Clams Fish Snails and Crustaceans - Fish

species endangered threatened salmon

Fish are cold-blooded vertebrates with fins. They occur in nearly all permanent water environments, from deep oceans to remote alpine lakes and desert springs. Marine fish inhabit the salty waters of oceans and seas. Freshwater fish inhabit inland rivers, lakes, and ponds. Anadromous fish are born in freshwater, migrate to the ocean to spend their adulthood, and then return to freshwater to spawn.

Fish are the most diverse vertebrate group on the planet and include thousands of different species. The largest known fish are the whale sharks, which can grow to be in excess of fifty feet long and weigh several tons. At the other end of the spectrum is Paedocypris progenetica, a tiny fish discovered in Sumatra, Indonesia, that is less than one-third of an inch in length.

FishBase (http://filaman.ifm-geomar.de/home.htm) is a comprehensive online database of scientific information about fish. It was developed by the WorldFish Center of Malaysia in collaboration with the Food and Agriculture Organization of the United Nations and is supported by many government and research institutions. As of February 2006 FishBase contains information on 29,300 fish species around the world, a number it calls "practically all fish species known to science." Scientists report that only a small fraction of these species have been assessed for their conservation status.

The U.S. Fish and Wildlife Service (FWS) listed a total of eighty-five endangered and forty-three threatened fish species in the United States as of February 2006. Nearly $475 million was spent under the Endangered Species Act (ESA) during fiscal year 2004 on imperiled fish.

General Threats to Fish

Fish species have become endangered and threatened in the United States for a variety of reasons, both natural and anthropogenic (caused by humans). Some scientists believe that natural threats, such as disease, have been aggravated by human actions that stress fish populations. Dams and other structures used for power generation, flood control, irrigation, and navigation have dramatically changed water flow patterns in many rivers. These impediments disrupt migration patterns and affect water temperature and quality. Likewise, dredging of river and stream beds to produce channels and filling of wetlands and swamps have changed water habitats.

Large nonnative fish species introduced to water bodies to improve recreational fishing prey on small imperiled fish and compete with large imperiled fish for food and space. Crowding also leads to uncharacteristic mating between fish species. This phenomenon results in hybrid offspring, some of which are sterile (cannot reproduce).

Many river and stream banks and adjacent lands have been stripped of vegetation by timber harvesting, crop growing, and excessive grazing of livestock. This eliminates habitat for insects and other tiny creatures that serve as foodstuff for fish. It also aggravates erosion problems and allows large amounts of dirt and silt to enter the water, effectively smothering the fish. In agricultural areas there is runoff of manure, fertilizers, and pesticides. Discharges of sewage and storm water contain high levels of biological contaminants. Industrial pollution introduces metal and organic chemicals to water bodies. Although not typically lethal, chemical and biological pollutants stress the immune systems of fish, placing them at greater risk of disease.

Imperiled Freshwater Fish

Freshwater fish listed under the Endangered Species Act are under the jurisdiction of the U.S. Fish and Wildlife Service. They include a wide variety of species and are found all over the country. The U.S. Geological Survey (USGS) estimates that the United States contains approximately 800 native freshwater species. Although most of these species are found in the eastern part of the country, the highest percentages of imperiled fish species are in the western states. According to the USGS this is because aquatic ecosystems in the western United States, particularly in the Southwest, have very high rates of endemism (that is, species found there are particular to that location).

Table 6.1 provides information about the freshwater fish species listed as endangered or threatened under the ESA as of February 2006. Most of the species have recovery plans in place. In general, imperiled freshwater fish are small in size and associated with flowing (lotic) waters, such as rivers and streams, rather than still (lentic) waters, such as lakes and ponds. Nearly half of the listed freshwater fish fall into four species groups: darters, chubs, daces, and shiners.

Table 6.2 shows the ten freshwater species with the highest expenditures under the ESA during fiscal year 2004. More than $45 million was spent on only two of the fish, the bull trout ($32.6 million) and the pallid sturgeon ($13.4 million).

BULL TROUT

Bull trout are relatively large fish that live in streams, lakes, and rivers. They can grow to weigh more than twenty pounds; however, those that inhabit small streams seldom exceed four pounds in weight. Bull trout are members of the char subgroup of the salmon family (Salmonidae). (See Figure 6.1.) Their backs are dark in color (green to brown) with small light-colored spots (crimson to yellow), while their undersides are pale. The fish prefer very cold and clean inland waters in the Northwest.

Historically bull trout were found throughout much of the northwestern United States and as far north as Alaska. Large populations have disappeared from major rivers, leaving mostly isolated pockets of smaller-sized fish in headwater streams. A variety of factors have contributed to the decline of the bull trout. The species is very sensitive to changes in water temperature and purity. Its survival is threatened by water pollution, degraded habitat, and dams and other diversion structures. In addition, introduction of a nonnative game fish called brook trout has been devastating. The two species are able to mate, but produce mostly sterile offspring—a genetic dead-end for the imperiled bull trout.

The legal history of the bull trout is extensive. In 1992 three environmental groups petitioned the U.S. Fish and Wildlife Service to list the fish as an endangered species under the ESA. In 1993 the agency concluded that listing for the species was warranted, but low in priority compared to other work of the FWS. This set off a long series of court battles that culminated in 1999 when all bull trout in the coterminous United States were listed as threatened under the ESA. In 2001 two of the original petitioners (Alliance for the Wild Rockies, Inc. and Friends of the Wild Swan, Inc.) filed a lawsuit against the FWS for failing to designate critical habitat for the bull trout. A settlement was reached in 2002. In September 2005 the FWS designated critical habitat for the bull trout as follows:

  • Idaho—294 stream miles and 50,627 acres of lakes or reservoirs
  • Montana—1,058 stream miles and 31,916 acres of lakes or reservoirs
  • Oregon—939 stream miles and 27,322 acres of lakes or reservoirs
  • Oregon/Idaho—17 stream miles
  • Washington—1,519 stream miles, 33,353 acres of lakes or reservoirs, and 985 miles of marine shoreline

The shaded river basins in Figure 6.2 were designated as critical habitat. The unshaded river basins were considered, but excluded from the final ruling.

