Following are accounts of the history of the fisheries for the more important anadromous fish in the Hudson River and comments on related factors. Tables 1 and 2 give data from Department records concerning the magnitude and value of the catch of different species and the types and amount of gear used.
The shad has been an important food fish since the arrival of the first settlers in the Hudson River area. It seems certain that the Indians used the resource long before the arrival of these settlers. During the long history of the fishery, there were two periods during which recorded catch records indicate that the shad population was at peak abundance, These were the years 1877 through 1901 and 1936 through 1949 (Table 3). During other years the catch was much lower. Many reasons have been advanced for the declines in abundance, the most frequent, perhaps, being the high rate of exploitation by the commercial fishery on the river.
During the 1800's, the fishery for shad on the Hudson River developed rapidly. Early fishing methods employed fyke and hoop nets, but by 1842 these were replaced by the more efficient stake gill net. Even at this early date., nets nearly blocked the channel and a decline in shad abundance was anticipated. Farmers salted shad in barrels for their own winter consumption, traveling miles to obtain the fish during the spring run. Considerable numbers were also salted and shipped commercially. Nursery and spawning grounds, which originally extended from Kingston to Glens Falls, were restricted in 1825 when a State dam was constructed at Troy, approximately 40 miles below Glens Falls. The combination of an intensive fishery and reduced spawning and nursery grounds apparently caused a reduction in the annual runs, for in 1868 the New York Fish Commission organized an artificial propagation operation with river fishermen. In the years 1883 to 1895, the State hatched and planted 33,322,500 shad fry in the Hudson, and from 1882 to 1895 the United States Fish Commission raised and, planted 2,000,000 eggs and 53,474,000 fry. The State Commission also urged in 1868 that the Legislature enact a law which would increase the lift period (times when gill nets must be out of the water) beyond the two nights and one day each week in effect during the open season from March 15 to June 15. But no action was taken.
In 1896, the Fisheries, Game and Forest Commission reviewed an 1895 census of the shad fishery in the Hudson River and found the industry to be of even greater value ($184,898) than anticipated. A total of 3,471 nets in both New York and. New Jersey landed 1,155,610 shad weighing 4,044,635 pounds. The Commission suggested that shad should be allowed to ascend unmolested two consecutive days and three nights in each week. The Commission also recommended rearing fry to fingerling size in controlled ponds adjacent to the river, and suggestions were made concerning fishways at the State dam in Troy. No action was taken on these matters.
Increases in abundance of shad during the late 1800's were attributed to artificial propagation, but when greatly diminished runs occurred during the first years of the 1900's the early enthusiasm for shad hatcheries was dampened. In 1944., the last hatchery-raised shad fry were planted in the Hudson River. A study of the relationship between hatchery production and the size of the shad run revealed no significant correlation. In view of recent findings which have shown that each female, spawning naturally, produces 100,000 to 500,000 eggs, this is not surprising. In most years, the State hatchery produced no more fry than would have been produced by four or five females of average size left free to spawn in the river.
Concern has been expressed from time to time over the effect of dredging upon the shad. Above the city of Hudson, a small channel was dredged between 1797 and 1831, and this was improved upon in the years which followed. In 1899, a 12-foot channel existed from Coxsackie to Waterford. This was dredged to 27 feet from Albany to Hudson and by 1931 this channel depth had been extended to New York City. These dredging operations destroyed many of the sandbars over which the shad spawned. In recent years dredging reached its peak between 1926 and 1934, and during the years immediately following the abundance of shad increased. It seems obvious that dredging of the sandbars did not diminish the shad's potential to reach high population levels.
As early as 1887, the disturbance of eggs and fry by ship traffic was cited as a cause for the shad's decline. A study of shipping on the river revealed no correlation between ship traffic and shad runs.
