DOI: 10.5063/f12z13f5
title: Biophysical Observations Aboard Alaska Marine Highway System Ferry: Tustumena, Gulf of Alaska (2004-2008)

description: An oceanographic measurement system aboard the Alaskan ferry Tustumena operated for four years in the Alaska Coastal Current with funding from the Exxon Valdez Oil Spill Trustee Council, the North Pacific Research Board and the National Oceanic and Atmospheric Administration. Sampling water from the sea chest of the ship at 4m, the underway system measured: (1) temperature and salinity: basic physical variables, (2) nitrate: an essential phytoplankton nutrient, (3) chlorophyll fluorescence: an indicator of phytoplankton concentration, (4) colored dissolved organic matter fluorescence: an indicator of terrestrial runoff, and (5) optical beam transmittance: an indicator of suspended sediment. The measurements show large spatial variability at short time scales, but spatially coherent climate change over annual time scales. Governed by snow and ice melt, the ocean climate transitioned from a warm, fresh regime in 2004-2005 to a cold, salty regime in 2007-2008. Agreement with observations at the GAK1 monitoring site near Seward, AK, extends their applicability to the northern Gulf of Alaskas continental shelf. Nitrate and chlorophyll measurements show nutrient-rich periods lead to increased phytoplankton. A computer monitor displayed the water temperature along the route and mapped the progress of the ferry. The successful measurement program and connections to long-term climate change demonstrate the utility of oceanographic measurements from ferryboats. Funding and support: Exxon Valdez Oil Spill Trustee Council Gulf of Alaska Ecosystem Monitoring and Research Program The Alaska Marine Highway System NOAA Pacific Marine Environmental Lab Kachemak Bay Research Reserve Citation: Cokelet, E. D., C. W. Mordy, A. J. Jenkins and W. S. Pegau, 2010. Biophysical Observations Aboard Alaska Marine Highway System Ferries, Exxon Valdez Oil Spill Gulf Ecosystem Monitoring and Research Project Final Report (Gulf Ecosystem Monitoring and Research Project 040699), Alaska Department of Fish and Game, Habitat Restoration Division, Anchorage, Alaska. -------------------------- Publications: --Cokelet, E. D., 2008. Tustumena Ferrybox, invited talk given at the Alaska Marine Science Symposium special session entitled Shipboard Observing Systems: Using Instruments and Humans, a Roundtable Discussion, 22 January 2008, Anchorage, AK. --Cokelet, E. D., A.J. Jenkins, C.W. Mordy, W.S. Pegau, S. J. Baird and M.E. Sullivan. 2009. Long-term Oceanographic Measurements in the Alaskan Coastal Current from a Ferry, Alaska Marine Science Symposium, 19-22 January 2009, Anchorage, AK. --Cokelet, E. D., A.J. Jenkins, C.W. Mordy, W.S. Pegau and M.E. Sullivan. 2008. The Annual Cycle of Water Properties in the Alaska Coastal Current from Ferry Measurements, poster presented at the Alaska Marine Science Symposium, 20-23 January 2008, Anchorage, AK. --Cokelet, E. D., A. J. Jenkins, W. S. Pegau, C. W. Mordy and M. E. Sullivan. 2005. GEM Biophysical Observations Aboard an Alaska State Ferry, talk given at the Marine Science in Alaska 2005 Symposium, 24-26 Jan 2005, Anchorage, AK. --Cokelet, E. D., A. J. Jenkins, W. S. Pegau, C. W. Mordy and M. E. Sullivan. 2005. GEM Biophysical Observations Aboard an Alaska State Ferry, talk given at the NOAA/FOCI seminar series, 16 Feb 2005, Seattle, WA. --Cokelet, E. D., A. J. Jenkins, W. S. Pegau, C. W. Mordy and M. E. Sullivan. 2005. Biophysical Observations Aboard an Alaskan State Ferry, talk given at the ASLO Summer Meeting 2005, 19-24 June 2005, Santiago de Compostela, Spain. --Cokelet, E. D., A. J. Jenkins, W. S. Pegau, C. W. Mordy and M. E. Sullivan. 2005. Biophysical Observations Aboard an Alaskan State Ferry, talk given at the NOAA/NMFS/Auke Bay Lab., 16 Nov 2005, Juneau, AK. --Cokelet, E. D., A. J. Jenkins, W. S. Pegau, C. W. Mordy and M. E. Sullivan. 2006. GEM Biophysical Observations Aboard the Alaskan State Ferry Tustumena, poster presented at Alaska Marine Science Symposium, 23-25 Jan. 2006, Anchorage, AK. --Cokelet, E. D., A. J. Jenkins, W. S. Pegau, C. W. Mordy and M. E. Sullivan. 2007. Climate Shift and Ecosystem Differences Observed in Alaskan Ferry Oceanographic Measurements, poster presented at the Alaska Marine Science Symposium, 21-24 January 2007, Anchorage, AK.