PALLID STURGEON

The pallid sturgeon is a unique and rare freshwater fish. The Fish and Wildlife Service calls it "the swimming dinosaur." It is descended from fishes that were common more than fifty million years ago. The pallid sturgeon has a long flat snout and a slender body that ends with a pronounced tail fin. (See Figure 6.3.) Adults range in size from three to five feet and typically weigh twenty-five to fifty pounds. The fish is a bottom-feeder and prefers large rivers of relatively warm free-flowing water with high turbidity (high mud content).

Historically the pallid sturgeon was found throughout the Mississippi and Missouri River systems from Montana and North Dakota south to the Gulf of Mexico. In the early 1900s specimens as large as eighty-five pounds and six feet long were reported. Over the next century the fish virtually disappeared. In 1990 it was listed under the ESA as endangered. Three years later a recovery plan was published by the FWS. The recovery plan blames human destruction and modification of habitat as the primary cause for the pallid sturgeon's decline.

Figure 6.4 shows the consequences of human alteration on the main stem of the Missouri River, one of the last known habitats of the fish. Forty percent of the river has been channelized (reconfigured to flow in a restricted path). Another 36% has been removed from contention due to construction of earthen dams during the early decades of the 1900s. The last 24% of river habitat has

TABLE 6.1 Endangered and threatened freshwater fish species in the United States, February 2006

TABLE 6.1
Endangered and threatened freshwater fish species in the United States, February 2006
Common name Scientific name Listing status a Recovery plan date Recovery plan stage b
Alabama cavefish Speoplatyrhinus poulsoni E 10/25/1990 RF(2)
Alabama sturgeon Scaphirhynchus suttkusi E None
Amber darter percina antesella E 6/20/1986 F
Apache trout Oncorhynchus apache T 9/22/1983 RF(1)
Arkansas River shiner Notropis girardi T None
Ash Meadows amargosa pupfish Cyprinodon nevadensis mionectes E 9/28/1990 F
Ash Meadows speckled dace Rhinichthys osculus nevadensis E 9/28/1990 F
Bayou darter Etheostoma rubrum T 7/10/1990 RF(1)
Beautiful shiner Cyprinella formosa T 3/29/1995 F
Big Bend gambusia Gambusia gaigei E 9/19/1984 F
Big Spring spinedace Lepidomeda mollispinis pratensis T 1/20/1994 F
Blackside dace Phoxinus cumberlandensis T 8/17/1988 F
Blue shiner Cyprinella caerulea T 8/30/1995 F
Bluemask (=jewel) darter Etheostoma species E 7/25/1997 F
Bonytail chub Gila elegans E 8/28/2002 RF(2)
Borax Lake chub Gila boraxobius E 2/4/1987 F
Boulder darter Etheostoma wapiti E,EXPN 7/27/1989 F
Bull trout Salvelinus confluentus T None
Cahaba shiner Notropis cahabae E 4/23/1992 F
Cape Fear shiner Notropis mekistocholas E 10/7/1988 F
Cherokee darter Etheostoma scotti T 11/17/2000 F
Chihuahua chub Gila nigrescens T 4/14/1986 F
Clear Creek gambusia Gambusia heterochir E 1/14/1982 F
Clover Valley speckled dace Rhinichthys osculus oligoporus E 5/12/1998 F
Colorado pikeminnow (=squawfish) Ptychocheilus lucius E,EXPN None
Comanche Springs pupfish Cyprinodon elegans E 9/2/1981 F
Conasauga logperch Percina jenkinsi E 6/20/1986 F
Cui-ui Chasmistes cujus E 5/15/1992 RF(2)
Dalta smelt Hypomesus transpacificus T 11/26/1996 F
Dalta dace Eremichthys acros T 5/27/1997 F
Desert pupfish Cyprinodon macularius E 12/8/1993 F
Devils hole pupfish Cyprinodon diabolis E 9/28/1990 F
Devils River minnow Dionda diaboli T 9/13/2005 F
Duskytail darter Etheostoma percnurum E, EXPN None
Etowah darter Etheostoma etowahae E 11/17/2000 F
Foskett speckied dace Rhinichthys oscuius ssp T None
Fountain darter Etheostoma fonticola E 2/14/1996 RF(1)
Gila chub Gila intermedia E None
Gila topminnow (including yaqui) poeciliopsis occidentalis E None
Gilla trout Oncorhynchus gilae E 9/10/2003 RF(3)
Goldline darter Percina aurolineata T 11/17/2000 F
Greenback cutthroat trout Oncorhynchus clarki stomias T 3/1/1998 RF(2)
Hiko White River springfish Crenichthys baileyi grandis E 5/26/1998 F
Humpback chub Gila cypha E 8/28/2002 RF(3)
Hutton tui chub Gila bicolor ssp. T None
Independence Valley speckled dace Rhinichthys osculus lethoporus E 5/12/1998 F
June sucker Chasmistes liorus E 6/25/1999 F
Kendall Warm Springs dace Rhinichthys osculus thermalis E 7/12/1982 F
Lahontan cutthroat trout Oncorhynchus clarki henshawi T 1/30/1995 F
Leon Springs pupfish Cyprinodon bovinus E 8/14/1985 F
Leopard darter Percina pantherina T 5/3/1993 RD(1)
Little Colorado spinedace Lepidomeda vittata T 1/9/1998 F
Little Kern golden trout Oncorhynchus aguabonita whitei T Exempt
Loach minnow Tiaroga cobitis T 9/30/1991 F
Lost River sucker Deltistes luxatus E 3/17/1993 F
Maryland darter Etheostoma sellare E 2/2/1982 F
Moapa dace Moapa coriacea E 5/16/1996 RF(1)
Modoc sucker Catostomus microps E Exempt
Mohave tui chub Gila bicolor mohavensis E 9/12/1984 F
Neosho madtom Noturus placidus T 9/30/1991 F
Niangua darter Etheostoma nianguae T 7/17/1989 F
Okaloosa darter Etheostoma okaloosae E 10/26/1998 RF(1)
Oregon chub Oregonichthys crameri E 9/3/1998 F
Owens pupfish Cyprinodon radiosus E 9/30/1998 F
Owens tui chub Gila bicolor snyderi E 9/30/1998 F
Ozark cavefish Amblyopsis rosae T 12/17/1986 F
Pahranagat roundtail chub Gila robusta jordani E 5/26/1998 F
Pahrump poolfish Empetrichthys latos E 3/17/1980 F
Paiute cutthroat trout Oncorhynchus clarki seleniris T 9/10/2004 RF(1)
Palezone shiner Notropis albizonatus E 7/7/1997 F
Pallid sturgeon Scaphirhynchus albus E 11/7/1993 F

