Trace elements in Alaska's ice seals in the 2000s and 2010s

Area of Science:

• Marine Mammal Ecology
• Environmental Toxicology
• Arctic Biology

Background:

• Ice-associated seals are vital subsistence resources and key Arctic predators.
• Understanding trace element levels is crucial for assessing seal health and ecological roles.

Purpose of the Study:

• Analyze trace element concentrations in four Alaskan seal species.
• Investigate trends, relationships with seal characteristics, and dietary indicators.
• Assess potential toxicological risks and nutritional benefits.

Main Methods:

• Analyzed 19 trace elements in liver, kidney, muscle, and blubber of ringed, bearded, spotted, and ribbon seals.
• Measured monomethyl mercury in a subsample.
• Compared concentrations across seal sex, age, and two time periods (2003-2007, 2011-2016).

Main Results:

• Trace element concentrations were generally low and comparable to previous studies.
• Found variations in concentrations related to seal sex and age.
• Observed a decline in magnesium levels over time in some species.
• Methyl mercury and total mercury levels reflected known feeding patterns.
• Cadmium concentrations were higher in bearded and ribbon seals, suggesting dietary differences.
• No significant difference in trace element levels between healthy and sick seals during an unusual mortality event.

Conclusions:

• Trace element levels in Alaskan ice seals are generally within safe ranges.
• Findings provide valuable data for risk assessments and understanding nutritional ecology.
• Trace elements can serve as indicators of diet and environmental changes in Arctic ecosystems.