TROUBLE IN THE “BLUE PEARL”: A 15 YEAR STUDY OF ANTHROPOGENIC THREATS AND FISH COMMUNITY CHANGE IN MONGOLIA’S LARGEST LAKE

Lake Hovsgol is the largest lake in Mongolia and the 17^th largest lake in the world by volume.  Despite its remote location and low local population density, Mongolia’s “Blue Pearl” is subject to many of the same threats as other large lakes around the world. Joint Mongolian-American research expeditions since 2006 show that levels of microplastic pollution rival those in more developed watersheds.  Extreme regional climate warming, changes in precipitation patterns, and increased demand for fish are all factors that may be responsible for declines in abundance and mean size of many of Lake Hovsgol’s fishes.  Data-limited stock assessment methods suggest that depletion of some fish species is now approaching or surpassing sustainable limits, despite official prohibitions on fishing. Life history and spawning site diversity within the endangered endemic Hovsgol grayling may provide a measure of resilience for this species.  However, fishes throughout the short food chain are heavily reliant on a single species of gammarid amphipod.

Primary Presenter: Olaf Jensen, University of Wisconsin-Madison (olaf.p.jensen@gmail.com)

Authors:

Olaf Jensen, UW-Madison, Center for Limnology  (olaf.p.jensen@gmail.com)

Bud Mendsaikhan, Mongolian Academy of Sciences, Institute of Geography and Geoecology  (budmendsaihan@gmail.com)

Batsaikhan Ganzorig, Taimen Conservation Fund  (hucho_ganzo@yahoo.com)

Sudeep Chandra, University of Nevada - Reno  (sudeep@unr.edu)

Christopher Free, University of California - Santa Barbara  (cfree@gmail.com)

Thomas Hrabik, University of Minnesota - Duluth  (thrabik@d.umn.edu)

Kirk Olson, Wisconsin Department of Natural Resources  (Kirk.Olson@wisconsin.gov)

Margaret Shaw, UW-Madison, Center for Limnology  (mjshaw89@gmail.com)

Talia Young, Haverford College  (tyoung@haverford.edu)