River pollution has been suggested often as the cause of the shad fishery's ills. Despite the popularity of this opinion, research reported upon in 1954 gave evidence that organic and industrial wastes were not significant factors in the decline in shad abundance in the Hudson River. Other research published in the same year demonstrated that no correlation existed between average oxygen content of Hudson River water and shad production from 1915 to 1951. Neither of these reports indicated, however, that sewage and chemicals dumped into the river do not kill eggs, larvae, juveniles and adults. On the contrary, comparison of minimum standards of dissolved oxygen, biochemical oxygen demand and bacteria counts with data from the river indicate that the Hudson River is not a good habitat for fish. The Albany-Hudson section was the most polluted. It is interesting that in the 1800's this section contributed significantly to the fishery and was considered as an important spawning area. At present few shad are caught there, and good evidence exists that spawning activity is greatly reduced in this section of the river.
In 1908,, a new State law required nets to be taken up at sunset Thursday and left out of water until Monday at sunrise in the hope that decreased fishing intensity would permit greater egg production and, subsequently, greater runs. During the last 58 years this lift period had been modified on occasion. During World War II, it was reduced and even abolished so that fish could contribute more toward the demand for protein. There are, fortunately, fishery data for enough years during which lift period alterations occurred that the relationship between the two may be examined. Two investigators, working independently, came to the conclusion that fluctuations of the shad fishery were associated with the length of the lift period, i.e., the most important factor was the number of shad escaping to spawn (Table 4). About 85 per cent of the variations in shad runs each year seem dependent upon the escapement of fish in the years in which they were spawned and upon the repeat spawners from the previous year. From the data presented, it appears that a 60-hour lift period each week during the present season (March 15 to June 1) is required to rehabilitate the shad fishery on the Hudson River.
Striped bass were undoubtedly sought by the early settlers along the Hudson River, If catch statistics from 1913 to 1964 are any indication, it is a good guess that this fish was never as abundant as the shad.
The 1869 report of the Commissioners of Fisheries mentioned that fishermen were convinced that striped bass were resident in the river the year around. This is in part true, although there is evidence from tagging that striped bass which originate from Hudson River spawning grounds contribute not only to the river fishery but to the fisheries on the coast of northern New Jersey and in western Long Island Sound. It is perhaps also true that the Hudson River stock, when 6 years or so of age, enters into fisheries beyond these limits. Furthermore, the river is important as a feeding and overwintering area for striped bass which originate in Delaware Bay and Chesapeake Bay.
Spawning grounds occur from Bear Mountain upstream to Kingston. Here the water is essentially fresh and just north of the section of the river where salinities rise sharply as one goes downstream. Nursery grounds for young of the year are in both brackish and fresh-water sections of the river. Brackish water appears to be the most desirable nursery, for here the young grow more rapidly.
In 1938, a fork length. of 16 inches was enacted as the minimum legal size for striped bass taken. This was proposed in order to take advantage of the species' rapid growth and to market the fish at the most acceptable size. Because of the limited migratory movement of the fish in their early years, this law has merit. However, there are good indications from tagging studies that the striped bass population is under-exploited in the Hudson River. At present, striped bass may not be taken by haul seines or fyke nets, and the season is closed from December 1 through March 15. There appears, then, to be a need to evaluate the size limit in the river in relation to the fishing rate and the migratory habits of the fish.
Striped bass populations are subject to the effect of dominant year classes, i.e., on occasion unusually large broods are produced, sometimes when the spawning population is at a low level. To learn what biological, physical and chemical factors cause such dominant year classes is of great importance. It would require a long-term study, but knowledge of the factors could increase the value of the fishery in the river.
In 1961, an hypothesis was presented that the increasing sewage in estuaries may have been indirectly responsible for the frequent occurrence of dominant year classes during the preceding several years. Data were given to show that striped bass eggs and larvae are adapted to survive in the turbid, high-nutrient-laden waters with low dissolved oxygen that result from high sewage effluent, whereas other species are not so adapted. A step in testing this hypothesis would be to isolate and investigate many of the domestic and industrial pollutants in relation to survival of eggs, larvae, juveniles and adults. Shortnosed Sturgeon and Atlantic Sturgeon
Since no distinction between the two species of sturgeon which inhabit the Hudson River has ever been made in records of the catch, it is difficult to discuss the history of the fishery, The Atlantic sturgeon has apparently contributed most to the take. This species migrates from the sea to spawn in the river when about 10 years of age (150 pounds, 75 inches). Immature fish are present in the river during their first 8 years of life, during which time they frequently become entangled in gill nets. The shortnosed sturgeon is a permanent resident of the river, growing less rapidly than the Atlantic sturgeon and spawning generally at 6 years (40 pounds, 21 inches).
