V. B. 1. Forage Fish |
The more common species identified as forage fish in Puget Sound include surf smelt (Hypomesus pretiosus), Pacific sand lance (Ammodytes hexapterus), and Pacific herring (Clupea harengus pallasi) (Washington State Department of Fish and Wildlife 2002b). All are small schooling fishes that represent a significant component of the prey base for marine mammals, sea birds, and other fish populations in the region. Likewise, forage fish are important as recreational fishing bait and contribute significantly to commercial and subsistence fisheries. Forage fish rely upon a variety of shallow and intertidal nearshore and estuarine habitats, particularly for spawning, and are a valuable indicator of the health and productivity of the marine environment.
Table V-1: Common and Scientific Names of WDFW Priority Fish Species.
| Common Name | Scientific Name | WDFW/Federal Population Status |
| Forage fish | ||
| Pacific Herring * | Clupea pallasi | Depressed |
| Surf Smelt * | Hypomesus pretiosus | |
| Eulachon | Thaleichthys pacificus | |
| Longfin smelt | Spirinchus thaleichthys | |
| Pacific Sand Lance * | Ammodytes hexapterus | |
| Salmonids | ||
| Chinook salmon * | Oncorhynchus tshawytscha | Threatened – Puget Sound ESU |
| Chum salmon * | Oncorhynchus keta | Threatened – Hood Canal ESU |
| Coho salmon * | Oncorhynchus kisutch | Candidate – Puget Sound / Georgia Strait ESU |
| Sockeye salmon * | Oncorhynchus nerka | |
| Pink salmon* | Oncorhynchus gorbuscha | |
| Cutthroat trout * | Oncorhynchus clarki | |
| Steelhead * | Oncorhynchus mykiss | |
| Bull trout * | Salvelinus confluentus | Threatened – Coastal - Puget Sound DPS |
| Groundfish | ||
| Pacific Cod * | Gadus macrocephalus | Critical |
| Walleye Pollock * | Theragra chalcogramma | Critical |
| Pacific Hake * | Merluccius productus | Critical/Candidate – Puget Sound ESU |
| Lingcod * | Ophiodon elongatus | Above Average |
| English Sole * | Pleuronectes vetulus | Below Average |
| Rock Sole * | Lepidopsetta bilineata | Average |
| Black Rockfish | Sebastes melanops | Unknown |
| Blue Rockfish | Sebastes mystinus | Unknown |
| Bocaccio Rockfish | Sebastes paucispinus | Unknown |
| Brown Rockfish * | Sebastes auriculatus | Depressed |
| Canary Rockfish | Sebastes pinniger | Unknown |
| China Rockfish | Sebastes nebulosus | Unknown |
| Copper Rockfish * | Sebastes caurinus | Depressed |
| Greenstriped Rockfish | Sebastes elongates | Unknown |
| Quillback Rockfish * | Sebastes maliger | Depressed |
| Redstripe Rockfish | Sebastes proriger | Unknown |
| Tiger Rockfish | Sebastes nigrocinctus | Unknown |
| Widow Rockfish | Sebastes entomelus | Unknown |
| Yelloweye Rockfish | Sebastes ruberrimus | Unknown |
| Yellowtail Rockfish | Sebastes flavidus | Unknown |
Asterisks denote species covered in text. Herring status based on Port Orchard/Port Madison stocks (Bargmann 1998). WDFW population status for groundfish (Puget Sound Water Quality Action Team 2002) based on South Puget Sound, which includes Hood Canal, central Sound, Whidbey basin, and southern Sound; Federal status indicated where appropriate.
Forage fish populations can fluctuate greatly depending on natural environmental factors. However, reproductive success may also be affected by human shoreline development, such as removal of overhanging vegetation within the riparian zone, loss of spawning substrate, and intertidal beach modification (Williams et al. 2001). For example, filling and shoreline "armoring" (e.g., bulkheading) of beaches into the upper intertidal zone can bury and damage forage fish spawning habitat. Recent studies have also shown that loss of overhanging riparian vegetation along shorelines causes significantly lower mean relative humidity, and higher mean light intensity, air temperature, and substrate temperature which may result in reduced survival of surf smelt eggs and larvae (Penttila 2001; Rice and Sobocinski 2002). Besides these studies, the specific impacts of human activities on spawning success are not well documented in the available literature.
