Read 82_11-046.pdf text version

REFERENCE COPY

Do N o t Remove from the Librarv U. S. Fish a n d W i l d l i f e Service Biological Report 82(11.46) National Wetlands Research Center April 1986 700 C a j u n Dome Boulevard Lafayette, Louisiana 70506 TR EL-82.4

Species Profiles: Life Histories and Environmental Requirements of Coastal Fishes and lnvertebrates (Pacific Southwest)

COMMON LITTLENECK CLAM

Fish and Wildlife Service U.S. Department of the Interior

Coastal Ecology Group Waterways Experiment Station U.S. Army Corps of Engineers

B i o l o g i c a l Report 82(11.46) T EL-82-4 R A p r i 1 1986

Species P r o f i l e s : L i f e H i s t o r i e s and Environmental Requirements o f Coastal Fishes and I n v e r t e b r a t e s ( P a c i f i c Southwest)

COMMON LITTLENECK CLAM

W i l l i a m N. Shaw Humboldt S t a t e U n i v e r s i t y Fred Tel onicher Marine Laboratory Trinidad, CA 95570

P r o j e c t Manager C a r r o l l Cordes Project O f f i c e r John Parsons National Coastal Ecosystems Team U.S. F i s h and W i l d l i f e Service 1010 Gause Boulevard S l i d e l l , LA 70458 Performed f o r Coastal Ecology Group Waterways Experiment S t a t i o n U.S. Army Corps o f Engineers Vicksburg, MS 39180 and National Coastal Ecosystems Team D i v i s i o n o f B i o l o g i c a l Services Research and Development F i s h and W i l d l i f e Service U.S. Department o f t h e I n t e r i o r Washington, DC 20240

This s e r i e s should be referenced as follows: U.S. F i s h and W i l d l i f e Service. 1983-19 Species p r o f i l e s : l i f e histories and environmental requirements o f c o a s t 5 f i s h e s and i n v e r t e b r a t e s . U. S. F i s h W i l d l . Serv. B i o l . Rep. 82(11). U.S. Army Corps o f Engineers, TR EL-82-4. T h i s p r o f i l e should be c i t e d as f o l l o w s : Shaw, W. N. 1986. Species p r o f i l e s : 1i f e h i s t o r i e s and environmental r e q u i r e ments o f coastal f i s h e s and i n v e r t e b r a t e s ( P a c i f i c Southwest)--common U.S. Army Corps l i t t l e n e c k clam. U.S. F i s h W i l d l . Serv. B i o l . Rep. 82(11.46). 11 pp. o f Engineers, TR EL-82-4.

.

PREFACE This species p r o f i l e i s one o f a series on coastal aquatic organisms, p r i n c i p a l l y f i s h , o f sport, commercial, o r ecological importance. The p r o f i l e s are designed t o provide coastal managers, engineers, and b i o l o g i s t s w i t h a b r i e f comprehensive sketch o f the b i o l o g i c a l c h a r a c t e r i s t i c s and environmental requirements o f the species and t o describe how populations o f the species may be expected t o r e a c t t o environmental changes caused by coastal development. Each p r o f i l e has sections on taxonomy, 1i f e h i s t o r y , ecological r o l e , environmental A t h r e e - r i n g binder i s requirements, and economic importance, i f applicable. used f o r t h i s series so t h a t new p r o f i l e s can be added as they are prepared. This p r o j e c t i s j o i n t l y planned and financed by the U.S. Army Corps o f Engineers and t h e U.S. F i s h and W i l d l i f e Service. Suggestions o r questions regarding t h i s r e p o r t should be d i r e c t e d t o the f o l 1owing addresses. Information Transfer S p e c i a l i s t National Coastal Ecosystems Team U.S. F i s h and W i l d l i f e Service d NASA-Sl i e l l Computer Complex 1010 Gause Boulevard S l i d e l l , LA 70458 one of

U. S. Army Engi neer Waterways Experiment S t a t i o n Attention: WESER-C Post O f f i c e Box 631 Vicksburg, M 39180 S

CONVERSION TABLE

M e t r i c t o U.S. Mu1 t i p l y m i l 1 lmeters (mn) centimeters (an) meters (m) k i 1m e t e r s ( km) square meters (m ) square k i 1m e t e r s ( km2) hectares (ha) l i t e r s (1) c u b i c meters (m3) cubic meters m i l 1 igrams [mg) grams (g) kilograms ( k ) m e t r i c tons r t ) m e t r i c tons k i 1ocal o r i e s (kcal ) Cel s i u s degrees 1.8(OC)

2

Custmary To Obtain Inches Inches feet m i l es square f e e t square m i l e s acres gal 1ons cubic f e e t acre-feet ounces ounces pounds pounds s h o r t tons B r i t i s h thermal u n i t s

&

+ 32

Fahrenheit degrees

U.S.

inches Inches f e e t ( ft ) fathoms m i l e s (mi) nautical miles ( m i ) square f e e t ( f t 2 ) acres 2 square m i l e s (mi ) gal 1ons ( gal ) cubic f e e t ( f t 3 ) acre-feet ounces (02) pounds ( l b ) s h o r t tons ( t o n ) B r i t i s h thermal u n i t s (Btu) Fahrenheit degrees

Customary t o M e t r i c 25.40 2.54 0.3048 1.829 1.609 1.852 m i l 1 imeters centimeters meters meters k i 1m e t e r s k i 1m e t e r s square meters hectares square k i l m e t e r s 1i e r s t c u b i c meters cubic meters 28.35 0.4536 0.9072 0.2520 0.5556(OF grams k i 1ograms m e t r i c tons k i 1ocal o r i es

- 32)

Celsius degrees

CONTENTS Page PREFACE CONVERSION TABLE ACKNOWLEDGMENTS

MORPHOLOGY/IDENTIFICATION AIDS

......................................................................iii .............................................................. i v ...............................................................v i NOMENCLATllRE/TAXONOMY/RANGE ....................................................1

