{"Bibliographic":{"Title":"A preliminary survey of benthic invertebrates in the vicinity of the Coos Bay, Oregon, navigation channel","Authors":"","Publication date":"1990","Publisher":""},"Administrative":{"Date created":"08-16-2023","Language":"English","Rights":"CC 0","Size":"0000028770"},"Pages":["Un511\nA Preliminary Survey\nof Benthic Invertebrates\nin the Vicinity of the Coos Bay,\nOregon, Navigation Channel\nby\nDavid R. Miller,\nRobert L. Emmett, and\nSusan A. Hinton\nApril 1990\nZONE\nCOASTA\nSTUDIE:","A PRELIMINARY SURVEY OF BENTHIC INVERTEBRATES IN THE VICINITY\nOF THE COOS BAY, OREGON, NAVIGATION CHANNEL\nLibrary\nby\nNorthwest\nNOAA.\n&\nDavid R. Miller\nAlaska\n2725\nNational\nFisharies\nRobert L. Emmett\nSeattle Montleke WA and Marine Fisharies Center Service\nand\nSusan A. Hinton\nFinal Report of Research\nfunded by\nU.S. Army Corps of Engineers\nPortland District\nP.O. Box 2946\nPortland, Oregon 97208\n(Contract DACW57-89-F-0467)\nand\nCoastal Zone and Estuarine Studies Division\nNorthwest Fisheries Center\nNational Marine Fisheries Service\nNational Oceanic and Atmospheric Administration\n2725 Montlake Boulevard East\nSeattle, Washington 98112\nApril 1990","CONTENTS\nPage\n1\nINTRODUCTION\n1\nMETHODS\n1\nBenthic Invertebrates\n3\nData Analysis\n4\nRESULTS\n6\nDISCUSSION\n8\nLITERATURE CITED\n10\nAPPENDIX\nLibrary\nNorthwest Fisheries Science Center\n2725 Montlake Blvd. E\nCeattle WA 98112","INTRODUCTION\nPotential biological impacts of deepening the Coos Bay, Oregon navigation\nchannel from River Mile (RM) 0 to 15 were discussed at an interagency meeting in\nMarch 1989. Participants included the U.S. Army Corps of Engineers (COE) (Division\nof Ecological Services, Portland District), the U.S. Fish and Wildlife Service, and the\nNational Marine Fisheries Service (NMFS) (Environmental and Technical Services\nDivision of the Northwest Region and Coastal Zone and Estuarine Studies [CZES]\nDivision of the Northwest Fisheries Science Center). One result of this meeting was a\ngeneral agreement that a preliminary biological survey was required to determine the\nneed for a comprehensive biological assessment of the area impacted by the deepening\nof the navigation channel. Subsequently, a cooperative agreement was reached between\nthe COE and CZES Division to collect sediment samples at selected intervals over the\nlength of the project and to determine the distribution and abundance of benthic\ninvertebrates. This report summarizes the results of this preliminary investigation.\nMETHODS\nBenthic Invertebrates\nBenthic invertebrates were collected at 20 stations in and adjacent to the\nnavigation channel from about RM 2 to 15 (Fig. 1) on 22-23 May 1989. A 0.1-m2\nGray-O'Hara box corer (Pequegnat et al. 1981) was used to collect one sample at each\nstation. Each sample was sieved through a 0.5-mm mesh screen, and the residue\ncontaining the macroinvertebrates was preserved with a buffered 5% formaldehyde\nsolution containing rose bengal (a protein stain). Benthic organisms were sorted from\nthe preserved samples, identified to the lowest possible taxonomic level (usually\nspecies), and counted. All specimens were placed in vials containing 70% ethyl alcohol\nand stored at the NMFS Point Adams Biological Field Station, Hammond, Oregon.","2\n14\n13\n10\n12\n15\n11\n16\n7\n8\n17\n6\n5b\n3\n19\n20\n2\nR.\nN\nWashington\nOregon\n2 miles\n0\n1\nFigure 1.--Benthic invertebrate sampling stations 1989. along the Coos Bay, Oregon\nnavigation channel, 22-23 May","3\nData Analysis\nFour community structure indices were calculated for each station.