Ecosystem-based approach protects biodiversity, productivity and humanity
By FRANK CARINI/ecoRI News staff
The growing pressures to feed, shelter and clothe 7 billion, and quickly multiplying, people is stressing the planet’s natural resources and forcing the way this natural capital must be managed and used, according to many of those challenged with changing the paradigm.
“There’s an importance to having diversity,” Janet Coit, director of the Rhode Island Department of Environmental Management (DEM), said this spring at a fishing symposium in Warwick, R.I. “Ecosystem management is a mystery and understanding the relationship between species and how to manage them is a real challenge.”
The longstanding traditional — and many would argue severely flawed — management strategy for fisheries and other natural resources has been to focus on one species/resource in isolation. But with a global population that has increased nearly 4-fold since 1900 and that is predicted to reach 9 billion by 2050, the status quo is severely outdated, if it ever truly worked at all.
An emphasis is now being placed on ecosystem-based management — an approach that considers interactions between humans and the environment to better manage natural resources and protect biodiversity.
The National Oceanic and Atmospheric Administration (NOAA), for example, is encouraging states to work together to implement ecosystem-based fisheries management in Chesapeake Bay. NOAA officials say such an approach would help restore, enhance and protect “living resources, their habitats and ecological relationships to sustain all fisheries and provide for a balanced Chesapeake Bay ecosystem.”
The rich estuarine ecosystem of Chesapeake Bay, much like Narragansett Bay, Long Island Sound, Buzzards Bay and Cape Cod Bay, has long supported major fisheries, the tourism industry and the livelihoods of many people and their families. But during the past several decades, the populations of many of the fish and shellfish in these vital waters have declined dramatically, because of pollution, habitat loss and overfishing.
To address the decline of a certain fish population, for instance, the traditional management strategy would be to decrease the number of that species that could be removed by fishing in a given year. But, as scientists, policymakers, fishermen and environmentalists are learning, the fishing of a single species is only one variable that impacts the health of its population and, ultimately, an entire ecosystem.
Other elements, long ignored, come in to play, such as interactions with other species, the effects of pollution and other stresses on habitat and water quality, and a changing climate.
Adapt or die
Jonathan Hare, director of NOAA’s Northeast Fisheries Science Center in Narragansett, R.I., told those who attended the late-March Southern New England Recreational Fishing Symposium, that climate change is real and has and will continue to impact local fish and shellfish populations.
He said climate change can have a negative or positive impact on fishing, noting that some species will migrate into southern New England waters and others, most notably cold-water fish such as cod and winter flounder, will migrate out. Either way, increasing ocean temperatures have significantly affected marine life, inducing shifts in distribution and changes in abundance.
Scientists studying the distribution of four commercial and recreational fish stocks in Northeast waters have found that climate change can have major impacts on the distribution of fish, according to a recent NOAA study. But the effects of fishing can be just as important and occur on a more immediate time scale, the study noted.
The four species studied — black sea bass, scup, summer flounder and winter flounder — have varied in abundance and have experienced heavy fishing pressure at times during the past four decades. For the study, scientists examined the distribution of the four species using Northeast Fisheries Science Center research trawl survey data collected between 1972 and 2008.
“The study combined a range of resources at the center, long-term oceanographic data and trawl survey data,” said Richard Bell, a research associate working at NOAA’s Narragansett laboratory and lead author of the study. “Using these data, we demonstrated how a combination of fishing and climate can influence the distribution of marine fish. It is not one or the other.”
To more effectively assess the health of any given fishery or natural resource and to determine the best way to manage it, the entire ecosystem must be taken into account, according to Hare.
The traditional stock-by-stock management approach assumes that what happens to one stock has no impact on another. Not true. In fact, different fish species interact with each other in many ways, according to the Woods Hole Oceanographic Institution (WHOI), and failing to account for these interactions can stymie efforts to rebuild stocks and manage them in a sustainable way.
For example, adult cod in Northeast waters eat a variety of other fish species, including herring, hake and flounder. An effort to re-build a cod stock that ends up shifting fishing effort onto to these species will work less well than one that protects both the cod and its prey, according to WHOI.