REASON FOR INCLUSION I N SERIES LIFE HISTORY Spawning Eggs and L a r v a l Stages P o s t l a r v a e and Recruitment M a t u r i t y and Life-Span GROWTH CHARAC'TERISTICS COMMERCIAL AND SPORT FISHERIES AQUACULTURE ECOLOGICAL ROLE ENVIRONMENTAL REQUIREMENTS Temperature and Sal in i t y Substrate Depth Other Environmental F a c t o r s

.................................................1 ...............................................3 .................................................................3 .....................................................................3 .......................................................4

...................................................4 .......................................................4 .......................................................5 ...............................................6

..................................................................6 ..............................................................7 ...................................................7 .....................................................7 ....................................................................8 ........................................................................8 ..................................................8 LITERATLIRE CITED ............................................................ 9

ACKNOWLEDGMENTS Much appreciated a r e t h e reviews by Kenneth K. Chew, U n i v e r s i t y o f Washington, and Howard M Feder, U n i v e r s i t y o f Alaska. Thomas Hassler, C a l i f o r n i a Coop. e r a t i v e F i s h e r y Research U n i t , k i n d l y acted as t h e l i a i s o n w i t h t h e N a t i o n a l Coastal Ecosystems Team and g r e a t l y f a c i l i t a t e d t h e completion o f t h i s r e p o r t ; Carol Wardrip o f t h e Fred T e l o n i c h e r Marine L a b o r a t o r y a l s o gave v a l u a b l e a s s i s t ance. David Moran served as A s s i s t a n t P r o j e c t O f f i c e r .

F i g u r e 1.

Canmon l i t t l e n e c k clam.

COMMON LITTLENECK CLAM

S c i e n t i f i c name Protothaca staminea (Conrad) Common Preferred common name l i t t l e n e c k clam (Figure 1 ) Other common names Native littleneck clam, rock bay cockle, hardshell c l am, Tomales Bay cockle, rock clam, ribbed carpet she1 1, steamer Pelecypoda Class Veneroida Order Family Vener idae

............ .......... ............

probably a r e t h e most p r o d u c t i v e area f o r clams i n C a l i f o r n i a (Frey 19711. Other concentrations are near Ma1 i b u Point and San Mateo P o i n t south o f San Clemente, Cal i f o r n i a , and Bodega and Tanales Bays n o r t h o f San Francisco. The clam i s r e l a t i v e l y scarce i n northern Cal i f o r n i a.

..................... ...................... .....................

MORPHOLOGY/IDENTIFICATION AIDS

The f o l lowing d e s c r i p t i o n s are The e x t r a c t e d from F i t c h (1953). s h e l l i s oval and has i n f l a t e d valves ornamented by we1 1-defined, r a d i a t i n g r i b s and l e s s prominent, concentric ridges. Lunule (heart-shaped impress i o n a n t e r i o r t o umbo) o f t e n i s o n l y f a i n t l y defined. The v e n t r a l margin i s s l i g h t l y crenulated. The p a l 1i a l sinus (U-shaped i n d e n t a t i o n ) extends

Geographic range: A l e u t i a n Islands, Alaska, south t o Cape San Lucas, Baja C a l i f o r n i a , Mexico; commerc i a l l y abundant o n l y n o r t h o f Oregon. I n California, the coastal waters near San Onofre, San Diego County (Figure 21,

BODEGA BAY TOMALES BAY

SAN FRANCISCO BA

CALIFORNIA

PACIFIC OCEAN

LOS ANGELES

F i g u r e 2. D i s t r i b u t i o n o f t h e l i t t l e n e c k clam along t h e C a l i f o r n i a coast. Greatest recorded abundance i s a t San Onofre, San Diego County (Frey 1971).

s l i g h t l y more than h a l f way t o Color i s a n t e r i o r adductor muscle. ye1 l o w i s h grey o r h i g h l y variable: grey i f i n sloughs and bays; o f t e n w h i t i s h w i t h geometric p a t t e r n s o f wavy brown l i n e s o r blotches on sides o f specimens along t h e open coast. The clam a t t a i n s a l e n g t h o f 6.4 cm. I t d i f f e r s from chione clams (Chione spp. ) and Japanese 1i t t l e n e c k clams (Tapes japonica) i n having a p a l l i a l sinus extending more than h a l f way t o t h e a n t e r i o r adductor muscle, and from the rough-sided clam (Protothaca l a c i n i a t a ) and t h i n - s h e l l e d l i t t l e n e c k (2. tenerrima) i n having clam r a d i a t i n g r i b s more prominent than concentric ridges.

LIFE HISTORY

REASON FOR INCLUSION I N SERIES The l i t t l e n e c k clam, r e l a t i v e l y common i n bays and e s t u a r i e s and i n cobble patches along t h e coast o f California, supports an important s p o r t she1 1 f i s h e r y .

The sexes of the common lit t l e n e c k clam are separate (Quayle 1943). The time o f spawning v a r i e s throughout its range, depending l a r g e l y on water temperature. Early s t u d i e s i n B r i t i s h Columbia r e p o r t spawning i n January (Fraser 1929) and i n February and March (Fraser and Smith 1928). On Wood Island, B r i t i s h Columbia, t h e tubules of t h e ovary are f i l l e d with follicular cells in December and January (Quay1e 1943 1. The growth o f gametes reaches a peak i n March and spawning begins i n A p r i l . Few spawn l a t e r than September. The male spawning c y c l e p a r a l l e l s t h a t of t h e female, but f o r unknown reasons lags behind t h a t o f t h e female by I n B r i t i s h Columbia, about 1 month. most clams spawn i n l a t e s p r i n g but some may spawn o f f and on throughout t h e summer (Quayle and Bourne 1972). I n Alaska, spawning s t a r t s i n mid-Julyowhen t h e water temperature i s I n Prince about 8 C (Glude 1978). W i 11iam Sound, Alaska, spawning begins i n l a t e May t o mid-June and continues i n t o September (Nickerson 1977). In summer, water temperature f 1u c t u a t i o n s are unusually strong, so t h e r e may be two periods o f high temperature and two corresponding spawning peaks. In a warmer than normal year, o n l y one temperature and spawning peak may be expected. I n Mugu Lagoon, Cal i f o r n i a, Peterson (1982 r e p o r t e d t h a t June marks t h e beginning of t h e season o f gamete release. He a l s o observed t h a t Protothaca' s gonad weight d e c l i n e d sharply between June and December, i n d i c a t i n g spawning between June and December. From s t u d i e s conducted by (19821, it Peterson and Quammen appears t h a t i n i t i a l s e t t i n g may occur as e a r l y as m i d - A p r i l . sperm During spawning, t h e eggs are discharged through and the

lit t l e n e c k clam Because t h e l i v e s i n shallow bays w i t h mud and sand bottoms, the h a b i t a t o f t h i s species i n C a l i f o r n i a i s e s p e c i a l l y vulnerable t o degradation because o f harbor development, dredging, and p o l l u t i o n . For example, the waters o f San Francisco Bay are so p o l l u t e d i n some areas that depuration is necessary before these and other clams can be eaten ( R i t c h i e 1977).

