Status of the European Green Crab in Oregon Estuaries during the Summer of 2002

Transcription

1 1 Status of the European Green Crab in Oregon Estuaries during the Summer of 2002 Sylvia Behrens Yamada and Tim Davidson Zoology Department, Oregon State University, Corvallis, OR TEL: ; FAX: ; Progress report prepared for: The Pacific States Marine Fisheries Commission 45 SE 82 nd Drive Suite 100 Gladstone, Oregon TEL: and The Alaska Department of Fish of Game Executive Summary: The recent invasion of Pacific Northwest estuaries by the European green crab, Carcinus maenas, caused much initial alarm. A large recruitment event resulted in the colonization of estuaries along the coasts of Oregon, Washington, and as far north as Nootka Sound on the west coast of Vancouver Island, British Columbia. So far, green crabs have not been found in the inland sea between Vancouver Island and the mainland. Monitoring efforts during the summer of 2002 in Oregon and Washington indicate that green crab populations still persist in coastal estuaries, but at much reduced levels. Population densities in all Pacific Northwest estuaries, even at their peak, were well below those observed in Europe, on the East Coast of North America and in Central California. Green crabs grow well in our estuaries and females are capable of reproduction. Recruitment of young green crabs has occurred in some Oregon and Washington estuaries since 1998, but their numbers have been very low. In the summer of 2002, we trapped only one young crab (39 mm carapace width) in Oregon. The recruitment event during the El Niño was linked to unusually strong northward-moving coastal currents. At velocities of up to 50 km/day, these currents had the potential to transport larvae from more established populations in California to the Northwest. Coastal transport events have been much weaker in recent years. Even though green crab abundances are down, it is imperative to continue monitoring efforts for two reasons: 1) to elucidate the process of range expansion of

2 2 non-indigenous marine species and 2) to serve as an early warning system for the next strong recruitment event of green crabs. Outreach Activities in 2002 July 19/03 Nov. 21/02 Sept. 29/02 June 26/02 Are European Green crabs establishing themselves in Oregon estuaries? Guest lecture by Sylvia Yamada The status of the European Green Crab in Pacific Northwest Estuaries: Current Status and Prediction for the Future. Talk given by Sylvia Yamada The status of the European green crab invasion in the Pacific Northwest and what to do about it! Talk given by Sylvia Yamada and Brett Dumbauld (WDFW) The status of the European Green Crab in Pacific Northwest Estuaries: Current Status and Prediction for the Future. Talk given by Sylvia Yamada University of Oregon Biological Invasions In Marine Environments (Bi 408/508) University of Oregon, Community Ecology class (Bi 472/572), Eugene, Oregon Meeting of the Pacific Coast Shellfish Growers Association and the National Shellfish Association, Newport, Oregon Invited seminar speaker: Oregon Institute of Marine Biology, Charleston, Oregon Background: The invasive European green crab (Carcinus maenas) was discovered in Oregon, Washington and British Columbia coastal estuaries in the late 1990 s. Warm temperatures and strong northward moving coastal currents (>50 km/day) during the 1997/1998 El Niño were correlated with the appearance of a strong year class of young green crabs in the summer of 1998 (Behrens Yamada and Hunt 2000). This year class most likely arrived as larvae from well-established source populations in California. Since these colonists are now approaching the end of its lifespan, the next few years will be critical in determining the fate of green crab populations on Pacific Northwest shores. While recruitment of young green crabs in Oregon and Washington has been sparse in the last few years, the females from the 1998-year class are now over 70 mm in carapace width and at the peak of their reproductive life (Behrens Yamada et al. submitted). Under

