blubber of Cape fur seals Arctocephalus pusillus pusillus off the Eastern Cape coast of South Africa
نویسندگان
چکیده
The concentration of heavy metals (Cd, Cu, Pb, Ni and Zn) and organochlorine contaminants (PCBs, DDT, DDE and DDD) in the blubber of 12 adult male Cape fur seals, Arctocephalus pusillus pusillus, inadvertently caught in trawl nets off the Eastern Cape coast of South Africa during commercial fishing operations between May 1993 and October 1994, was investigated. The median and range of concentrations for each metal were, in μg/g wet weight: Cd, 0.4 (<0.04–0.53); Cu, 2.6 (2.17–7.43); Pb, 0.7 (0.54–0.99); Ni, 17.7 (9.39–23.18) and Zn, 11.5 (3.14–16.65). Dry weights were: Cd, 0.5 (<0.04–0.59); Cu, 2.9 (2.47–8.45); Pb, 0.6 (0.54–1.14); Ni, 17.0 (10.79–28.22) and Zn, 12.8 (3.61–20.26). Concentrations of Cd, Pb and Zn were in the limits of reported values; however Cu and Ni levels were considerably higher. There is no evidence that the elevated levels of Cu and Ni reported in this study would pose a serious threat to the health of individual animals; however, high concentrations of these metals may be sufficient to result in some additional stress to animals when they mobilise their lipid reserves during illness or starvation. Nickel and Cd concentrations appeared to increase with age; however, small sample size prevented statistical analysis. Concentrations of organochlorines (μg/g wet weight) were below the limit of detection. Concentrations of heavy metals and organochlorine contaminants
منابع مشابه
Intraguild predation and partial consumption of blue sharks Prionace glauca by Cape fur seals Arctocephalus pusillus pusillus
Intraguild predation and partial consumption of blue sharks Prionace glauca by Cape fur seals Arctocephalus pusillus pusillus C Fallows, HP Benoît & N Hammerschlag To cite this article: C Fallows, HP Benoît & N Hammerschlag (2015) Intraguild predation and partial consumption of blue sharks Prionace glauca by Cape fur seals Arctocephalus pusillus pusillus, African Journal of Marine Science, 37:1...
متن کاملMarine predator–prey contests: Ambush and speed versus vigilance and agility
Differences in relative strengths and weaknesses between predators and prey under tactical contexts result in complex and dynamic contests between them. These contests are often brief and difficult to observe in marine systems. Here, we employ basic principles of underwater optics and physics to provide a conceptual understanding of mechanisms underlying predator prey interactions between white...
متن کاملRunning the gauntlet: a predatoreprey game between sharks and two age classes of seals
We present both an empirical study and a behavioural game model exploring a predatoreprey game between white sharks, Carcharodon carcharias, and Cape fur seals, Arctocephalus pusillus pusillus, around a small island colony in South Africa. Behavioural tactics used by adult seals appear to account for the variance in risk from sharks, while shark tactics seem more influenced by the behaviour of ...
متن کاملCoping with Heat: Function of The Natal Coat of Cape Fur Seal (Arctocephalus Pusillus Pusillus) Pups in Maintaining Core Body Temperature
Cape fur seal (Arctocephalus pusillus) pups spend the first weeks of life exclusively or mainly ashore. They are exposed to intense solar radiation and high temperatures for long time periods, which results in temperatures up to at least 80°C on their black natal coat. To test the hypothesis that the natal coat has a crucial function in coping with these extreme conditions, we investigated the ...
متن کاملPatterns of long-term climate variability and predation rates by a marine apex predator, the white shark Carcharodon carcharias
Understanding potential responses of aquatic animals to climate variability is important, given the wide-ranging implications of current and future climatic change scenarios. Here, we used long-term data from natural predator−prey interactions between white sharks Carcharodon carcharias and Cape fur seals Arctocephalus pusillus pusillus in False Bay, South Africa, paired with environmental moni...
متن کامل