Quantcast
Environmental News for a Healthier Planet and Life

How Acidification, Overfishing and Plastics Threaten the World's Oceans

Oceans
How Acidification, Overfishing and Plastics Threaten the World's Oceans

June 8 is World Oceans Day. It's a fitting time to contemplate humanity's evolving relationship with the source of all life. For much of human history, we've affected marine ecosystems primarily by what we've taken out of the seas. The challenge as we encounter warming temperatures and increasing industrial activity will be to manage what we put into them.

As the late American marine biologist, author and conservationist Rachel Carson wrote, "It is a curious situation that the sea, from which life first arose, should now be threatened by the activities of one form of that life. But the sea, though changed in a sinister way, will continue to exist: the threat is rather to life itself." Photo credit: World Oceans Day

As a top predator, humans from the tropics to the poles have harvested all forms of marine life, from the smallest shrimp to the largest whales, from the ocean's surface to its floor. The staggering volume of fish removed from our waters has had a ripple effect through all ocean ecosystems. Yet the ocean continues to provide food for billions of people, and improved fishing practices in many places, including Canada, are leading to healthier marine-life populations. We're slowly getting better at managing what we catch to keep it within the ocean's capacity to replenish. But while we may be advancing in this battle, we're losing the war with climate change and pollution.

In the coming years, our ties to the oceans will be defined by what we put into them: carbon dioxide, nutrients washed from the land, diseases from aquaculture and land-based animals, invasive species, plastics, contaminants, noise and ever-increasing marine traffic. We once incorrectly viewed oceans as limitless storehouses of marine bounty and places to dump our garbage; now it's clear they can only handle so much.

The Intergovernmental Panel on Climate Change's recent report described how ingredients in the ocean's broth are changing dramatically. Life in the seas is closely linked to factors in the immediate surroundings, such as temperature, acidity or pH, salinity, oxygen and nutrient availability. These combine at microscopic levels to create conditions that favor one form of life over another and emerge into complex ecosystems.

The oceans now absorb one-quarter of the atmosphere's CO2. That's bad news for organisms with calcium carbonate shells that dissolve in acidic conditions. We're witnessing the effects of ocean acidification on shellfish along the West Coast of North America. Earlier this year, a Vancouver Island scallop farm closed after losing 10 million scallops, likely because of climate change and increasing acidity. The U.S. National Oceanic and Atmospheric Administration has also linked oyster die-offs along the Pacific coast to climate change.

While we may be getting better at figuring out how to sustainably harvest crabs, lobsters and sea urchins, we're just starting to investigate whether they can even survive in oceans altered by climate change.

Whales also offer a glimpse into our changing relationship with oceans. From the 17th century until well into the 20th, commercial whaling in Canada left populations severely depleted. Now, our most endangered whales are threatened by industrial activity. The St. Lawrence beluga population, for example, was decimated by hunting until 1979. Today's biggest threats include contaminants, vessel traffic and industrialization, including a proposal to develop an oil port in the heart of their critical habitat.

Although the conservation challenge is daunting, nurturing functioning ecosystems offers hope. Healthy oceans ensure we can continue to enjoy seafood—and they're more resilient to increasing human impacts. If the global fishing industry wants to ensure its survival, it should advocate for marine ecosystem conservation.

By continuing to improve fisheries, protect habitat, carefully control industrial activities and create marine protected areas, we can maintain marine ecosystems that are better able to adapt to the pressures of climate change and other human activities. That's happening on the Pacific North Coast, thanks to a partnership between the B.C. government and First Nations to develop marine plans to guide future ocean uses.

Although there's much to lament about the state of the oceans, I remain inspired by the David Suzuki Foundation's Ocean Keepers and others working to defend our precious coastal waters. With less than five per cent of the oceans explored, we have much left to discover and learn.

As the late American marine biologist, author and conservationist Rachel Carson wrote, "It is a curious situation that the sea, from which life first arose, should now be threatened by the activities of one form of that life. But the sea, though changed in a sinister way, will continue to exist: the threat is rather to life itself."

Written with Contributions from David Suzuki Foundation Senior Research Scientist Scott Wallace.

——–

YOU MIGHT ALSO LIKE

Scientists to Build Underwater Bio-Dome Simulating Future Ocean Acidification Levels 

Climate Change Affects Antarctica’s Ocean Salinity, Trapping Heat in Deep Water

Scientists Warn of Emerging Impacts From Arctic Ocean Acidification 

——– 

Ningaloo Reef near Exmouth on April 2, 2012 in Western Australia. James D. Morgan / Getty Images News

By Dana M Bergstrom, Euan Ritchie, Lesley Hughes and Michael Depledge

In 1992, 1,700 scientists warned that human beings and the natural world were "on a collision course." Seventeen years later, scientists described planetary boundaries within which humans and other life could have a "safe space to operate." These are environmental thresholds, such as the amount of carbon dioxide in the atmosphere and changes in land use.

Read More Show Less

EcoWatch Daily Newsletter

A 3-hour special film by EarthxTV calls for protection of the Amazon and its indigenous populations. EarthxTV.org

To save the planet, we must save the Amazon rainforest. To save the rainforest, we must save its indigenous peoples. And to do that, we must demarcate their land.

Read More Show Less

Trending

UN Secretary General Antonio Guterres delivers a video speech at the high-level meeting of the 46th session of the United Nations Human Rights Council UNHRC in Geneva, Switzerland on Feb. 22, 2021. Xinhua / Zhang Cheng via Getty Images

By Anke Rasper

"Today's interim report from the UNFCCC is a red alert for our planet," said UN Secretary General Antonio Guterres.

The report, released Friday, looks at the national climate efforts of 75 states that have already submitted their updated "nationally determined contributions," or NDCs. The countries included in the report are responsible for about 30% of the world's global greenhouse gas emissions.

Read More Show Less
New Delhi's smog is particularly thick, increasing the risk of vehicle accidents. SAJJAD HUSSAIN / AFP via Getty Images

India's New Delhi has been called the "world air pollution capital" for its high concentrations of particulate matter that make it harder for its residents to breathe and see. But one thing has puzzled scientists, according to The Guardian. Why does New Delhi see more blinding smogs than other polluted Asian cities, such as Beijing?

Read More Show Less
A bridge over the Delaware river connects New Hope, Pennsylvania with Lambertville, New Jersey. Richard T. Nowitz / Getty Images

In a historic move, the Delaware River Basin Commission (DRBC) voted Thursday to ban hydraulic fracking in the region. The ban was supported by all four basin states — New Jersey, Delaware, Pennsylvania and New York — putting a permanent end to hydraulic fracking for natural gas along the 13,539-square-mile basin, The Philadelphia Inquirer reported.

Read More Show Less