\n1) Shannon-Weaver Diversity Index (H') (Shannon and Weaver 1963):\nS\nH' -\ni=1\nwhere Pi = Xa/n (Xa is the number of individuals of a particular species in the sample,\nn is the total number of individuals in the sample), and S = number of species.\n2) Simpson Diversity Value (SDV) (Simpson 1949):\nS\nSDV = 1 - EPi2\ni=1\nwhere Pi = Xa/n (Xa is the number individuals of a particular species in the sample, n\nis the total number of individuals in the sample), and S = number species. Diversity\nvalues are sensitive to two components, the number of species in a sample (species\nrichness) and the distribution of individuals among species (evenness) (Lloyd and\nGhelardi 1964).\n3) Species Richness (SR) was estimated using Margalef's formula (Margalef 1958):\nSR = (s - 1) / In(n) -\nwhere S = number of species and n = total number of individuals in the sample.\n4) Species Evenness (J') was calculated using Pielou's formula (Pielou 1966):\nJ' = H'/log2s\nwhere H' = Shannon-Weaver Diversity Index, and 8 = number of species.\nCluster analysis, using the Bray-Curtis dissimilarity index with a group-averaging\nfusion strategy (Clifford and Stephenson 1975), was used to identify station groupings","4\nthat had similar species and densities. A 0.5 dissimilarity value was considered a\nsignificant difference between groups. The number of each species/m² per station was\nused in this analysis. Species with densities <10/m2 were excluded to reduce the effect\nof rare species.\nRESULTS\nA total of 121 invertebrate taxa with a mean density of 2,617/m2 were identified\nfrom the Coos Bay navigation channel. Highest invertebrate densities were found in\nthe lower estuary (RM 2 to 5) at Stations 1, 4, 5, and 5b. These four stations had a\nmean invertebrate density of 10,441/m2 with an individual high density of 13,546/m2 at\nStation 4. In contrast, the remaining 16 stations had a mean density of 661/m2, with\nan individual high density of 1,521/m2 at Station 12 (Table 1).\nCommunity structure indices (H', SDV, SR, and J') are shown in Table 1. These\nvalues generally reflect the relatively low number of taxa at most stations (range 6 to\n22); the exceptions were stations 5 and 5b with 50 and 53 species and SR values of\n7.83 and 7.47, respectively. Dominant species were the polychaetes Polygordius sp. and\nMediomastus californiensis at the four high density stations, and the polychaetes\nHeteropodarke heteromorpha and Glycera tenuis and the cumacean Eudorellopsis sp. at\nthe lower density stations. Corophium sp. (an amphipod which is an important\ncomponent of the diet of salmonids and several other species of marine and estuarine\nfishes), several species of clams, Dungeness and red rock crabs, oysters, bay mussels,\nghost shrimp, kelp worms, or mud shrimp (all species of potential commercial,\nrecreational, or ecological importance in the Coos Bay estuary [Roye 1979]) were either\nnot found at the stations sampled or were found to be extremely restricted in\ndistribution.\nCluster analysis indicated that the stations could be divided into five groups based\non similarity of species and their densities. The groups were composed of 1) Stations 2,","5\nTable 1.--Benthic invertebrates at 20 sampling stations in and adjacent to the Coos\nBay, Oregon, navigation channel, 22-23 May 1989.