"We are set down eighty miles within a river…so stored with sturgeon and other sweet fish as no man’s fortune has ever possessed the like. And, as we think, if more may be wished in a river it will be found." - George Percy, Jamestown, 1607
To George Percy and other early settlers, the Chesapeake and its tributaries seemed an inexhaustible resource. One contemporary of Percy’s commented on how a single net had pulled in so many “sturgeon, bass and other great fish” that—had they possessed enough salt—“we might have taken as much fish as would have served us that whole year.”
The perception that the Bay’s bounty was inexhaustible continued into modern times, resulting in ongoing “boom and bust” cycles as individual species were overexploited, a situation compounded by degraded habitats and water pollution.
Total catches have declined by nearly a third in the past half century. In the 1950s, Bay landings routinely exceeded 300,000 metric tons of fish a year. As recently as a decade ago, annual catches still exceeded 250,0000 metric tons.
Today, Baywide harvests have fallen to about 200,000 metric tons. The diversity of the catch has also declined, especially as catches of oysters and shad—important species just 50 years ago—have nearly vanished. Today, 80 percent of the Bay’s total catches consist of just two species: menhaden and blue crabs.
To be sure, on a per-acre basis, the Chesapeake remains one of the most productive areas of coastal water in the nation. But its fisheries are clearly in decline.
To change that, a new 360-page report, “Fisheries Ecosystem Planning for Chesapeake Bay,” offers a sweeping strategy to coordinate and improve the way fish—and their habitats—are managed in the Bay.
The new approach calls for managing not just individual species, but casting the management net over the entire ecosystem—from habitat in the farthest headwater stream to water quality at the Bay’s mouth, and possibly beyond,
“This changes the thinking about managing fisheries,” said Ed Houde, a fisheries scientist with the University of Maryland’s Center for Environmental Science. “Traditionally, we managed fisheries by regulating catches and efforts of fishermen.
“Here, we shift the emphasis. We’re thinking about the ecosystem as the productive engine we have to keep running to ensure the sustainability of the individual fisheries.”
If the health of the ecosystem is improved, the report says, the abundance of fish species—and ultimately the level of sustainable catches — should increase.
“While reducing fishing mortality may allow declining populations to rebound, protecting and restoring habitat in the Bay may make populations less sensitive to fishing and other pressures,” the report said. “Persuasive data from a range of marine systems suggest that rebuilding ecosystems represents the best strategy for preserving fisheries along with other essential services provided by aquatic ecosystems.”
With many fisheries in collapse across the nation—and around the world—ecosystem approaches to fisheries management have been gaining momentum. At the direction of Congress, a scientific panel developed guidelines for fisheries ecosystem planning that were presented in a 1999 report.
In 2000, the National Oceanic and Atmospheric Administration’s Chesapeake Bay Office and the Bay Program’s Scientific and Technical Advisory Committee sponsored a workshop which led to a recommendation that such a plan be developed for the Bay. A team of scientists who were experts in some aspect of Bay fishery science or ecology spent the last three years—on a volunteer basis—crafting the document, which is the first fisheries ecosystem plan in the nation, and is expected to serve as a model for others.
“They set out to do something that they believed was going to be good for the Bay,” said Margaret McBride, a fisheries scientist with NOAA’s Chesapeake Bay Office. “The problems of the Chesapeake Bay are quite recognizable by everyone in terms of some of our most important fisheries being in such a state of decline.”
Of 22 major commercial or ecologically important Bay species, the report found that only three are considered to have a high abundance today. One is considered extirpated (Atlantic sturgeon), populations of seven others are considered low, and there’s not enough information to estimate the abundance of six others.
Traditional fisheries management plans are written as if a species lives in an ocean environment by itself—not in a waterbody shared by predators and prey, compromised by pollution and where key habitats are destroyed or degraded.
Under the new ecosystem-based plans envisioned by the report, species would still be managed by regulating catches. But those catch limits would take into account how harvests may affect other species and the ecosystem as a whole.
Menhaden, for instance, would be managed to ensure that there were enough fish to feed striped bass and other predators—as well as to consume excess growth of algae in the Bay and sustain a fishery.
Oysters are not only a commercial species, but are important ecosystem “engineers” that provide habitat for others. A wide array of species use oyster reefs in the Bay, the report said, including at least 57 fish species. Chesapeake oyster reefs have some of the highest fish densities reported outside tropical coral reefs.
And eventually, blue crabs might be managed not only to maintain the crab fishery, but also to control populations of marsh grass snails which, left unchecked, could destroy marsh habitats critical to crabs and many other Bay species.
The Bay Program’s Chesapeake 2000 agreement calls for developing “ecosystem-based multispecies management plans for targeted species” by 2005, and for revising existing fisheries management plans using “multispecies management and ecosystem approaches” by 2007.
