The fish and shellfish of the Chesapeake are the most tangible symbol of the Bay, but we the people have taken them for granted. Historically, we've done a poor job as stewards of these valuable resources. Water pollution affects all the Bay's fisheries, undermining efforts by the Chesapeake Bay Foundation and other stakeholders to work with government agencies to rebuild the stocks. As a result, many of the Chesapeake Bay's fisheries have been reduced in diversity and productivity.
A Delicate Balance Between Conservation and Harvest
Fisheries management is comprised of two basic functions: conservation—determining how many fish, crabs, and oysters can be caught without harming the resource; and allocation—determining who gets to catch these resources. Over the past twenty years, fishery managers and scientists have begun to realize that conservation is actually more complex than simply figuring out how to avoid over-harvest of each species.
In fact, aquatic food webs are complex and deeply intertwined. Increasingly the conservation community is attempting "multi-species management" that takes the complexity into account. One especially difficult element is that some of these species play vital ecological roles in estuaries like the Chesapeake, over and above their immediate value to us. For example, the three-dimensional reefs that oysters build form "keystone communities" that burst with many other forms of life, from seaworms, anemones, mud crabs, and barnacles to large predator fish and even sea turtles. Moreover, those oysters also feed on tiny plant plankton cells, filtering the water in the process and converting those algae into valuable meat. Similarly, menhaden filter tiny planktonic animals from the water, serving as the nutritious food links between them and predators like rockfish (striped bass) and even seabirds like loons and gannets. In these two examples and many others, fish and shellfish are at least as important to leave in the water as to harvest. Balancing ecological needs with human demands is a daunting scientific challenge, but this kind of conservation will be necessary to keep our coastal ecosystems healthy in the twenty-first century.
Historically, conservation has too often been compromised to satisfy allocation pressures, with the result being depleted fisheries. CBF believes these two functions must be separate, and to advance this fundamental concept, we focus on conservation issues. For conservation to be successful, we believe it must be based on science with input from fishermen. CBF promotes the use of the best available scientific information as the basis for conservation decisions, but when information is incomplete, we advocate "erring on the side of the resource."
American Shad & River Herring
Topping catches in the 1800s, but absent from today's top ten list, are shad and herring—anadromous species that live primaryly at sea but travel up coastal tributaries to spawn in fresh water. The largest, American shad, had such prolific spawning runs that it was the dominant Bay commercial fishery for nearly 200 years. Largely forgotten now because overfishing and dams blocking their migrations finally snuffed out these runs, American shad have been under catch moratoria for decades.
Atlantic menhaden have been the number one fishery in the Chesapeake by weight for decades (several hundred thousand metric tons each year). These fish are caught primarily to be rendered by the ton into oil and fish meal for dietary supplements and animal feed. Whether this is the best use of this ecologically critical species—it is essential food for a variety of fish, birds, and mammals—is open to debate. A significantly smaller harvest serves as bait, especially for crab pots.
Although the homeport of the Bay’s menhaden fleet—Reedville, Virginia—is one of the top ports in the country in weight landed annually (#2 in 2010), its rank in value of catch was only 25th in 2010 and the menhaden population is now at an all-time low. Catches were cut back 20 percent beginning in 2013. A new population assessment in 2015 led to relaxing that limit by 10 percent in 2016 and another 6.5 percent early in 2017, but a scientific process is well underway to establish ecological reference points (ERPs) that recognize the role of menhaden in coastal and Bay food webs and set catch limits conservatively enough to keep those food webs healthy. The ERPs, slated for review late in 2017, will guide future management of the fishery.
Crabs have shown steady improvement since 2014, as indicated by the 2016 winter survey and the improved catches of crabbers during the 2016 season. We hope that bayside communities dependent on crabs, like Smith and Tangier Islands, will see brighter economic futures with the increase in population.
Maryland and Virginia partnered on cutbacks in the catch of female crabs in 2008 to meet new, science-based guidelines for the fishery. These changes helped to double the population by 2010, but the population dropped back to its previous low level in 2014 before rising again in 2015 and 2016.