\nSDV\nH'\nSR\nJrd\nNumber\nDensity of\nStation\nof taxa\ninvertebrates\n(number/m²\n11,764\n2.11\n0.61\n2.13\n0.53\n1\n16\n657\n2.46\n0.73\n2.65\n0.69\n2\n12\n2.45\n0.75\n2.35\n0.74\n3\n10\n479\n0.64\n2.93\n0.45\n4\n22\n13,546\n2.02\n7.83\n0.80\n5,450\n4.54\n0.93\n5\n50\n3.57\n0.80\n7.47\n0.62\n5b\n53\n11,004\n0.72\n6\n12\n375\n2.56\n0.74\n3.07\n0.62\n1.62\n0.63\n7\n7\n427\n1.77\n1,105\n1.59\n0.55\n1.29\n0.57\n8\n7\n2.27\n0.70\n2.40\n0.65\n9\n11\n667\n0.59\n1.29\n0.61\n10\n6\n500\n1.57\n11\n16\n552\n3.03\n0.78\n3.78\n0.76\n2.61\n0.54\n12\n14\n1,521\n2.06\n0.57\n2.18\n0.70\n1.84\n0.73\n13\n8\n469\n3.71\n0.90\n4.01\n0.91\n14\n17\n563\n4.16\n0.70\n15\n20\n1,000\n3.04\n0.77\n3.45\n0.88\n4.01\n0.84\n16\n17\n563\n3.16\n0.84\n3.64\n0.81\n17\n15\n490\n0.82\n2.49\n0.84\n19\n10\n386\n2.79\n20\n11\n823\n2.25\n0.66\n2.29\n0.65\nMeans\n17\n2,617\nShannon-Weaver Diversity Index\na\nb\nSimpson Diversity Value\nSpecies Richness\ne\nd\nSpecies Evenness","6\n3, 6, 7, 8, 9, 10, 11, and 13 (mean density 581/m2, 10 taxa); 2) Stations 1, 4, and 12\n(mean density 8,944/m², 17 taxa); 3) Stations 14, 15, and 16 (mean density 709/m², 18\ntaxa); 4) Stations 5 and 5b (mean density 8,227/m², 52 taxa); and 5) Stations 17, 19,\nand 20 (mean density 566/m², 12 taxa).\nDISCUSSION\nThe Coos Bay estuary is characterized by complex physical, chemical, and\nbiological interactions. These interactions are strongly influenced by the Bay's unique\nestuarine physiography which includes numerous sloughs, broad tide flats, extensive\nseagrass (eelgrass and ditchgrass) meadows, and intricate twisting and turning side\nchannels. Large-scale seasonal changes in temperature, tidal circulation, estuarine\nflushing, freshwater inflow (ranging from 100 cubic feet per second [cfs] in the summer\nto 100,000 cfs in the winter from about 30 tributaries [COE 1975]) all influence\nfreshwater and saltwater mixing (Arneson 1975) and contribute to this complexity.\nMajor estuarine alterations (e.g., channel deepening, extensive filling and diking,\naccelerated erosion and sediment deposition, construction of jetties and breakwaters)\nhave, over the years, already significantly impacted these interactions. Future\nmodifications to the estuary should be carefully evaluated to ensure that Coos Bay will\ncontinue as a biologically productive, multiple-use estuary.\nThis preliminary survey of the Coos Bay navigation channel indicated the presence\nof a diverse and, in some areas, dense benthic infauna. However, based on this limited\nsampling, benthic invertebrate densities appear to be generally lower than those of the\nUmpqua River estuary where invertebrate densities ranged from <200 to >50,000/m2\n(Bottom et al. 1985, Miller et al. 1989) and the Columbia River estuary where densities\nranged from <1,000 to >60,000/m2 (Durkin and Emmett 1980). Nonetheless, a channel\ndeepening project of this magnitude has the potential to markedly alter ecological\nrelationships by changing the complex pattern of freshwater inflow, tidal circulation,","7\nestuarine flushing, and freshwater and saltwater mixing. More direct biological\nimpacts are also likely as side-channel sloughing increases the channel width. At a\nminimum, additional survey work will be required to evaluate benthic species\ncomposition and density at stations adjacent to the existing channel and to obtain\ncritical data on natural seasonal variation in infaunal community structure. Based on\nthis need, it is recommended that a more comprehensive areal survey over a minimum\nof four seasons be conducted before dredging and that follow-up surveys be conducted\nafter dredging. It is only through this type of comprehensive assessment that the\nimpacts of channel deepening on the aquatic resources can be determined.