This brings me to the issues that are currently present within our waters. Extensive coastal pollution, climate change, over-fishing and the practice of deep-sea trawling. Many sharks are being killed from over-fishing and trade. Since sharks are the 'apex predator' of the seas, they have a big role on the balance of the ecosystem, they are on top of the food chain. Each life form in the ocean works together within the environment to help recycle waste, maintain the ecosystem, and provide services that others use and benefit from.
Dead zones within an ocean are low-oxygen areas that are caused by excessive nutrient pollution from human activities coupled with other factors that deplete the oxygen required to support most marine life in bottom and near-bottom water. When oxygen gets too low, marine life cannot be supported. Countries have been aiming towards restoring and conserving wetlands. The main goal is to assure the damage does not pass the point of no return.
The attached graph is compiled by Secretariat of the Convention on Biological Diversity (2010) Global Biodiversity Outlook. It shows a great visual of the increase in number of dead zones over many years. One can simply start by shrinking the dead zones. This can be done by not polluting our rivers with dumping, clean up sewage plants, preserve wetlands and also promote farming practices that reduce runoff.