Stability for the Bay's blue crab population has been limited by degraded habitat, in particular underwater grass bed coverage, which is fortunately beginning to show signs of improvement. Blue crabs need grass beds for nursery areas and protection from predators. New management approaches also need to be explored.
Despite the good news, the crab population has not reached its target level, a fact that emphasizes the need to stay the course with science-based limits. This iconic symbol of the Chesapeake is resilient, but our appetite for it—in all its forms—demands caution and restraint lest we "love it to death."
The oyster fishery reached its height in the late nineteenth century, but unrestrained harvest destroyed the tall reefs that had accumulated over millennia, while pollution and disease drove the stock further down. Fifty years ago, the catch still ranked third in the Chesapeake, but it crashed in the 1990s and ‘00s. On the bright side, the harvests have bounced back lately, exceeding one million bushels total in the 2014-15 and 2015-16 seasons. Both the public and private fisheries are growing, and Virginia, especially is experience increased numbers of wild oysters and a growing new aquaculture industry. Today, two-state harvest has risen back to fourth place, but the current stock is still less than 5 percent of what it was before 1850, and the Bay's ecological need for this filter feeder demands major restoration.
As with menhaden, there is now a growing realization that oysters provide much more than seafood. They filter the Bay's water by grazing algae, while their shells build reefs that offer important habitat in much the same way that corals do in warmer waters. The nooks and crannies of these reefs provide spaces for communities of small worms, crustaceans, mud crabs, fish, and other invertebrate animals that form the basis for much of the Chesapeake's deep-water food webs. Scientists refer to these reefs as "keystone communities," critical components in a healthy Bay. The degradation and depletion of the reefs over the past century and a half has played an important role in the fishery's decline.
Finally, though, there is some better oyster news emerging. Good spat sets (baby oysters attaching to shells of more mature oysters) in 2010, 2012, and 2015 are part of the story, but good survival of those oysters is even bigger news. Heightened mortality from disease has hurt the Bay's oysters since the 1960s, but there is growing evidence that in certain parts of the Bay the survivors are developing genetic disease tolerance and passing it on to their offspring. Oyster reef restoration programs have ramped up in recent years and appear to be boosting the population, while exporting spat (baby oysters) to waters open for harvest. State and federal efforts are focusing on creating healthy reef systems in target tributaries, an enlightened strategy that should be continued. At present, those target tributaries include the Lafayette, Lynnhaven, and Piankatank Rivers in Virginia and the Choptank (specifically Harris Creek and the Tred Avon River) and the Little Choptank in Maryland. Each state is in the process of choosing two more targets.
Striped Bass (a.k.a. Rockfish)
The news is good, with a healthy dose of caution. Overfishing devastated the Chesapeake’s rockfish stocks in the 1970s, but intensive conservation efforts in the 1980s, '90s, and '00s restored them to peak historical levels. Rigorous interstate management plans coordinated and enforced by the Atlantic States Marine Fisheries Commission (www.asmfc.org) deserve much of the credit for the rebound. However, this favorite fish of both anglers and watermen has now dropped back to a lower—and probably more realistic—level in line with the current carrying capacity of its Bay and coastal habitats.
The latest scientific assessment of the population says that "the stock is not overfished, and overfishing is not occurring," but the spawning stock (mature females) in 2015 was close to the minimum threshold (set conservatively, well above the level of the 1980s) designated in the species’ coastal management plan. Fortunately, good recruitment (spawns) in 2011 and 2015 will begin to bring the numbers back up as these fish mature.
In addition, fishery managers from Maine to North Carolina—the migratory range of Chesapeake rockfish—have cut back both recreational and commercial harvests to help reverse the decline. Concerns remain that striped bass may not have enough food in the form of Atlantic menhaden—an ecologically rich little fish and the preferred food of striped bass. Low summer dissolved oxygen conditions in the Chesapeake (driven by pollution-fueled algae blooms) sometimes force the young fish that stay here into higher water temperatures than they prefer, causing stress that can lead to bacterial infections. The bottom line, though, is that there are beautiful rockfish out there to catch and celebrate, and we have the scientific tools to manage them sustainably. We just have to continue to pay attention, and never take them for granted as we once did.