\nThis report does not constitute NMFS's formal comment under the Fish and\nWildlife Coordination Act or the National Environmental Policy Act.","8\nLITERATURE CITED\nArneson, R. J.\n1975. Seasonal variation in tidal dynamics, water quality, and sediments in the\nCoos Bay estuary. M. Oc. E. Thesis. Oregon State Univer., Corvallis, OR.\n250 p.\nBottom, D. L., B. A. Miller, and K. K. Jones.\n1985. A baseline survey: fish and invertebrates in the lower Umpqua River\nestuary, Oregon. Unpubl. manuscr. Oregon Dept. Fish Wildl., Corvallis, OR.\n80 p.\nClifford, H. T., and W. Stephenson.\n1975. An introduction to numerical classification. Academic Press, New York, NY.\n229 p.\nCOE (U.S. Army Corps of Engineers).\n1975. Coos Bay, Oregon, deep draft navigation project: environmental impact\nstatement, draft supplement. Vol I and II. U. S. Army Corps of Engineers,\nPortland District, Portland, OR. 287 p.\nDurkin, J. T., and R. L. Emmett.\n1980. Benthic invertebrates, water quality, and substrate texture in Baker\nBay, Youngs Bay, and adjacent areas of the Columbia River estuary. U.S. Dept.\nof Commer., Natl. Oceanic Atmos. Admin., Nat. Mar. Fish. Serv., Northwest and\nAlaska Fish. Cent., Seattle, WA. (Final Report to U.S. Fish and Wildlife Service).\n44 p.\nLloyd, M., and R. J. Ghelardi.\n1964. A table for calculating the \"equitability\" component of species diversity. J.\nAnim. Ecol. 33:217-225.\nMargalef, R.\n1958. Information theory in ecology. Gen. Syst. 3:36-71.\nMiller, D. R., R. L. Emmett, and R. J. McConnell.\n1989. Benthic invertebrates at a test dredged-materials disposal site in the\nUmpqua River, Oregon. U.S. Dept. of Commer., Natl. Atmos. Oceanic Admin.,\nNat. Mar. Fish. Serv., Northwest Fish. Cent., Seattle, WA. (Final Report to\nU.S. Army Corps of Engineers). 20 p.\nPequegnat, W. E., L. H. Pequegnat, P. Wilkinson, J. S. Young, and S. L. Kiessger.\n1981. Procedural guide for designation surveys of ocean dredged material disposal\nsites. Tech. Rep. EL-81-1 to Chief of Engineers, U.S. Army, Washington D.C.\n268 p.\nPielou, E. L.\n1966. The measurement of diversity in different types of biological collections. J.\nTheor. Biol. 13:131-144.\nRoye, C.\n1979. Natural resources of Coos Bay Estuary. Oregon Dept. Fish Wildl., Portland,\nOR. (Final Report to Oregon Land Conservation and Develop. Comm.). 87 p.","9\nShannon, C.E., and W. Weaver.\n1963. The mathematical theory of communication. Univ. Illinois Press, Urbana,\nIL. 117 p.\nSimpson, E. H.\n1949. Measurement of diversity. Nature 163:688.","10\nAPPENDIX","11\nAppendix Table 1.--Benthic invertebrates at 20 sampling stations in and adjacent\nto the navigation channel in Coos Bay, Oregon, 22-23 May 1989.\nStation 1\nMean\nTotal\nTaxa\nnumber\nnumber\n/m²\n364.7\n35\nNemertinea\n10.4\n1\nParaonella platybranchia\n10.4\n1\nPolydora socialis\n10.4\n1\nEuclymeninae sp. juvenile\n177.1\n17\nOphelia sp. 1 juvenile\n875.3\n84\nHesionura coineaui difficilis\n83.4\n8\nPisione sp. indeterminate\n1,146.2\n110\nHeteropodarke heteromorpha\n406.4\n3\nGlycera tenuis\n7,106.4\n682\nPolygordius sp. indeterminate\n1,104.5\n106\nSaccocirrus exoticus\n93.8\n9\nMytilidae sp. juvenile\n270.9\n26\nTellina nuculoides\n10.4\n1\nEogammarus confervicolus\n10.4\n1\nEohaustorius sawyeri\n83.4\n8\nDendraster excentricus\nNumber of taxa = 16\nNumber of invertebrates/sample: 1,129.0\nNumber of invertebrates/m²: 11,764.2\nH' = 2.11 SDV = 0.61 SR = 2.13 J' = 0.53\nLibrary\nforthwest Fisheries Science Center\n2725 Montlake Blvd. E\nSeattle, WA 98112","12\nAppendix Table 1.-Continued.