3 3 favorable conditions they could produce more than one brood a year (d Udekem d Acoz 1993). Furthermore, another El Niño event could bring more larvae from California. Scientists, managers and shellfish growers are concerned that increases in the abundance and distribution of this efficient predator and competitor could permanently alter native marine communities and threaten commercial species such as juvenile Dungeness crab, juvenile flatfish and bivalves (Lafferty and Kuris 1996, Jamieson et al. 1998). The goal of this study is to estimate the current densities and predict the future status of the European green crab in Oregon estuaries and the Pacific Northwest. This was accomplished by: Estimating the size/age structure and density of the adult green crab population. Estimating the size/age structure and density of young-of-the-year green crabs. Comparing patterns in recruitment strength over time and place and correlating them to ocean current patterns. Sampling Methods for Green Crabs in Oregon Our sampling effort focused on four Oregon estuaries: Coos, Yaquina, Netarts and Tillamook (Appendix 1). All four estuaries were sampled at least twice during the summer of 2002 (Appendix 2). In each estuary, we selected study sites within various habitat types and tidal levels. Since green crabs are rare and patchily distributed, we did not choose our sites randomly. Instead, we selected sites that were known to have harbored green crabs in the past as well as new sites with suitable habitat. We learned that green crabs are most abundant in tidal marshes, sloping mudflats and tidal channels where salinities remain above 15 and temperatures range between o in the summer. Green crabs were noticeably absent from the cooler, more saline mouths of estuaries, which are dominated by the larger and more aggressive red rock crab, productus (Hunt and Behrens Yamada 2003). Since C. maenas larvae settle high on the shore (Zeng et al. 1999), and crabs move into deeper water as they age (Crothers 1968), we adapted our collecting methods and

4 4 locations to effectively sample all age classes of C. maenas. Since traps differ in their sampling efficiency for different sizes of crabs, we used two trap types (Table 1). Folding fish traps, with their wide slit-like openings, work well for adult crabs larger than 40 mm carapace width (CW); while minnow traps with their small mesh size (0.5 cm) retain young-of the-year green crabs. Typically, green crabs start entering these baited traps when they are around mm CW. We sampled young-of the-year green crabs in the high and mid intertidal with minnow traps and larger adult crabs in the low intertidal and subtidal zones with folding traps (Appendix 2). Table 1. Types of traps used for sampling C. maenas in Oregon estuaries. Size selectivity is given in carapace width (CW). Trap Type Description Dimensions Tidal Height Minnow/ Crayfish Folding Fish Trap Wire mesh (0.5 cm) cylinder with two 5 cm openings Plastic mesh (2 cm) with two slit openings (45 cm) 21 cm diameter 37 cm long Medium to high 63 x 46 x 23 cm Subtidal to lower intertidal Size Selectivity (CW) Medium mm Large >40 mm Rocks were added to the traps to weigh them down and to provide shelter for the crabs. We cut salmon backbones into sections and place them into egg-shaped commercial bait containers (15 x 8 mm). Holes (1cm) in the sides and lids of the containers allow bait odors to diffuse. One bait container with fresh bait was placed in a trap and left for hours. At low tide, we retrieved the traps, identified all crabs to species and noted the sex and carapace widths (CW) of all green crabs. Green crabs were measured between the tips of their fifth anterio-lateral spines using vernier calipers. Native crabs were released while green crabs were removed from the ecosystem and destroyed.

5 5 Results Densities of Green Crabs in Oregon Estuaries Table 2. Summary of Green crab trapping data for the summer of CPUE = catch per unit effort (#crabs/trap-day). Data compiled from Appendix 2. Estuary Number of trap-days Number of Green crabs trapped CPUE Range of Carapace Width (mm) Coos Bay Yaquina Netarts Tillamook Bay The relative abundances of green crabs retrieved from Oregon estuaries during the summer of 2002 are tabulated in Appendix 2 and summarized in Table 2. Catch per effort was much lower in Tillamook and Coos Bay (0.03) than in Yaquina Bay (0.15). This discrepancy, in part, is due to the unusually high catches at one the Oregon Coast Aquarium site on August 13 (Appendix 3). Comparison of catches in Coos and Yaquina Bay for 2002 and 1999 indicates that green crab abundance has decreased by an order of magnitude in three years. Catches averaged from 0.3 to 0.8 crabs per trap per day in 1999 but only from 0.03 to 0.15, in 2002 (Tables 2, 3). Table 3. Green crab trapping data for the Summer of CPUE = catch per unit effort (#/trap-day). Asterisk indicates that carapace width data were lumped for Yaquina Bay stations and ranged from mm. Data complied from Hauck 2000 and Hunt and Behrens Yamada Estuary/site Number of trap-days Number of Green crabs trapped CPUE Coos/Pony Point Coos/Russell Point Coos/Roseburg Range of Carapace Width (mm)

