Sea Change: How We are Altering Everything

by Abby Sullivan

Photo courtesy of the author

In light of the BP Oil spill, it seems like an appropriate time to discuss the health of our oceans and how we, as humans, are altering and changing these vast bodies of water in ways previously thought to be unimaginable. What were once local problems in our waters have become increasingly disturbing and global in nature. Until the 1950’s, people considered the oceans inexhaustible. Today everyone from marine biologists to glaciologists to meteorologists all concur that our oceans are in peril and if we do not drastically change our relationship to the sea, it may be lead to our ultimate demise. I moved to Iceland a year ago to study Marine and Coastal Resource Management. What I learned about the ways we are altering everything in our ocean ecosystems has been a startling, sobering experience. As with most environmental issues, the problems caused by the state of our seas is deeply linked with issues of inequality, poverty and greed. And for me, what is the most disturbing thought is how shortsighted we are—we are stealing from future generations, destroying what is not ours to destroy. I hope to highlight a few of the largest issues we must overcome to save our seas.

Vital to Life: Yours, Mine, and our Grandchildren’s

“Without Blue, there is no green.” These are the words of Sylvia Earl, the iconic oceanographer who was the chief scientist for the National Oceanic and Atmospheric Administration from 1990-1992 (Watch her TED talk here). Earl asserts that without healthy oceans and coasts, life cannot be sustained on earth—at least not life as we know it today. The ecosystem services that the oceans provide are invaluable and largely taken for granted. The oceans are linked to our atmosphere and regulate the climate, and our coasts protect us from storms. Phytoplankton—single-celled plants—are the base of the food chain in our oceans and provide the earth with at least half of its oxygen supply. Oceans also act as natural carbon sinks. According to the Natural Resource Defense Council, the oceans have absorbed roughly 25% of all carbon dioxide produced from burning fuel since the industrial revolution. In addition to these ecosystem services, the oceans are the most productive environments on this earth. The Food and Agriculture Organization of the United Nations found that in 2004 fish provided 2.6 billion people with 20% of their average per capita animal protein intake. Recently, Ray Hilborn from the School of Aquatic and Fishery Sciences of the University of Washington reported that if we replaced all fish protein with protein from land-based agriculture, we would need extra grazing land equal to all of the world’s rainforest 22 times over. Again, quoting Sylvia Earl, “the oceans are our life support systems.” Listed below are some of the major threats driven by human activity that are deteriorating that life support system and some suggestions as to how we can change our actions to save ourselves.

Declining Fish Stocks

Photo courtesy of the U.S. National Archives

Simply put, we are eating up all the fish in the ocean. In my marine conservation class, when talking about the possibility of a drastically altered ocean without many of the large fish we eat today, my professor, Bradd Barr, of the National Marine Sanctuaries Program stated, “The scary thing is, this is not hyperbole!” Countless fisheries scientists have been warning us and recommending conservative fishing quotas that are ignored and sometimes even doubled by the political decision makers. Before entering this master’s degree program I had heard something about the global overfishing crisis, but it was still shocking to read studies in class indicating that most of our large fish species such as Tuna, Cod, Grouper, Shark and Marlin are overexploited and could face extinction. A recent study by ecologist Boris Worm of Dalhousie University and Ray Hilborn (2009) found that, despite declining exploitation rates, 63% of assessed fish stocks worldwide need rebuilding and that exploitation rates need to be lowered further to prevent collapse of vulnerable species. The current poster child of fish exploitation is the Atlantic Bluefin Tuna. Since 1970 their stocks have decreased by at least 80% (See Block, et al., 2005). In March of this year, in what many see as a missed opportunity, the UN rejected a bid to list the Atlantic Bluefin Tuna under Appendix I (a complete ban) of the Convention on International Trade in Endangered Species (CITES). Lobbying from Japan, Canada and many developing countries allowed economic interest to trump scientific evidence and conservation. While a ban on Bluefin Tuna may have had devastating effects on the livelihood of today’s fisherman, the eventual collapse of the entire species could deny future generations of this resource altogether. Unfortunately, we have already seen this happen. Nova Scotia’s oceans were once characterized as being so thick with Atlantic Cod that it was difficult to navigate a boat through the waters. Atlantic Cod survived in their current form for roughly ten million years until industrial fishing decimated the population. In 1992 Canada issued a complete moratorium on fishing for Atlantic Cod, leaving 40,000 workers jobless. Entire communities were uprooted. Even with this 18-year moratorium the Atlantic Cod stocks off the coast of Nova Scotia have not recovered.

I have not even touched upon the additional ecological damage that is sometimes caused by fishing, such as destroying habitats and reefs by bottom trawling, catching the non-target species as by-catch, killing seabirds and changing the genetic make-up of fish stocks. But there is hope when it comes to fisheries management. Exploitation rates are starting to decline and fisheries managers are beginning to apply ecosystem based management principles. These methods take the entire ecosystem into account for a more holistic approach for management decisions. Governments need to stop issuing subsidies to fisherman who can no longer make a living from depleted fish stocks. Subsidies create incentive to expand fishing fleets while fish stocks continue to face collapse. Marine Protected Areas (MPAs)—the equivalent of national parks in the ocean—need to be established and supported. They are one of the best tools we have to help fish stocks recover and to prevent complete ecological destruction. Sadly, less than 1% of the global oceans are protected. Check out sustainable fisheries labeling through the Marine Stewardship Council here and print out the Seafood Watch Sustainable Seafood Pocket Guide from the Monterey Bay Aquarium. This guide will fit into your wallet and help you purchase fish that are caught in a sustainable manner.


