EPA's Vessel General Permit and Small Vessel General

1995 (Peterson et al. 2000), the Atlantic sturgeon fishery was closed by the Atlantic States
Marine Fisheries Commission in 1998, when a coastwide fishing moratorium was imposed for
20-40 years, or at least until 20 year classes of mature female Atlantic sturgeon were present
(ASMFC 1998).
Since the closure of the Atlantic sturgeon fishery, the only assessments of adult spawning
populations have been made in the Hudson and Altamaha Rivers. While Atlantic sturgeon have
been captured, tagged, and tracked through estuaries and rivers along the East Coast, no other
estimates of spawning run size or juvenile population sizes have been made. Estimating the
number of spawning adults relies on the assumptions that 1) all adults that migrate into the
freshwater portion of a river are native to that river and 2) all adults are making that upstream
migration with the intention of spawning. Kahnle et al. (2007) reported that approximately 870
adults per year returned to the Hudson River between 1985 and 1995. Peterson et al. (2008)
reported that approximately 324 and 386 adults per year returned to the Altamaha River in 2004
and 2005, respectively.
Juvenile Atlantic sturgeon abundance may be a more precise way to measure the status of
Atlantic sturgeon populations because it is believed that all age-1 and age-2 juveniles are
restricted to their natal rivers (Dovel and Berggren 1983, Bain et al. 1999), avoiding the
assumptions noted above. Peterson et al. (2000) reported that there were approximately 4,300
age-1 and -2 Atlantic sturgeon in the Hudson River between 1985 and 1995. Schueller and
Peterson (2010) reported that age-1 and -2 Atlantic sturgeon population densities ranged from
1,000 to 2,000 individuals over a 4 year period from 2004 to 2007.
Threats
Sturgeon are often caught as bycatch in other fisheries, and this poses a major threat to the
species. Most Atlantic sturgeon managers and researchers consider water quality as a moderate
risk to every DPS in the United States (ASSRT 2007). During all stages of development,
Atlantic sturgeon are sensitive to temperatures above 28°C (Niklitschek and Secor 2005, Kahn
and Mohead 2010, Niklitschek and Secor 2010) and dissolved oxygen levels below 4.3 to 4.7
parts per million (Secor and Niklitschek 2002, Niklitschek and Secor 2009a). Juvenile sturgeon
are also stressed by high salinities until they mature and out migrate. Additionally, sturgeons
generally and Atlantic sturgeon specifically are sensitive to pesticides, heavy metals, and other
toxins in the aquatic environment.
Life history
While intensely studied since the 1970s, many important aspects of Atlantic sturgeon life history
are still unknown. The general life history pattern of Atlantic sturgeon is that of a long lived, late
maturing, iteroparous, anadromous species. The species’ historic range included major estuarine
and riverine systems that spanned from Hamilton Inlet on the coast of Labrador to the Saint
Johns River in Florida (reviewed in Murawski and Pacheco 1977, Smith and Clugston 1997).
Atlantic sturgeon spawn in freshwater, but spend most of their sub-adult and adult life in the
marine environment. While few specific spawning locations have been identified in the United
States, through genetic analysis, many rivers are known to support reproducing populations.
Early life stage Atlantic sturgeon coupled with upstream movements of adults suggest spawning
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