Sediment core sampling on White Bear Lake, MNĀ  July 2019; Matt Wersebe (r) and Mark Edlund (St. Croix Watershed Research Station) hold up a sediment core taken at a water depth of ~80 feet. Note: the color transition from black (top) to gray (bottom) representing post- and pre-colonization time periods (time horizon transition is ca. 1850).
Matt Wersebe setting up a sediment core for extrusion at the St. Croix Watershed Research Station (July 2019).



Polar Bear – Churchill, Manitoba, Canada, August 2012
Churchill, Manitoba, Canada: Bluff C – Pond 23, August 2012
Churchill, Manitoba, August 2012 – Bluff B; L-R, Marcin Wojewodzic, Dagmar Frisch, Puni Jeyasingh, L.J. Weider
Summer 2010: Coring South Center (SC) Lake, MN: L-R; L.J. Weider, Ryan O’Grady
Tundra Northwest ’99 (TNW’99) Expedition – Arctic Canada – Sampling a tundra pond, Devon Island, August 1999
Daphnia attack, Devon Island, August 1999
Flagship of the Canadian Coast Guard – Louis S. St. Laurent – Beaufort Sea, August 1999 during TNW’99 expedition
TNW’99 Expedition August 1999: Helo-deck on the “Louie”, off the north coast of Banks Island, NW Passage, Canada – we are getting ready to load up and set off for Banks Island. L-R: Bertie Bertilsson, Hans Borg, Marcus Meili, L.J. Weider


August 1992 – Reindeer Plain on Svalbard – LJ Weider is sorting samples of Daphnia collected from tundra ponds in the region. Photo courtesy of Anders Hobaek (NIVA, Norway)