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Annual Movements of Shortnose and Atlantic Sturgeons in the Merrimack River, Massachusetts
Author(s) -
Kieffer Micah C.,
Kynard Boyd
Publication year - 1993
Publication title -
transactions of the american fisheries society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.696
H-Index - 86
eISSN - 1548-8659
pISSN - 0002-8487
DOI - 10.1577/1548-8659(1993)122<1088:amosaa>2.3.co;2
Subject(s) - fishery , salinity , saline water , acipenser , spring (device) , environmental science , fish <actinopterygii> , discharge , fresh water , oceanography , sturgeon , geography , biology , geology , drainage basin , mechanical engineering , cartography , engineering
We used biotelemetry to study the movements of 23 adult shortnose sturgeons Acipenser brevirostrum and 23 subadult Atlantic sturgeons Acipenser oxyrhynchus oxyrhynchus in the lower 46 km of the Merrimack River between 1987 and 1990. Shortnose sturgeons used two freshwater reaches and one saline reach annually. Sexually mature fish began moving upriver from freshwater wintering areas to a spawning site in April, when increasing river temperature reached about 7°C and decreasing river discharge reached about 570 m 3 /s. Following spawning in late April–early May, fish moved downriver either to a freshwater reach where they remained all year or farther downriver to a saline reach where they remained for up to 6 weeks. After fish used the saline reach, they returned upriver to fresh water. Atlantic sturgeons entered the river from coastal waters by mid–late May, when increasing river temperatures reached 14.8–19.0°C and decreasing river discharge reached 303–675 m 3 /s, occupying a saline reach with 0.0–27.5‰ salinity. After using the same saline reach visited briefly in spring by shortnose sturgeons, Atlantic sturgeons emigrated from the river by October when maximum river temperatures were 13.0–18.4°C. We observed no tagged Atlantic sturgeons in the river in successive years. Except for use of the saline reach during spring, the two species were spatially separate.