At one time in the early history of settlement, sturgeon supported a good market for caviar and fresh fish. In 1875, reduced catches promoted attempts to propagate sturgeon artificially. These attempts were never successful. An 1888 report of the U. S. Fish Commission stated that the caviar industry was responsible for the decline in the fishery.
A State law in 1926 prohibited the taking of either sturgeon between September 2 and May 30 and set size limits of 42 inches on Atlantic sturgeon and 20 inches on shortnosed sturgeon. There is no evidence that these measures were effective. A slow rate of growth and high fishing rates were perhaps the reason. Today, there is no closed season on Atlantic sturgeon, and the size limit is 30 inches. Possibly this limit is inadequate to provide a spawning population of sufficient size to maintain the population at anything but low levels. It may also be that pollutants adversely affect the eggs, larvae and juvenile fish. There is good reason to investigate these possibilities, for the sturgeon fishery was once of considerable commercial value.
Catches of alewifes and blueback herring since 1913 do not reflect their actual abundance in the Hudson River. These herring are not in great demand, even though they produce a good pickled fish. In 1935, the Conservation Department expressed concern about the under-exploitation of the herring resources. Probably the resource is still not properly utilized., for these fish offer a good source for pet food as well as a pickled product.
In recent years there have been many complaints about off flavor of fish taken in the Hudson River. This has affected the acceptability and the price of shad and striped bass from the river. A high proportion of the fish are said to taste like gasoline or kerosene, and the off flavor has been attributed to oil spillage at unloading installations and to deliberate pumping of bilges by tankers. There are regulations concerning oil pollution, and these should be enforced so that the fish products of the river may be of high quality.
Information concerning the difficulties encountered at the Indian Point generating plant owned by the Consolidated Edison Company was documented in the 1965 hearings before the Subcommittee on Fisheries and Wildlife Conservation of the U. S. Committee on Merchant Marine and Fisheries. Fish mortalities involving striped bass, white perch, tomcod, American smelt and unidentified species of herring occurred at the intake and travelling screen section of the plant where the river water is pumped into the installation to cool the generators. Recent reports indicate that, although mortalities still occur, they are not as great. The reduction has come about through modification by the Consolidated Edison Company.
Recent plans by the same company to construct a pumped-storage generating plant at Cornwall have presented the problem of mortalities to Hudson River fish once again, and proposed use of river water at Chelsea by New York City indicates that demands upon the water resource of the river will increase in the future. Past experience reveals that the problems of plant modification in relation to fish protection require time and expert advice so that modification time may be reduced to a minimum.
Because of the increased demand that is being placed upon the water resources of the Hudson River, it is necessary to consider several features of the relationship between fish and river environment. Anadramous fish cannot survive the transition from salt water to fresh water at will. The transition requires physiological adaptations, and these adaptations are successful as long as there is a reasonably long salinity gradient. Further., the distribution of many of the organisms upon which these anadramous fish feed as larvae, juveniles and adults is controlled by salinity. Changes in salinity at particular locations can cause alterations in the abundance of such organisms, which may reduce the suitability of an area as a nursery or feeding ground. It is also of concern that a positive downstream flow of water is required by anadramous fish to enable them to reach their spawning grounds. These relationships strongly indicate that there is a point beyond which manipulation of water resources will affect seriously the abundance of anadramous fish in the Hudson River.
Species relationships have been studied in unpolluted and polluted waters. It is characteristic of unpolluted waters that there are numerous species of fish and that many of these occur in substantial numbers. On the other hand, in waters polluted by domestic, commercial and thermal effluents, the environment is dominated by one species and relatively fewer species are present. In polluted waters, in addition to toxicity and off flavor factors, the diversity of species tends to be low and unpredictable. It is possible, therefore, that a river which should support good populations of shad, striped bass and alewife can be dominated by blueback herring through the effects of pollution.
