Macrobenthos Communities of Cambridge, Mcbeth and Itirbilung Fiords, Baffin Island, Northwest Territories, Canada' ALEC E

ARCTIC VOL. 46, NO. 1 (MARCH 1993) P. 60.71

Macrobenthos Communities of Cambridge, McBeth and Itirbilung Fiords, Baffin Island, Northwest Territories, Canada' ALEC E. AITKEN* and JUDITH FOURNER3

(Received 2 January 1992; accepted in revised form 4 November 1992)

ABSTRACT. Thirtyeight marine invertebrates, including molluscs, echinoderms, polychaetesand several minor taxa, havebeen added to the previously described benthic macrofauna inhabiting Cambridge, McBeth and Itirbilung fiords in northeastern Baffin Island, Northwest Territories, Canada. The fiords lie fully within the marine arctic zone and organisms exhibiting panarctic distributions constitute the majority of speciescollected from them. Macrobenthic associations recordedin the fiords are comparable, both with respectto species composition and habitat, to benthic invertebrate associationsoccurring on the Baffin Island continental shelf andin east Greenland fiords, reflecting the broad environmental tolerances of the organisms constituting the benthic associations.Deposit-feediig organisms dominatethe fiord macrobenthos, notably nuculanid bivalves, ophiuroid echinoderms and elasipod holothurians. The foraging and locomotory activities of these organisms may influence benthic communitystructure by reducing the abundance of sessile and/or tubiculous benthos. Key words: marine benthos, eastern Baffin Island, fiords, continental shelf, zoogeography, ecology

RfiSUMfi. Trente-huit invedbrts marins, y compris des mollusques, des khinodermes, des polychhtes et divers taxons mineurs ont et6 ajoutes a la macrofaune benthique dkrite prkedemment habitant les fjords Cambridge, McBeth et Itirbilung dans le nord-est de la terre de Baffin situ& dans les Temtoires du Nord-Ouest au Canada.Les fjords sontsituts entihrement dans la zone arctique marineet des organismes affchant une distribution panbode constituent la majorit6des eswsrecueillies dans cesfjords. Les associations macrobenthiquesrelevks dans les fjords sont comparables, sur le plan de la composition comme sur celui de l'habitat, aux associations d'invert6brBs benthiquesque l'on trouve sur le plateau continental de la terre de Baffin et dans les fjords du Groenlandoriental, ce qui reflhtela grande toltrance environnementale des organismes formant les associations benthiques. Les organismes quise nourrissent sur le fond dominentle macrobenthos des fjords, en particulier les nucules, lesophiurides et les holothuries Blasipodes. Les activitts de paturage et de locomotion de ces organismes peuvent influencer la structure de la communaute5 benthique en rauisant l'abondance du benthos sessile et/ou tubicole. Mots clts: benthos marin, terre de Baffin orientale, fjords, plateau continental, ZoogBographie, kologie Traduit pour le journal par NBsida Loyer.

