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Selecting Bioindicator Species for Human, Ecological, and Cultural Well-Being

Posted at 4:09 pm June 25, 2015, in Research Highlights

Published study by Burger, Gochfeld, et al.

We all share a global environment, and each of us has certain desires, expectations and needs on how the finite resources of the earth should be used and shared or monopolized.  One way to measure environmental quality and monitor changes is by tracking selected bioindicator species.  Various interests compete for the use of limited resources.  Some users (e.g. miners) remove resources. Some users (e.g. polluters) degrade them. Some users merely enjoy seeing the resources. Economic profit interests are often pitted against aesthetic/recreational interests on the one hand or subsistence interests on the other.  Large scale industrial mariculture (fish farms) typically displace coastal communities, usurp local fishing grounds, despoil recreational areas, contaminate inland and coastal waters, and adversely impact wildlife.  However, it’s not enough to simply say these things and point fingers.  Environmental regulators and courts require numbers.  Documentation of declines of subsistence and recreational fish harvests or the numbers of migratory shorebirds, provide metrics that have been used to protect habitats and their occupants, both human and wildlife, from unsustainable exploitation.

EOHSI researchers Joanna Burger and Michael Gochfeld have been studying a variety of wildlife species that intersect human activities along coastlines. Along with colleagues at Vanderbilt University and the NJ Department of Environmental Protection, they examined the complexity of selecting species that can serve as bioindicators of human health, ecosystem well-being, and cultural values.  In their paper published in the journal Environmental Monitoring and Assessment, Burger notes “There is considerable interest in developing bioindicators of ecological health that are also useful indicators for human health and cultural well-being. Yet, human health assessment usually encompasses physical/chemical exposures and not cultural well-being.”

Red-Knot

These Red Knots have migrated from wintering grounds in South America, to Delaware Bay where they spend two weeks fattening on Horseshoe Crab eggs to fuel the last step of their migration to Arctic breeding grounds. Note that bird on left has a field readable flag identifying where and when it was captured.

Their research focused on two species, both heavily impacted by human activities. The Chinook or King Salmon (Oncorhynchus tshawytscha) is one of the most valuable species in the Pacific Northwest, supporting commercial, recreational, and tribal subsistence harvests. Salmon breed in fresh water streams. The young migrate downriver to the ocean where they mature, and after several years, they migrate back to their natal stream, past an obstacle course of dams, power plant turbines, and hungry fishermen (humans, birds, and bears). Highly prolific when conditions are favorable, salmon populations withstood exploitation until the mid-1900s. But the construction of dams along the Columbia River, shoreline agricultural development, and industrial pollution have combined to cause serious declines in salmon populations. The ability to measure salmon populations, either with aerial nest counts or counts at fish ladders that bypass dams, made it possible to convince all parties that the then-current harvests were unsustainable. Extensive management has resulted in a turn-around in King Salmon populations, a gratifying success by the numbers. The Red Knot (Calidris canutus rufa), a sandpiper that breeds in the Arctic and winters in South America, offers another example of useful biometrics, convincing authorities, to regulate harvests and prevent overexploitation. On their northward migration to the Arctic, the Red Knots stop for two weeks at Delaware Bay to tank up on Horseshoe Crab eggs before flying non-stop for thousands of miles. However, overharvesting of Horseshoe Crabs, beginning in the 1980s, reduced the food availability for the knots, and their numbers crashed. Gochfeld suggests that “there are several endpoint types to examine for a given species, including physical environment, environmental stressors, habitat, life history, demography, population counts, and cultural/societal aspects.” The cultural values include maintaining the recreational and subsistence cultures that rely on salmon, while protecting a migratory shorebird, of great interest to eco-tourists on the Delaware Bay beaches, and an important part of the bay’s ecosystem, not to mention the Arctic ecosystem in which they raise their young.

Citation: Burger J, Gochfeld M, Niles L, Powers C, Brown K, Clarke J, Dey A, Kosson D. Complexity of bioindicator selection for ecological, human, and cultural health: Chinook salmon and red knot as case studies. Environ Monit Assess. 2015 Mar;187(3):102. DOI:10.1007/s10661-014-4233-4. PMID:25666646