The Japanese lit t l e n e c k clam, apparently introduced w i t h shipments o f P a c i f i c o y s t e r seed, i s r a p i d l y r e p l a c i n g t h e common lit t l e n e c k clam i n San Francisco and Tomales Bays (Smith and Kato 1979; J.T. Carlston, W i l l i a m College, Mass., pers. comm.). A h a b i t a t s u i t a b i l i t y index model o f t h e l i t t l e n e c k clam a l s o has been prepared by t h e U.S. F i s h and W i l d l i f e Service (Rodnick and L i 1983).

siphon (Quayle and Bourne 1972) and mass f e r t i l i z a t i o n takes place i n t h e open water. Eqqs and Larval Staqes The embryos develop i n t o a trochophore 1a r v a l stage (60-80 vm) about 12 h a f t e r f e r t i 1i z a t i o n (Quayle and Bourne 1972). The veliger ( s t r a i g h t - h i n g e stage) develops i n t h e next 24 h. A c i l i a t e d velum develops and helps t h e l a r v a swim and m a i n t a i n i t s e l f i n t h e upper p a r t o f t h e water column. Larvae feed on phytoplankton and are about 0.15 mm long a f t e r 1 week. The v e l i g e r s develop an umbo (prodissoconch) and may reach a l e n g t h o f 0.26 t o 0.28 mm i n 2 weeks. Fraser (1929) found l a r v a e up t o 0.5 mm l o n g in B r i t i s h Columbia, Prior to metamorphosis, t h e v e l i g e r s develop a f o o t and an eye spot, move t o t h e bottom, and search f o r a s u i t a b l e surface on which t o s e t t l e . Once a s u i t a b l e surface i s found, t h e l a r v a e undergo metamorphosis and a t t a c h t o t h e surface by s e c r e t i n g byssal threads. Depending on food supply and temperature, t h e p l a n k t o n i c 1a r v a l stage g e n e r a l l y l a s t s about 3 weeks (Quayle and Bourne 1972). The l a r v a l stage i s a c r i t i c a l one and breeding success o r f a i l u r e i s f r e q u e n t l y determined a t t h i s time (Quayle and Bourne 1972). Larvae are a t t h e mercy o f c u r r e n t s and may be c a r r i e d away from s e t t l i n g areas and perish. Post l a r v a e and Recruitment Postlarvae are epifaunal and m o r t a l i t y may be h i g h (Paul and Feder 1973). A f t e r settlement, m o r t a l i t y i s highest d u r i n g o r a t t h e end o f the f i r s t year (Schmidt and Warme 1969). Highest m o r t a l i t y i s i n the w i n t e r . I n Mugu Lagoon, California, clams t h a t had s e t i n mid-April i n sand were 7.6 n long by mid-June whereas those i n mud were 8.3 nm long b y mid-June (Peterson 1982). Unlike

t h e Washington clams, Saxidomus, which remain permanently at site of settlement, young lit t l e n e c k clams can crawl, using t h e i r foot, t o other areas. The extent of annual r e c r u i t m e n t o f 1it t l e n e c k clams v a r i e s g r e a t l y between areas. Peterson (1975 found highest t h a t Protothaca had t h e variance i n numbers o f a l l species c o l l e c t e d i n 10 sampling p e r i o d s over a 3-year period, suggesting a h i g h v a r i a b i l i t y i n recruitment. I n sand, experimental 1y increased adult d e n s i t i e s had no s i g n i f i c a n t e f f e c t on r e c r u i t m e n t , whereas i n mud, h i gh a d u l t d e n s i t i e s reduced r e c r u i t m e n t up t o 60%. I n Prince W i l l i a m Sound, Alaska, the clam's northern l i m i t , r e c r u i t m e n t was e r r a t i c and t h e r e was 1it t l e r e c r u i t m e n t from 1967 t o 1971, probably due to poor spawning c o n d i t i o n s (Paul and Feder 1973; Paul e t a l . 1976a). W i t v and Life-The o n l y data on m a t u r i t y are from n o r t h P a c i f i c populations. At I s 1and, Ladysmi t h Harbor, Woods B r i t i s h Columbia, sexual d i f f e r e n t i a t i o n was apparent when clams were 15 t o 35 mm l o n g o r d u r i n g t h e i r second o r t h i r d year o f 1i f e (Quayle 1943). Mature clams were u s u a l l y 22 t o 35 mn long. A t P r i nce W i 11ia m Sound, Alaska, t h e youngest sexual mature clam was 3 years o l d and 13 mn long (Nickerson 1977). In British Columbia, Fraser and Smith (1928) found some mature 2-year-old clams ; about one-half of t h e clams spawned f o r t h e f i r s t time a t t h e end of t h e second year o f l i f e (25 mn long). The l i f e span o f t h e l i t t l e n e c k clam v a r i e s among d i f f e r e n t l o c a t i o n s . T h e i r l i f e span i n years, their lengths, t h e i r location, and t h e authors are as f o l l o w s : 13 years (62 mn), Porpoise Island, Alaska (Paul e t a l . 1976b); 10 years (54 t o 63 mn), B r i t i s h Columbia, Canada (Frager and Smith 1928; Quayle and Bourne 1972);