6 6 Lumber Fossil Point Yaquina/Hatfield Marine Science Center Yaquina/Idaho point Yaquina/Sawyer s Landing Yaquina/Sally s Bend C Yaquina/Johnson * Slough Yaquina/Sally s * Bend Yaquina/Oregon * Coast Aquarium Yaquina/Hatfield Marine Science Center * Age Structure of Green Crabs in Oregon Estuaries From previous mark and recapture studies and from shifts in size frequency distributions over time (Behrens Yamada et al. submitted) we estimated the age of some of the green crabs retrieved from Oregon estuaries in the summer of 2002 (Appendix 3). Large crabs over 85 mm in carapace width with hard, worn carapaces were assigned to the 98 yearclass. Crabs between 70 and 85 are difficult to age and are estimated to comprise the 98, 99 and 00 year classes. Crabs from mm were assigned to the 01 year-class and the one crab under 50 mm was classified as a new recruit (02 year-class). The retrieval of at least 17 green crabs from the 98-year-class, suggests that the original colonizers from the 1997/1998 El Niño were still well represented in Oregon estuaries in 2002, especially in Coos Bay. We did not find any evidence of recent recruitment in Coos Bay since the summer of None of the crabs we trapped in Coos Bay in 1999, 2000, 2001 and 2002 were young-of-the-year crabs. This observation was confirmed by three oyster-growers from this area. Eight of the ten crabs retrieved in 2002 in Coos Bay

7 7 were hard males over 82 mm in CW. The presence of large barnacles on worn carapaces, together with red or orange coloration suggests that these crabs had not molted in a long time. Three dead crabs were found on the shore, of which two exhibited no external bodily damage. It is possible that these crabs have reached their natural life span and that others from the 98 year-class will soon follow. Green crabs in Europe and Maine have a maximum longevity of around 4-5 years (Berrill 1982, Dries and Adelung 1982). Recruitment over time and place While we found now evidence of recent green crab recruitment in Coos Bay, that was not the case for Tillamook and Yaquina Bay, nor for two southern Washington estuaries. For example, we could assign 2/4 crabs from Tillamook Bay and 8/30, from Yaquina Bay to the 01 year-class (Appendix 3). Green crabs from the two southern Washington estuaries exhibited a similar size range as crabs from Tillamook and Yaquina Bays (Figure 1). The presence of crabs smaller than 70 mm in carapace width suggests that these four estuaries experienced recruitment since 1998 (Figure 1)..

8 Number of Crabs 8 Figure 1. Size frequency distribution of green crabs retrieved from Oregon and Washington estuaries during the summer of While more large crabs were found in Oregon, especially in Coos Bay, the size range of crabs in the two states was similar. (Data for Washington supplied by Washington Department of Fish and Wildlife.) Green Crabs Summer Oregon Washington Carapace Width Periodic sampling of young-of the-year green crabs in Yaquina Bay and Willapa Bay, Washington indicates that some recruitment occurred in recent years. At the end of the growing season, in late summer and fall of 1998, we observed a fair number of young green crabs ranging in carapace width from mm in both estuaries (Table 4). Catches of young crabs in subsequent years, however, decreased considerably. Recruitment in 2000 was at least one order of magnitude lower than in 1998 at both sites. Recruitment in 2002 was the lowest, with only one young-of-the-year crab recovered in Yaquina Bay, Oregon and one in Willapa Bay Washington (Table 4). Table 4. Relative abundance (CPUE) and mean carapace (CW) width of young-ofthe-year C. maenas at the end of their first growing season in Yaquina Bay, Oregon and Willapa Bay, Washington. Crabs were caught between September and early

9 9 December. Catch per unit effort (CPUE), reported as number of crabs per trap per day, is only a rough measure of relative abundance since total effort varied between years and data represents a mix of pitfall trap and baited trap data. (N=sample size, SD=Standard Deviation). Data for Willapa Bay were provided by the Washington Department of Fish and Wildlife. Year Class N Estuary Average CPUE Mean CW (mm) SD Range (mm) Yaquina Yaquina Yaquina Yaquina Not sampled Yaquina Willapa Willapa Willapa Willapa Check with ODFW Willapa ~ 44 Check with ODFW What factors contribute to strong green crab recruitment and range expansion? Behrens and Hunt (2000) combined size data from green crab sightings and growth measurements of tagged crabs to infer that there have been three northern range expansion on the West Coast on North America: 1993, 1995/6 and 1997/8. Each of these events is correlated with unusually strong northward-moving coastal currents during the winter and early spring (Table 5). For example, northward coastal currents off the Oregon coast during the winter of 1997/98 reached 50 km/hour (Huyer et al. 1998; Barth and Smith 1998). We believe that these unusually strong pole-ward currents during El Niño conditions can act as transport mechanism for moving green crab larvae from established source population in California to the Pacific Northwest. Table 5. Relative strength of pole-ward coastal currents from January to April and observed green crab recruitment strength and range expansions. Since the strength of pole-ward coastal currents is correlated with sea level, we used the mean monthly sea level anomalies for the San Francisco tidal station: ftp://ilikai.soest.hawaii.edu/islp/slpp.anomalies

