Pollution and global warming have put the marine life on the brink of mass extinction, which can be compared with what happened millions of years ago.
Death of coral reefs, loss of biodiversity due to invasive species, the spread of "dead zones", blooms of toxic algae, depletion of fish stocks — all on the rise, according to a new report, sponsored by the International Programme for ocean monitoring. Moral of the document is that the marine life is dying faster than the most pessimistic forecast predicted a couple of years ago.
These symptoms can be seen as a precursor of a broader network of disintegration of biological and chemical interactions, which some scientists call the biosphere. All five previous mass extinction events in Earth's history preceded similar processes taking place in the ocean. "We are talking about the consequences that will occur in a single generation," — emphasizes Oxford professor Alex Rogers, co-author of the report.
All drivers of these processes are the result of human activity, it is global warming, ocean acidification and hypoxia. Until now, these factors are usually studied separately. Scientists are only now beginning to understand their relationship. "We underestimated the risk and did not realize that the degradation of the marine life more than the sum of individual effects of reasons," — said Mr. Rogers.
The chain reaction began with the release of huge amounts of carbon in the planet's climate system. Ocean in this system acts as a huge sponge, absorbing more than a quarter of carbon dioxide, which is released as a result of human activity. When the sponge is full, begin to break down carefully balanced ecosystem, and from the latter depends on the welfare of marine life and in the end — all life on Earth. "The rate at which carbon is absorbed, is already far surpassed last significant extinction of marine species that occurred 55 million years ago", — the report says. Then disappeared for about half of deep creatures. This event, known as pozdnepaleotsenovy thermal maximum, may be nothing more than a dress rehearsal for what awaits us in the future.
Its share in the overall picture makes pollution — discharge of nitrogenous fertilizers, pathogens and hormones. Because of this, in particular, dying corals, which play an important role in many marine ecosystems that define the lives of hundreds of millions of people.
Some species of large fish and sharks were caught on 90%, which led to the destruction of the food chain across the ocean and the unbalanced growth of algae, jellyfish and other "opportunistic" flora and fauna.
"We — the latest generation, which is the time to address these issues" — warns report co-author Daniel Laffoli, head of the World Commission on Protected Areas, International Union for Conservation of Nature.