4

16 years (42 t o 50 mn), Olson Bay, Prince W i l l i a m Sound, Alaska (Paul e t a l . 1976a); 15 years, Galena Bay, Prince W i l l i a m Sound, Alaska (Paul and Feder 1973; Nickerson 1977); and 7 years, Mugu Lagoon, Cal i f o r n i a (Schmidt and Warme 1969). GROWTH CHARACTERISTICS Some s c i e n t i s t s be1 i e v e t h a t 1it t l e n e c k c l ams can be a c c u r a t e l y aged by counting t h e r i n g s on t h e The r i n g s are s h e l l (see F i g u r e 1 ) . much c l o s e r together when growth slows in the winter because of low metabolism. Hughes and Clausen (19801, however, expressed c a u t i o n about aging 1i t t l e n e c k clams by she1 1 rings. They observed excessive v a r i a t i o n i n r i n g p a t t e r n s among specimens i n t h e same p o p u l a t i o n from Newport Bay, Oregon. Fraser and Smith (1928) also reported that any disturbance t h a t i n t e r r u p t s growth can cause r i n g formation. Rings can be evaluated as an aging t o o l by marking t h e s h e l l and then recovering t h e clams f o r examination a t a l a t e r date (Paul and Feder 1973). The growth o f l i t t l e n e c k clams v a r i e s throughout i t s range. Growth curves are a v a i l a b l e f o r clam populat i o n s from Alaska, B r i t i s h Columbia, and C a l i f o r n i a (Figure 3 ) and f o r an experimental p l o t i n Oregon (Figure 4). I n P r i n c e W i l l i a m Sound, Alaska, clams reach t h e marketable l e n g t h o f 30 mm i n 8 years (Feder and Paul 1973; Paul and Feder 1973), b u t a t Porpoise I s l a n d , southeast Alaska, clams reach t h i s l e n g t h i n 4 t o 5 I n waters years (Paul e t a l . 1976b). near Sidney, B r i t i s h Columbia, t h e range o f l e n g t h o f t h e clams f o r each 1st y e a r o f l i f e was as f o l l o w s : year, 11-17 nun; 2nd year, 22-33 mm; 3 r d year, 36-51 mm; 4 t h year, 37-51 mm; 5 t h year, 43-55 mm; 6 t h year, 44-57 mm; 7 t h year, 47-60 mm; 8 t h year, 49-61 mm; 9 t h year, 51-62 mm; and 1 0 t h year, 54-63 mm (Fraser and The authors r e p o r t e d Smith 1928).

-

O b i

i i i i Ago <yoarals i i a

i o ~ ii z 1 5

Figure 3. Ages and corresponding s h e l l lengths (mm) o f the common l i t t l e n e c k clam from (A) Porpoise Island, southeast Alaska; (B) Galena Bay, Prince W i l l iam Sound, Alaska; (C) V i c t o r i a , B r i t i s h Columbia, Canada (Paul e t a l . 1976b); (D) S t r a i t o f Georgia, B r i t i s h Columbia, Canada (Quayle and Bourne 1972); and (E) Mugu Lagoon, C a l i f o r n i a (Schmidt and Warme 1969).

6

12

1 8 24 30 Time (months)

36

42

Figure 4. Growth curve o f l i t t l e n e c k clams planted i n an a r t i f i c i a l substrate plot, Yaquina Bay, Oregon (Lukas 1973) over a period o f 38 months (Sept. 30, 1 9 7 0 - ~ p r i l 12, 1973).

wide d i f f e r e n c e s i n growth r a t e s among t h e years. I n Mugu Lagoon, C a l i f o r n i a , t h e growth r a t e o f l i t t l e n e c k clams was c o n s i s t e n t l y depressed a t experi m e n t a l l y induced high i n t r a s p e c i f i c densities. I n mud t h e clam's l i n e a r growth declined more than i n sand as intraspecific density increased (Peterson 1982). I n Alaska, clams at t h e higher t i d e l e v e l s had t h e best A t Kiket growth (Nickerson 1977). I s 1and, Washington, however, the best growth was near mean lower low water and l e s s r a p i d a t higher and lower t i d e l e v e l s . Growth was b e t t e r on t h e n o r t h side o f t h e i s l a n d because o f more s t a b l e water temperatures and sal i n i t i e s (Houghton 1977).

-

I n B r i t i s h Columbia l i t t l e n e c k clams are 37 mn long i n 3.5 t o 4 years and 63 mn l o n g i n 10 years (Glude 1978). I n t h e S t a t e o f Washington, it takes 4 t o 6 years f o r clams t o reach commercial l e n g t h (1.5 inches). In Oregon, clams planted on a r t i f i c i a l s u b s t r a t e (Figure 4 ) were 37 mn long i n 42 months (Lukas 1973). In C a l i f o r n i a , clams reach l e g a l s i z e (1.5 inches) i n 2 years (Frey 1971), a1 though i n Mugu Lagoon (Figure 3) i t appears t o take up t o 7 years t o reach l e g a l size. COMMERCIAL AND SPORT FISHERIES Littleneck clams are of commercial importance o n l y i n B r i t i s h Columbia and Washington (Amos 1966). The U.S. catch on t h e west coast i n 1963 produced 214,400 1b o f meat worth $107,194. I n B r i t i s h Columbia, t h e annual commerci a1 1andi ngs ranged from 21,300 t o 521,900 1b i n 1951-1969 (Quayle and Bourne 1972). Clams a r e e i t h e r dug w i t h l o n g - t i n e d rakes o r w i t h a h y d r a u l i c clam dredge. As many as 2,500 clams p e r hour can be c o l l e c t e d by a clam dredge i n areas o f h i g h d e n s i t y (Nickerson 1977). The clams are marketed f r e s h f o r steaming as f a r south as San Francisco.