10 10 YEAR Relative Strength of Pole-ward Currents at San Francisco during the first four months of year. January February March April Observed Green Crab Range Expansion and Recruitment Good (N. California) ? Good (S. Oregon) Very Good (Vancouver Island.) Poor Poor 2001 Poor 2002 Poor Conclusions The abundance of green crabs in Oregon estuaries has decreased by an order of magnitude from 0.3 to 0.8 crabs per trap per day in 1999 to 0.03 to 0.15 crabs per trap per day in While female crabs are capable of producing viable larvae, recruitment has been poor since Green crab populations in Oregon and Washington are persisting, but at low densities. We speculate that larval abundance in the Pacific Northwest is still too low, and/or currents are too unfavorable to affect significant local recruitment. Green crab range expansions along our coast appear to be linked to strong El Niño conditions. Acknowledgements We are grateful to Brett Dumbauld and the staff of the Washington Department of Fisheries and Wildlife for their collaboration in our joint goal of elucidating the life

11 11 history of green crabs in the Pacific Northwest. We appreciate the green crabs sighting reported by Jesse Hayes, David Smith and an anonymous fisher in Alsea Bay as well as the reports from shellfish growers in Coos Bay. Accommodations while sampling in Coos Bay and Yaquina Bay were provided by the Oregon Institute of Marine Biology and the Hatfield Marine Science Center. We thank Annette and Harry Daughters of the Bay Street Crab Company in Corvallis for continually supplying us with fresh bait. Literature Cited Barth, J.A. and R.L. Smith The Coastal Ocean off Oregon and Northern California during the El Niño, Part 3: A Lagrangian View. Transactions of the American Geophysical Union 79(45): F485 Behrens Yamada, S Global Invader: The European Green Crab. 123 pages. Oregon Sea Grant, Washington Sea Grant. Behrens Yamada, S., A. Kailin, C. Hunt, B.D. Dumbauldt and R. Figlar-Barnes (200_). Growth and persistence of the recent invader Carcinus maenas in Pacific Northwest estuaries. Submitted to Biological Invasions. Behrens Yamada, S. and C. Hunt The arrival and spread of the European green crab, Carcinus maenas, in the Pacific Northwest. Dreissena! 11 (2): 1-7. Berrill, M The life cycle of the green crab Carcinus maenas at the northern end of its range. Journal of Crustacean Biology 2: Crothers, J.H The biology of the shore crab Carcinus maenas (L.). 2. The life of the adult crab. Field Studies 2: Dries, M and D. Adelung Die Schlei, ein Modell für die Verbreitung der Strandkrabbe Carcinus maenas. Helgoländer Meeresuntersuchungen 35: d Udekem d Acoz, C Activités reproductrices saisonnières des différentes classes de tailles d une population de crabes verts Carcinus maenas(linnaeus, 1758) dans le sud de la mer du Nord. Cahiers de Biologie Marine 35:1-13. Hauck, L.L Use of tethered prey for estimating the impact of the invasive European green crab. Senior Thesis, Biology Department, Oregon State University, Corvallis, Oregon Hunt, C.E. and S. Behrens Yamada Biotic resistance experienced by an invasive

12 12 crustacean in a temperate estuary. Biological Invasions 5 (1). Huyer, A., J.A. Barth, J. Fleischbein, P.M. Kosro, R.L. Smith The Coastal Ocean off Oregon and Northern California during the El Niño, Part 1: Temperature, Salinity and Geostropic Velocity Fields.. Transactions of the American Geophysical Union 79(45): F485 Jamieson, G.S., E.D. Grosholtz, D.A. Armstrong and R.W. Elner Potential ecological implications for the introduction of the European green crab, Carcinus maenas, (Linnaeus), to British Columbia, Canada and Washington, USA. Journal of Natural History 32: Lafferty, K. and A. Kuris Biological control of marine pests. Ecology 77: Zeng, C., P. Abello, and E. Naylor Endogenous tidal and semilunar moulting rhythms in early juvenile shore crabs Carcinus maenas: implications for adaptations to a high intertidal habitat. Marine Ecology Progress Series 191:

