Dataset: contaminants_Metals
Deployment: NEC-EM2001-1

The heavy metals As, Cu, Se, Zn, were detected in most fish at all sites, while Hg, Cd, and Ag were detected primarily in cod from the three GB sites. Several metals including Al, Cr, Mn, Tl, and V were detected in only a few fish across all sites or not at all. These metals were dropped from the analysis. Statistical analysis of the four metals detected in all sites reveals a trend in which the concentrations are consistently lower in the SB cod compared to the GB cod. This is interesting, since the sediment trends suggest slightly higher concentrations of metals in SB and WB, compared to GB, although as noted earlier, the sediment data are limited to only two samples and thus can only be considered as a very limited data set. Comparing our results for metals to those of Hellou et al., (1992) who measured trace metals in cod livers collected off the coast of Newfoundland, the mean concentration of Cd in fish from GB was roughly 8-10 fold higher than those concentrations reported by Hellou and Cu is up to 3-fold higher. We were unable to compare our data with concentrations recently reported by the USGS National Water Quality Assessment Program, because they report concentrations in fillet rather than in liver (USGS 2002). Interestingly, the concentrations of Cd in GB cod livers from our study were within the range of concentrations found in fresh water fish (measured as whole-bodies) collected from a lake contaminated by an electroplating plant, and are comparable to some of the higher mean concentrations of cadmium (which ranged from 0.1-19.6) in NOAA’s 1987 Status and Trends report (NOAA 1987). The Cd concentrations measured in the GB cod are also within range of cadmium concentrations reported in tilefish livers from several deep sea canyons located in the Middle Atlantic Bight, including one location (Lydonia Canyon) on Georges Bank (Steimle et al., 1996; Steimle et al., 1990). Cadmium and copper are known reproductive and developmental toxicants in fish (reviewed in Sorensen 1991; Jarvinen and Ankley 1999). However, the potential for adverse reproductive or developmental effects in cod caused by Cd at the concentrations measured in this study remain unclear, because the majority of toxicity data relate either exposure concentrations to toxicity, rather than tissue concentrations, or were designed to evaluate life stages and endpoints other than those of interest in this current study. In the gonads, the only metals consistently detected were Fe, Na, Se, K and Zn. Both selenium and Zn were higher in gonads compared to livers, which is in agreement with an earlier study by Hellou et al. (1992), who noted their importance for the normal functioning of certain enzymes.

The heavy metals As, Cu, Se, Zn, were detected in most fish at all sites, while
Hg, Cd, and Ag were detected primarily in cod from the three GB sites. Several metals
including Al, Cr, Mn, Tl, and V were detected in only a few fish across all sites or not at
all. These metals were dropped from the analysis. Statistical analysis of the four metals
detected in all sites reveals a trend in which the concentrations are consistently lower in
the SB cod compared to the GB cod. This is interesting, since the sediment trends suggest
slightly higher concentrations of metals in SB and WB, compared to GB, although as
noted earlier, the sediment data are limited to only two samples and thus can only be
considered as a very limited data set. Comparing our results for metals to those of Hellou
et al., (1992) who measured trace metals in cod livers collected off the coast of
Newfoundland, the mean concentration of Cd in fish from GB was roughly 8-10 fold
higher than those concentrations reported by Hellou and Cu is up to 3-fold
higher. We were unable to compare our data with concentrations recently reported by the
USGS National Water Quality Assessment Program, because they report concentrations
in fillet rather than in liver (USGS 2002).
Interestingly, the concentrations of Cd in GB cod livers from our study were within the
range of concentrations found in fresh water fish (measured as whole-bodies) collected
from a lake contaminated by an electroplating plant, and are comparable to some of the
higher mean concentrations of cadmium (which ranged from 0.1-19.6) in NOAA’s 1987
Status and Trends report (NOAA 1987). The Cd concentrations measured in the GB cod
are also within range of cadmium concentrations reported in tilefish livers from several
deep sea canyons located in the Middle Atlantic Bight, including one location (Lydonia
Canyon) on Georges Bank (Steimle et al., 1996; Steimle et al., 1990).
Cadmium and copper are known reproductive and developmental toxicants in fish
(reviewed in Sorensen 1991; Jarvinen and Ankley 1999). However, the potential for
adverse reproductive or developmental effects in cod caused by Cd at the concentrations
measured in this study remain unclear, because the majority of toxicity data relate either
exposure concentrations to toxicity, rather than tissue concentrations, or were designed to
evaluate life stages and endpoints other than those of interest in this current study.
In the gonads, the only metals consistently detected were Fe, Na, Se, K and Zn. Both
selenium and Zn were higher in gonads compared to livers, which is in agreement with an
earlier study by Hellou et al. (1992), who noted their importance for the normal
functioning of certain enzymes.