Seabirds as Environmental Indicators
While various marine species have been used as environmental sentinels, the unique utility of piscivorous seabirds has been documented consistently in the literature. Piscivorous seabirds typically have higher contaminant levels than seabirds feeding on plankton or other lower trophic level prey, and additionally have lower variance in organochlorine concentrations than do fish or marine mammals. Therefore, a relatively small sample size of seabird tissues (i.e. eggs or blood) can be collected from centralized colonies to provide sufficient statistical power with limited environmental impact and low sampling costs. Lipid-rich seabird eggs provide an ideal matrix to measure lipophilic contaminants, where concentrations reflect biomagnification and maternal transfer. From a human health perspective, chemicals detected in coastal species (like seabirds) inform us of contamination risks to the high-density human population living in urbanized and industrialized coastlines.
Many targeted ecotoxicological studies in avifauna have extensively highlighted adverse and sub-lethal health consequences associated with typically monitored, persistent organic pollutants (i.e. PCBs, PBDEs, DDTs, etc.). Nontargeted analytical approaches – which identify typically unmonitored contaminants – may be particularly valuable for monitoring highly impacted, urbanized sites due to the potential influx of unrecognized and/or unknown anthropogenic compounds. The Lewison Lab has begun to demonstrate the utility of the nontargeted analytical approach, using GCxGC/TOF-MS, in identifying halogenated organic compounds in a piscivorous seabird, the Black skimmer (Rynchops niger), inhabiting an urbanized coastal area of San Diego Bay, CA. Our results highlight the importance of employing complex analytical tools to assess true contaminant burdens in organisms, as well as to demonstrate the value of using environmental sentinels, like seabirds, to proactively identify both emerging and previously unknown contaminants.
Many targeted ecotoxicological studies in avifauna have extensively highlighted adverse and sub-lethal health consequences associated with typically monitored, persistent organic pollutants (i.e. PCBs, PBDEs, DDTs, etc.). Nontargeted analytical approaches – which identify typically unmonitored contaminants – may be particularly valuable for monitoring highly impacted, urbanized sites due to the potential influx of unrecognized and/or unknown anthropogenic compounds. The Lewison Lab has begun to demonstrate the utility of the nontargeted analytical approach, using GCxGC/TOF-MS, in identifying halogenated organic compounds in a piscivorous seabird, the Black skimmer (Rynchops niger), inhabiting an urbanized coastal area of San Diego Bay, CA. Our results highlight the importance of employing complex analytical tools to assess true contaminant burdens in organisms, as well as to demonstrate the value of using environmental sentinels, like seabirds, to proactively identify both emerging and previously unknown contaminants.