Adult Atlantic sturgeon
Background
Atlantic sturgeon of the Hudson River Estuary have supported some level of subsistence or commercial fishing since colonial times. Reported commercial landings of Atlantic sturgeon are available for New York State from 1880 through 1995. Until about 1980, most of the landings came from the Hudson River. Highest annual landings of the time series (231,000 kg) occurred in 1898. Landings quickly dropped to 15,000 kg or less per year and remained at low levels through the early 1980's. In 1985, South Carolina closed one of the few active fisheries open in the southern states. Market demand remained high and effort and harvest increased substantially in New York and New Jersey. Greatest increase in landings was in the near shore ocean along Long Island and the New Jersey coast.
In 1990, the Atlantic States Marine Fisheries Commission (ASMFC) adopted an interstate fishery management plan for Atlantic sturgeon. States with open fisheries began to monitor harvest. In addition, New York initiated population modeling to determine acceptable levels of harvest from the Hudson River stock. In 1993 through 1995, New York regulated the Atlantic sturgeon fishery with size limits, seasons, area closures, and as more data became available, it became apparent that the Hudson River stock was being over fished. NY implemented a harvest moratorium in 1996. New Jersey followed with a zero quota in the same year. In 1998, the Atlantic States Marine Fisheries Commission adopted Amendment 1 to the Interstate Fishery Management Plan for Atlantic Sturgeon. This amendment banned possession of Atlantic sturgeon in all US Atlantic coastal states. It also recommended that states with spawning populations sample adults every five years and identify bycatch losses in state waters.
Spawning locations of Atlantic sturgeon within the Hudson River Estuary remain poorly delineated. Several authors have investigated spawning activity of Atlantic sturgeon within the estuary, but have drawn differing conclusions about spawning location. We hope to learn more about these locations using the sonic tagged fish.
Juvenile Atlantic sturgeon remain within the estuary between two and eight years. When juveniles begin to emigrate they travel widely along the Atlantic coast and its estuaries. However, the stock identification of these fish is completely unknown. Almost nothing is known regarding the migratory behavior, distribution, habitat needs of mature Atlantic sturgeon after leaving fresh-water systems.
Threats
Although harvest of Atlantic sturgeon from the Hudson River Estuary has ended, threats to stock recovery continue. Within the estuary, habitat disturbance and alteration from navigation dredging and occasional petroleum spills pose potential threats to spawning. The NYSDEC attempts to regulate dredging and provide special protection from spills, but these efforts are hampered by inadequate information on specific timing and location of spawning. Within the ocean, mature Atlantic sturgeon are potentially affected by dredge spoil dumping, and bycatch in existing fisheries. Consequences of these losses to a specific stock such as that from the Hudson are impossible to determine because stock specific ocean migration patterns are completely unknown and thus bycatch losses cannot be assigned to stock.
Adult Capturing and Tagging
As recommended by ASMFC, we started a project in collaboration with Hudson River Estuary Program, USFWS, Pew Institute, Hudson River Foundation, and National Fish and Wildlife Foundation. The plan was to catch the fish in the lower river and which would allow us to follow them to their spawning areas. Sampling was conducted in the spring/summer of 2006 and 2007.
Objectives
The objective of this study is to track adult Atlantic sturgeon entering the Hudson River in order to locate spawning grounds. Tasks to accomplish include:
(1) capture of prespawning adult Atlantic sturgeon in the Hudson River estuary;
(2) tagging all unmarked fish, and
(3) attach satellite tags to fish to learn more about their seasonal ocean movement
2006 Sampling
We caught 44 adults. The majority (42 out of 44) of adult Atlantic sturgeon were captured in the Rogers Point - Norrie Point area. The two remaining adults were captured in the Catskill area. Ten pop-off archival tags (PAT) and 12 sonic tags were applied to adult Atlantic sturgeon. Of the 12 sonic tags, 10 were surgically implanted in the body cavity of the fish, and two were applied externally via a loop of 400 lb. test monofilament.
2007 Sampling
We caught 25 adults. We were able to intercept the fish in Haverstraw Bay this year. Five fish (4 males and 1 female) were caught and had a sonic tagged externally attached. 14 fish were caught in the Rogers Point - Norrie Point area and the remaining 6 fish were caught near Diamond Reef in Upper Newburgh Bay. 13 fish are equipped with satellite tags to monitoring their movement on the east coast. 11 fish are equipped with sonic tags to help us determine spawning areas and habitat usage.
Data are currently being summarized and will be available in early 2008.
This logo represents the Hudson River Estuary Program and our efforts to protect this important estuary.