TABLE 6.1 Endangered and threatened freshwater fish species in the United States, February 2006 [CONTINUED] Adapted from "Listed FWS/Joint FWS and NMFS Species and Populations with Recovery Plans (Sorted by Listed Entity)" and "Listed U.S. Species by Taxonomic Group," in Threatened and Endangered Species System (TESS), U.S. Department of the Interior, U.S. Fish and Wildlife Service, February 17, 2006, http://ecos.fws.gov/tess_public/SpeciesRecovery.do?sort=1 and http://ecos.fws.gov/tess_public/SpeciesReport.do?kingdom=V&listingType=L (accessed February 17, 2006)

TABLE 6.1
Endangered and threatened freshwater fish species in the United States, February 2006 [CONTINUED]
Common name Scientific name Listing status a Recovery plan date Recovery plan stageb
aE=endagered, T=threatened, EXPN=experimental population, non-essential.
bRecovery plan stages: F=final, D=draft, RD=draft under revision, RF=final revision, O=other.
SOURCE: Adapted from "Listed FWS/Joint FWS and NMFS Species and Populations with Recovery Plans (Sorted by Listed Entity)" and "Listed U.S. Species by Taxonomic Group," in Threatened and Endangered Species System (TESS), U.S. Department of the Interior, U.S. Fish and Wildlife Service, February 17, 2006, http://ecos.fws.gov/tess_public/SpeciesRecovery.do?sort=1 and http://ecos.fws.gov/tess_public/SpeciesReport.do?kingdom=V&listingType=L (accessed February 17, 2006)
Pecos bluntnose shiner Notropis simus pecosensis T 9/30/1992 F
Pecos gambusia Gambusia nobilis E 5/9/1985 F
pygmy madtom Noturus stanauli E 9/27/1994 F
Pygmy sculpin Cottus paulus (=pygmaeus) T 8/6/1991 F
Railroad Valley springfish Crenichthys nevadae T 3/15/1997 F
Razorback sucker Xyrauchen texanus E 8/28/2002 RF(1)
Relict darter Etheostoma chienense E 7/31/1994 D
Rio Grande silvery minnow Hybognathus amarus E 7/8/1999 F
Roanoke logperch Percina rex E 3/20/1992 F
San Marcos gambusia Gambusia georgei E 2/14/1996 RF(1)
Santa Ana sucker Catostomus santaanae T None
Scioto madtom Noturus trautmani E Exempt
Shortnose sucker Chasmistes brevirostris E 3/17/1993 F
Slackwater darter Etheostoma boschungi T 3/8/1984 F
slender chub Erimystax cahni T 7/29/1983 F
Smoky madtom Noturus baileyi E, EXPN None
Snail darter Percinal tanasi T 5/5/1983 F
Sonora chub Gila ditaenia T 9/30/1992 F
Spikedace Meda fulgida T 9/30/1991 F
Spotfin chub Erimonax monachus EXPN, T None
Tidewater goby Eucyclogobius newberryi E None
Topeka shiner Notropis topeka (=tristis) E None
Unarmored threespine stickleback Gasterosteus aculeatus williamsoni E 12/26/1985 RF(1)
Vermilion darter Etheostoma chermocki E 7/21/2005 D
Virgin River chub Gila seminuda (=robusta) E 4/19/1995 RF(2)
Waccamaw silverside Menidia extensa T 8/11/1993 F
Warm Springs pupfish Cyprinodon nevadensis pectoralis E 9/28/1990 F
Warner sucker Catostomus warnerensis T 4/27/1998 F
Watercress darter Etheostoma nuchale E 3/29/1993 RF(2)
White River spinedace Lepidomeda albivallis E 3/28/1994 F
White Riever springfish Crenichthys baileyi baileyi E 5/26/1998 F
White sturgeon Acipenser transmontanus E None
Woundfin Plagopterus argentissimus E, EXPN None
Yaqui catfish Ictalurus pricel T 3/29/1995 F
Yaqui chub Gila purpurea E 3/29/1995 F
Yellowfin madton Nolurus flavipinnis EXPN,T None

experienced changes in water flows due to dam operations. The middle portion of the Mississippi River has also been extensively channelized and diked to prevent flooding and improve barge navigation.

Pallid sturgeons are believed to be very sensitive to changes in the velocity and volume of river flows. They are nearly blind and forage along muddy river bottoms feeding on tiny fish and other creatures that prefer turbid waters. Dams and channelization have reduced erosion of riverbank soil into the Missouri and Mississippi Rivers. This has given other fish species with better eyesight an advantage over the pallid sturgeon at finding small prey. In addition, mating between the pallid sturgeon and the shovelnose sturgeon in the lower Mississippi River has produced a population of hybrid sturgeon that is thriving compared to their imperiled parents.