\nStation 2\nMean\nTotal\nTaxa\nnumber\nnumber\n/m²\n10.4\n1\nNemertinea\n31.3\n3\nOphelia sp. 1\n218.8\nHeteropodarke heteromorpha\n21\n250.1\n24\nGlycera tenuis\n10.4\nPolygordius sp. indeterminate\n1\n20.8\n2\nMytilidae sp. juvenile\n41.7\n4\nTellina nuculoides\n10.4\n1\nArchaeomysis grebnitzkii\n10.4\n1\nLamprops carinata\n10.4\n1\nEudorellopsis sp. indeterminate\n10.4\n1\nCrangonidae - larvae\n31.3\n3\nDendraster excentricus\nNumber of taxa = 12\nNumber of invertebrates/sample: 63.0\nNumber of invertebrates/m²: 656.5\nH' = 2.46 SDV = 0.73 SR = 2.65 J' = 0.69","13\nAppendix Table 1.--Continued.\nStation 3\nTotal\nMean\nTaxa\nnumber\nnumber\n/m²\n10.4\n1\nNemertinea\n10.4\nParaonella platybranchia\n1\n10.4\n1\nOphelia sp. 1 juvenile\n135.5\n13\nHeteropodarke heteromorpha\n187.6\n18\nGlycera tenuis\n52.1\n5\nTellina nuculoides\n31.3\n3\nArchaeomysis grebnitzkii\n10.4\nEohaustorius sp. juvenile\n1\n10.4\n1\nCrangonidae - larvae\n2\n20.8\nCancer magister - megalopa\nNumber of taxa = 10\nNumber of invertebrates/sample: 46.0\nNumber of invertebrates/m²: 479.3\nH' = 2.45 SDV = 0.75 SR = 2.35 J' = 0.74","14\nAppendix Table 1.--Continued.\nStation 4\nMean\nTotal\nTaxa\nnumber\nnumber\n/m²\n812.8\n78\nNemertinea\n10.4\n1\nHeteromastus filiformis\n52.1\n5\nMediomastus californiensis\n93.8\n9\nOphelia sp. 1\n3,021.8\n290\nHesionura coineaui difficilis\n1,354.6\n130\nHeteropodarke heteromorpha\n10.4\n1\nSyllidae sp. (epitoke)\n10.4\n1\nExogone sp. (epitoke)\n208.4\n20\nGlycera tenuis\n10.4\n1\nMicropthalmus sp. 1\n7,408.6\n711\nPolygordius sp. indeterminate\n20.8\n2\nOligochaeta\n10.4\n1\nOcenebra sp. indeterminate\n20.8\n2\nEpitonium indianorum\n20.8\n2\nBivalvia sp. indeterminate\n333.4\n32\nMytilidae sp. juvenile\n20.8\n2\nMacoma sp. indeterminate\n52.1\n5\nTellina nuculoides\n10.4\n1\nArchaeomysis grebnitzkii\n20.8\n2\nLamprops nr. quadriplicata\n10.4\n1\nCumella vulgaris\n31.3\n3\nDendraster excentricus\nNumber of taxa = 22\nNumber of invertebrates/sample: 1,300.0\nNumber of invertebrates/m?: 13,546.0\nH' = 2.02 SDV = 0.64 SR = 2.93 J' = 0.45","15\nAppendix Table 1.-Continued.\nStation 5\nMean\nTotal\nTaxa\nnumber\nnumber\n/m²\n20.8\n2\nAnthozoa\n208.4\n20\nNemertinea\n41.7\n4\nProtodorvillea gracilis\n10.4\n1\nScoloplos armiger\n302.2\n29\nSpiophanes bombyx\n20.8\n2\nCirratulidae sp. indeterminate\n41.7\n4\nCaulleriella hamata\n10.4\n1\nTharyx multifilis\n1,021.2\n98\nMediomastus californiensis\n10.4\n1\nPraxillella sp. indeterminate\n20.8\n2\nOphelia sp. 1\n31.3\n3\nPhyllodoce williamsi\n41.7\n4\nEumida sanguinea\n31.3\nHesionura coineaui difficilis\n3\n41.7\n4\nLepidonotus squamatus\n177.1\n17\nPaleanotus bellis\n291.8\nHeteropodarke heteromorpha\n28\n166.7\n16\nMicropodarke dubia\n10.4\n1\nSyllidae sp. indeterminate\n72.9\n7\nAutolytus sp. indeterminate\n208.4\n20\nPionosyllis uraga\n10.4\n1\nSyllis heterochaeta\n83.3\nSphaerosyllis brandhorsti\n8\n10.4\n1\nGlycera capitata\n20.8\n2\nGlycera tenuis\n10.4\n1\nMicropthalmus sp. 1\n20.8\n2\nOwenia fusiformis\n93.9\n9\nPolycirrus sp. complex\n250.1\n24\nChone dunneri\n166.7\n16\nPolygordius sp. indeterminate\n10.4\n1\nSaccocirrus exoticus\n41.7\n4\nOligochaeta\n41.7\n4\nNudibranchia sp. indeterminate\n10.4\n1\nOcenebra sp. indeterminate\n677.3\n65\nMytilidae sp. juvenile\n10.4\n1\nClinocardium sp. juvenile\n114.6\n11\nProtothaca staminea\n31.3\n3\nMacoma nasuta\n145.9\n14\nMacoma sp. indeterminate\n31.3\n3\nTellina nuculoides\n104.2\n10\nCirripedia\n41.7\nMelita desdichada\n4\n114.6\n11\nCorophium brevis","16\nAppendix Table 1.--Continued.\nStation 5\nTaxa\nTotal\nMean\nnumber\nnumber\n/m²\nCorophium nr. panamense\n2\n20.8\nPhotis nr. brevipes Juv.