Chapter 4. Refuge Biology and Habitats
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Protection Island and San Juan Islands National Wildlife Refuges CCP/WSP Chapter 4. Refuge Biology and Habitats This chapter addresses the biological environment of the Protection Island and San Juan Islands National Wildlife Refuges (NWRs); however, it is not an exhaustive overview of all species and habitats. The chapter begins with a discussion of biological integrity, as required under the National Wildlife Refuge Administration Act, as amended. The biological integrity (601 FW3) analysis section introduces the biological environment by describing the native wildlife and vegetation that occur on the two Refuges in comparison to the surrounding landscape. The bulk of the chapter is then focused on the presentation of pertinent background information for the priority habitats and species that the Refuge Complex personnel will actively manage to accomplish biological conservation and/or restoration. The priority habitats and species are collectively known as the ‘priority resources of concern’ designated under this CCP. Background information includes description, location, condition, trends, key ecological attributes, and threats associated with each priority resource of concern. The information presented herein was used by the CCP team to develop goals and objectives for each of the priority resources of concern. 4.1 Biological Integrity Analysis The National Wildlife Refuge System Improvement Act of 1997 directs the Service to ensure that the biological integrity, diversity, and environmental health (BIDEH) of the Refuge System are maintained for the benefit of present and future generations of Americans. In simplistic terms, elements of BIDEH are represented by native fish, wildlife, plants, and their habitats as well as those ecological processes that support them. National Wildlife Refuge System Policy on BIDEH (601 FW 3) also provides guidance on the consideration and protection of the broad spectrum of fish, wildlife, and habitat resources found on refuges and associated ecosystems that represents BIDEH on each refuge. Through the consideration of BIDEH, the refuges will provide habitat for all appropriate native species. Refuge management priorities may change over time, and since the CCP is designed to be a living, flexible document, changes will be made as needed and at appropriate times as identified by refuge personnel. Protection Island NWR is located in the southeast corner of the Strait of Juan de Fuca approximately 2 miles from the mouth of Discovery Bay. Approximately 70% of the island’s roughly 370 acres consists of an upland plateau surrounded by very high, steep-sloped sandy bluffs. Currently, about 80% of the plateau is covered by grassland and 20% by mixed coniferous forest. Sediment derived from the steep unvegetated bluffs along the north and south shorelines and transported by longshore currents to the ends of the crescent-shaped island results in two sand and gravel spits: Kanem Point on the southwest and Violet Point on the southeast. The San Juan Islands NWR is located within the San Juan Archipelago, at the convergence of the Strait of Juan de Fuca and the Strait of Georgia. Geologically, the 83 small rocks, islands, and reefs comprising the Refuge contain extensive exposures of sedimentary, metamorphic, and/or volcanic bedrock which are occasionally overlain with glacial and alluvial deposits, particularly on the larger islands. The combination of these soil characteristics, near-drought conditions during the summer months, and highly variable topography and aspect results in a diverse assemblage of plant communities and ecological systems that range from xeric to mesic (Franklin and Dyrness 1988). The BIDEH of the ecosystems, including and surrounding the Refuges, have undergone dramatic alterations since pre-settlement times. The most discernible changes are related to: a) the conversion and development of large portions of coastal areas into agriculture, housing, commercial, and industrial lands; b) human-caused wildlife disturbance; c) the introduction of contaminants into the aquatic environment; d) fisheries bycatch and marine debris; e) the alteration of fire regimes; f) the loss of native species Chapter 4. Refuge Biology and Habitats 4-1 Protection Island and San Juan Islands National Wildlife Refuges CCP/WSP accompanied by a large influx of non-native and invasive plants and animals into the system; and g) climate change. This section discusses the connection between these main landscape-level changes with the current vegetation and wildlife on the lands and waters occupied by the Refuges. This summary is not a complete analysis of all factors related to changes in native vegetation, fish and wildlife. For the purposes of this document, we define the Salish Sea as encompassing the Strait of Juan de Fuca, Puget Sound (Olympia north to Deception Pass and west to Hood Canal), and the Strait of Georgia (See Figure 1.1). This area effectively defines the ecosystem that encompasses the refuges. We use this term wherever relevant; however, it is a relatively new term and spans international boundaries. Therefore, throughout this chapter, we may refer to the sections of the Salish Sea listed above when a study, survey, or other source reports only for that section. 