The WDFW considers forage fish to be a key component of the marine ecosystem in Washington. As a result, all known forage fish spawning sites in Washington State are considered "marine habitats of special importance" and have been given enhanced "no net loss" protection in the application of Washington Administrative Code (WAC) "Hydraulic Code Rules" (Shull 2000). All proposed shoreline construction activities are reviewed by state agencies for impacts to forage fish spawning habitat. In cases where no satisfactory redesign or mitigation is possible, a hydraulic permit may be denied. In-water work windows have been established for the protection of forage fish populations (WAC-220-110-271) (Table V-2). The following work windows have been established for the protection of forage fish in the area of Bainbridge Island, based on guidance from the WDFW, National Marine Fisheries Service (NMFS), and the US Fish and Wildlife Service (USFWS) (R. Liera, USACE, personal communication, 2002).
Table V-2. In-Water Work Windows for Forage Fish
| Species | Work Allowed | No Work Allowed |
| Surf smelt | April 1-August 31 | September 1-March 31 |
| Sand lance | March 2-October 14 | October 15-March 1 |
| Herring | May 1-January 14 | January 15-April 30 |
Known forage fish spawning areas on Bainbridge Island have been documented by WDFW (Appendix A – Fish Occurrence Map), although studies confirming the frequency of use within these areas is often limited. In many cases, additional spawning areas are suspected but await documentation. Specific information follows on the general nearshore ecology, habitat requirements, and Bainbridge Island distributions of these three common forage species.
Pacific sand lance (Ammodytes hexapterus)
Pacific sand lance are highly abundant forage fish that are widely distributed throughout Puget Sound bays and nearshore habitats (Emmett et al. 1991) (Figure V-4). Though poorly known as a species, they have a somewhat unique diurnal behavior pattern involving feeding in the open water during the day and burrowing into the sand at night. Juveniles rear in bays, inlets, and nearshore waters throughout Puget Sound (Lemberg et al. 1997). Adult and juveniles are planktivorous carnivores and prey heavily upon calanoid copepods (Fresh et al. 1981).
Figure V-4. Pacific sand lance (Ammodytes hexapterus) (Source: WA Dept of Ecology 2002b)
Pacific sand lance populations in Puget Sound are thought to be obligate intertidal spawners (Bargmann 1998). Spawning occurs once a year from November to February at tidal elevations ranging from +5 feet (MLLW) to about MHHW (Washington State Department of Fish and Wildlife 2002b). Sand lance deposit eggs over a variety of beach substrates, including soft sandy beaches, muddy low-energy beaches, and beaches of higher energy with gravel up to 3 cm diameter (Penttila 1995; Washington State Department of Fish and Wildlife 2002b). After spawning, sand lance eggs often acquire a partial coat of sand, which may assist in moisture retention at low tide. Sand lance perennially use isolated patches of suitable spawning habitat, suggesting some degree of active searching behavior by pre-spawning adults (Penttila 1995).
Sand lance spawning activity has been identified on a number of beaches along Bainbridge Island, including Eagle Harbor, Manzanita Bay, and Port Madison Bay, and along the western shorelines of Agate Pass, including Agate Point and Battle Point (Appendix A – Fish Occurrence Map). However, spawning densities and population distributions (age classes and recruitment) are not documented in these areas.
Surf smelt (Hypomesus pretiosus)
Adult surf smelt are widespread in Puget Sound waters and generally inhabit shallow nearshore habitats over a variety of substrates throughout the year (Emmett et al. 1991; Bargmann 1998) (Figure V-5). They feed on a variety of zooplankton and epibenthic organisms, including planktonic crustaceans and fish larvae (Emmett et al. 1991). Juvenile surf smelt reside in nearshore waters and estuaries where they feed and rear (Emmett et al. 1991; Lemberg et al. 1997).
