In April of this year, a group of scientific experts came together to discuss an issue whose consequences will influence the planet and our society for generations to come. They met at the University of Oxford to discuss the current state and eventual fate of our ocean. “The ocean,” as stated in the workshop’s summary report, “is the largest ecosystem on Earth, supports us and maintains our world in a habitable condition.”
For three days, 27 scientists, representing 18 prominent research and conservation organizations worldwide, reviewed the latest findings on ocean stresses – and in particular the consequences of multiple, combined stresses – for marine life and the human population. The scientists found that stressors in combination may magnify the negative effect of each one occurring alone.
Based on this recognition, the scientists at this meeting concluded that
we have underestimated the overall risks and that the whole of marine degradation is greater than the sum of its parts, and that degradation is now happening at a faster rate than predicted.
In short, things for the ocean are worse than we thought, and getting worse faster than expected.
All too often, we take for granted the fact that our oceans feed us, support our coastal communities, and drive our tourism economies. Unfortunately, these ocean ecosystems are severely stressed, from nutrient pollution, chemical dumping, over fishing, marine debris, invasions of exotic species, warming waters and, perhaps most alarming, a drop in ocean pH to levels not seen for more than 8000 centuries: acidification of our oceans. Individually, these stressors would be cause for concern. In combination with each other, this expert group of scientists concluded, they are driving our ocean toward the brink of a mass extinction and ecosystem collapse.
One example of the multiplier effect on marine life comes from plastic debris and toxic chemicals. Plastics make their way as trash into the ocean where they break down into small particles that are consumed by marine life, like sea turtles, sea birds, and microscopic plankton. Consumption of plastic alone becomes fatal for marine life (when they consume so much indigestible material that they stop eating all together and starve to death). But the surfaces of plastic particles also easily absorb chemical pollutants, so they amplify the load of chemical pollution on these creatures.
The levels of chemical pollution are on the rise in even the most remote seas where no human development exists. Many of these chemical pollutants, like flame retardants and fluorinated compounds are poured down home sinks, or expelled as waste from industrial facilities, directly into the ocean. Plants and animals have not evolved ways to break down these new synthetic compounds, so they “bioaccumulate,” meaning they become increasingly concentrated as they are passed up the food chain, or passed in marine mammals from mothers to calves in their milk, until many of our top oceanic predators, our most majestic creatures, are swimming toxic waste.
Another example of what the scientists call “negatively synergistic” environmental harms is the combination of destructive fishing practices, nutrient runoff, and the presence of hormone-disrupting pharmaceuticals in our wastewater on coral reefs. But now, these precious ecosystems, known as the rainforests of the sea, do not have to just contend with overfishing, nutrient, and wastewater pollution. Now the reefs, like the mangroves, salt marsh estuaries, and seagrass meadows, in their damaged and less resilient state, must also face a rapidly changing climate and its dual effects of ocean warming and acidification. Coral reefs are more likely to bleach when exposed to both increased temperature and acidification than if they are exposed to either condition separately.
Add both conditions to pre-existing stressors, and 35% of the world’s reefs are classified as in a critical or threatened stage. Scientific projections indicate that without urgent action, coral reef ecosystems could be eliminated in 30-50 years.
The death and decline of coral reefs, the most diverse ecosystems on the planet, dramatically impairs the reproduction and development of hundreds of other species that call them home. When a reef ecosystem collapses and does not recover, it quickly becomes dominated by algae, and the phenomenal biodiversity once present disappears. For human society, this is accompanied by a loss of food, income, and the billion-dollar per year tourist industries.
The workshop report echoes the overwhelming body of peer-reviewed science and literature on climate change and carbon pollution, stating that:
Human actions have resulted in warming and acidification of the oceans and are now causing increased hypoxia (lack of oxygen). Studies of the Earth’s past indicate that these are the three symptoms…associated with each of the previous five mass extinctions on Earth.
