Humans wiping out coastal marine life, study shows

Human exploitation of coastal waters and estuaries has wiped out 65% of their wetland and sea-grass habitats and depleted 90% of marine species, new research suggests.

Exploitation of resources is the primary cause, made worse by habitat destruction and pollution, according to a research study published in Science which investigated the human impact on estuaries and coastal eco-systems as far back as the Roman times.

Humans caused 96% of species extinctions as demand for resources such as fish, oil and luxury goods grew, and degraded water quality 10-1,000 fold, according to the study. Entitled “Depletion, Degradation, and Recovery Potential of Estuaries and Coastal Seas,” it is the most comprehensive effort to quantify the damage humanity has caused to estuary and coastal eco-systems of its kind.

The team of international experts from behind the study found a strong acceleration of human interference with marine eco-systems over the last 300-150 years – a trend closely tied to population growth, an increase in demand for resources and the spread of industrialisation.

“Throughout history, estuaries and coastal seas have played a critical role in human development as a source of ocean life, habitat for most of our commercial fish catch, a resource for our economy, and a buffer against natural disasters,” said Dr. Heike K. Lotze, a marine biologist at Canada’s Dalhousie University, who led the research.

He lamented the lack of attention paid to the destruction of coastal marine life by politicians and the press:

“These once rich and diverse areas are a forgotten resource. Compared to other ocean ecosystems such as coral reefs, they have received little attention in the press and are not on the national policy agenda. Sadly, we have simply accepted their slow degradation,” he said.

Modern conservation efforts are bringing “signs of recovery,” especially when they deal with the cumulative impact of several human activities – efforts to curb the impact of two or more activities were responsible for 78% of recoveries of species, the scientists found.

But while estuary eco-systems were on the way to recovery in developed countries, in the developing world the trend was worsening largely due to human population growth, they said.

“The 2004 Asian Tsunami and 2005 Hurricane Katrina helped us recognize how important healthy estuaries are in our lives,” said Jeremy Jackson from the Scripps Institution of Oceanography in California.

“Thanks to this study, we can now see much more clearly what coastal ecosystems looked like before humans interfered with them, which has given us a historical baseline and a vision for how to regenerate diverse, resilient ecosystems that can thrive in the centuries to come.”

Goska Romanowicz

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