13 13 Appendix 1. Description of Carcinus maenas sampling sites in Oregon estuaries during the Summer of Coos Bay Site Date Tidal Height Location Description S Water Temp. Jordan s Cove 25-Jun High Beach, Marsh N Glasgow 25-Jun High Quail road, mudflat N Russell Point 26-Jun High Bridge/oyster flats N Pony Creek 27-Jun High Anoxic mud, weathered cement structures N Pigeon Point 28-Jun High Washed up Ulva, anoxic mud, weathered cement structures N Charleston Bridge 28-Jun High Under bridge, Sand flat N Glasgow 15-Sep High Quail Road, mudflat N Eastside Road 15-Sep High South of Kentuck inlet, along road, next to tidal channel N North of Golf Course 15-Sep High Near Miller's Lane, next to "No Dumping" sign, mudflat N Jordan s Cove 16-Sep High Beach, Marsh N South Slough 16-Sep High South of Charleston Bridge, sand flat N Haynes Inlet 16-Sep High Next to Clausen Oyster 35 N Roseburg Lumber 25-Jun low Parallel to road N Glasgow 25-Jun mid Quail road to bridge N Russell Point 26-Jun low/mid Bridge/oyster flats Y Pony Point/Airport 27-Jun low/mid Point to boat ramp, rip rap Y Pigeon Point 28-Jun low Tidal channels carved through sandstone strata N Charleston Bridge 28-Jun low Pilings/clam beds N Yaquina Bay Air Temp. Sawyer's Landing 24-Jul high Rip rap and sandy mudflat on both sides of Store/Dock N Idaho Point Road 24-Jul high Low sloping mudflat, lots of marsh vegetation, many tidal creeks N Sally's Bend A 7-Aug high At elbow near road entrance, mudflat, large Scirpus patches Y Sally's Bend B 7-Aug high Across from George St., Scirpus patches N Johnson Slough 7-Aug high Below bridge, dry mudflat around creek, Salicornia patches N HMSC Pump house 13-Aug high Rip rap around dock, sandy mudflat and boulders N Oregon Coast Aqua. 13-Aug high Tidal channel draining mudflat, along nature trail N Idaho Point Marina 17-Jul low Marina in large tidal creek, Z. marina in creek, mudflat Y Green Crabs Found?

14 14 HMSC Pump house 17-Jul low Rip rap around dock, sandy mudflat and boulders N Sawyer's Landing 27-Jul low Rip rap and sandy mudflat on both sides of store/dock N Sally's Bend C 27-Jul low Near fishing platform Y Johnson Slough 7-Aug low Below bridge, dry mudflat around creek, Salicornia patches Y Oregon Coast Aqua. 13-Aug low Tidal channel draining mudflat, along nature trail Y Sally s Bend A 19-Oct High At elbow near road entrance, mudflat, large Scirpus patches N Tillamook Bay Tillamook Spit A 12-Jul high mudflat- vegetation ecotone N Tillamook Spit B 12-Jul high Long stretch of rip rap ending at an elbow with abundant Scirpus Y Dick Point 20-Aug high pilings scattered throughout site, Z. marina N Tillamook Spit B 20-Aug high Long stretch of rip rap ending at an elbow with abundant Scirpus N Culvert-Bay Ocean 12-Jul low Salt water pond draining to mudflat via culvert N Rd Dick Point 12-Jul low pilings scattered throughout site, Z. marina N Tillamook Spit A 12-Jul low mudflat- vegetation ecotone N Tillamook Spit B 12-Jul low Long stretch of rip rap ending at an elbow with abundant Scirpus Y Dick Point 20-Aug low pilings scattered throughout site, Z. marina N Garibaldi Docks 20-Aug low Garibaldi Boat Docks N Netarts Bay Whiskey Creek 11-Jul high Tidal Creek, washed up Z. marina and algae N Whiskey Creek 20-Aug high Tidal Creek, washed up Z. marina and algae N Mile 2 11-Jul low Along Netarts Rd., Scirpus and Z. japonica 15.5 N Whiskey Creek 11-Jul low Tidal Creek, washed up Z. marina and algae N

