Prepared in cooperation with Kenai Fjords National Park Kittlitz’s and Marbled Murrelets in Kenai Fjords National Park, South-Central Alaska: At-Sea Distribution, Abundance, and Foraging Habitat, 2006–08 Open-File Report 2010–1181 U.S. Department of the Interior U.S. Geological Survey Cover: Two species of Brachyramphus murrelet in alternate plumage; Marbled murrelet (left) and Kittlitz’s murrelet (right). Photographs by Mayumi Arimitsu. Kittlitz’s and Marbled Murrelets in Kenai Fjords National Park, South-Central Alaska: At-Sea Distribution, Abundance, and Foraging Habitat, 2006–08 By M.L. Arimitsu, J.F. Piatt, M.D. Romano, E.N. Madison, and J.S. Conaway Prepared in cooperation with Kenai Fjords National Park Open-File Report 2010-1181 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior KEN SALAZAR, Secretary U.S. Geological Survey Marcia K. McNutt, Director U.S. Geological Survey, Reston, Virginia: 2010 For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment, visit http://www.usgs.gov or call 1-888-ASK-USGS For an overview of USGS information products, including maps, imagery, and publications, visit http://ww.usgs.gov/pubprod To order this and other USGS information products, visit http://store.usgs.gov Suggested citation: Arimitsu, M.L., Piatt, J.F., Romano, M.D., Madison, E.N., and Conaway, J.S., 2010, Kittlitz’s and Marbled Murrelets in Kenai Fjords National Park, south-central Alaska: At-sea distribution, abundance, and foraging habitat, 2006–08: U.S. Geological Survey Open-File Report 2010-1181, 68 p. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. 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Contents Abstract ............................................................................................................................................................1 Introduction.......................................................................................................................................................2 Methods............................................................................................................................................................3 At-Sea Surveys.............................................................................................................................................4 Productivity Surveys .....................................................................................................................................5 Telemetry......................................................................................................................................................5 Marine Habitat...............................................................................................................................................6 Oceanography...........................................................................................................................................6 Tidal Current Velocity................................................................................................................................7 Zooplankton ..............................................................................................................................................7 Hydroacoustics..........................................................................................................................................8 Nearshore Fish..........................................................................................................................................8 Data Analysis................................................................................................................................................9 Results............................................................................................................................................................12 Population, Distribution, and Abundance ....................................................................................................12 Kittlitz’s Murrelets ....................................................................................................................................12 Marbled Murrelets ...................................................................................................................................12 Brachyramphus Murrelets .......................................................................................................................13 Density........................................................................................................................................................13 Productivity .................................................................................................................................................14 Observations of Radio-Marked Kittlitz’s Murrelets ......................................................................................14 Marine Habitat.............................................................................................................................................15 Oceanography.........................................................................................................................................15 Prey Availability.......................................................................................................................................17 Habitat Model ..........................................................................................................................................18 Discussion ......................................................................................................................................................18 Survey Design.............................................................................................................................................19 Population and Distribution .........................................................................................................................20 Telemetry....................................................................................................................................................21 Productivity .................................................................................................................................................21 Habitat ........................................................................................................................................................22 Oceanography.........................................................................................................................................22 Prey Availability.......................................................................................................................................23 Acknowledgments ..........................................................................................................................................25 References Cited............................................................................................................................................26 Appendix 1. Total Count of All Birds and Marine Mammals Observed on Early Season Surveys, Kenai Fjords, Alaska, 2006–08........................................................................................................59 Appendix 2. Total Count of All Birds and Marine Mammals Observed on Mid-Season Surveys, Kenai Fjords, Alaska, 2006–08......................................................................................................................61 Appendix 3. Total Count of Birds and Marine Mammals Observed on Late-Season Surveys, Kenai Fjords, Alaska, 2006–08.......................................................................................................................63 Appendix 4. Catch Per Unit Effort (CPUE, # m-3) and Frequency of Occurrence (FO) of Small Zooplankton at Stations Sampled with a Ring Net, Kenai Fjords, Alaska, 2007 .................................65 Appendix 5. Catch Per Unit Effort (CPUE, # m-3) and Frequency of Occurrence (FO) of Small Zooplankton at Stations Sampled with a Ring Net, Kenai Fjords, Alaska, 2008 ...................................67 iii Figures Figure 1. Map showing Kenai Fjords study area showing place names used in this report ...........................30 Figure 2. Map showing marine bird transect locations in Kenai Fjords National Park, Alaska, summers 2006–08..........................................................................................................................................31 Figure 3. Map showing fledgling survey lines in Aialik Bay and Northwestern Lagoon, Alaska, 2007 ...........32 Figure 4. Map showing approximate area (blue) covered by boat-based and aerial relocation surveys for radio-marked Kittlitz’s murrelets in the lower Kenai Peninsula area, May 10–July 1, 2006 ............................33 Figure 5. Map showing beach seine (triangles), oceanography stations (squares), and large Isaacs-Kidd Midwater Trawl (IKMT, red circles) stations sampled in Kenai Fjords, Alaska................................................34 Figure 6. Map showing large Isaacs-Kidd midwater trawl locations (red circles and black crosses),