Effect of habitat use on PCB body burden in Hudson River striped bass (Morone saxatilis)

Abstract

The Hudson River commercial striped bass (Morone saxatilis) fishery has been closed since 1976 due to high polychlorinated biphenyl (PCB) contamination. Accurate forecasting of PCB levels in striped bass has been confounded by high variance in contamination among individuals. We investigated the relationship between habitat use and PCB contamination in Hudson River and Long Island Sound striped bass using electron microanalysis of otolith strontium to generate time series of individual salinity habitation. Males with highly contaminated levels (mean PCB = 8.3 ppm) showed freshwater resident behavior, rarely experiencing salinities >5 ppt. Several individuals showed large habitat shifts. Shifts from brackish or marine habitats to freshwater habitats were often associated with high PCB levels. A third pattern was apparent in large females, where polyhaline/euhaline salinity habitation was associated with lower PCB levels. Total PCB body burden was inversely correlated with mean salinity encountered during the most recent growth season prior to capture. Fish with recent exposure to polyhaline salinities showed high variability in PCB body burdens (0.4-9.0 ppm), suggesting a local source of PCB contamination in the New York Harbor region.

Identification of riverine, estuarine, and coastal contingents of Hudson River striped bass based upon otolith elemental fingerprints

“…1). Contingents of striped bass were initially classified on the basis of visual inspection of salinity chronologies (Zlokovitz & Secor 1999). Mean lifetime salinity (the mean of all salinity records from transect points for an individual) corroborated these classifications (Table 1).…”

“…Migrations within populations are affected by changes in population abundance, climate, flow regimes, and degradation of migration corridors (Leggett 1977). Variable migrations result in differential vulnerability to exploitation and habitat degradation (Kohlenstein 1981, Limburg & Schmidt 1990, Rose & Leggett 1991Frank 1992, Fogarty 1998, Zlokovitz & Secor 1999. Measuring migration variability within populations is complex because methodologies (e.g.…”

“…Clark's contingent hypothesis was revisited by Zlokovitz & Secor (1999), who used microprobe analysis of otolith Sr to explore ontogenetic patterns of migration and habitat use. Otolith Sr serves as a tracer of salinity encountered by striped bass (Secor et al 1995a), and thus microprobe of Sr across annuli within the microstructure of otoliths can be used to reconstruct lifetime history of habitat use along a salinity gradient (Secor & Piccoli 1996).…”

Dynamics of white perch Morone americana population contingents in the Patuxent River estuary, Maryland, USA

“…For example, Clark (1968) described 2 striped bass contingents in the Hudson River estuary: one that would migrate annually from the river to coastal habitats and another comprised of individuals that were spawned in the river and never left. Secor et al (2001) have since observed 3 contingents in the same population, and the migration patterns of these contingents have been used to explain individual variability in PCB (polychlorinated biphenyl) contamination of striped bass in the Hudson River (Zlokovitz & Secor 1999, Ashley et al 2000, Zlokovitz et al 2003. Another example of population contingents is seen in Japanese eels.…”

Intercept Telemetry of the Hudson River Striped Bass Resident Contingent: Migration and Homing Patterns

“…McLaren et al (1981) also described separate migration behaviors in which one group begins a coastal migration after spawning and the other remains resident in the river. Recent otolith microchemistry studies have verified this migratory behavior and classified three contingents: (1) a resident contingent that inhabits the freshwater and oligohaline tidal portion of the Hudson River; (2) an estuarine contingent that inhabits the lower estuary, including the New York City harbor and western Long Island Sound regions; and (3) a migratory contingent that inhabits marine environments and makes annual excursions into freshwater for spawning (from here on, contingents will be labeled ''resident,'' ''estuarine,'' and ''migratory'' after Zlokovitz and Secor 1999, Secor et al 2001, and Zlokovitz et al 2003). …”