\n32\n333.4\nLeptochelia dubia\n7\n72.9\nCancer magister\n3\n31.3\nDendraster excentricus\n11\n114.6\nAsteroidea\n1\n10.4\nPycnogonida\n4\n41.7\nNumber of taxa = 50\nNumber of invertebrates/sample: 523.0\nNumber of invertebrate/m²: 5,449.7\nH' = 4.54 SDV = 0.93 SR = 7.83\nJ' = 0.80","17\nAppendix Table 1.--Continued.\nStation 5b\nTotal\nMean\nTaxa\nnumber\nnumber\n/m²\n10.4\n1\nPorifera\n83.4\n8\nNemertinea\n72.9\n7\nLeitoscoloplos pugettensis\n41.7\n4\nScoloplos armiger\n10.4\n1\nPolydora sp. indeterminate\n4,574.4\nMediomastus californiensis\n439\n10.4\n1\nEteone californica\n20.8\n2\nEumida sanguinea\n10.4\n1\nPolynoidae sp. indeterminate\n10.4\n1\nHarmothoe imbricata\n23\n239.7\nLepidonotus squamatus\n20\n208.4\nPaleanotus bellis\n10.4\n1\nGyptis brevipalpa\n72.9\n7\nAutolytus sp. indeterminate\n8\n83.4\nPionosyllis uraga\n1\n10.4\nSyllis elongata\n1\n10.4\nSyllis sp. indeterminate\n31.3\nSphaerosyllis brandhorsti\n3\n114.6\nSphaerosyllis hystrix\n11\n1\n10.4\nNereidae sp. indeterminate\n17\n177.1\nNereis sp. juvenile\n93.8\n9\nGlycinde picta\n2\n20.8\nLumbrineris sp. indeterminate\n52.1\n5\nMicropthalmus sp. 1\n1\n10.4\nSabellaria cementarium\n198.0\n19\nPolycirrus sp. complex\n62.5\n6\nChone dunneri\n302.2\nPolygordius sp. indeterminate\n29\n35\n364.7\nOligochaeta\n6\n62.5\nNudibranchia\nLittorina sp. indeterminate\n11\n114.6\n11\n114.6\nBivalvia sp. indeterminate\n1,208.7\nMytilidae sp. juvenile\n116\n1\n10.4\nHiatella arctica\n10.4\nTeredinidae sp. indeterminate\n1\n18\n187.6\nProtothaca staminea\nMacoma sp. juvenile\n57\n593.9\n1\n10.4\nOxyurostylis pacifica\n1\n10.4\nCumella vulgaris\n10.4\nEudorellopsis sp. indeterminate\n1\n10.4\nEohaustorius sp. juvenile\n1\n114.6\n11\nPontogeneia rostrata\nPontogeneia sp. juvenile\n1\n10.4","18\nAppendix Table 1.-Continued.\nStation 5b\nTotal\nMean\nTaxa\nnumber\nnumber\n/m²\n583.5\n56\nCorophium brevis\n531.4\n51\nPhotis brevipes\n2\n20.8\nCaprellidae sp. indeterminate\n323.0\n31\nLeptochelia dubia\n20.8\n2\nHeptacarpus pictus\n10.4\nCancer magister - megalopa\n1\n52.1\n5\nCancer magister\n10.4\n1\nOphiuroidea\n10.4\nAsteroidea (Pisaster sp. juvenile)\n1\n52.1\n5\nPycnogonida\nNumber of taxa = 53\nNumber of invertebrates/sample: 1,056.0\nNumber of invertebrates/m²: 11,003.5\nH' = 3.57 SDV = 0.80 SR = 7.47 J' = 0.62","19\nAppendix Table 1.--Continued.\nStation 6\nTaxa\nTotal\nMean\nnumber\nnumber\n/m²\nNemertinea\n1\n10.4\nSpiophanes bombyx\n2\n20.8\nHeteromastus filiformis\n1\n10.4\nHeteropodarke heteromorpha\n15\n156.3\nGlycera tenuis\n10\n104.2\nPolygordius sp. indeterminate\n1\n10.4\nOligochaeta\n1\n10.4\nMytilidae sp. juvenile\n1\n10.4\nTellina nuculoides\n1\n10.4\nArchaeomysis grebnitzkii\n1\n10.4\nHemilamprops sp. indeterminate\n1\n10.4\nDendraster excentricus\n1\n10.4\nNumber of taxa = 12\nNumber of invertebrates/sample: 36.0\nNumber of invertebrates/m²: 375.1\nH' = 2.56 SDV = 0.74 SR = 3.07 J' = 0.72","20\nAppendix Table 1.-Continued.\nStation 7\nTotal\nMean\nTaxa\nnumber\nnumber\n/m²\nSpiophanes bombyx\n1\n10.4\n156.3\nHeteropodarke heteromorpha\n15\n208.4\n20\nGlycera tenuis\n10.4\nPolygordius sp. indeterminate\n1\nArchaeomysis grebnitzkii\n2\n20.8\n10.4\nLamprops quadriplicata\n1\n10.4\n1\nEogammarus sp. juvenile\nNumber of taxa = 7\nNumber of invertebrates/ample: 41.0\nNumber of invertebrates/m²: 427.2\nSDV = 0.62 SR = 1.62\nJ' = 0.63\nH' = 1.77\nLibrary\nFisharies Science Center\nMontlake Blvd. E\nWA 98117","21\nAppendix Table 1.-Continued.