We are now talking about changes whose precedents can only be found in geologic time. I’ve often said how we’ve veered outside of the bandwidth of carbon concentration that has prevailed for 800,000 years. This comparison is to mass ocean extinction events 55 and 251 million years ago. Back then, the rates of carbon entering the atmosphere in the lead up to these extinctions are estimated to be 2.2 and 1-2 Gigatons of carbon per year respectively, over several thousand years. But, as this new report identifies, “Both these estimates are dwarfed in comparison to today’s emissions of roughly 30 Gt of CO2 per year.” Such a massive dumping of carbon pollution into our atmosphere creates the prospect of devastating damage to our oceans.
And, in fact, we may already be witnessing this devastation. In one breathtaking part of the report, the scientists remark that, “The speeds of many negative changes to the ocean are near to or are tracking the worst-case scenarios from the IPCC and other predictions.” The IPCC, or Intergovernmental Panel on Climate Change, created several scenarios predicting how the earth’s natural systems could respond to ever-increasing amounts of carbon dioxide in the atmosphere. This report says observations are worse than the IPCC’s worse case scenarios. The predictions of the IPCC have received a lot of special-interest-sponsored mockery on this Floor, but these aren’t predictions now -- they’re observations. For instance, the decrease in Arctic Sea Ice cover and the melting of the Greenland and Antarctic ice sheets, which hold enough water to raise sea levels by more than 200ft, are actually occurring, and faster than expected. Correspondingly, sea levels are rising.
Likewise, the report observes, “acidification is occurring faster than in the past 55 million years, and with the added man-made stressors of overfishing and pollution undermining ocean resilience.”
These observations should be sobering. Not only are the changes great, but they are happening so quickly that marine life cannot adapt.
Numerically, the average ocean pH has decreased from 8.2 to 8.1 since the industrialized revolution. This seems like a small change, but the pH scale is logarithmic, so the change is profound. If that same amount of change in pH occurred in our blood, we could suffer respiratory or kidney failure. It is not difficult to imagine how this change has huge consequences for marine life and especially the calcifying organisms, like coral reefs, shellfish, and plankton, which are increasingly becoming soluble in their environment as it becomes increasingly acidic. If this unprecedented rate of change in ocean pH continues it could mean an almost 200% decrease by mid century. It is not an exaggeration to say that we are on the verge of an ecosystem collapse that we could see happen in a single generation.
Though mass extinction events have occurred in the past, workshop participants state that, “comparing the current environmental change with these events is difficult because the rates of environmental change are unprecedented. It is therefore difficult to predict what the outcome of the current anthropogenic experiment will be.” However, the report continues: “it can be said that we are pushing the Earth system to its limits.”
The workshop participants concluded, “Unless action is taken now, the consequences of our activities are at a high risk of causing, through the combined effects of climate change, overexploitation, pollution and habitat loss, the next globally significant extinction event in the ocean.” Again, they mean in geologic time
So what will we do? This is not the first report to state with certainty that our oceans, and thus our ocean dependent populations and economies, are in serious jeopardy. In 2003 the Pew Ocean Commission report led off with the following, “America’s oceans are in crisis and the stakes could not be higher.” In 2004, the U.S. Commission on Ocean Policy, as mandated by Congress in the Oceans Act of 2000, published their final report and pronounced, “The importance of our oceans, coasts, and Great Lakes cannot be overstated; they are critical to the very existence and wellbeing of the nation and its people. Yet, as the 21st century dawns, it is clear that these invaluable and life-sustaining assets are vulnerable to the activities of humans.”
Nearly two centuries ago, the poet Byron could write,
Roll on, thou deep and dark blue Ocean – roll!
Ten thousand fleets sweep over thee in vain;
Man marks the earth with ruin – his control
Stops with the shore;
Now, in 2011, this international group of scientists reminds us that, “the human interactions with the ocean must change with the rapid adoption of a holistic approach to sustainable management of all activities that impinge marine ecosystems.”
Mr. President we must work together to preserve and protect the ocean ecosystems we rely on so heavily. For we, too, are greater than the sum of our parts. In a bi-partisan effort Senator Snowe and I have introduced the National Endowment for the Oceans to provide dedicated funding for ocean and coastal research, restoration, protection, and conservation. Too often the knowledge and information needed to better protect and understand these ecosystems comes too late, or not at all. We hope to change that. Together we can turn the tide to protect the ocean and our society, but if we are to have any chance, we must act soon and we must make progress quickly. I look forward to working with my colleagues to confront these looming challenges.