In California there was commercial d i g g i n g p r i o r t o World War 11, b u t now most o f t h e beds have been overexploited and o n l y s p o r t clamming i s permitted. San Francisco Bay i s t h e o n l y l a r g e area i n C a l i f o r n i a w i t h s u f f i c i e n t clam abundance t o support a commercial f i s h e r y ( R i t c h i e 19771, b u t because o f p o l l u t i o n , a l l clams from San Francisco Bay would have t o be depurated before sale. Because of d a i l y catch l i m i t o f 50 clams, a canmercial f i s h e r y i s u n l i k e l y t o develop. L i t t l e n e c k clams are n o t harvested i n Prince W i l l iam Sound o r e l sewhere i n Alaska as a consequence of p a r a l y t i c s h e l l f i s h poison o f PSP (Anonymous 1974). Eating s h e l l f i s h t h a t have consumed l a r g e amounts o f the poisonproducing microscopic d i noflagel l a t e Gonyaulax c a t e n e l l a can cause serious i l l n e s s ( N i s h i t a n i and Chew 1983). Sport clamming i n C a l i f o r n i a i s done b y hand w i t h a rake or shovel (Frey 1971). Clam d i g g i n g tends t o be concentrated i n the i n t e r t i d a l areas p r i m a r i l y d u r i n g low t i d e . Fifty clams y i e l d about 1.5 l b of e d i b l e meat. The major problem o f t h e s p o r t clam f i s h e r y i n C a l i f o r n i a i s t h e discharge o f sewage and animal wastes i n t o e s t u a r i e s and nearshore marine waters ( R i t c h i e 1977). Although t h e r e i s a coastwide warning o f t h e dangers of p a r a l y t i c s h e l l f i s h poison frm May 1 t o October 31, t h e poison i s n o t a problem. AQUACULTURE Littleneck clams are not c u l t u r e d on t h e west coast. Ritchie ( 1977 concluded t h a t clam farming should be permi t t e d i n C a l i f o r n i a o n l y i n those areas where no other endemic species o f clams are present. C u l t u r e under these r e s t r i c t i o n s would i n v o l v e some form o f beach r e h a b i l i t a t i o n and/or t h e p l a n t i n g o f hatcheryproduced seed. I n many areas, r e s i d e n t s might o b j e c t t o u s i n g p u b l i c

lands f o r p r i v a t e b e n e f i t ( R i t c h i e 1977). As a r e s u l t of s t r i n g e n t S t a t e 50 clam l i m i t l d a y ) and laws (e.g., economic considerations, t h e p o t e n t i a1 for littleneck clam culture in C a l i f o r n i a i s low. ECOLOGICAL ROLE The littleneck clam is a suspension feeder, col l e c t i n g e v e r y t h i n g i n t h e plankton small enough t o be ingested (Schmidt and Warme 1969). The s i z e of p a r t i c l e ingested i s c o n t r o l l e d by t h e s i z e of t h e mouth opening o r t h e l i f e stage. o s t l a r v a e can feed o n l y on p a r t i c es under 10 v m i n diameter, p r i m a r i l y b e n t h i c diatoms and perhaps sediment b a c t e r i a (Peterson 1982). Because most l i t t l e n e c k clams l i v e i n t h e i n t e r t i d a l zone, most f e e d i n g i s a t high t i d e .

p a r a s i t e s a r e k i l l e d by cooking and cannot i n f e c t humans even when a l i v e . The l i t t l e n e c k clam has many predators. In Mugu Lagoon, Cal i f o r n i a , Peterson ( 1982) observed caused by the snai 1 f a t a l it i e s Pol in i c e s r e c l usianus and t h e crab Cancer anthonvi L i t t l e n e c k clams makep 1 6 % e d i e t o f t h e octopus O c t o ~ u s d o f l e i n i (Hartwick e t al. 1981). The clams eaten were 15 t o 70 m long, b u t most were 40 t o 50 mn long. The i n t e n s i t y o f p r e d a t i o n was r e l a t e d t o d i s t a n c e between t h e den of t h e octopus and t h e gravel beaches where t h e clams l i v e d .

.

-

-

-

7

Unl ik e many species o f clams, l i t t l e n e c k s can move b y u s i n g t h e i r f o o t (Peterson 1982) and reburrow (Quayle and Bourne 1972). Clams i n h e a v i l y populated areas may move t o l e s s densely populated areas, and clams exposed by dredging can reburrow a f t e r dredging i s completed. Over 88% o f t h e clams l e s s than l e g a l s i z e reburrowed i n both " s o f t " and "hard" bottoms a f t e r exposure (Quayle and Bourne 1972). Feder and Paul (1973) demonstrated t h e 1it t l e n e c k ' s a b i l it y t o reburrow through a mark and recapture study. E p i z o i c growth on littleneck clams i s rare; and Peterson (1982) s t a t e d t h a t f o u l i n g organisms are e i t h e r scraped off i n reburrowi ng o r a r e smothered. No epidemic disease has been found i n l i t t l e n e c k clams (Quayle and Bourne 1972). Two species o f t e t r a p h y l l i d i a n cestodes were found i n l i t t l e n e c k clams i n Humboldt Bay, C a l i f o r n i a , and l i t t l e n e c k clams o f t e n contained l a r g e numbers of larval tapeworms (Sparks and Chew 1966; Warner and Katkansky 1969). These

aastro~ods. Two carnivorous Forreria belcheri and sha;kyu; festivus, prey on l i t t l e n e c k clams (Schmidt and Warme 1969). Sea s t a r s ( ~ y c n o p o d ~he1ianthoi des) prey on 1 - i t t l e n e c clams i n Prince W i l l iam Sound, Alaska (Paul and Feder 1975). The sea o t t e r (Enhvdra l u t r i s ) a l s o i s a major p r e d a t o r of clams (Feder and Paul, U n i v e r s i t y of Alaska; pers. Other predators are comm. 1. polychaetes, fishes, and ducks (Quayle and Bourne 1972). Small f i s h e s have been found t o n i p on t h e siphons o f littleneck clams, reducing clam growth (Peterson and Quammen 1982).

