Ocean Life Fading: What Can Be Done?

Marine reserves are essential to protect the biodiversity that maintains ecosystem integrity, say the report’s authors, Michelle Allsopp, Richard Page, Paul Johnston, and David Santillo. The four environmental experts call for a radical change in fisheries management, from a single-species approach to one that is ecosystem based and also includes the use of precautionary measures to tackle pollution and to reduce carbon dioxide emissions that are changing the temperature and chemistry of the oceans.

“The oceans cannot save themselves,” says Christopher Flavin, president of the Worldwatch Institute. “Collective commitments to thriving ecosystems are needed to save overfished species from being systematically depleted from compromised habitats.”

Major reasons for the depletion of fish stocks include overfishing, the use of bottom trawling and other destructive fishing techniques, unsustainable aquaculture, and illegal, unregulated, and unreported (IUU) fishing.

Bottom trawling has been likened to forest clearcutting. As fishers drag heavy nets and other gear across the sea floor, this causes massive collateral damage to corals and other features that offer protection and habitat for many creatures.

Bycatch is a growing problem, killing or injuring hundreds of thousands of seabirds, turtles, marine mammals, and other marine species annually. In some cases, industrial fishers discard nearly half their dead or dying catch back into the sea.

While fish farming adds to the world’s fish supply, in some intensive aquaculture systems the weight of fishmeal inputs is greater than the weight of farmed fish produced. Producing some carnivorous fish, like salmon, requires amounts of fishmeal between 2.5 and 5 times the amount of fish produced. For tuna raised on ranches, the weight of wild fish used is about 20 times the weight of tuna produced.

IUU fishing accounts for up to 20 percent of the global catch and is worth $4–9 billion a year. As industrial countries see their own fish stocks fall and impose stricter controls, fishers often move to developing-country waters where effective control is absent—jeopardizing the livelihoods of fishing communities.

Human-induced climate change is predicted to increase sea-surface temperature, raise sea levels, and reduce sea-ice cover. Polar regions may already be suffering from climate change. In one sector of the Southern Ocean, krill densities fell by an estimated 80 percent between 1976 and 2003, correlating with losses in the extent and duration of sea ice the previous winter and leaving penguins, albatrosses, seals, and whales especially vulnerable. In parts of the Arctic, the impacts of climate change on sea ice and snowfall may be affecting the breeding success of ivory gulls, ringed seals, and polar bears.

Pollution from chemical, radioactive, and nutrient sources; oil spills; and marine debris can contaminate the marine environment, kill organisms, and undermine ecosystem integrity. Of particular concern is the effect on marine wildlife of persistent organic pollutants (POPs), especially those chemicals not yet regulated under the 2001 Stockholm Convention, such as brominated flame retardants.

Marine debris, including plastics and derelict fishing gear, is responsible for causing death and injury to many marine species, among them seabirds, turtles, and marine mammals. Large oxygen-depleted “dead zones,” made worse by excessive nitrogen runoff from fertilizers, sewage discharges, and other sources, are further signs that the oceans are under severe stress.

A well-designed global network of marine reserves, covering key ecosystems and habitats, could help reverse the devastating toll human actions are taking on the world’s oceans, note the authors. Marine reserves are a proven method for restoring fish populations:

At the Soufriere Marine Management Area in St. Lucia in the Caribbean, three years of protection tripled the biomass of commercial fish species within the closed reserves. After five years, in areas outside the reserves, biomass doubled and average catches per trip increased 46 to 90 percent depending on the size of trap used.

Marine reserves established in the Red Sea in 1995 increased the catch per unit of effort in surrounding areas by more than 60 percent after five years of protection.

There is currently no mechanism under existing international agreements to create a global marine reserve network encompassing the high seas—areas beyond national jurisdiction. The authors suggest a new implementation agreement under the United Nations Convention on the Law of the Sea (UNCLOS) to establish and manage such reserves. They call for an integrated, precautionary, and ecosystem-based approach to the conservation and sustainable management of the marine environment in the high seas.

The authors also recommend moving negotiations on fish and fish products out of the World Trade Organization and into other multilateral fora where commercial and trade interests do not dominate. They call for an end to “sweetheart” agreements that allow industrial countries to fish liberally in developing-country waters: in the case of tuna fishing in the Pacific, the economic return from access fees and licenses paid by foreign fleets is at most 5 percent of the $2 billion the fish is worth. Fairer deals would allow coastal states to manage resources more sustainably and ensure continued livelihoods for communities.

A holistic, ecosystem-based approach, where demands on marine resources are managed within the limits of what the ecosystem can provide, is needed to protect marine biodiversity. “Current presumptions that favor freedom to fish and freedom of the seas will need to be replaced with the new concept of freedom for the seas,” notes the report.