4.1.1 Habitat Loss or Degradation Habitat conversion for human uses within the Salish Sea, which includes Protection Island and the San Juan Islands, has been rapid since the mid-late 1800s and continues today, bringing profound and widespread alterations to the watersheds and shorelines of the region. Logging and the milling of logs were among the earliest and more defining aspects of early settlement. Lower floodplains and tidal wetland areas were diked and drained in order to become prime locations for agricultural settlement. Major river delta areas such as Seattle and Tacoma were converted into centers of industrial and urban development. Today, over 40% of the region has been converted to urban or agricultural uses while most of the remainder is in production forestry (Floberg et al. 2004). Furthermore, as residential, commercial, and industrial development occurs in close proximity to water, spit features and other low-lying sediment depositional areas along the shoreline were modified by armoring (bulkheads consisting of rock, concrete, and timber), large revetments (sloped face to protect a bank or shore structure, usually constructed of rock), causeways (fill corridors that extend across embayments), groins (cross-shore structures designed to trap sediment), overwater structures, fill, and dredging (Johannessen and MacLennan 2007). Approximately 34 percent, or 805 miles, of the shoreline inventoried by the Washington State ShoreZone Inventory has undergone such modifications (WDNR 2001). Shore modifications, almost without exception, impact the ecological functioning of nearshore coastal systems. The proliferation of these structures has been viewed as one of the greatest threats to the ecological functioning of coastal systems (PSAT 2003a, Thom et al. 1994). 4.1.2 Human-caused Wildlife Disturbance Many of our partners have identified this threat in their plans and have identified similar strategies to ours to address this threat (USFWS 2005, WDFW 2005, Evens and Kennedy 2007, Mills et al 2005, NMFS 2008, Tessler et al 2007, USFWS 2007). The counties containing the Refuges (San Juan, Jefferson, Whatcom, Skagit, and Island) have experienced rapid (>50% increase) human population growth over a twenty year period from 1980 to 2000 (WSDOT 2009). Additionally, this area has become an increasingly popular tourist destination, particularly during the summer months. As a result, activities such as fishing, boating, recreational aviation, camping, and other economic and recreational activities have increased within the coastal areas. These activities often cause stress, reduced productivity, and increased predation of seabirds and pinnipeds associated with the Refuges (Rojek et al. 2007). Please refer to the Priority Resources of Concern sections for further discussion and detailed descriptions of habitat, associated wildlife, and disturbance factors. 4.1.3 Oil Spills and Other Contaminants These two Refuges are particularly vulnerable to the threat of oil spills. Shipping lanes for cargo ships 4-2 Chapter 4. Refuge Biology and Habitats Protection Island and San Juan Islands National Wildlife Refuges CCP/WSP and large oil transport vessels that carry crude oil to refineries are located throughout the Salish Sea with primary ports in Seattle, Tacoma, Olympia, Port Angeles, Everett, Bellingham, Anacortes, Washington, and Vancouver, B.C. Tanker traffic alone through this area carries over 15 billion gallons of oil each year (WDOE 2009). Such high vessel presence increases the risk of oil spills that can cause devastation to the marine ecosystem. Additionally, other sources of hydrocarbon pollution from diesel, gasoline, kerosene, lubricant and various industrial oils are just as toxic to wildlife but can occur at a much smaller scale and may not be properly tracked (USFWS 2005). In addition to the threat of oil spills, over the past 150 years human activities around the Salish Sea have introduced a variety of persistent, bioaccumulative toxic chemicals into the environment at levels that can be harmful to both humans and wildlife. These toxic chemicals include heavy metals such as lead, mercury, and copper, as well as organic compounds such as polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCB), dioxins,