-

I n t r a n s p l a n t experiments i n Mugu Lagoon, Cal i f o r n i a, t h e deepdwelling b i v a l ve Sanauinolaria n u t t a l l ii has no d i s c e r n i b l e i n f l u e n c e on t h e shallow-dwelling l i t t l e n e c k clam (Peterson and Andre 1980). ENVIRONMENTAL REQUIREMENTS

Larval 1it t l e n e c k clams normally l i v e i n a r e l a t i v e l y narrow range o f Near temperature and s a l in i t y . Newport, Oregon, t h e optimum water temperature range i s 10 t o 15 O C and t h e optimum s a l i n i t y range i s 27 t o 32 p p t (Phi bbs 1971). Adult 1it t l e n e c k clams can withstand water

temperatures fo r m near f r e e z i n g t o 25 OC, and t h e s a l i n i t y tolerance f o r adults ranges from about 20 ppt or less, t o 3 0 p p t i n Prince William Sound, Alaska (61 ude 1978). Substrate

quarters of t h e i n t e r t i d a l zone down t o a depth of 13 m. They stated t h a t clams burrow down t o a maximum depth o f 16 cm. I n Alaska, clams l i v e i n the 1.5 t o 1.0 m t i d a l range (Paul e t a1 1976a; Nickerson 1977).

.

Other Environmental Factors L i t t l e n e c k clams l i v e i n the coarse, sand t o mud sediments o f bays, sloughs and estuaries i n C a l i f o r n i a ( F i t c h 1953). On t h e open coast, they l i v e i n nearly any area where there are rocky p o i n t s o r r e e f s made up of small cobbles over coarse sand. In southeastern and south-central Alaska, l i t t l e n e c k clams are comnon on sandy gravel beaches. I n some coastal waters o f C a l i f o r n i a , there are wide f l u c t u a t i o n s i n clam abundance because heavy r u n o f f from creeks causes extensive sanding-in o f cobble beaches which decimates clam h a b i t a t (Frey 1971). L i t t l e n e c k clam populations in those areas t h a t have undergone sanding-in may r e q u i r e as many as 5 years t o recover (Frey 19711. L i t t l e n e c k clams l i v e o f t e n on small beaches t h a t e x i s t i n pockets on rocky shorelines, or i n small patches of l a r g e r beaches (Fraser and Smith 1928). The best beaches f o r l i t t l e neck clams are those w i t h coarse sand o r f i n e ravel mixed w i t h mud. stones, Apparently l i t t l e n e c k or she1 s. clams do poorly i n f i n e sand. Heavy metals have been concentrated in lit t l e n e c k clams because long- 1ived sedentary animals concentrate such common1y contaminants. L i t t l e n e c k clams are h i g h l y s e n s i t i v e t o copper which i s used i n a n t i f o u l i n g boat paints (Roesi j a d i 1980a, 1980b). A 15% m o r t a l i t y of clams was reported a t copper concentrations o f 7 and 18 pg/l a f t e r 30 days o f exposure. A t 39 and 82 pg/l, m o r t a l i t y was 86% and 97%, respectively, after 30 days of exposure. Copper concentrates i n the g i l l s and d i s r u p t s r e g u l a t i o n of c e l l u l a r sodium and potassium. The uptake o f heavy metals i n l i t t l e n e c k clams has been monitored i n Elkhorn Slough, C a l i f o r n i a (Graham 1972). She1 1 concentrations (ppm dry weight) were as follows: Ag, 5.8; Cd, 2.9; C r , 6 . 7 ; Cu, 11.5; Mn, 16.8; Pb, <9.0; and Zn, 9.2. The q u a n t i t i e s (ppm) i n the clam meat were as follows: Ag, <1.0; Cd, 5.7; Cr, <1.5; Cu, 7.5; Mn, 11.5; Pb, 5.2; and Zn, 67.7. The q u a n t i t i e s o f heavy metals i n the l i t t l e n e c k clam generally were lower than those i n other s h e l l f i s h i n Cal i f o r n i a. Crabs consumed more clams fo r m o i l e d than from unoiled sand because clams do not burrow as deep i n o i l e d sand (Pearson e t a1 1981). Slow reburrowing i n o i l e d sand also led t o increased predation. Small clams are f a r more vulnerable t o crab predation than l a r g e ones,

!'

Depth Littleneck clams are most abundant i n the lower p a r t of the i n t e r t i d a l zone and s u b t i d a l l y t o a depth of 3 m (Glude 1978). Maximum burrowing depth i s about 15 cm. Quayle and Bourne (1972) observed l i t t l e n e c k clams from t h e lower three

.

LITERATURE CITED Amos, M.H. 1966. C m e r c i a l clams o f t h e North American P a c i f i c coast. U.S. F i s h W i l d l . Serv. Circ. 237. 18 PP. Anonymous. 1974. P a r a l y t i c s h e l l f i s h poisoning and t h e law. Alaska Seas Coasts 2(1):5. Bureau o f Marine Fisheries. 1949. The comnercial f i s h catch of C a l i f o r n i a f o r t h e year 1947 w i t h an h i s t o r i c a l review 1916-1947. C a l i f . Dep. F i s h Game Fish. B u l l . 74. 267 pp. Feder, H.M., J.C. Hendee, P. Holmes, GJ Muel l e r , and A. J. Paul. .. 1979. Examination o f a r e p r o d u c t i v e c y c l e o f Protothaca staminea using h i stological, wet weight-dry weight ratios, and condition indices. Vel iger 22 (2 :182-187. Feder, H.M., and A. J. Paul. 1973. Abundance estimations and growthr a t e comparisons f o r t h e clam Protothaca staminea from three beaches i n Prince W i l l i a m Sound, Alaska, w i t h a d d i t i o n a l comments on size-weight relationships, harv e s t i n g and marketing. Alaska Sea Grant Program Rep. 73-2. 34 pp. Fitch, J.E. 1953. Common marine b i v a l v e s o f C a l i f o r n i a . C a l i f . Dep. F i s h Game Fish. B u l l . 90. 102 pp. 1929. The spawning and Fraser, C.M. f r e e swimmina l a r v a l Deriods o f axi id om us and- Pa h i a ' Trans. R. 3oc. Can. Ser. &95-198. Fraser, C.M., and G.M. Smith. 1928. Notes on t h e ecology o f t h e l i t t l e neck clam, Paphi a stami nea Conrad. Trans. R. Soc. Can. Ser. 3, 22:249269. Frey, H.W. 1971. C a l i f o r n i a ' s l i v i n g marine resources and their utilization. C a l i f . F i s h and Game, The Resources Agency. 148 pp. Glude, J.B. 1978. The clams genera Mercenqri a, Saxidomus, Protothaca, Ta~es, M_yq, Pano~e, and S ~ i s u l a a l i t e r a t u r e review and analysis o f t h e use o f thermal e f f l u e n t i n t h e c u l t u r e o f clams. Aquaculture Cons u l t a n t Rep. 74 pp. Graham, D.L. 1972. Trace metal l e v e l s i n i n t e r t i d a l mollusks o f C a l i f o r n i a . Veliger 14(4):365-372. Hartwick, B., L. Tulloch, and S. MacDonald 1981. Feedina and growth o f O c t o ~ u sdof l e i n i ( Wul k e r ) Veliger 19(2):163-166.