Figure V-5. Surf smelt (Hypomesus pretiosus) (Source: WA Dept. of Ecology 2002c)
In Washington, surf smelt are thought to belong to geographically distinct stocks based on their temporal use of spawning grounds, although possible extensions of spawning seasons await investigation. Adult surf smelt may return to the same spawning ground each year and many stocks spawn year-round over two “seasons”, which are considered peaks in spawning activity (Lemberg et al. 1997). Surf smelt have specific spawning requirements and generally deposit their adhesive, semi-transparent eggs on beaches composed primarily of coarse sand and pea gravel (1 to 7 mm in diameter). Within Puget Sound, spawning occurs on the highest tides during the early evening, with concentrations usually at tidal elevations between +7.0 feet (MLLW) and the mean higher-high water line (Washington State Department of Fish and Wildlife 2002c; Washington State Department of Ecology 2002c). Freshwater seepage areas are believed to be a preferred spawning habitat because of lower fluctuations in gravel moisture and temperature.
Surf smelt spawning areas have been documented within Port Madison Bay, Manzanita Bay, Eagle Harbor, and Blakely Harbor, as well as along bluff areas along the northeast shoreline of Bainbridge Island (Appendix A – Fish Occurrence Map). Additional spawning areas are suspected but await documentation.
Pacific herring (Clupea harengus pallasi)
Pacific herring are one of the most widely known and best studied forage fish species in Washington (Bargmann 1998; Stout et al. 2001a) (Figure V-6). At least 18 Pacific herring stocks, defined by spawning ground, occur inside Puget Sound (Lemberg et al. 1997). Some herring stocks appear to have an annual migration from inshore spawning grounds to open-ocean feeding areas, whereas others appear to be resident in the Puget Sound basin year around (Emmett et al. 1991; Washington State Department of Fish and Wildlife 2002a). Juveniles remain primarily in inshore waters during their first summer (Emmett et al. 1991). Pacific herring are selective pelagic plankton feeders, consuming primarily copepods, decapod crab larvae, and chaetognaths in shallow nearshore waters (Fresh et al. 1981). In turn, herring represent a considerable percentage of the diet for several predatory marine fish species, including: Pacific cod (42%), walleye pollock (32%), lingcod (71%), Pacific halibut (53%), and coho and chinook salmon (58%) (Nightingale and Simenstad 2001b).
Figure V-6. Pacific herring (Clupea harengus pallasi) (from Hart 1988).
Adult Puget Sound herring stocks move onshore in schools during winter and spring to holding areas prior to moving to inshore spawning grounds (O'Toole 1995; Lemberg et al. 1997). Adults appear to consistently return to their natal spawning grounds, and during spawning migrations, may greatly reduce or stop feeding (Emmett et al. 1991; Lemberg et al. 1997). Herring deposit their transparent, adhesive eggs on intertidal and shallow subtidal eelgrass and marine algae from mid January to mid April (O'Toole 1995; Stout et al. 2001a; Washington State Department of Fish and Wildlife 2002a). Eggs may be deposited anywhere between the upper limits of high tide to a depth of -40 feet MLLW, but most spawning takes place between 0 and -10 feet MLLW (Washington State Department of Fish and Wildlife 2002a).
Herring spawn along much of the north and northwestern shorelines of Bainbridge Island from north of Battle Point to Point Monroe, including Manzanita and Port Madison Bays (Appendix A – Fish Occurrence Map). Likewise, holding areas for pre-spawn herring occur in Port Orchard (to the southwest) and north of Bainbridge Island. Bainbridge Island spawning grounds are used by the Port Orchard/Port Madison herring stock, which spawn primarily from January through April. The annual spawning biomass for this stock has averaged 1,281 tons/year from 1977-1996; however the current status of this stock is “depressed” considering historic population levels (Bargmann 1998). Pacific herring once spawned in Eagle Harbor and supported a local fishery in the early part of the century, though reports in the 1940’s had indicated declines by this time (Chapman et al. 1941).
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