Habitat Areas of Particular Concern on the West Coast
HAPCs are considered high priority areas for conservation, management, or research because they are important to ecosystem function, sensitive to human activities, stressed by development, or are rare.
Along the West Coast, the Pacific Fishery Management Council identifies habitats that fall within “Habitat Areas of Particular Concern” (HAPC) and recommends these to NOAA Fisheries consistent with the Magnuson-Stevens Act. HAPCs are considered high priority areas for conservation, management, or research because they are important to ecosystem function, sensitive to human activities, stressed by development, or are rare. These areas provide important ecological functions and/or are especially vulnerable to degradation and can be designated based on either specific habitat types or discrete areas. HAPCs are a discrete subset of essential fish habitat (EFH), as illustrated below.
The HAPC designation does not automatically confer additional protections or restrictions upon an area, but they help to prioritize and focus conservation efforts. Although these habitats are particularly important for healthy fish populations, other EFH areas that provide suitable habitat functions are also necessary to support and maintain sustainable fisheries and a healthy ecosystem.
HAPCs have been identified under the Pacific Coast Groundfish Fishery Management Plan (FMP) and the Pacific Coast Salmon FMP as follows:
The groundfish HAPCs are based on both specific habitat types and discrete areas (see map of groundfish HAPCs). The map represents only a first approximation of the habitat type HAPCs because they are not comprehensively mapped and may vary in location and extent over time. See the Pacific Coast Groundfish FMP for more detail.
Estuaries: The inland extent of the estuary HAPC is the high water tidal level along the shoreline or the upriver extent of saltwater intrusion, defined as upstream and landward to where ocean-derived salts measure less than 0.5 parts per thousand (ppt) during the period of average annual low flow. The seaward extent is an imaginary line closing the mouth of a river, bay, or sound; and to the seaward limit of wetland emergents, shrubs, or trees occurring beyond the lines closing rivers, bays, or sounds. This HAPC also includes those estuary-influenced offshore areas of continuously diluted seawater.
Canopy Kelp: The canopy kelp HAPC includes those waters, substrate, and other biogenic habitat associated with canopy-forming kelp species (e.g., Macrocystis spp. and Nereocystis spp.).
Seagrass: The seagrass HAPC includes those waters, substrate, and other biogenic features associated with eelgrass species (Zostera spp.), widgeongrass (Ruppia maritima), or surfgrass (Phyllospadix spp.).
Rocky Reefs: The rocky reefs HAPC includes those waters, substrates and other biogenic features associated with hard substrate (bedrock, boulders, cobble, gravel, etc.) to MHHW. A first approximation of its extent is provided by the substrate data in the groundfish EFH assessment GIS. However, at finer scales, through direct observation, it may be possible to further distinguish between hard and soft substrate to define the extent of this HAPC.
Areas of Interest: Areas of interest are discrete areas that are of special interest due to their unique geological and ecological characteristics. The following areas of interest are designated HAPCs:
- Off of Washington: All waters and sea bottom in state waters shoreward from the three nautical mile boundary of the territorial sea shoreward to MHHW.
- Off of Oregon: Daisy Bank/Nelson Island, Thompson Seamount, President Jackson Seamount.
- Off of California: all seamounts, including Gumdrop Seamount, Pioneer Seamount, Guide Seamount, Taney Seamount, Davidson Seamount, and San Juan Seamount; Mendocino Ridge; Cordell Bank; Monterey Canyon; specific areas in the Federal waters of the Channel Islands National Marine Sanctuary; specific areas of the Cowcod Conservation Area.
The following describe components of the salmon HAPCs. For a more detailed description of these HAPCs, see Appendix A to the Pacific Coast Salmon FMP.
Complex Channels and Floodplains: Both complex channels and floodplains provide valuable habitat for all Pacific salmon species. Complex channels consist of meandering, island-braided, pool-riffle and forced pool-riffle channels. Complex floodplain habitats consist of wetlands, oxbows, side channels, sloughs and beaver ponds, and steeper, more constrained channels with high levels of large woody debris (LWD). Densities of spawning and rearing salmon are highest in areas of high-quality, naturally-functioning floodplain habitat and in areas with LWD, compared to anthropogenically modified floodplains.
Complex floodplain habitats are dynamic systems that change over time. As such, the habitat-forming processes that create and maintain these habitats (e.g., erosion and aggradation, input of large wood from riparian forests) should be considered integral to the habitat.
Thermal Refugia: Thermal refugia typically include coolwater tributaries, lateral seeps, side channels, tributary junctions, deep pools, areas of groundwater upwelling, and other mainstem river habitats that are cooler than surrounding waters (≥2° C cooler). Spatial scales can range from entire tributaries (e.g., spring-fed streams), to stream reaches, to highly localized pockets of water only a few square meters in size embedded within larger rivers.
Thermal refugia provide areas to escape high water temperatures and are critical to salmon survival, especially during hot, dry summers in California, Idaho, and eastern Oregon and Washington. Thermal refugia also provide important holding and rearing habitat for adults and juveniles.
Thermal refugia are susceptible to blockage by artificial barriers. Reduced flows can also reduce or eliminate access to refugia. Loss of structural elements such as large wood can also influence the formation of thermal refugia.
Spawning Habitat: Salmon spawning habitat is typically defined as low gradient stream reaches (<3%), containing clean gravel with low levels of fine sediment and high inter gravel flow. Many spawning areas have been well defined by historical and current spawner surveys, and detailed maps exist for some watersheds. Spawning habitat is especially sensitive to stress and degradation by a number of land- and water-use activities that affect the quality, quantity, and stability of spawning habitat (e.g., sediment deposition from land disturbance, streambank armoring, water withdrawals).
Estuaries: Estuaries include nearshore areas such as bays, sounds, inlets, river mouths and deltas, pocket estuaries, and lagoons influenced by ocean and freshwater. Because of tidal cycles and freshwater runoff, salinity varies within estuaries and results in great diversity, offering freshwater, brackish and marine habitats within close proximity. Such areas tend to be shallow, protected, nutrient rich, and are biologically productive, providing important habitat for marine organisms, including salmon.
Marine and Estuarine Submerged Aquatic Vegetation: Submerged aquatic vegetation includes the canopy kelps and eelgrass. These habitats have been shown to have some of the highest primary productivity in the marine environment and provide a significant contribution to the marine and estuarine food webs.
Kelps are brown macroalgae and include those that float to form canopies and those that do not, such as Laminaria spp. Canopy-forming kelps of the eastern Pacific Coast are dominated by two species, giant kelp (Macrocystis pyrifera) and bull kelp (Nereocystis leutkeana). Kelp plants, besides requiring moderate to high water movement and energy levels, are most likely limited by the availability of suitable substrate. Native eelgrass (Zostera marina) forms dense beds of leafy shoots year-round in the soft sediments of the lower intertidal and shallow subtidal zone. Eelgrass forms a three-dimensional structure in an otherwise two-dimensional (sand or mud) environment.