California Coastal National Monument Literature Search and Summarization of Key Biological Resources of the Monument Seabirds and Marine Mammals Prepared For: Bureau of Land Management California Coastal National Monument 299 Foam Street Monterey, CA 93940 Contact: Rick Hanks Prepared By: Mad River Biologists 1497 Central Avenue McKinleyville, CA 95519 David Fix, Biologist Heather Beeler, Biologist Ron LeValley, Senior Biologist Submitted: June 15, 2002 ____________________________________________ Table of Contents I. Introduction .............................................................................................................................. 3 The Offshore Rocks .................................................................................................................... 3 Description of Habitat................................................................................................................. 3 General Management Considerations........................................................................................ 4 Fishing..................................................................................................................................... 4 Recreational Kayaking and Scuba Diving .............................................................................. 5 Seaweed collecting.................................................................................................................. 5 Management recommendations to reduce direct human disturbances ................................... 5 Invasive Species.......................................................................................................................... 6 Plants....................................................................................................................................... 6 Canada Geese.......................................................................................................................... 6 Mammals................................................................................................................................. 6 Interaction with other native species....................................................................................... 6 Management recommendations to reduceimpacts from invasive species .............................. 6 Oil spills.................................................................................................................................. 7 Data Gaps................................................................................................................................ 7 II. Seabird Species Accounts....................................................................................................... 8 Leach’s Storm-Petrel .................................................................................................................. 8 Ashy Storm-Petrel..................................................................................................................... 10 Black Storm-Petrel.................................................................................................................... 12 Fork-tailed Storm-Petrel ........................................................................................................... 14 Brown Pelican........................................................................................................................... 17 Double-crested Cormorant........................................................................................................20 Pelagic Cormorant .................................................................................................................... 22 Brandt’s Cormorant .................................................................................................................. 25 Snowy Egret.............................................................................................................................. 28 Black-crowned Night-Heron..................................................................................................... 29 Peregrine Falcon ....................................................................................................................... 30 Black Oystercatcher.................................................................................................................. 32 Western Gull ............................................................................................................................. 35 Common Murre......................................................................................................................... 38 Pigeon Guillemot ...................................................................................................................... 42 Xantus’s Murrelet ..................................................................................................................... 45 Cassin’s Auklet ......................................................................................................................... 48 Rhinoceros Auklet .................................................................................................................... 51 Tufted Puffin............................................................................................................................. 55 Literature Cited – Seabirds........................................................................................................ 58 III. MARINE MAMMAL SPECIES ACCOUNTS ................................................................ 64 Northern Fur Seal...................................................................................................................... 64 Steller Sea Lion......................................................................................................................... 66 California Sea Lion................................................................................................................... 69 Harbor Seal ............................................................................................................................... 71 Northern Elephant Seal............................................................................................................. 73 Sea Otter.................................................................................................................................... 75 Literature Cited – Marine Mammals........................................................................................ 78 BLM CCNM Issues and Species MRB June, 2002 Page 2 I. Introduction On January 11, 2000, President Clinton established by proclamation the California Coastal National Monument (CCNM). The proclamation identified the Bureau of Land Management (BLM) as the managing agency. The CCNM includes all unappropriated or unreserved lands and interests in lands owned or controlled by the United States in the form of islands, rocks, exposed reefs, and pinnacles above the mean high tide within 12 nautical miles of the shoreline of the State of California. The proclamation specifically identifies the pelagic, nearshore, and terrestrial bird species associated with the CCNM, as well as the importance of this nearshore ocean zone for pinnipeds, general biodiversity, and other species and resources of scientific interest. In anticipation of the development of a management plan for the CCNM, the BLM recognized the need to identify key biological resources, their distribution throughout the CCNM, and their relative importance to the species themselves and to ecosystem viability. With this information available early in the planning process, issues related to the management of these species can serve as both sideboards within which other uses can be directed, and as opportunities for ensuring species viability and increasing public awareness of these resources. This document focuses on the breeding marine birds and mammals of the CCNM. A literature search was conducted to provide a summary of existing information regarding the distribution and status of these species in the CCNM. The information is presented in three sections, the first being a summary of major issues regarding management of these species. The second is an account of each species considered, including pertinent biological data that would be of assistance to land managers. The third segment is a brief geographic discussion focusing on management issues relative to their location in the state. An appendix includes tabulated information suitable for inclusion in a GIS layer. This appendix contains the geographic information gleaned from the literature and in communication with active researchers in California. The Offshore Rocks The proclamation establishing the CCNM described the included islands as “all unappropriated or unreserved lands and interests in land owned or controlled by the United States in the form of islands, rocks, exposed reefs, and pinnacles above mean high tide within 12 nautical miles of the shoreline of the State of California.” In the geographic extent of the monument, there are 12,767 offshore rocks or islands recognized. Of these, 11,507 of them fall under the jurisdiction of the BLM and therefore the CCNM. Only 70 of these rocks are larger than 1 acre and of these only 11 are greater than 5 acres in size. Description of habitat These offshore rocks within the CCNM are distributed along the entire length of California. They are typically small in size, close to the mainland and of low