Sturgeon by-products continued to be exported to Europe through the 1700s. Its tender meat, comparable to pork or swordfish, was often smoked and eaten. Little went to waste as even the sturgeon’s air bladders were valuable, used to make isinglass (a clear gelatin), jellies, clarifying agents for beverages, plasters, waterproofing agents, adhesives and lubricants. By the end of the 19th century, the demand for sturgeon meat and roe had become so large, annual landings as high as seven million pounds were reported.
By the mid-1800s, east coast bays and rivers such as the Hudson, Susquehanna, Delaware, St. Mary’s and St. John’s had exploded with vast commercial fisheries. Meanwhile, Atlantic sturgeon had become one of the most valuable commercial fisheries in the Chesapeake, particularly in the Potomac, York and James rivers. While landings peaked at 725,000 pounds in 1890, fishing continued at a rate that overwhelmed the stock’s ability to keep pace. By 1920, that figure had plummeted to a paltry 22,800 pounds. It’s been 30 years since the last egg-laden female recorded in Maryland was found in the Nanticoke River and the stock remains so depleted that few people now associate the species with the Bay. Biologists believe that the few juvenile sturgeon observed since then have migrated into the Bay from elsewhere.
The restoration effort
While biologists are working hard to restore the Atlantic sturgeon, it will take much more than the reduction of fishing pressure to bring it back. Today the majority of sturgeon lost before reaching maturity are taken as incidental catch in other fisheries. And while sturgeon have few predators outside of sharks and humans (and boat propellers), biological characteristics make them particularly vulnerable to human-induced impacts and changes to it habitats.
Degradation of habitat from increased development and deforestation has reduced the amount of decaying organic matter entering the sturgeon’s historic spawning streams and rivers -Ð forest litter needed to keep eggs from being swept downstream. Water quality is also critical to the survival of adults and juveniles. While certain organic materials are necessary, excessive amounts of nutrients in waterways can create sudden blooms of phytoplankton. After the phytoplankton die, decomposition uses up large amounts of oxygen, leading to dangerously low dissolved oxygen levels along the bottom where sturgeon feed.
And like all anadromous fish, Atlantic sturgeon must have access to their spawning grounds.
By removing blockages or altering the design of dams to accommodate fish passage, sturgeon can reach the upstream
areas that are critical to their reproduction. Still, scientists are not entirely certain that the fish return to their native rivers to spawn as other fish do.
Biologists believe the Atlantic sturgeon population is actually composed of several strains unique to the specific river systems or bays in which they were spawned. Presumably, sturgeon native to a certain area are better adapted to the local environmental conditions than other sturgeon.
In the face of these rather grim statistics, the Maryland Department of Natural Resources Fisheries Service (DNR), the U.S. Fish and Wildlife Service (USFWS), and Chesapeake Biological Laboratory (CBL) embarked on a joint effort to enhance the Chesapeake Bay sturgeon population. This effort began when USFWS biologists collected broodstock from the Hudson River in New York and artificially spawned them at the Lamar Hatchery in Pennsylvania. Some of these juveniles were then transported to Maryland to be raised in a state hatchery or at the Potomac Electric Power Company. The remaining fry followed at a later time, after they had reached stocking size.
In 1996, 3,000 of these hatchery-raised sturgeons were stocked in the Nanticoke River. All were implanted with coded wire tags and floy tags were inserted in the larger sturgeon’s tails. A reward program offered anglers $25 per returned tag, which would provide important data on movement patterns, growth, habitat and by-catch mortality. This information would in turn determine whether the Chesapeake Bay and its tributaries could provide suitable habitat that would allow for feeding, growth, and survival. To date, recaptures from this effort have indicated promising potential for hatchery restoration efforts.
DNR and the USFWS have also been working with watermen to tag wild sturgeon caught in commercial fishing gear. Watermen receive $100 for each live sturgeon they report and $25 for hatchery fish. This has proven to be another valuable source for garnering information about sturgeon in the Chesapeake, and while the data collected indicates the presence of a migratory sturgeon population, there is no existing evidence to indicate a naturally reproducing population in Maryland’s portion of the Bay.
DNR’s efforts to bring about a stable reproducing population in the Chesapeake continue. In 1999, fisheries managers began making plans to use its captive population as broodstock for a sturgeon-stocking program at the Manning Hatchery located in Cedarville. This decision was based on tag returns, improvements in water quality and habitat data, and the reopening of more than 300 miles of Maryland historic spawning streams through the fish passage program.
In addition, the department obtained 20 wild sturgeons ranging in size from 18 to 48 inches from commercial watermen working from Eastern Bay south to Hooper’s Island. These fish are now in the process of being domesticated and will be added to the current population of 200 captive sturgeons. The hope is to be able to speed the growth rate and sexual maturation of the juvenile sturgeons by providing optimal growth conditions, with preliminary maturation studies beginning during the next two years and spawning soon after.
An indicator of Bay health
Proponents of these programs see the sturgeon as an ultimate indicator species for Bay health; a long-lived fish whose survival would reflect the ability to maintain habitat quality over decades. Sturgeon would be particularly valuable in that regard because they primarily feed on bottom-dwelling benthic organisms, such as worms and mussels. Those species are some of the most stressed creatures in the Chesapeake because of chronic low-oxygen conditions on the Bay bottom that result from nutrient pollution.
In the meantime, hope springs eternal in many an angler’s heart that the Atlantic sturgeon will buck the odds and manage to make a comeback in the Bay. As summer arrives, remnants of this once-dominant population still lurk in the Bay’s depths, largely unseen as oblivious anglers delight in their hauls of rockfish and blues. But to catch one of these ghost fish brings both a whiff of nostalgia -- and a stubborn faith that the fortunes of the Chesapeake will return the species to their rightful prominence as in days of yore.
Dorcas Coleman is a staff writer in DNR’s Public Communications Office and assistant editor of this publication.
