INTERESTING TIMES

Because mercury bio-accumulates, and otters are SO carnivorous, they are like the canary in a coalmine for the detection of mercury. The Wisconsin Dept of Natural Resources asked all the otter trappers for the carcasses and tested various tissues for mercury levels. The levels were highest in fur, with descending concentrations in these tissues: liver, kidney, muscle, and brain. Methyl-mercury made up a greater percentage of total Hg in brain and muscle compared to liver and kidney tissue. So far none of the otters appears to be sickened by their mercury load. The levels in the fur are directly related to the levels in internal tracking, so I suspect future research may follow living otters to see what they're taking in. "A gradient" in tissue concentrations was noted from north to south, but they don't say which way the gradient goes. Perhaps more to the south, like in fish? We shall see.

SOURCES
http://dnr.wi.gov/environmentprotect/pbt/research/OtterSummaryAbstract.pdf
http://www.springerlink.com/content/m4pg0184615kr4hk/
http://www.ncbi.nlm.nih.gov/pubmed/17926081

Also, at http://www.glc.org/glad/projects/basu09/ they are monitoring eagles and otters for biomarkers. The specific aims of this proposal are: 1) Exposure Assessment : to determine tissue mercury and PBDE levels in river otters and bald eagles from several Great Lakes states, with a focus on animals collected from existing statewide monitoring programs in Michigan and Wisconsin; 2) Health Assessment : to determine river otter and bald eagle health status by means of neurochemical biomarker studies on key receptors (muscarinic, glutamate) and enzymes (monoamine oxidase, cholinesterase) in physiologically important brain regions; 3) Risk Characterization : to determine if there is a statistical association between mercury and PBDE exposure (Aim #1) and alterations in neurochemical biomarkers (Aim #2); and 4) Education and Capacity Building : to build capacity among academic researchers and government/state managers and to disseminate results to scientific and regulatory communities.

Got in this afternoon, tired, but with a smile on my face. Neptunia and I paddled 17 miles from Beasley Flats to Childs in two and a half river days, carrying our gear in inflatable kayaks. On the way we saw a great variety of ducks, geese, herons, snatchers and thatchers and bobbers and swoopers--who knows what but many kinds of beatiful birds. In one place we floated right under a high cliff with a bald eagle nest. The mama bird was keeping an eye on us and feeding fledgings and the papa bird was circling overhead. We located a Sinagua tribe cliff dwelling just above Palisades, and farther downstream we saw three otters playing in the river. The otters were working their way upstream to check us out, moving from eddy to eddy, and peering around the edges of rocks for a better look. Near the takeout we visited the Childs hot springs, and I would go back there any day. I tried a new practice on this trip: 10-breath mindfulness meditations, occurring throughout the day. It is a wonderful practice for the backcountry....and I will soon find out how it can fit into my daily life.

Perhaps the most amazing discovery of the trip was the contents and quality of otter shit. It took us a while to sort out exactly what it was.... I brought back a sample, let me know if you want to see it. Let me just say that otter rectums must be considerably tougher than human rectums. That's the trip report for now---I have a biochemistry takehome exam to tackle.

( Hints about River Otter Shit )