The fisheries ecosystem plan provides the framework for how such plans may be developed.
It is an “umbrella document” that gives managers information on the structure and function of the ecosystem in which fishing activities take place. By using the information in the document, managers can get an idea about how their decisions may affect the ecosystem and, in turn, how other components of the ecosystem may affect a particular fishery.
For example, the plan sketches out food webs for each major species, starting with algae and bottom-dwelling worms or clams, and ending with top predatory fish, birds and humans.
It also calls for managers to begin taking into account external factors that affect fisheries. For example, scientists increasingly recognize that climate patterns that fluctuate over periods of roughly a decade can dramatically affect certain fisheries. Such climate patterns can determine whether a fishery management plan is successful or fails, and plans may need to be adjusted for such cycles.
It also outlines a broad vision that includes new ways to help mange fisheries in the future.
Instead of setting catch limits just for individual species, the plan suggests that caps be set for the combined landings of all species taken from the Bay. And it says that some areas of the Bay might be made off-limits to fishing altogether. It calls for new regulatory powers to protect fish habitat, as well as a Baywide “no net loss” goal to protect against the further loss and degradation of fishery habitat.
Perhaps most fundamentally, the plan calls for a precautionary approach to fisheries management which suggests that, when faced with uncertainty, fisheries managers and others should err on the side of protecting the resource.
In effect, the precautionary approach shifts the burden of proof—instead of having to prove a particular action would harm a resource, the burden is placed on proving it will not harm the resource.
That’s a reversal from the past when the perception that the Bay’s fisheries were limitless may have contributed to lax controls that led to overfishing or ignoring that habitats critical to supporting fish were in decline, the report said.
In a potentially controversial idea, the report suggests that an entire new watershedwide agency be created to manage fisheries more holistically.
The report envisions a new type of organization, which includes not only fisheries officials but also representatives from environmental enforcement agencies and perhaps other departments, as an important element of fisheries ecosystem management.
“Almost all of the things we recommend require more than just goodwill from other agencies and responsible bodies,” Houde said. “There is going to have to be more collaboration among existing agencies that have different authorities and responsibilities. How to get this broad-based ecosystem approach instituted is one of the things that has worried a lot of people,”
To be sure, such big changes may not happen for a while. Houde emphasized that the document is “incremental and adaptive. It is a strategic plan.”
Some of the early actions could be relatively simple. The Bay Program in recent years has taken steps toward improving habitats. Last year, it approved new water quality criteria that spell out in detail the water quality conditions needed to support aquatic life in the Bay. It has also set new restoration goals for underwater grass beds, a key habitat for many species.
Fishery managers could begin moving toward ecosystem management approaches simply by adopting those goals into their management plans. Today, fishery management plans often say little about water quality or habitat needs of the species being managed.
But in the future, such plans may spell out in detail the amount of grass beds, oyster reefs and of dissolved oxygen needed to help species thrive, and where those habitats should be located. Good habitats are not enough, the report notes. They need to be arranged in ways that make sense for fish. A high-quality habitat blocked by an area of low water quality is worthless.
And, initial multispecies plans don’t have to include an entire food web; they could focus on key interactions. “A multispecies plan can be two species,” Houde said. “If we could get a management plan that included both menhaden and striped bass in its considerations—or maybe menhaden, striped bass and blue crab — that would be a nice start.”
One of the most problematic issues in taking big steps forward is gaining the increased information needed to truly support ecosystem-based management. The Bay is considered the best-studied ecosystem in the world, yet much about it remains unknown.
Key links in the Bay’s food web are not understood, and even the abundances of many species are not well known. The Bay anchovy is the most abundant fish in the Chesapeake, and a critical food for many species, but it’s role in the ecosystem is largely unstudied.
Of the Bay’s 22 important species identified in the report, 10 have never been the subject of a stock assessment. The report says more emphasis needs to be placed on monitoring in the Bay.
“Research is a big chunk of change,” said Derek Orner, of NOAA’s Chesapeake Bay Office. “A lot of the time it takes a decline to get people’s attention, like with striped bass, blue crabs and oysters.”
He and others acknowledge that reversing problems created over decades will be a long process. “It’s a tiered approach. We are going to incorporate a few things into this first rendition of plans,” Orner said. “Then, as we update and revise those plans in the future, we are going to have more information.”
The report notes that the Chesapeake is fundamentally changed since the days of early colonists. No pristine areas remain. And the food web has already gone through “significant alterations” from human impacts such as pollution and overfishing.
But more than ever, according to the report, it is evident that trying to restore fisheries will mean trying to restore the fish habitat.
The report is available on NOAA’s Chesapeake Bay web site: http://noaa.chesapeakebay.net