All of these factors combine to provide a bleak outlook for the future of the pallid sturgeon. The Fish and Wildlife Service recovery plan notes that "it is unlikely that successfully reproducing populations of pallid sturgeon can be recovered without restoring the habitat elements (morphology, hydrology, temperature regime, cover, and sediment/organic matter transport) of the Missouri and Mississippi Rivers necessary for the species continued survival."

Herb Bollig and George Jordan reported in "U.S. Fish and Wildlife Service Stocks Endangered Pallid Sturgeons in Missouri River" (September 2005, http://mountain-prairie.fws.gov/PRESSREL/05-62.htm) that since 1994 more than 100,000 pallid sturgeons have been bred in captivity and placed in river waters in the states of Montana, North Dakota, Nebraska, Iowa, Kansa, Missouri, and Louisiana. The fish are spawned and reared at the agency's Gavins Point National Fish Hatchery near Yankton, South Dakota. This is the only hatchery in the nation engaged in breeding the pallid sturgeon. During 2004 the facility underwent a major construction program TABLE 6.2 The ten listed freshwater fish entities with the highest expenditures under the Endangered Species Act, fiscal year 2004 Adapted from "Table 1. Reported FY2004 Expenditures for Endangered and Threatened Species, Not Including Land Acquisition Costs, " Federal and State Endangered and Threatened Species Expenditures: Fiscal Year 2004, U.S. Department of the Interior, U.S. Fish and Wildlife Service, January 2005, http://www.fws.gov/endangered/expenditures/reports/FWS%20Endangered%20Species%202004%20Expenditures%20Report.pdf (accessed February 11, 2006)

TABLE 6.2
The ten listed freshwater fish entities with the highest expenditures under the Endangered Species Act, fiscal year 2004
Rank Entity Status* 2004 expenses
* T=threatened; E=endangered
SOURCE: Adapted from "Table 1. Reported FY2004 Expenditures for Endangered and Threatened Species, Not Including Land Acquisition Costs," Federal and State Endangered and Threatened Species Expenditures: Fiscal Year 2004, U.S. Department of the Interior, U.S. Fish and Wildlife Service, January 2005, http://www.fws.gov/endangered/expenditures/reports/FWS%20Endangered%20Species%202004%20Expenditures%20Report.pdf (accessed February 11, 2006)
1 Trout, bull T $32,570,600
2 Sturgeon, pallid E $13,370,173
3 Minnow, Rio Grande silvery E $8,073,562
4 Sucker, razorback E $7,548,642
5 Chub, humpback E $6,670,006
6 Sturgeon, white E $5,689,173
7 Pickeminnow (=Squawfish), Colorado except Salt and Verde E $5,316,746
River drainages, Arizong
8 Chub, bonytail E $4,864,566
9 Sucker, shortnose E $4,453,465
10 Sucker, Lost River E $4,253,222

FLGURE 6.1 Bull trout "Bull Trout," in Bull Trout (Salvelinus confluentus), U.S. Department of the Interior, U.S. Fish and Wildlife Service, January 2003, http://training.fws.gov/library/Pubs/bulltrt03.pdf (accessed February 13, 2006)that included the addition of new specially designed tanks for the endangered fish. Despite the success of the breeding operation, the FWS notes that "this stocking effort alone will not recover the species." Habitat improvement is the only step that biologists believe will save the pallid sturgeon from extinction.

In July 2005 the FWS initiated a five-year status review for the pallid sturgeon. The agency will collect scientific and commercial data that have become available since the species was listed as endangered in 1990. This information will be used to determine if the listing is still appropriate.

RECOVERY PLANS FOR FRESHWATER FISH

As shown in Table 6.1 there were recovery plans for nearly ninety populations or species of freshwater fish as of February 2006. Most of the plans have been finalized. Copies of the plans can be accessed from the Web site of the Threatened and Endangered Species System (TESS) of the U.S. Fish and Wildlife Service (http://ecos.fws.gov/tess_public/TESSWebpageRecovery?sort=1).

Imperiled Marine and Anadromous Fish

Marine and anadromous fish primarily inhabit salty waters. There were only nine such species listed under the Endangered Species Act as of February 2006. They are under the jurisdiction of the National Marine Fisheries Service. Listed species found in the Pacific Northwest and their current status (E—Endangered and T—Threatened) are as follows:

  • Chinook salmon—E, T
  • Chum salmon—T
  • Coho salmon—E, T
  • Sockeye salmon—E, T
  • Steelhead—E, T

In addition there is an endangered species of Atlantic salmon found in the gulf of Maine. Imperiled non-salmonid species are gulf sturgeon (threatened), shortnose sturgeon (endangered), and smalltooth sawfish (endangered).

More than $79 million was spent under the ESA on marine and anadromous fish in 2004. Expenditures are broken down by species in Table 6.3.

PACIFIC SALMONIDS

Pacific salmonids are found in waters of the northwestern United States and belong to the genus Oncorhynchus. There are five species of Pacific salmon: chinook, chum, coho, pink, and sockeye. All but the pink salmon are listed under the ESA as endangered and/or threatened. As shown in Table 2.8 in Chapter 2, four of the ten species with the highest expenditures under the ESA in fiscal year 2004 were Pacific salmonids.

Pacific salmon pose unique protection challenges because they are anadromous. Salmon eggs (or roe) are laid in the bottom gravel of cold freshwater streams where they incubate for five to ten weeks. Each egg ranges in size from one-quarter to one-half inch in size, depending on species. The eggs hatch to release baby fish (or alevin) that are called fry as they mature. Once a fry reaches about three inches in length it is called a finger-ling. This typically takes less than a year.