It is unfortunate that our oceans are essentially downstream from everything: industrial waste, debris, untreated sewage, medicine, eroded soil and fertilizer runoff. All of these contaminants are being pumped directly into our oceans or make their way to the sea through our river systems, turning our coastal seas into chemically altered environments. Eutrophication generally refers to an abundance of organic matter in our oceans and seas created from an excess of nutrients. Added nutrients, mainly nitrogen and sometimes phosphorous from fertilizer, livestock waste and fossil fuel combustion, have created large increases in phytoplankton or algal blooms. Ironically, these blooms of growth lead to what we call “dead zones” in our waters. This influx of organic matter eventually dies and falls to the ocean floor where microbes break it down in a process that uses dissolved oxygen within the environment. When oxygen levels are depleted drastically enough, the environment becomes hypoxic and most living things flee or die. Since the 1960’s the number of dead zones has been rising exponentially. Diaz and Rosenberg (2008) report that 400 systems now have “dead zones” covering a total of 245,000 square kilometers.

Image courtesy of the NASA earth observatory.

We know that restoring and preserving watersheds and wetlands is one of the keys to solving the eutrophication problem. Wetland plants and fungus can absorb nutrients before they make it into our oceans. Additionally, we can buy organic produce and eat less meat, this will help reduce the demand for fertilizer used in food production and reduce the livestock waste making its way into our streams and rivers.

Ocean Acidification and Climate Change

Jeremy Jackson (Watch his TED talk here), a marine ecologist at UCSD, states that, “… the really scary things are the physical, chemical, oceanographic things that are happening.” He is referring to ocean acidification and the warming of our seas. We know that by burning fossil fuels, we are changing the atmosphere and altering our climate. What came as a surprise to me was the way anthropogenic (human induced) CO₂ emissions are drastically affecting our oceans. Elizabeth Kolbert, an environmental journalist, wrote in The New Yorker that: “Nearly half of all the carbon dioxide that humans have emitted since the start of the nineteenth century has been absorbed by the sea.”

This occurs because our atmosphere is directly linked to our oceans, and CO₂ is transferred from the air to the water. Even though these stores help mitigate the effects CO₂ on our climate, the process also alters the chemistry of our oceans by decreasing the pH level, making it more acidic. In a mere 200 years, we have increased the ocean’s acidity by 30%. Increased acidity makes it harder for species to create shells and for corals to create skeletons out of calcium carbonate. Pteropods are small, snail-like creatures that are vital to the ocean food chain. Pteropods build shells, which makes them vulnerable to ocean acidification. Gretchen Hoffman of the University of California Santa Barbara states: “They are harbingers of change. It’s possible by 2050 they may not be able to make a shell anymore. If we lose these organisms, the impact on the food chain will be catastrophic.”

The warming of the earth has created warmer seas. Warmer seas make it harder for water to cycle, harder for upwelling of nutrients and for oxygen to make it to deeper waters, making the ocean more stratified and more like a desert. The Polar Regions are also heating up, causing ice to melt and creating what are called positive feedback loops. These occur because decreased ice means that less sunlight is being reflected and more is being absorbed, leading to warmer waters and, in turn, more ice melt. Increasing water temperatures alter vital habitats, such as coral reefs. Coral reefs turn white when they become stressed and we call the process coral bleaching. Widespread coral bleaching and mortality is projected to occur in the next 30 to 50 years due to the stress of ocean acidification and the  rise of ocean temperatures.

Photo of the maximum Arctic sea ice extent 2008-09 courtesy of NASA Goddard's Scientific Visualization Studio

Forces of Change: Will We Change Ourselves?

The issues discussed here are a few of the major threats to the ocean, but they are just the tip of the iceberg. Many other human-induced problems in our waters also deserve critical attentions, such as the spread of invasive species or the massive plastic gyres that have formed in five of our oceans. These problems are inextricably linked and make the cumulative impact of our actions that much more detrimental. The thing that gives me hope is that we are causing these problems through our actions, so all it takes is a change in our behavior to begin the healing process. Jeremy Jackson says, “The final analysis: What we really need to change is ourselves.” Unfortunately, this is hard to do, but I have to hope that spreading this information is the first step to changing our behavior. More science is needed as well as political will. If we can show people the wonders of the sea and teach people about the ecosystem services of the ocean that are essential to life on earth, I believe we can change our actions and create new stewards of the environment—stewards of the seas. ▢

Abby Sullivan is currently a Master’s student at the University of Akureryri through the University Centre of the Westfjords in Isafjordur, Iceland. She studies coastal and marine resource management with a focus on conservation and polar regions. Abby hopes to use her undergraduate study of photography in conjunction with her current research to promote environmental awareness and conservation.

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