Source: Venngage
One of the most noticeable threats is overfishing. Marine scientists consider overfishing to be the worst impact humans are having on the oceans. We’ve now almost emptied the oceans. We have systematically depleted the fish in our oceans. It has environmental and social consequences. Socially, it threatens food security for millions of people around the world and, environmentally, it destroys ocean ecosystems all over the world. By capturing fish faster than they can reproduce, people are essentially harming an entire ecosystem that interact with those species, from the food they eat to the predators that eat them. Two shocking facts are that we have already lost two-thirds of the large fish in the ocean and one in three fish populations have collapsed since 1950. 90% of the world's fisheries are already fully exploited or overfished, while billions of unwanted fish and other animals die unnecessarily each year. In fact, unsustainable fishing is the largest threat to ocean life and habitats. Previously, people caught fish with small boats and rods close to the shore. And then people exhausted the pelagic fish (including herring and tuna). Further, then, people went deeper, catching species, which can live to 150 years and don’t breed until they are 20 years old. People use destructive methods in how they pull catches, such as bottom trawling which destroys sea floor habitat and scoops up many unwanted fish and animals that are tossed aside. They also pull far too many fish to be sustainable, pushing many species to the point of being listed as threatened and endangered. These losses inevitable make the ecosystems more vulnerable to other disturbances, including pollution. Overfishing’s impact relates to wiping out a species, as well as other species of marine animals that are dependent upon those fish for survival. Not only that but it can cause marine animals to starve because people take food from their mouths in too large of numbers for them to be able to get their fill. Knowledge is power. Thus, it is important for people to properly know what types of seafood can be sustainably eaten, whether that is the species of seafood or the method by which it is caught. This will then ensure that the ocean's fisheries are healthy. As a result of technological advances of the last few hundred years, it has resulted in unsustainable levels of harvest, threatening fish stocks and the integrity of entire marine ecosystems. Thus, it not only has ecological impacts, but declining fisheries also result in economic loss and decreased food security. Furthermore, ghost fishing is an environmentally harmful issue. It is caused when lost or discarded fishing gear continues to catch fish and other marine life. The traps frequently trigger a chain-reaction problem when larger predators come to eat the smaller ones that have been ensnared, only to get tangled themselves. It commonly occurs when passive gear has been abandoned. It also poses a serious threat to other ocean vessels.

Source: Oceana

Pollution
While carrying serious consequences, oil spills and other pollution at sea, account for a small fraction of ocean pollution. Approximately half of all ocean pollution comes from land-based activities, like sewage, industrial and agricultural runoff, garbage dumping, and chemical spills. Pollutants from land, including plastics, untreated sewage, garbage, pesticides, industrial chemicals, and fertilizers, frequently end up in the oceans, either by deliberately dumping it or it enters from water run-off and the atmosphere. Moreover, this careless action is harmful for the entire marine food chain with undesirable consequences. One aspect of pollution that detrimentally affects the ocean is major oil spills, periodically causing major incidents. People are still dependent on the ocean to dilute agricultural and sewer runoff. The ocean is the world’s largest “sink”, absorbing about half of the CO2 created by burning fossil fuels and how we manage the ocean can increase that natural absorption rate.

Plastic pollution


This is one of the most noticeable threats. It’s shockingly astonishing to see how much of our trash finds its way into the ocean.  Because plastic is so durable (it can persist in the oceans for tens of thousands of years), it has significant ecological impacts as it resists the pull of time and bio-degradation that return most materials back into biologically useful forms. People’s use of plastic has risen, and also, simultaneously, the amount that has been dumped, blown, tossed, or dropped into the world’s oceans and rivers. For example, a Pacific Ocean Garbage Patch exists which is an area in the Pacific Ocean between the West Coast of America and the Hawaiian islands that, due to the circular ocean currents surrounding it, collects and aggregates plastic waste. Worryingly, there are places within the garbage patch that have more plastic than plankton. Plastic in the waters leach chemicals and are frequently mistaken as food by marine wildlife. Marine debris endangers human health and hurt business and tourism by dirtying our beaches and coastlines. An estimated 60-80 per cent of all marine debris originates from land-based sources. Human industry is responsible for dumping an ever-growing amount of trash and pollution into oceans. Over-consumption has led to pollution. The oceanic environment and its wildlife are severely choking on plastic. All plausible solution for this is to stop pollution at the source. Animals become easily entangled and trapped in our garbage, and it can destroy delicate sea life such as coral and sponges. Sea turtles and dolphins often mistakenly see plastic bags as their favorite foods, jellyfish and squids, choking them or clogging their digestive system. Pollution from the land is creating oxygen-deprived dead zones where plants and animals can’t survive. Plastic debris revolves around gyres in the world’s oceans: two in the Pacific, two in the Atlantic, one in the Indian Ocean.