At some point during their first two years the young salmon (now called smolts) migrate downstream to the ocean. There they spend several months or years of their adulthood. When they reach sexual maturity males and females journey back to the streams where they were born to mate and deposit eggs. This is called spawning. Pacific salmon make the round-trip only once. They expend all their energy swimming back upstream and FIGURE 6.2 critical habitat designated for bull, trout, September, 2005 "Final, Critical Habitat", in Bull Trout, Columbia/Klamath Population U.S. Department of the Interior, U. S. Fish, and Wildlife Service, Pacific Region, 2006 http://www.fws.govlpacific/bulltrout/final_colka/map.html (accessed February 10,2006) Pallid sturgeon Mark P. Dryer and Alan J. Sandvol, "Pallid Sturgeon (Scaphirhynchus albus)," in Recovery Plan for the Pallid Sturgeon (Scaphirhynchus albus), U.S. Department of the Interior, U.S. Fish and Wildlife Service, November 7, 1993, http://ecos.fws.gov/docs/recovery_plans/1993/931107.pdf (accessed February 13, 2006)die soon after the eggs are laid and fertilized. Their upstream habitats can be hundreds and even thousands of miles away from their ocean habitats. It is a long and dangerous journey both ways.

Predator fish and birds eat salmon fry, fingerlings, and smolts as they make their way to the ocean. Bears, birds, marine mammals, and humans prey on the adult fish as they migrate upstream. Waterfalls, rapids, dams and other water diversions pose tremendous obstacles to Pacific salmon as they try to travel across long distances.

Salmon heading to the same general location travel upstream in groups called stocks or runs. Stocks migrate at different times of the year depending on geographical and genetic factors. Figure 6.5 illustrates the life cycle of a stock that migrates upstream from late summer through FIGURE 6.4 Consequences of Missouri River alterations on pallid sturgeon habitat Adapted from Mark P. Dryer and Alan J. Sandvol, "Habitat Loss," in Recovery Plan for the Pallid Sturgeon (Scaphirhynchus albus), U.S. Department of the Interior, U.S. Fish and Wildlife Service, November 7, 1993, http://ecos.fws.gov/docs/recovery_plans/1993/931107.pdf (accessed February 13, 2006) TABLE 6.3 The ten listed marine/anadromous fish entities with the highest expenditures under the Endangered Species Act, fiscal year 2004 Adapted from "Table 1. Reported FY 2004 Expenditures for Endangered and Threatened Species, Not Including Land Acquisition Costs," in Federal and State Endangered and Threatened Species Expenditures: Fiscal Year 2004, U.S. Department of the Interior, U.S. Fish and Wildlife Service, January 2005, http://www.fws.gov/endangered/expenditures/reports/FWS%20Endangered%20Species%202004%20Expenditures%20Report.pdf (accessed February 11, 2006)

TABLE 6.3
The ten listed marine/anadromous fish entities with the highest expenditures under the Endangered Species Act, fiscal year 2004
Species 2004 expenses
SOURCE: Adapted from "Table 1. Reported FY 2004 Expenditures for Endangered and Threatened Species, Not Including Land Acquisition Costs," in Federal and State Endangered and Threatened Species Expenditures: Fiscal Year 2004, U.S. Department of the Interior, U.S. Fish and Wildlife Service, January 2005, http://www.fws.gov/endangered/expenditures/reports/FWS%20Endangered%20Species%202004%20Expenditures%20Report.pdf (accessed February 11, 2006)
Chinook salmon $32,570,600
Steelhead $13,370,173
Coho salmon $8,073,562
Sockeye salmon $7,548,642
Atlantic salmon $7,496,334
Chum salmon $6,670,006
Shortnose sturgeon $2,311,905
Gulf sturgeon $933,374
Smalltooth sawfish $75,900
Total $79,050,496

early fall. During its lifetime a Pacific salmon is exposed to three different water environments: freshwater streams and rivers, estuaries (areas where freshwater and saltwater meet), and the ocean.

Chinook salmon are the largest of the Pacific salmonids, averaging about twenty-five pounds in adulthood. (See Figure 6.6.) They spend two to seven years in the ocean and travel up to 2,500 miles from their home streams. Coho, sockeye, and chum salmon adults average approximately ten to twelve pounds.

The National Marine Fisheries Service estimates that as many as sixteen million salmon per year migrated upstream in waters of the northwestern United States prior to the arrival of European settlers. Extensive fishing and canning operations quickly decimated the salmon population. As early as 1893 federal officials warned that the future of salmon fisheries had a "disastrous outlook." During the 1890s hatcheries began operating and stocking rivers and streams with "farm-raised" salmon. Over the next century salmon populations were further stressed as natural river flows were dramatically altered with dams, navigational structures, and irrigation systems. Figure 6.7 shows the distribution of salmon hatcheries and dams in the Columbia River basin of the Pacific Northwest. As of 2003 there were twenty-three major dams on mainstem rivers in the basin, more than 300 smaller dams on tributaries, and more than eighty hatcheries.

Endangered and threatened salmon are identified by their water of origin and, in most cases, by their upstream migration season. In 1990 the winter-run stock of Chinook salmon from the Sacramento River was designated as threatened under the ESA, the first Pacific salmon to be listed. It was reclassified to endangered four years later. During the 1990s and early 2000s the NMFS identified thirty-five Evolutionarily Significant Units (ESUs) of Pacific salmonids and listed sixteen of them as endangered or threatened. (See Table 6.4 for the status of these fish as of January 2006.) Two ESUs are "Species of Concern" meaning that the agency has some concerns regarding threats to these species, but lacks sufficient information indicating the need to list them under the ESA.

Biologists blame four main threats, called "the four H's" for the imperiled state of Pacific salmonids:

  • Habitat degradation—channelization, dredging, water withdrawals for irrigation, wetland losses, and diking have changed river, stream, and estuary environments.
  • Harvesting levels—Over fishing for more than a century has decimated salmon populations.
  • Hydropower—Impassable dams have rendered some historical habitat unreachable by salmon. Most modern dams have fish ladders, stepping-stone waterfalls that allow salmon a path up and over the dams. However, all dams affect water temperature, flows, and quality.
  • Hatcheries—Biologists fear that hatchery releases overburden estuaries with too many competing fish at the same time.

In addition to these threats, scientists believe that climate changes and the presence of nonnative aquatic species are detrimental to salmon populations.

