Figure 14.3. Historic commercial fishery landings of Atlantic sturgeon in the Hudson River Estuary, 1880-1995.
spawn, production estimates were up, and adult age structure was stabilized. It was then that the Chesapeake stock was declared restored. The state management agencies were not complacent about their success. Even with record numbers of fish, management restrictions were loosened slowly. Commercial harvest quotas were increased, and recreational size limits were lowered to 28 inches.
Annual tracking of mortality rate of the stock is still key. Harvest from all sources is compiled annually. Spawning stocks are monitored for age structure and survival. Young-of-year abundance estimates provide early warning of changes that may come.
Atlantic sturgeon live approximately 60 to 80 years. Males mature by age 8 to 12 and 15 to 20 years for females. Females spawn every three years.
Migratory range:entire Atlantic coast, Canada to FL
Records of sturgeon harvest are available as far back as the 1880s, a time when harvest levels climbed to record highs. The high harvest level essentially clear-cut the once robust population. The Hudson's Atlantic sturgeon stock continued to remain severely depressed through the rest of the twentieth century (Fig. 14.3).
A vestigial fishery persisted in the river through the 1980s, made up of a small group of fishers taking a few fish each year for their caviar and meat. However, interest in this fishery began to change in the late 1980s. Elsewhere on the east coast, other Atlantic sturgeon stocks had already been overfished and harvest restricted or eliminated. The mostimportantwere those that targeted sturgeon produced in the rivers of North Carolina, South Carolina, and Georgia (Smith, 1985). These fisheries stimulated a market demand for smoked sturgeon products as the supply was eliminated through regulation of harvest. In ocean waters, interest rose in the late 1980s targeting the immature sturgeon for the smoked meat market, especially in New York and New Jersey (Waldman, Hart, and Wirgin, 1996).
This market shift occurred while the restrictions in stripedbass management were taking hold along the Atlantic coast. Atlantic sturgeon was among the species that became fishing targets to make up for lost income. In addition, import restrictions from the Middle East (Iran was a source of much of the caviar available in the United States) greatly enhanced the value of any domestic source of caviar. Some of the Hudson's shad fishers began to experiment and eventually became very successful at capturing adult Atlantic sturgeon.
Based on the success of rebuilding the striped bass stocks, the Atlantic Coastal Fisheries Cooperative Management Act was passed in December
1993. This act gave the same stringent enforcement power to all FMPs developed under ASMFC. States, with NewYork in the lead, began to look with much scrutiny at the condition of the River's Atlantic sturgeon stock and the rate at which they were being fished.
With their long lifetime, older age at maturity, and irregular spawning schedules, Atlantic sturgeon are easily over-fished. Young individuals were being harvested in coastal waters as they left the Hudson at age three to seven to begin their long marine residence before they mature ten to fifteen years later. Few fish were surviving to return to the river, and even here a fishery targeted the spawning adults. In 1995, New York tried to implement controls in the fishery with season and area closures, followed in 1996 with the imposition of a quota system, limiting the total take. But by 1997, New York's stock assessment demonstrated that harvest and fishing rates were severely over the limit that the population could handle. A moratorium was put in place that year, and by 1998 the entire U.S. Atlantic coast was closed to harvest. The interstate management plan set a forty-year time limit for the coast-wide moratorium based on the life history of the animal. That is, within the next forty years, the current spawning population's young should be able to grow and mature to produce one more generation before examining the reopening of any fishery.
American shad in the Hudson River live 13 to 15 years. Males begin to spawn by age 3 to 5, females by age 5 to 7.
Migratory range of Hudson shad: Atlantic coast, Canada to NC
At the turn of the twentieth century, the new immigrant population continued to swell the growing Atlantic coast cities, including NewYork. It amazed them to find that every spring fish returned to the Hudson by the thousands, an easy food supply to feed the hungry. Unfortunately for shad, it earned recognition as the second highest harvested fish on the east coast following Atlantic cod. Atlantic sturgeon came in third. The seemingly unlimited harvest, however, wore down the stock, and before long shad suffered the same fate in the Hudson as in other Atlantic coast rivers.
The story of respite, rebuild, overharvest, and collapse occurred several times for the Hudson shad stock (Hattala and Kahnle, 1997). During periods of lowered fishing pressure, the stock rebuilt between collapses. However, the resiliency of this highly fecund species was slowly being eroded as the century wore on. The first collapse occurred prior to the known record. United States Fish Commission reports documented that in the 1870s the Hudson stock was "over-fished and in need of replenishment." Seth Green, then working for New York State, began a hatchery to stock shad in the spawning areas in the upper reaches of the tidal Hudson and even above the Troy Dam (Cheney, 1896). Fishing was not the only problem for the stock. Spawning areas were lost as the shallow bays behind the river's islands were slowly filled with dredge spoil from creation of a shipping channel to the Port of Albany. Nearly a third of the upper tidal Hudson was filled, almost all of it shad spawning habitat. Water quality in the spawning reach also suffered through much of the twentieth century (Faigenbaum, 1937; Burdick, 1954; Talbot, 1954; Boyle, 1979) until improvements to sewage treatment were made.
The gaps in the fishery landings records from the early 1900s (Fig. 14.4) are thought to be from lack of fishing activity. This lack of fishing would have allowed the shad stock to rebuild to a size necessary to produce the dramatically large harvest that occurred during the years leading up to World War II. Fishing this available food source became a valued trade during the war, so much so that fishing rules in the river were suspended. Each spring in the war period, hundreds of fishermen set their nets, and riverside communities took as many fish as the nets could bear.
In less than twelve years, the next stock collapse was underway: the greater the effort, the fewer the fish. In addition, water quality worsened. Sewage poured in and habitat suffered. In the summer, sections of the river, around Albany and the lower estuary, were completely devoid of oxygen. A few shad kept returning, but the overall stock size remained much reduced from its former status. This problem was not unique to the Hudson: for example, the Delaware River was so polluted between
American Shad: Annual NY Landings
500 il t
1850 1900 1950 2000 2050
American Shad: NY Landings Since 1950
1850 1900 1950 2000 2050
American Shad: NY Landings Since 1950
Trenton and Philadelphia that this entire segment went anoxic in the summer months, preventing any movement of fish, such as migrating shad (Chittenden, 1969).
Finally in the mid 1970s, the environmental movement gained momentum. With the passage of the much-strengthened amendments of the Clean Water Act in 1972, the sewage dumping eventually abated. The river slowly started to recover, along with its fisheries.
Humanity's influence again was felt, just as in the case of Atlantic sturgeon. During the recovery effort for striped bass, many near-shore ocean fishers shifted their focus to American shad. These "ocean intercept" fisheries directed their fishing pressure onto mixed assemblages of east coast shad stocks, including the Hudson's. Some stocks began to show declines, or no sign of recovery, despite restoration programs. Since 1991, the Hudson's shad stock began its latest decline, showing classic signs of overfishing. Individuals are smaller at any given age, and fewer older fish are returning to spawn.
A 40% reduction in effort of the directed ocean intercept fishery occurred in 2003 followed by a complete closure on December 31, 2004. How effective will this measure be? At this point, it is unclear how quickly the stocks will respond to the reduced harvest. Directed fishing may come to an end, but in some cases, shad picked up in other fisheries may become discarded bycatch. Continued monitoring of this bycatch will be a key element in managing the coastwide restoration. In the Hudson River, it is still unknown whether further cutbacks will be required, for example, closure of more spawning area, or lengthening the lift (no fishing) period.
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