15 15 Appendix 2. Relative abundance of crab species and sculpins (Numbers/trap/day) in Oregon estuaries during the Summer of Coos Bay Site Date Trap Type Zone Carcinus maenas Mean CPUE (Catch/trap/day) Hemigrapsus oregonensis Hemigrapsus nudus magister magister (Recruits) productus Sculpin Number Traps Roseburg Lumber 25-Jun Fish Zostera marina Glasgow 25-Jun Fish Zostera japonica Russell Point 26-Jun Fish Z. marina/scirpus Pony Point/Airport 27-Jun Fish Zostera marina Pigeon Point 28-Jun Fish Zostera marina Charleston Bridge 28-Jun Fish Zostera marina Jordan s Cove 25-Jun Minnow Fucus/Scirpus Glasgow 25-Jun Minnow Scirpus Russell Point 26-Jun Minnow Fucus Pony Creek 27-Jun Minnow Fucus Pigeon Point 28-Jun Minnow Fucus Charleston Bridge 28-Jun Minnow Fucus Glasgow 15-Sep Minnow Scirpus Eastside Road 15-Sep Minnow Scirpus, Z. japonica North of Golf Course 15-Sep Minnow Scirpus, Z. japonica Jordan s Cove 16-Sep Minnow Fucus/Scirpus South Slough 16-Sep Minnow Below Marsh Haynes Inlet 16-Sep Minnow Below Marsh

16 16 Yaquina Bay Site Date Trap Type Zone Carcinus maenas Mean CPUE (Catch/trap/day) Hemigrapsus oregonensis Hemigrapsus nudus magister magister (Recruits) productus Idaho Point Marina 17-Jul Fish Zostera marina HMSC Pump house 17-Jul Fish Zostera marina Sawyer's Landing 27-Jul Fish Zostera marina Sally's Bend C 27-Jul Fish Zostera marina Johnson Slough 7-Aug Fish Below Barnacles Oregon Coast Aqua. 13-Aug Fish Subtidal Sculpin Number Traps Sawyer's Landing 24-Jul Minnow Fucus Idaho Point Road 24-Jul Minnow Fucus Sally's Bend A 7-Aug Minnow Zostera japonica Sally's Bend B 7-Aug Minnow Zostera japonica Johnson Slough 7-Aug Minnow Fucus HMSC Pump house 13-Aug Minnow Fucus Oregon Coast Aqua. 14-Aug Minnow Fucus Sally's Bend A 19-Oct Minnow Zostera japonica Tillamook Bay Site Culvert-Bay Ocean Rd Date Trap Type Zone Carcinus maenas Mean CPUE (Catch/trap/da y) Hemigrapsus oregonensis Hemigrapsus nudus magister magister (Recruits) productus Sculpin 12-Jul Fish Subtidal Number Traps

17 17 Dick Point 12-Jul Fish Zostera marina Tillamook Spit A 12-Jul Fish Zostera japonica Tillamook Spit B 12-Jul Fish Zostera japonica Dick Point 20-Aug Fish Zostera marina Garibaldi Docks 20-Aug Fish Subtidal Tillamook Spit A 12-Jul Minnow Salicornia/Scirpus Tillamook Spit B 12-Jul Minnow Fucus Dick Point 20-Aug Minnow Scirpus Tillamook Spit B 20-Aug Minnow Fucus Netarts Bay Site Date Trap Type Zone Carcinus maenas Mean CPUE (Catch/trap/da y) Hemigrapsus oregonensis Hemigrapsus nudus magister magister (Recruits) productus Whiskey Creek 11-Jul Fish Creek Sculpin Number Traps Whiskey Creek 11-Jul Minnow Fucus Mile 2 11-Jul Minnow Zostera japonica Whiskey Creek 20-Aug Minnow Fucus Note: updated 11/20/02