\nStation 8\nTotal\nMean\nTaxa\nnumber\nnumber\n/m²\n10.4\n1\nNemertinea\n10.4\nParaonella platybranchia\n1\n10\n104.2\nOphelia sp. 1\n687.7\nHeteropodarke heteromorpha\n66\n23\n239.7\nGlycera tenuis\n10.4\nMacoma sp. indeterminate\n1\n41.7\n4\nLamprops carinata\nNumber of taxa = 7\nNumber of invertebrates/sample: 106.0\nNumber of invertebrates/m²: 1,104.5\nSDV = 0.55 SR = 1.29\nJ' = 0.57\nH' = 1.59","22\nAppendix Table 1.--Continued.\nStation 9\nTotal\nTaxa\nMean\nnumber\nnumber\n/m²\n10.4\nNemertinea\n1\nOphelia sp. 1\n1\n10.4\nHeteropodarke heteromorpha\n26\n270.9\n239.7\nGlycera tenuis\n23\nNephtys sp. juvenile\n2\n20.8\nOligochaeta\n2\n20.8\nMacoma sp. indeterminate\n2\n20.8\nTellina carpenteri\n1\n10.4\nLamprops quadriplicata\n3\n31.3\nPhotis nr. brevipes juvenile\n1\n10.4\nDendraster excentricus\n2\n20.8\nNumber of taxa = 11\nNumber of invertebrates/sample: 64.0\nNumber of invertebrates/m²: 666.9\nH' = 2.27 SDV = 0.70 SR = 2.40 J' = 0.65","23\nAppendix Table 1.-Continued.\nStation 10\nTotal\nMean\nTaxa\nnumber\nnumber\n/m2\n10.4\n1\nNemertinea\n20.8\n2\nSpiophanes bombyx\n250.1\nHeteropodarke heteromorpha\n24\n198.0\n19\nGlycera tenuis\n10.4\n1\nOligochaeta\n10.4\nCancer magister - megalopa\n1\nNumber of taxa = 6\nNumber of invertebrates/sample: 48.0\nNumber of invertebrates/m²: 500.2\nSDV = 0.59 SR = 1.29\nJ' = 0.61\nH' = 1.57","24\nAppendix Table 1.--Continued.\nStation 11\nTaxa\nTotal\nMean\nnumber\nnumber\n/m²\nNemertinea\n1\n10.4\nSpiophanes bombyx\n3\n31.3\nMagelona longicornis\n2\n20.8\nHeteromastus filiformis\n2\n20.8\nOphelia sp. 1\n7\n72.9\nEteone sp. juvenile\n1\n10.4\nHeteropodarke heteromorpha\n2\n20.8\nGlycera tenuis\n23\n239.7\nOligochaeta\n2\n20.8\nMacoma sp. indeterminate\n1\n10.4\nTellina nuculoides\n3\n31.3\nArchaeomysis grebnitzkii\n2\n20.8\nHemilamprops sp. indeterminate\n1\n10.4\nCancer magister\n1\n10.4\nDendraster excentricus\n1\n0.4\nAmmodytes hexapterus\n1\n10.4\nNumber of taxa = 16\nNumber of invertebrates/sample: 53.0\nNumber of invertebrates/m²: 552.3\nH' = 3.03 SDV = 0.78 SR = 3.78 J' = 0.76","25\nAppendix Table 1.-Continued.\nStation 12\nMean\nTotal\nTaxa\nnumber\nnumber\n/m²\n125.0\n12\nNemertinea\n20.8\n2\nNematoda\n20.8\n2\nSpiophanes bombyx\n20.8\n2\nHeteromastus filiformis\n31.3\n3\nMediomastus californiensis\n10.4\n1\nOphelia sp. 1\n969.1\n93\nHeteropodarke heteromorpha\n10.4\n1\nSyllidae sp. indeterminate\n10.4\n1\nSphaerosyllis brandhorsti\n135.5\n13\nGlycera tenuis\n20.8\n2\nMicropthalmus sp. 1\n20.8\n2\nMytilidae sp. juvenile\n20.8\n2\nMacoma sp. indeterminate\n104.2\n10\nLamprops nr. quadriplicata\nNumber of taxa = 14\nNumber of invertebrates/sample: 146.0\nNumber of invertebrates/m²: 1,521.3\nH' = 2.06 SDV = 0.57 SR = 2.61 J' = 0.54","26\nAppendix Table 1.-Continued.\nStation 13\nTaxa\nTotal\nMean\nnumber\nnumber\n/m²\nNemertinea\n5\n52.1\nNaineris uncinata\n1\n10.4\nMagelona sacculata\n1\n10.4\nCaulleriella hamata\n1\n10.4\nOphelia sp. 1\n7\n72.9\nHeteropodarke heteromorpha\n22\n229.2\nGrandifoxus grandis\n1\n10.4\nDendraster excentricus\n7\n72.9\nNumber of taxa = 8\nNumber of invertebrates/sample: 45.0\nNumber of invertebrates/m²: 468.9\nH' = 2.18 SDV = 0.70 SR = 1.84\nJ' = 0.73","27\nAppendix Table 1.--Continued.\nStation 14\nTaxa\nTotal\nMean\nnumber\nnumber\n/m²\nNemertinea\n5\n52.1\nLeitoscoloplos pugettensis\n1\n10.4\nSpiophanes bombyx\n4\n41.7\nMediomastus californiensis\n5\n52.1\nHeteropodarke heteromorpha\n11\n114.6\nAutolytus sp. indeterminate\n2\n20.8\nGlycera tenuis\n2\n20.8\nNephtys caecoides\n1\n10.4\nOwenia fusiformis\n2\n20.8\nMacoma sp. juvenile\n1\n10.4\nCirripedia\n3\n31.3\nOxyurostylis pacifica\n1\n10.4\nLamprops nr. quadriplicata\n1\n10.4\nEogammarus confervicolus\n6\n62.5\nAoroides sp. indeterminate\n3\n31.3\nCaprellidae sp. indeterminate\n2\n20.8\nCancer magister\n4\n41.7\nNumber of taxa = 17\nNumber of invertebrates/sample: 54.0\nNumber of invertebrates/m²: 562.7\nH' = 3.71 SDV = 0.90 SR = 4.01 J' = 0.91","28\nAppendix Table 1.