FIGURE 6.5 Life cycle of Pacific salmon "Figure 1A. A Generalized Depiction of the Pacific Salmon Life Cycle," in The Northwest Fisheries Science Center Strategic Research Plan for Salmon, Final Draft, U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, June 17, 2004, http://www.nwfsc.noaa.gov/publications/researchplans/salmon_research_plan6.17.04%20.pdf (accessed February 13, 2006)

STEELHEAD

Steelhead are members of the Oncorhynchus genus and have the scientific name Oncorhynchus mykiss. Freshwater steelhead are called rainbow trout. Anadromous steelhead are also trout, but they are associated with salmon due to similarities in habitat and behavior. Steelhead are found in the Pacific Northwest and are anadromous like salmon with two major differences: steelhead migrate individually, rather than in groups, and can spawn numerous times, not just once.

As of January 2006 the National Marine Fisheries Service had identified fifteen distinct population segments (DPSs) of steelhead as shown in Table 6.5. Ten of these DPSs are listed under the ESA as endangered or threatened. In addition, there is one DPS classified as a "Species of Concern," and a DPS in Washington's Puget Sound is undergoing status review. Table 6.3 indicates that $13.4 million was spent on steelhead under the ESA during fiscal year 2004.

Steelhead face the same threats as Pacific salmon—habitat loss and alteration, over-harvesting, dams and other water obstacles, and competition with hatchery fish.

RECOVERY PLANS FOR MARINE AND ANADROMOUS FISH

Final recovery plans have been published by the NMFS for the shortnose sturgeon (1998), gulf sturgeon (2005), and Atlantic salmon (2005). Copies of the recovery plans are available at the Web site of the NMFS Office of Protected Resources (http://www.nmfs.noaa.gov/pr/recovery/).

In July 2005 the National Marine Fisheries Service announced its intention to develop recovery plans for sixteen populations of Pacific salmon and steelhead FIGURE 6.6 Some Pacific salmon species Bob Savannah, artist, "Pacific Salmons," in Pictures/Graphics, Wildlife Sketches, U.S. Department of the Interior, U.S. Fish and Wildlife Service, Undated, http://www.fws.gov/pictures/lineart/bobsavannah/pacificsalmons.html (accessed February 15, 2006)found in Washington, Oregon, and Idaho that are listed as endangered or threatened under the Endangered Species Act. The agency will collect data and information from state, tribal, and local entities regarding the status and threats associated with these fish. The first proposed recovery plan was released by the NMFS for public comment in late December 2005. It covered the Puget Sound area. Plans for populations in other areas were under development in 2006.

Imperiled Fish around the World

The International Union for the Conservation of Nature and Natural Resources (IUCN; now known as the World Conservation Union) listed 800 species of fish as threatened in its 2004 Red List of Threatened Species, nearly half of the 1,721 species evaluated. However, the IUCN notes that there are in excess of 28,000 known fish species. It is expected that many more fish species will be listed in the future as more evaluations are completed.

As of January 2006 the United States listed eleven foreign species of fish as endangered. The endangered fish and their primary habitat areas are as follows:

  • Ala balik (trout)—Turkey
  • Ayumodoki (loach)—Japan
  • Mexican blindcat (catfish)—Mexico
  • Asian bonytongue—Indonesia, Malaysia, Thailand
  • Thailand catfish—Thailand
  • Thailand giant catfish—Thailand
  • Cicek (minnow)—Turkey
  • Nekogigi (catfish)—Japan
  • Miyako Tango (Tokyo bitterling)—Japan
  • Ikan Temoleh (minnow)—Cambodia, Laos, Malaysia, Thailand, and Vietnam
  • Totoaba (seatrout or weakfish)—Mexico (Gulf of California)

In addition, there is one foreign fish listed under the ESA as threatened—the beluga sturgeon, which is found in the Caspian and Black Seas and the rivers that drain to them.

Beluga Sturgeon

The beluga sturgeon (Huso huso) is in danger because it is the source of beluga caviar, one of the most coveted luxury foods in the world. Caviar is the processed and salted eggs of large fish. These eggs are called roe while they are still enclosed in the ovarian membrane of the female fish. The sturgeon must be killed to extract its roe. Felicity Barringer and Florence Fabricant reported in the New York Times that beluga caviar sold for $200 an ounce in the United States, and the nation consumed 60% of the world's supply of the delicacy ("In Conservation Effort, U.S. Bans Caspian Beluga Caviar," September 30, 2005).

In 2000 a coalition of U.S. environmental groups petitioned the U.S. Fish and Wildlife Service to list the beluga sturgeon as endangered under the ESA. The coalition, named Caviar Emptor (http://www.caviaremptor.org), claimed that the population of the species had declined by 90% between 1980 and 2000 due to overfishing. In 2002 the Natural Resources Defense Council sued the FWS, because the agency had not responded to the petition. Two years later the beluga sturgeon was listed as threatened, rather than endangered, under FIGURE 6.7 Distribution of salmon hatcheries and dams in the Columbia River basin, 2003 D.L. Bottom, C.A. Simestad, J. Burke, A.M. Baptista, D.A. Jay, K.K. Jones, E. Casillas, and M.H. Schiewe, "Figure 6. Present Distribution of Salmon Hatcheries and Mainstem and Secondary Dams (StreamNet 2003) Along Rivers and Streams of the Columbia River Basin," in Salmon at River's End: The Role of the Estuary in the Decline and Recovery of Columbia River Salmon, U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Northwest Fisheries Science Center, 2005, http://www.nwfsc.noaa.gov/assets/25/6294_09302005_153156_SARETM68Final.pdf (accessed February 13, 2006)TABLE 6.4 Listing status of West Coast salmon populations, January 2006 "Endangered Species Act Status of West Coast Salmon & Steelhead," in Salmon Populations: Snapshot of ESU Status, U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, January 19, 2006, http://www.nwr.noaa.gov/ESA-Salmon-Listings/Salmon-Populations/upload/1pgr.pdf (accessed February 13, 2006)

