Mixed-function oxidase activity in seabirds and its relationship to oil pollution

Area of Science:

• * Environmental toxicology
• * Avian ecophysiology
• * Xenobiotic metabolism

Background:

• * Mixed-function oxidases (MFOs) are crucial for metabolizing xenobiotics.
• * Seabirds are exposed to environmental contaminants, necessitating studies on their metabolic capabilities.
• * Understanding MFO activity in different species and life stages is vital for ecological risk assessment.

Purpose of the Study:

• * To determine hepatic MFO activity in herring gulls throughout their breeding season.
• * To compare MFO activity among adult Leach's storm-petrels, guillemots, and Atlantic puffins.
• * To investigate the effects of Prudhoe Bay crude oil on MFO activity in Atlantic puffins (adults and nestlings).

Main Methods:

• * Measurement of hepatic enzyme activities including epoxide hydrolase, aldrin epoxidase, and cytochrome P450-dependent enzymes.
• * Determination of MFO activity in various seabird species: herring gulls, Leach's storm-petrels, guillemots, and Atlantic puffins.
• * Assessment of MFO induction following exposure to Prudhoe Bay crude oil in Atlantic puffins.

Main Results:

• * Hepatic MFO activity varied in herring gulls across the breeding season.
• * Atlantic puffins generally displayed higher MFO activity compared to Leach's storm-petrels and guillemots.
• * Crude oil exposure induced MFO activity in both adult and nestling Atlantic puffins.

Conclusions:

• * Seabird species exhibit differential MFO activities, with implications for contaminant metabolism.
• * Atlantic puffins show a notable response to crude oil exposure, indicating potential toxicological impacts.
• * Seasonal variations in MFO activity in herring gulls warrant further investigation regarding breeding success and contaminant exposure.