See full version: 10 Threats to Ocean Life
Another example is illegal harvest of crab by Russian fishing fleets, either by unpermitted vessels or permitted vessels that have already exceeded their allowable catch. This illegally harvested crab is sold in competition with legally harvested crab, causing losses to fishermen that fish legally. It was estimated that in 2012, over 40% of the king crab sold in global markets was illegally harvested in Russian waters. [links]
Stationary species such as corals are even more affected. These species can't easily move to new locations. Warmer waters may cause an increase in coral bleaching events, in which corals shed the zooxanthellae that give them their brilliant colors. more
A 2016 study found shorter term impacts in tide pools. The study by Kwiatkowski, et.al. found that ocean acidification can affect marine life in tide pools, especially at night. Water already affected by ocean acidification can cause shells and skeletons of tide pool animals to disintegrate at night. This can affect animals like mussels, snails, and coralline algae.
Despite knowing relatively little about the ocean and its inhabitants, we've managed to screw it up quite a bit with human activities. Reading about different marine species, you often read about their population status or threats to the species. In this list of threats, the same ones appear over and over. The issues may seem depressing, but there's hope - there are many things each of us can do to help.
In many areas, overfishing occurs for seafood. In some cases, it is because animals are caught for use in medicines (e.g., seahorses for Asian medicines), for souvenirs (again, seahorses) or use in aquariums. more
Stop eating fish and shellfish entirely. If you simply cannot live without it, limit your intake drastically. If you must purchase fish or other seafood products, follow sustainable seafood guides like this one, published by Monterey Bay Aquarium. [links]
The second major problem associated with climate change is ocean acidification. The ocean is a natural carbon sink, which means that it absorbs carbon dioxide from the atmosphere and converts it into oxygen. However, increased atmospheric concentrations of carbon dioxide have led to the ocean becoming oversaturated, and increasingly acidic as a result. Ocean acidification degrades marine structures made of calcium carbonate, including corals and certain shellfish species. These species form the basis of the marine food chain, and their collapse as a result of acidification has a catastrophic domino effect. more
The ocean has facilitated human life for as long as we have existed. As well as providing an invaluable source of food, the ocean helps to regulate the global climate, and generates 70 percent of our oxygen. The survival of all species, including humans, depends upon the continued health of the marine environment. In recent years, however, it has become clear that the ocean is suffering because of human exploitation. A resource that once seemed limitless is now at risk of complete collapse. To repair the marine environment, we must understand the issues that are threatening it. Here we’ll take a look at three of the most serious threats to our oceans and also what we can personally do to mitigate them.
Our seas are at risk from every corner. Here are three of the most significant threats to our oceans today.
As the world’s human population grows, so does the demand for seafood. To meet that demand, commercial fisheries have developed methods that allow them to catch tons of fish at a time, to the point where doing so is no longer sustainable. Overfishing occurs when more fish are caught than can be replaced through natural reproduction. It has brought more than 85 percent of the world’s fisheries to the brink of collapse in just the last 50 years. The delicate balance upon which the marine ecosystem depends has been compromised, and certain targeted species (including the bluefin tuna and the Atlantic cod) are now facing extinction. more
Oceans cover 70% of the earth’s surface. For a healthy planet, we need healthy oceans. Yet they are under threat. Here are five of the biggest challenges our oceans face, and what we can do to solve them.
Climate change arguably presents the greatest threat to ocean health. It is making oceans hotter, promoting acidification, and making it harder to breathe in them by reducing dissolved oxygen levels. Imagine how poorly a fish in an aquarium would fare if we turned up the heat, dripped in acid, and pulled out the oxygen bubbler. This is slowly but surely what we are doing to our oceans.
Almost a third of global fish stocks are overfished. Fish that were once extremely abundant, such as bluefin tuna, are now becoming increasingly endangered. Illegal, unreported and unregulated fishing can cost the global economy up to $23 billion annually. Restaurants and seafood markets in many areas routinely serve endangered seafood species that are the underwater equivalent of a rhino or a panda. more
One of the other major ways in which we can help minimise our impact on the oceans and ensure its natural resources are available for future generations is to be as efficient with our energy usage and waste disposal as possible. The more we can reduce our use of things such as electricity, fuel, water and plastic bags, as well as recycling as much as possible, the better. Lowering our contributions to carbon emissions will count directly towards preventing further warming and acidification of our oceans, whilst being mindful of our waste and choosing to recycle will help minimise our personal contributions to pollution.
4. Pollution can poison marine life and decimate entire marine environments. Vast quantities of solid and chemical waste from human activities are continually dumped and leach into the oceans, including plastics, sewage, sediment, oil and toxins that accumulate in food webs.
Both fertilisers and untreated sewage are high in nutrients and so can cause eutrophication in coastal areas (flourishing algal blooms that thrive on the nutrients) thereby smothering other marine life by dramatically depleting available oxygen. This can create vast expanses of dead ocean, as is already apparent in the Gulf of Mexico and Baltic Sea. more
A sustainable fishery means that catch rates do not exceed the recovery rate of the population – there is little to no bycatch and minimal environmental impact. Using our purchasing power to favour sustainable fisheries can instantly help combat many of the threats our oceans face. Overfishing is of course addressed directly, but choosing sustainable fish can also help prevent the loss of important habitats and predators. Most declines in shark populations are attributable to bycatch in other targeted fisheries, such as those long-lining for tuna and swordfish, and some unsustainable fishing methods such as bottom trawling and certain types of aquaculture (fish farming) can cause considerable habitat destruction. Aquaculture can even contribute directly to overfishing as vast quantities of wild fish are caught to supply the farms; for instance each pound of salmon farmed typically requires five pounds of wild fish caught to make fish meal.
What Can You Do? here
3. Climate change is warming the oceans and making them more acidic. This will create vast dead zones as plankton and corals – the primary producers for nearly all marine life – struggle to survive under increasingly inhospitable conditions.
Ocean acidification, caused by excess CO2 dissolving in the sea to form carbonic acid, has the potential to literally dissolve the skeletons and shells of marine creatures such as corals leading to devastating effects on marine ecosystems. more
1. Overfishing depletes stocks of fish beyond their ability to recover, disrupting the ecosystem and eliminating a valuable source of food and income.
In recent years the insatiable demand for both Atlantic cod and bluefin tuna has caused their populations to have declined dramatically leaving them on the edge of extinction.