TABLE 6.4
Listing status of West Coast salmon populations, January 2006
Speciesa Current Endangered Species Actlisting Statusb
aThe Endangered Species Act (ESA) defines a "species" to include any distinct population segment of any species of vertebrate fish or wildlife. For Pacific salmon, National Oceanic & Atmospheric Administration (NOAA) fisheries considers an evolutionarily significant unit, or "ESU," a "species" under the ESA. For Pacific steelhead, NOAA fisheries has delineated distinct population segments (DPSs) for consideration as "species" under the ESA.
bUpdated final listing determinations for 16 salmon species were issued on June 28, 2005 (70 FR 37160). Updated final listing determinations for 10 West Coast steelhead species were issued on January 5, 2006 (71 FR 834). The final "not warranted" listing determination for Oregon Coast coho salmon was announced on January 19, 2006 (71 FR 3033). On September 2, 2005, we issued final critical habitat designations for 19 West coast salmon and steelhead species (70 FR 52488 and 52630).
SOURCE: "Endangered Species Act Status of West Coast Salmon & Steelhead," in Salmon Populations: Snapshot of ESU Status, U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, January 19, 2006, http://www.nwr.noaa.gov/ESA-Salmon-Listings/Salmon-Populations/upload/1pgr.pdf (accessed February 13, 2006)
Sockeye salmon (Oncorhynchus nerka) 1 Snake River Endangered
2 Ozette Lake Threatened
3 Baker River Not warranted
4 Okanogan River Not warranted
5 Lake Wenatchee Not warranted
6 Quinalt Lake Not warranted
7 Lake Pleasant Not warranted
Chinook salmon (O. tshawytscha) 8 Sacramento River winter-run Endangered
9 Upper Columbia River spring-run Endangered
10 Snake River spring/summer-run Threatened
11 Snake River fall-run Threatened
12 Puget Sound Threatened
13 Lower Columbia River Threatened
14 Upper Willamette River Threatened
15 Central Valley spring-run Threatened
16 California coastal Threatened
17 Central Valley fall and late fall-run Species of concern
18 Upper Klamath-Trinity Rivers Not warranted
19 Oregon coast Not warranted
20 Washington coast Not warranted
21 Middle Columbia River spring-run Not warranted
22 Upper Columbia River summer/fall-run Not warranted
23 Southern Oregon and Northern California Coast Not warranted
24 Deschutes River summer/fall-run Not warranted
Coho salmon (O. kisutch) 25 Central California coast Endangered
26 Southern Oregon/northern California Threatened
27 Oregon coast Not warranted
28 Lower Columbia River Threatened
29 Southwest Washington Not warranted
30 Puget Sound/Strait of Georgia Species of concern
31 Olympic peninsula Not warranted
Chum salmon (O. keta) 32 Hood Canal summer-run Threatened
33 Columbia River Threatened
34 Puget Sound/Strait of Georgia Not warranted
35 Pacific Coast Not warranted

the ESA. Environmentalists were highly critical of the decision.

In March 2005 the FWS imposed conditions that limited imports and domestic trade in sturgeon products. The agency gave importing nations six months to provide information regarding their conservation measures to prevent overfishing of the species. In September 2005 the FWS announced that it had not received the required information from five countries around the Caspian Sea. A ban was imposed on imports of beluga sturgeon products from Azerbaijan, Iran, Kazakhstan, the Russian Federation, and Turkmenistan. The ban can be lifted in the future if the proper information is submitted to the FWS. Conservation information was submitted by Black Sea countries and was being reviewed by the agency in 2006.

SNAILS CLAMS AND CRUSTACEANS

Clams, snails, and crustaceans are invertebrates. Clams and snails are in the phylum Mollusca. Mollusks have soft bodies usually enclosed in a thin hard shell made of calcium. The U.S. Fish and Wildlife Service uses the generic term "clam" to refer to clams and mussels, but there are physical and reproductive differences between the two creatures. In general, mussels are larger than clams and have an oblong lopsided shell, as opposed to the round symmetrical shell of the clam.

Crustaceans are a large class of creatures with a hard exoskeleton, appendages, and antennae. This class includes lobsters, shrimps, and crabs.

As shown in Table 1.2 in Chapter 1, there were 131 species of clams (including mussels), snails, and

TABLE 6.5 Listing status of West Coast steelhead populations, January 2006 "Endangered Species Act Status of West Coast Salmon & Steelhead," in Salmon Populations: Snapshot of ESU Status, U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, January 19, 2006, http://www.nwrnoaa.gov/ESA-Salmon-Listings/Salmon-Populations/ (accessed February 13, 2006)

TABLE 6.5
Listing status of West Coast steelhead populations, January 2006
Speciesa Current Endangered Species Act listing Status b ESA listing actions under review
aThe Endangered Species Act (ESA) defines a "species" to include any distinct population segment of any species of vertebrate fish or wildlife. For Pacific salmon, National Oceanic & Atmospheric Administration (NOAA) fisheries considers an evolutionarily significant unit, or "ESU," a "species" under the ESA. For Pacific steelhead, NOAA fisheries has delineated distinct population segments (DPSs) for consideration as "species" under the ESA.
bUpdated final listing determinations for 16 salmon species were issued on June 28, 2005 (70 FR 37160). Updated final listing determinations for 10 West Coast steelhead species were issued on January 5, 2006 (71FR 834). The final "not warranted" listing determination for Oregon Coast coho salmon was announced on January 19, 2006 (71 FR 3033). On September 2, 2005, we issued final critical habitat designations for 19 West Coast salmon and steelhead species (70 FR 52488 and 52630).
cA petition to list Puget Sound steelhead was received on September 13, 2004. The species is currently under review.
SOURCE: "Endangered Species Act Status of West Coast Salmon & Steelhead," in Salmon Populations: Snapshot of ESU Status, U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, January 19, 2006, http://www.nwrnoaa.gov/ESA-Salmon-Listings/Salmon-Populations/ (accessed February 13, 2006)
Steelhead (O. mykiss) 36 Southern California Endangered
37 Upper Columbia River Threatened
38 Central California Coast Threatened
39 South central California Coast Threatened
40 Snake River basin Threatened
41 Lower Columbia River Threatened
42 California Central Valley Threatened
43 Upper Willamette River Threatened
44 Middle Columbia River Threatened
45 Northern California Threatened
46 Oregon Coast Species of concern
47 Southwest Washington Not warranted
48 Olympic peninsula Not warranted
49 Puget Sound Under review • ESA listing statusc
50 Klamath Mountains province Not warranted