Source: Unknown

Climate Change
The temperature rise over the past century is estimated at about 0.1 degree Celsius – that’s enough to kill the algae that keep corals alive, move species into new areas, and cause sea levels to rise. It is actually getting warmer faster than predicted. The effects of climate change would continue to play out for a century, even if people stopped pumping additional carbon dioxide into the atmosphere. Global warming is essentially creating a climate time bomb by storing enormous amounts of heat in the waters of the north Atlantic. Climate change is caused by the release of greenhouse gases (GHGs) into our atmosphere – primarily caused by the burning of fossil fuels. Fossil fuels, such as petroleum and coal, release carbon dioxide that traps heat in our atmosphere. Warmer waters would receive less protection from sunlight, which would warm them further. Heat stored in the oceans could be released into the atmosphere in the future, lessening efforts to stabilize global temperatures with cuts in man-made greenhouse gas emissions. Warmer air and water temperatures result in loss of sea ice, sea level rise, ocean acidification and extreme weather. All these aspects threaten fish and wildlife populations as well as our quality of life.

Acidification
Acidification relates to carbon dioxide, dissolving in oceans to form carbonic acid. The greater the acidity, the less able marine-calcifying organisms are to form shells which disrupt their reproductive process. Oceanic acidity has increased by 25% since the industrial revolution. It will eventually destroy much marine life if it increases at this rate. In the future, there will be a tipping point where the oceans become too acidic to support life that can't quickly adjust. Thus, many species will go extinct, from shellfish to corals as well as the fish that depend on them.

Habitat destruction and degradation
Another way in which ecosystems (which marine plants and animals need for their survival) are systematically destroyed, include clearing mangrove forests for shrimp production and scraping entire ecosystems off seamounts, or underwater mountain ranges via deep-sea trawling. Furthermore, fields of dying coral occur, and the sea grass and mangrove forests get whittled away by human development, wind, and sea.

Inadequate Protection
Even though, oceans cover over 70% of our planet’s surface, only a tiny fraction are protected: just 3.4%. More and better managed Marine Protected Areas are urgently required. Else, the future of the ocean’s rich biodiversity remains uncertain.

Tourism & Development
All over the world, coastlines have unfortunately been gradually turned into new housing and tourist developments. Unrestricted coastal development is severely impacting wetland and coastlines. As a result of this intense human presence, it has taken a toll on marine life.

Shipping
Because the oceans are huge “highways” where people ship all kinds of goods. But due to the heavy traffic, it has left a lasting mark: oil spills, ship groundings, anchor damage, and the dumping of rubbish, ballast water, and oily waste. All of these factors are endangering marine habitats around the world.
 
Oil & Gas
Important reserves of oil, gas, and minerals lie deep beneath the seafloor. But, prospecting and drilling poses a key threat to sensitive marine habitats and species. When oil is extracted from the ocean floor, other chemicals like mercury, arsenic, and lead come up with it. Furthermore, the seismic waves used to find oil harm aquatic mammals and disorient whales.

Aquaculture
Many times, the farming of fish and shellfish harms wild fish, through the pollution the farms discharge, escaped farmed fish, increased parasite loads, and the need to catch wild fish as feed.

Invasive species
Most aquatic invasive species are spread by human activities such as shipping or the aquarium trade. Once invasive species have been introduced to a new environment, it can negatively impact the environment, economy, and human health, and threatening native ecosystems and biodiversity.

Commercial Whaling
This is still a concern nowadays. The shocking practice was rampant for such an extensive period, that, sadly, many whale species may never recover.

Conclusion
Source: Greenpeace
It’s clear that as a result of human activity, especially over the last few decades, it has undoubtedly pushed oceans to their limit. One thing is for certain: the largest living space on Earth is fast deteriorating. Urgent strategies are required to deal with it, and to reduce other pressures on marine habitats already stressed by these factors. The health of our oceans should be a top priority, in the fight for the environment.

References

http://thankyouocean.org/threats/