.

.

Houghton, J.P. 1977. Age and growth o f Protothaca staminea (Conrad) and Saxidomus qiqanteus (Deshayes) a t K i k e t Island, Washington. Proc. Natl. Shellfish. Assoc. 67:119. (Abstr. Hughes, W. W. , and C. D. C l ausen. 1980. V a r i a b i l i t y i n t h e formation and d e t e c t i o n o f growth increments i n bivalve shells. Paleobiology 6(4): 503-51 1 . Lukas, G. 1973. C l am-abalone spawning and rearing. F i s h Commiss i o n o f Oregon Completion Report f o r t h e period J u l y 1970-June 1973, J u l y 1973. PL 89-304, Proj. 1-60-R. 24 P P

Nickerson, R.B. 1977. A study o f t h e l i t t l e n e c k clam (Protothaca staminea Conrad) and t h e b u t t e r clam ( S a x i domus biqanteus Deshayes) i n a ' h a b i t a t p e r m i t t i n g coexistence, Prince W i l l iam Sound, Alaska. Proc. N a t l . S h e l f i s h . Assoc. 67:85-102.

-~

s p e c i f i c competition i n t h e population biology of two infaunal suspension-feedi ng bivalves, staminea and Chione L e l la. Ecol Monogr. 52(4):437-475.

m-

.

u-

N i s h i tani, L. , and K. K. Chew. 1983. Gathering safe s h e l l f i s h i n Washington. Wash. Sea Grant Program Advis. Rep. 6 pp. Paul, A.J., and H.M. Feder. 1973. Growth, recruitment, and d i s t r i b u t i o n o f t h e 1 i t t l e n e c k clam, Protothaca staminea, i n Galena Bay, n, l Alaska. U. S. P r i n c e W i l -d Natl. Mar. F i s h ~er;. Fish. B u l l . 71(3) :665-677. Paul, A. J., and H.M. Feder. 1975. The food o f t h e sea s t a r P cno odia he1 ianthoides (Brandt) Ri 1 l lam bound. Alaska. O ~ h eia l Paul, A. J. , J.M. Paul, and H.M. Feder. 1976a. Recruitment and growth i n t h e b i v a l v e Protothaca staminea, a t Olsen Bay, Prince W i l l i a m Sound, t e n years a f t e r t h e 1964 earthquake. Vel i g e r 18(4):385-392. Paul, A. J., J.M. Paul, and H.M. Feder. 1976b. Growth o f t h e l i t t l e n e c k clam, Protothaca staminea, on Porpoise I s l a n d . southeast Alaska. Pearson, W.H., D.L. Woodruff, P.C. Sugarman, and B.L. Olla. 1981. E f f e c t s o f o i l e d sediments on p r e Protod a t i o n on l i t t l e n e c k clam, thaca staminea, by t h e dungeness crab, Cancer maqister. Estuarine Coastal Shelf Sci 13(4):445-454.

Peterson, C.H., and S.V. Andre. 1980. An experimental a n a l y s i s o f i n t e r s p e c i f i c competition among marine f i l t e r feeders i n a soft-sediment environment. Ecology 61( 1):129-139. Peterson, C.H., and M.L. Quamen. 1982. Siphon nipping: i t s importance t o small f i s h e s and i t s impact on growth o f t h e b i v a l v e Protothaca staminea (Conrad). J. Exp. Mar. B i o l . Ecol. 63:249-268. Phibbs, F.D. 1971. Temperature, s a l i n i t y and clam larvae. Proc. 61:13. Natl. Shellfish. Assoc. (Abstr. Quayle, D.B. 1943. Sex, gonad development and seasonal gonad changes i n Paphia staminea Conrad. J. Fish. Res. Board Can. 6(2):140-151. Quayle, D.B., and N. Bourne. 1972. The clam f i s h e r y o f B r i t i s h Columbia. Fish. Res. Board Can. B u l l . 179. 70 pp. Ritchie, T.P. 1977. A comprehensive review o f t h e commercial clam indust r i e s i n t h e United States. U.S. Natl. Mar. Fish. Serv. 106 pp. Rodnick, K., and H.W. Li. 1983. H a b i t a t s u i t a b i 1 it y index model : littleneck clam. U.S. Fish W i l d l Serv. FWS/OBS-82/10.59. 15 PP

.

.

Peterson, C.H. 1975. Stability of species and community f o r t h e benthos o f two lagoons. Ecology 56: 958-965. Peterson, C.H. 1982. The importance o f predation and i n t r a - and i n t e r -

Roesi j a d i , G. 1980a. Influence o f c o m e r on t h e a i 11s o f t h e l i t t l e neck clam ~ r o t o t h a c a staminea. Proc. Natl. Shellfish. Assoc. 70(1):129. (Abstr. 1980b. Influence o f Roesi j a d i , G. copper on the clam Protothaca staminea: e f f e c t s on g i 1 I s and occurrence of copper-bindi ng

proteins. Biol 158:233-247.

. Bull.

(Woods ole)

Schmidt, R.R., and J.E. Yarme. 1969. Population c h a r a c t e r i s t i c s o f Protothaca staminea (Conrad) from Mugu Lagoon, C a l i f o r n i a . Veliger 12(2): 193-199. Smith, S.E., and S. Kato. 1979. The f isheries of San Francisco Bay: past, present and f u t u r e . Pages 445-467 i n 7.5. Conornus, ed. San F r a n c i s c o Bay, t h e unurbanized estuary.