TABLE 6.6 The ten listed clam, snail, and crustacean entities with the highest expenditures under the Endangered Species Act, fiscal year 2004 Adapted from "Table 1. Reported FY 2004 Expenditures for Endangered and Threatened Species, Not Including Land Acquisition Costs," in Federal and State Endangered and Threatened Species Expenditures: Fiscal Year 2004, U.S. Department of the Interior, U.S. Fish and Wildlife Service, January 2005, http://www.fws.gov/endangered/expenditures/reports/FWS%20Endangered%20Species%202004%20Expenditures%20Report.pdf (accessed February 11, 2006)

TABLE 6.6
The ten listed clam, snail, and crustacean entities with the highest expenditures under the Endangered Species Act, fiscal year 2004
Ranking Entity Category Listing⟩ Expenditure
⟩E=endangered, T=threatened.
SOURCE: Adapted from "Table 1. Reported FY 2004 Expenditures for Endangered and Threatened Species, Not Including Land Acquisition Costs," in Federal and State Endangered and Threatened Species Expenditures: Fiscal Year 2004, U.S. Department of the Interior, U.S. Fish and Wildlife Service, January 2005, http://www.fws.gov/endangered/expenditures/reports/FWS%20Endangered%20Species%202004%20Expenditures%20Report.pdf (accessed February 11, 2006)
1 Higgins eye pearlymussel Clam E $1,302,660
2 Vernal pool fairy shrimp Crustacean T $1,018,842
3 Carolina heelsplitter Clam E $991,892
4 Vernal pool tadpole shrimp Crustacean E $665,972
5 Oahu tree snail Snail E $613,532
6 Riverside fairy shrimp Crustacean E $542,464
7 Utah valvata snail Snail E $481,764
8 Clubshell (except where listed as experimental populations) Clam E $475,560
9 Pink mucket peralymussel Clam E $366,725
10 San Diego fairy shrimp Crustacean E $311,484

crustaceans listed under the ESA as endangered or threatened as of February 2006. Most imperiled are clams/mussels (seventy U.S. species and two foreign species). There were thirty-six U.S. species of snails and one foreign species listed under the ESA. Listed crustaceans include twenty-two U.S. species. Table 6.6 shows the ten clam, snail, and crustacean entities with the highest expenditures under the ESA during fiscal year 2004.

The vast majority of imperiled clams/mussels, snails, and crustaceans in the United States are freshwater species that inhabit inland rivers, primarily in the Southeast.

Freshwater Mussels in the United States

Mussels are bivalved (two-shelled) creatures encased in hard hinged shells made of calcium. The freshwater species can grow to be up to six inches in length. The United States, with nearly 300 species, has the greatest diversity of freshwater mussels in the world. According to the U.S. Geological Survey (USGS) (March 2006, http://cars.er.usgs.gov/Southeastern_Aquatic_Fauna/Freshwater_Mussels/freshwater_mussels.html), approximately 90% of these creatures live in southeastern states. Most of them are found burrowed into the sand and gravel beds of rivers and streams making up the Mississippi River system. Mussels have a foot-like appendage that acts like an anchor to hold them in place. They can use this appendage to move themselves very slowly over small distances. Mussels tend to congregate in large groups called colonies.

Mussels are filter-feeders. They have a siphoning system that sucks in food and oxygen from the water. Their gills can filter impurities out of the water. Thus, mussels are tiny natural water purifiers.

Most mussel species have a unique way of spreading their offspring. A female mussel can produce several thousand eggs in a year. After the eggs are fertilized they develop into larva and are released. The larva latch on to the fins or gills of passing fish and they stay there until they have grown into baby clams. At that point they turn loose of the fish and drop to the river bottom. The larvae are called glochidia. It is believed that glochidia are harmless to the fish upon which they hitchhike. This parasitic relationship allows mussels to spread and distribute beyond their usual range.

MUSSEL DECLINES

Unfortunately, many freshwater mussel populations are in danger of extinction. Information about the seventy U.S. species of endangered and threatened clams and mussels as of February 2006 is shown in Table 6.7. Nearly $7.3 million was spent under the ESA during fiscal year 2004 to protect clams and mussels. Just over $1.3 million of this money was devoted to the Higgins' eye mussel, a species found in the Midwest.

The decline of freshwater mussels began in the 1800s. Many of the creatures have an interior shell surface with a pearl-like sheen. These pearlymussels were in great demand as a source of buttons for clothing until the invention of plastic. Collectors also killed many mussels by prying them open looking for pearls. Until the 1990s mussel shells were ground up and used in the oyster pearl industry. Another cause for decline has been habitat disturbance, especially water pollution and the modification of aquatic habitats by dams. The invasive zebra mussel has also harmed native freshwater mussel species by competing with them for food and other resources.

ZEBRA MUSSELS—AN INFESTATION

In 1988 an unwelcome visitor was discovered in the waters of Lake St. Clair, Michigan—a zebra mussel. The zebra mussel is native to eastern Europe. It is smaller than the freshwater mussels found in the United States and has a different method for spreading its young. The larva of zebra musses do not require a fish host to develop into babies. They can attach to any hard surface under the water. This allows zebra mussels to spread much easier and quicker than their American counterparts.