18 18 Appendix 3. Carcinus maenas catches and sightings in Oregon Estuaries during the Summer of Year Classes are estimates based on crab size, carapace coloration, hardness and presence of large barnacles. Only one recent recruit was found at Sally s Bend in Yaquina Bay on August 13. Missing limbs are numbered in sequence: 1= Right claw; 5= last leg on right side, 6= left claw, 10=last leg on left side. Asterisk indicates that carapace was measured in inches and converted to mm. Bay Site Date Sex CW Color Year Class Condition/Comments Coos Bay Russell Point 6/26/2002 Male 97.4 Yellow 98 #1 missing Coos Bay Russell Point 6/26/2002 Male 86.8 Red 98 4, 7 missing, barnacles Coos Bay Pony Point 6/27/2002 Female 69 Green Coos Bay Pony Point 6/27/2002 Male 87.9 Orange 98 Coos Bay Pony Point 6/27/2002 Male 92.8 Yellow-Green 98 Coos Bay Pony Point 6/27/2002 Male 89.4 Red 98 barnacles Coos Bay Pony Point 6/27/2002 Male 87 Orange-Red 98 Dead: 1,2,4,10 and puncture in carapace Coos Bay Pony Point 6/27/2002 Male 92.2 Orange-Red 98 Dead: 8 Coos Bay Pony Point 6/27/2002 Male 82.3 Orange-Red 98 Dead: 5,8,10 Coos Bay Pony Point 7/15/2002 Male 75.6 Hard/Green Dave Smith Yaquina Bay Sally's Bend C 7/2/2002 Male 89.3 Orange-Red 98 Barnacles Yaquina Bay Sally's Bend C 7/2/2002 Male 90.3 Orange-Red 98 Barnacles Yaquina Bay Idaho Point Marina 7/17/2002 Male 91.2 Yellow 98 Yaquina Bay Idaho Point Marina 7/17/2002 Male 88.8 Yellow 98 Yaquina Bay Sally's Bend C 7/27/2002 Male 85.4 Yellow 6,9,10 Missing Yaquina Bay Sally's Bend C 8/7/2002 Male 84.6 Yellow Yaquina Bay Johnson Slough 8/7/2002 Male 86.8 Orange 98 1 dactyl missing, 7, Barnacles Yaquina Bay Johnson Slough 8/7/2002 Male 92.5 Orange 98 7 missing, Barnacles Yaquina Bay Sally's Bend A 8/13/2002 Male 38.9 Green 02 only recruit found in 2002 Yaquina Bay Oregon Coast Aqua. 8/13/2002 Male 82.2 Orange 1 dactyl missing, 5 tip gone, Barnacles Yaquina Bay Oregon Coast Aqua. 8/16/2002 Male 88.4 Yellow 98 5 missing Yaquina Bay Oregon Coast Aqua. 8/16/2002 Male Orange Yaquina Bay Oregon Coast Aqua. 8/16/2002 Male Orange/white Yaquina Bay Oregon Coast Aqua. 8/16/2002 Male 70.2 Green Yaquina Bay Oregon Coast Aqua. 8/16/2002 Male Green 01 Yaquina Bay Oregon Coast Aqua. 8/16/2002 Male Green 01 6 missing Yaquina Bay Oregon Coast Aqua. 8/16/2002 Female 57.3 Green 01

19 19 Yaquina Bay Oregon Coast Aqua. 8/16/2002 Male 89.2 Green 98 Yaquina Bay Oregon Coast Aqua. 8/16/2002 Male 74.9 Orange/White 2 newly re-grown, barnacles Yaquina Bay Oregon Coast Aqua. 8/16/2002 Male 71.9 Yellow/Green Yaquina Bay Oregon Coast Aqua. 8/16/2002 Male 85.2 Yellow Yaquina Bay Oregon Coast Aqua. 8/16/2002 Male 83.7 Orange 7missing, barnacles Yaquina Bay Oregon Coast Aqua. 8/21/2002 Male Green 01 Yaquina Bay Oregon Coast Aqua. 8/21/2002 Male Orange 01 6 missing Yaquina Bay Oregon Coast Aqua. 8/28/2002 Male 58.6 Yellow 01 6 dactyl missing Yaquina Bay Oregon Coast Aqua. 8/28/2002 Male 74.5 Yellow 4, 5 missing Yaquina Bay Oregon Coast Aqua. 8/28/2002 Male 68 Yellow 01 Yaquina Bay Oregon Coast Aqua. 8/28/2002 Male 55.4 Yellow 01 Tillamook Tillamook Spit B 7/12/2002 Female 61.9 Green 01 Tillamook Tillamook Spit B 8/20/2002 Male 60.7 Yellow-green 01 Tillamook Hayes oyster farm 9/15/2002 Male 86* Green Jesse Hayes Tillamook Hayes oyster farm 9/15/2002 Male 70* Green Jesse Hayes Alsea Bay Middle of Bay, fishing 8/23/2002 Male 89.2 Yellow 98 Unknown sports fisher