1966. Sparks, A.K., and K.K. Chew. Gross i n f e s t a t i o n o f t h e l i t t l e n e c k clam (Venerupsis staminea) w i t h t h e larval cestode (Echeneibothrium sp. 1. J. Invertebr. Pathol. 8:413416.

Warner, R.U., and S.C. Katkansky. 1969. The i n f e s t a t i o n o f t h e clam Protothaca staminea by two species of Tetraphyl 1i d i a n cestodes SPP. 1. J. (Echenei b o t h r i urn Invertebr. Pathol 13(1): 129-133.

.

SOY?? -101

REPORT DOCUMENTATION 1. M m R T N o . ; B i o l o g i c a l Report 82(11.46)* PAGE

4. Title and lubtttle

1'

3. I)ec,v~*nt's Access~onNO

s nepan oat.

Species P r o f i l e s : L i f e H i s t o r i e s and Environmental Requirements o f Coastal Fishes and I n v e r t e b r a t e s ( P a c i f i c Southwest)--Common

A p r i l 1986

L

. .

9. h + n n t n (

N. s a w

Oqenlzetlen Name end & d n s s 80. ~ m ~ m t T e s r m o r ~ Untt 81. b n t r a c t ~ n Gran((G1 u

NO.

Humboldt S t a t e U n i v e r s i t y Fred Telonicher Marine Laboratory T r i n i d a d , C 95570 A

1 . SOOll~dy 2 OqanlZOtlWI N e m and MdlWss

NO.

(Q

National Coastal Ecosystems Team F i s h and W i l d l i f e Service U.S. Department o f the I n t e r i o r Washington, D 20240 C

U.S. Army Corps o f Engineers Waterways Experiment S t a t i o n P.O. Box 631 Vicksburg, M 39180 S

8% TVW d Reoon

.

Pend h

n

d

*U.S.

1 .

Army Corps o f Engineers Report No. T EL-82-4 R

A b a h ( U m k 2W -1

Species p r o f i l e s are 1it e r a t u r e summaries o f t h e taxonomy, morphology, d i s t r i b u t i o n , l i f e h i s t o r y , and environmental requirements o f coastal aquatic species. They a r e prepared t o a s s i s t i n environmental impact assessment. Common 1it t l e n e c k clam (Protothaca staminea) supports an important s p o r t f i s h e r y i n t h e P a c i f i c Southwest Region, b u t has no commercial importance. The species i s d i s t r i b u t e d from Alaska t o Baja, C a l i f o r n i a . The egg develops i n t o t h e trochophore stage 12 h a f t e r f e r t i l i z a t i o n , and t h e p l a n k t o n i c l a r v a l stage l a s t s about 3 weeks. Adults usual l y mature i n the second o r t h i r d year o f l i f e . M o r t a l i t y i s g r e a t e s t e a r l y i n l i f e . I n t r a s p e c i f i c competition among a d u l t s i s more evident i n mud than i n sand. Most l i t t l e n e c k clams l i v e i n t h e lower i n t e r t i d a l zone. L i t t l e n e c k clams concentrate heavy metals and are h i g h l y s e n s i t i v e t o copper.

17. Dosumrr( Anmlnis

L i f e cycles Fisheries Sediments Clams Aquaculture

a. O e u r i @ o n

Feedi ng habi t s Growth Canpeti t i o n Contaminants

terms

L Identlfien/OD.n.nded

Protothaca staminea

I

Ecological r o l e Common 1it t l e n e c k clam

L COSATI n e l d / t r o u p

Envi ronmental requirements

1 L Ave~lebllily Statement

19. %curtly Class Q i) R e m a 1

~ n c l a s s!led i

21. NO. Of ream.

11

a.m c e

OPTIONAL FORM 272 (4-77) (Forrmrly N T I S 3 5 ) h v e n m e n t ot Commerce

n l i m i t e d r e 1ease

(Sea ANSI-239.18)

. .

1. S.c~rlW 0 Class (rhlq r e el

~ n c l a s sf i e 8

U.S.G.P.O.

1986/661-638

REGION 1

Regional Director U.S. Fish and Wildlife Service Lloyd Five Hundred Building, Suite 1692 500 N.E. Multnornah Street Portland, Oregon 97232

REGION 2

Regional Director U.S. Fish and Wildlife Service P.O. Box 1306 Albuquerque, New Mexico 87 103

REGION 3

Regional Director U.S. Fish and Wildlife Service Federal Building, Fort Snelling Twin Cities, Minnesota 55 1 1 1

REGION 4

Regional Director U.S. Fish and Wildlife Service Richard B. Russell Building 75 Spring Street, S.W. Atlanta, Georgia 30303

REGION 5

Regional Director U.S. Fish and Wildlife Service One Gateway Center Newton Corner, Massachusetts 02158

REGION 6

Regional Director U.S. Fish and Wildlife Service P.O. Box 25486 Denver Federal Center Denver, Colorado 80225

REGION 7

Regional Director U.S. Fish and Wildlife Service 1011 E. Tudor Road Anchorage, Alaska 99503

DEPARTMENT OF THE INTERIOR

U.S. FISH AID WILDLIFE SERVICE

As the Nation's principal conservation agency, the Department of the Interior has responsibility for most of our,nationally owned public lands and natural resources. This includes fostering the wisest use of our land and water resources, protecting our fish and wildlife, preserving theenvironmental and cultural values of our national parks and historical places, and providing for the enjoyment of life through outdoor recreation. The Department assesses our energy and mineral resources and works to assure that their development is in the best interests of all our people. The Department also has a major responsibility for American Indian reservation communities and for people who live in island territories under U.S. administration.

Information

21 pages

Find more like this

Report File (DMCA)

Our content is added by our users. We aim to remove reported files within 1 working day. Please use this link to notify us:

Report this file as copyright or inappropriate

1270231

You might also be interested in

BETA
Egypt - Egypt Hydrocarbon Company Ammonium Nitrate Plant - ESIA Summary
Vietnam