-Continued.\nStation 15\nTaxa\nTotal\nMean\nnumber\nnumber\n/m²\nAnthozoa polyps\n41\n427.2\nNemertinea\n3\n31.3\nLeitoscoloplos pugettensis\n1\n10.4\nScoloplos armiger\n3\n31.3\nSpiophanes bombyx\n1\n10.4\nMediomastus californiensis\n17\n177.1\nOphelia sp. 1\n1\n10.4\nHeteropodarke heteromorpha\n2\n20.8\nAutolytus sp. indeterminate\n1\n10.4\nGlycera tenuis\n4\n41.7\nGlycinde picta\n2\n20.8\nNephtys caecoides\n1\n10.4\nOligochaeta\n5\n52.1\nClinocardium sp. juvenile\n1\n10.4\nMacoma sp. indeterminate\n5\n52.1\nLamprops nr. quadriplicata\n1\n10.4\nGammaridae\n1\n10.4\nEogammarus confervicolus\n2\n20.8\nPhotis macinerneyi\n1\n10.4\nDendraster excentricus\n3\n31.3\nNumber of taxa = 20\nNumber of invertebrates/sample 96.0\nNumber of invertebrates/m²: 1,000.3\nH' = 3.04\nSDV = 0.77\nSR = 4.16\nJ' = 0.70","29\nAppendix Table 1.--Continued.\nStation 16\nTotal\nMean\nTaxa\nnumber\nnumber\n/m²\n1\n10.4\nNemertinea\nNaineris uncinata\n10\n104.2\nScoloplos armiger\n1\n10.4\nParaonella platybranchia\n1\n10.4\nSpio butleri\n2\n20.8\nSpiophanes bombyx\n1\n10.4\nMediomastus californiensis\n5\n52.1\nOphelia sp. 1 juvenile\n1\n10.4\nHeteropodarke heteromorpha\n12\n125.0\n20.8\nGlycera tenuis\n2\nGlycinde armigera\n1\n10.4\n31.3\nGlycinde picta\n3\nNephtys sp. juvenile\n1\n10.4\n41.7\nOligochaeta\n4\nMacoma sp. indeterminate\n7\n72.9\nLamprops quadriplicata\n1\n10.4\nDendraster excentricus\n1\n10.4\nNumber of taxa = 17\nNumber of invertebrates/sample: 54.0\nNumber of invertebrates/m? 562.7\nH' = 3.45 SDV = 0.88 SR = 4.01 J'=0.84","30\nAppendix Table 1.-Continued.\nStation 17\nTotal\nMean\nTaxa\nnumber\nnumber\n/m²\n20.8\n2\nParaprionospio pinnata\n10.4\nMagelona sacculata\n1\n10.4\n1\nBarantolla americana\n20.8\n2\nGlycinde picta\n10.4\nPolygordius sp indeterminate\n1\n20.8\n2\nSaccocirrus exoticus\n125.0\n12\nOligochaeta\n10.4\nBivalvia sp. indeterminate\n1\n1\n10.4\nMacoma nasuta\n93.8\n9\nMacoma sp. indeterminate\n10.4\nArchaeomysis grebnitzkii\n1\n104.2\nLamprops nr. quadriplicata\n10\n10.4\nEogammarus confervicolus\n1\n20.8\n2\nAoroides sp. indeterminate\n10.4\nGrandifoxus grandis\n1\nNumber of taxa = 15\nNumber of invertebrates/sample: 47.0\nNumber of invertebrates/m²: 489.7\nH' = 3.16 SDV = 0.84 SR = 3.64 J' = 0.81","31\nAppendix Table 1.--Continued.\nStation 19\nTaxa\nTotal\nMean\nnumber\nnumber\n/m²\nParaprionospio pinnata\n3\n31.3\nGlycinde picta\n2\n20.8\nOligochaeta\n5\n52.1\nMacoma nasuta\n1\n10.4\nMacoma sp. indeterminate\n3\n31.3\nOxyurostylis pacifica\n1\n10.4\nLamprops nr. quadriplicata\n10\n104.2\nEudorellopsis sp. indeterminate\n1\n10.4\nGammaridae\n1\n10.4\nEogammarus confervicolus\n10\n104.2\nNumber of taxa = 10\nNumber of invertebrates/sample: 37.0\nNumber of invertebrates/m²: 385.5\nH' = 2.79 SDV = 0.82 SR = 2.49\nJ' = 0.84","32\nAppendix Table 1.-Continued.\nStation 20\nTotal\nMean\nTaxa\nnumber\nnumber\n/m²\n10.4\n1\nPygospio elegans\n41.7\nParaprionospio pinnata\n4\n10.4\n1\nBarantolla americana\n10.4\nHeteropodarke heteromorpha\n1\n1\n10.4\nGlycinde picta\n13\n135.5\nOligochaeta\n3\n31.3\nBivalvia sp. indeterminate\n31.3\n3\nMacoma nasuta\n72.9\n7\nMacoma sp. indeterminate\n448.1\nEudorellopsis sp. indeterminate\n43\n20.8\nCorophium sp. juvenile\n2\nNumber of taxa = 11\nNumber of invertebrates/sample 79.0\nNumber of invertebrates/m²: 823.2\nH' = 2.25 SDV = 0.66 SR = 2.29 J' = 0.65"]}