An ecosystem is a geographically specified system of organisms, including humans, the environment and the processes that control its dynamics. Ecosystem approaches to management use integrated approaches to study and manage the resources of an entire ecosystem. This approach considers the cumulative impacts from various sources and the balance of conflicting uses, and includes multiple factors such as pollution, coastal development, harvest pressure, watershed management, and predator/prey and other ecological interactions.
“Ecosystem-based fisheries management is a way to sustain the benefits people get from the ocean by accounting for the interconnections among marine life, humans and the environment,” Greg Wells, speaking for the Pew Charitable Trusts’ U.S. Oceans Environmental Group, told the nearly 100 people who attended the Southern New England Recreational Fishing Symposium. “We need to make decisions based on understanding how an ecosystem works to be able to maintain it health and productivity.”
The theme of that March 24 daylong conference was how to grow recreational fish to abundance through ecosystem-based management. “We need to protect and grow our recreational fishing resource in Rhode Island,” said Rich Hittinger, symposium director and first vice president of the Rhode Island Saltwater Anglers Association, which sponsored the event.
Hittinger noted that, according to NOAA, the recreational fishing resource in Rhode Island supports 2,000 full-time jobs and has a $208 million annual impact on the state’s economy.
Ensuring the long-term health of important marine species will depend upon the ability to understand and account for the interactions among those species, their environment, and the people who rely upon them for food, commerce and sport, according to The Pew Charitable Trusts.
The organization has recommend that ecosystem-based fisheries management be incorporated into the Magnuson-Stevens Act. Among the ideas it has presented include:
Reduce waste from bycatch. Bycatch refers to the non-target fish, marine mammals, birds, turtles and other wildlife that are caught and then discarded — often dead or dying. Despite legal requirements for managers to report on and minimize bycatch, government scientists estimate that close to 1 out of every 5 pounds of fish taken from the sea is wasted. The law should be strengthened to avoid bycatch, minimize the mortality of these animals, and meet a 1996 provision establishing adequate levels of bycatch monitoring and reporting.
Protect fish habitats. Coral reefs, fish spawning aggregation sites and other marine habitats provide vital areas for fish to reproduce, feed and/or take shelter. Little has been done to reduce damage from destructive fishing practices and non-fishing activities even though the law requires managers to designate and, to the extent practicable, protect essential fish habitats. Congress should enhance habitat protections, including measurable goals and conservation provisions that are reviewed at least every five years, to minimize adverse effects on habitat and to promote restoration and conservation.
Conserve forage fish. Small fish such as menhaden and herring are a primary source of food for many species of birds, marine mammals and large fish, including the striped bass, tuna, and salmon that support important commercial and recreational fisheries. However, forage fish populations are too often managed without adequate consideration of their vital role as prey, or not managed at all. Congress should require managers to protect forage fish with science-based catch limits that account for their unique role in the ecosystem.
Start smart. Unprecedented shifts in the range and behavior of fish populations because of climate change and the continuing demand for fish will create situations where fishing can expand to new areas, or new species will become fishery targets. Currently, a fishery can begin without adequate information about its potential impacts on the ecosystem or management measures to prevent overfishing and habitat damage. Congress should establish a more common-sense approach that would identify these potential impacts and establish science-based management before fishing is allowed.
Plan for the whole ecosystem. Fishery management should be guided by ecosystem plans instead of by decisions predominately based on a single stock without regard to the health of other species, their common habitat or impacts on the broader marine environment.
The concepts behind ecosystem-based fisheries management also can and, many would argue, should be applied to how we manage the use of rain forests, wetlands, salt marshes, farmland and open space. The use of any natural resources comes with tradeoffs — societal, economical and environmental. There are consequences to other wildlife, tourism, business, and land and water quality.
Those who support ecosystem-based management say the planet’s natural resources need to be managed with a cautious approach.
“Focusing on a system rather than a single population takes into account habitat, prey, competitors,” Wells said. “It also addresses managing the human uses of the ecosystem. Humans have a major impact, good and bad.”