INTRODUCTION PHYSICAL ENVIRONMENT The benthic macrofauna inhabiting the fiords of eastern Baffm The physical environmentof eastern Canadian arctic fiords Island has been the subject of several recent studies (Aitken differs significantly from the fiord environments of western et al., 1988; Dale et al., 1989; Syvitski et al., 1989). This study NorthAmerica and Europe. The restricted circulation and focuses on the benthic macrofauna of Cambridge, McBeth andassociated low levels of dissolved oxygen that characterize the Itirbilung -fiords recently described by Syvitski et al. (1989) latter (Syvitski et al., 1986) have not been observed in Baffin (Fig. 1). These authors conducted a reconnaissance benthic Island fiords (Dale et al., 1989). Circulation occurs through- sampling program within the fiords as part of the sedimentologyout depth, largely via isohaline circulation and wind-induced of ArcticFiords Experiment (SAFE) organized by the mixing (Gade et al., 1974; Perkin and Lewis, 1978; Neilsen Geological Survey of Canada (Syvitski and Schafer, 1985). and Ottesen-Hansen,1980; Gilbert, 1983); thus these watersare Syvitski et al. (1989) recognized several benthic macrofaunal oxygen rich (Table1) and supporta diverse benthic macrofauna. associations within these three fiords; these are, in order of The distributionof water masses within the fiords and over depth,the PortZandia association(mean depth 55 m),the the continental shelfof eastern Baffii Island directly influences Onuphid association (mean dep~272 m) and the Maldanid the distribution of arctic marine invertebrates (Grainger,1954, association (mean depth 418 m). 1955; Macpherson, 1971; Lubinsky, 1980). Severaldistinct The work of Curtis (1972) and Dale et al. (1989) indicates water masses occur along the eastern Baffin Island coast. A that diverse mollusc, polychaete and echinoderm populations,seasonally variable shallow water mass develops in July and as well as a variety of minor phyla, inhabitcanadian arctic fiords. August from the mixing of Baffin Current water with freshwater In light of this information, the authors reexamined the benthic from rivers and melting sea ice. The temperatureof this water material collected from Cambridge, McBethand Itirbilung fiords mass ranges from0°C to 8°C and the salinity ranges from less by Syvitskiet al. (1989) with the goalto 1) refine the systematic than 2Ooh to 3Ooh (Ellis, 1960; Fissel et al., 1981). This study of the benthic organisms in the collectionsand 2) to further shallow water mass develops to depths of 5-60 m within the our understanding of the zoogeography and ecology of benthic fiords (Gilbert, 1978; Trites, 1985) and 50-100 m depth across organisms inhabiting the fiords and continental shelf of Baffin the continental shelf (Ellis,1960; Fissel et al., 1981). The near- Island. As a result of this research, 15 species of molluscs, shore habitat is defined to be those areas influenced by this 4 species of echinoderms, 17 species of polychaetes, a sponge, seasonally variable shallow water mass. an ascidian, a sipunculid and a priapulid have been added to The Baffin Island Current lies below the shallow surface water the benthic macrofauna described previously from Cambridge,mass. It is formed by cold, low-salinity water (-1.8"C to McBeth and Itirbilung fiords. 1.8"C; < 30.0-34So/bo; Dunbar, 1951; Meunch, 1971) that lSedimentology of Arctic Fiords Experiment (SAFE) contribution number 37 *Fisheries and Oceans Canada, Institut Maurice Lamontagne, C.P. 1O00, 850 Route de la Mer, Mont-Joli, Quebec, Canada G5H 324; present address: Department of Geography, University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7N OW0 31nvertebrate Zoology Division, Annelid Section, Canadian Museum of Nature, Pd. Box 3443, Station D, Ottawa, Ontario, Canada KIP 6P4 @The Arctic Institute of North America EASTERN BAFFIN ISLAND MARINE BENTHOS / 61 flows southward at depthsof 100-300 m across the continental The Greenland Currentflows below theBaEn Island Current. shelf of eastern Baflh Island. This water mass is of Atlantic It is a relatively warm, saline water mass (0-2.00C, 34.2-35960; originand enters Baffin Bayvia Davis Strait,where it is Bailey, 1957; Meunch, 1971) that flows southward at depths modified by cooling and mixing with surface runoff in north- of 300-1300 m across the outer continental shelfand slope of eastern Baffin Bay,or it is modified by cooling and freshening eastern Baffin Island. This water origjnatm in the Atlantic Ocean within the Arctic Ocean priorto entering BaffinBay via Smith, and is advected north via Davis Strait into Baffin Bay by the Jonesand Lancaster sounds (Meunch, 1971). Trites (1985) West Greenland Current. Here the Greenland Current water reported Baffii Island Current water at depths as great asm 325 mixes withBaflin Island Current water and loses heat as it flows in Baffin Island fiords. The inner shelf habitat is defined to besouthward along the Baffin Island coast. Greenland Current those areas influenced by the Baffin Island Current. waters enter Baffin Island fiords where sill depths permit, 85"N 80"N 85"N 75"N 70"N I I I I Arctic Ocean fl KEISER FRANZ JOSEPH k 20"W

30"W

Greenland

40"W

55"N

50"W 62 / A.E. AITKENand J. FOURNIER

TABLE 1. Physical parameters of the fiords studied

Dissolved oxygen FiordlengthMaximum depthOuter sill depthLargetidalrange (mL.L") Fiord oun) (m) (m) (m) Date (D/M/Y) Surfacea Bottomb 61 708 Cambridge 61 439 1.8 22-23/09/82 8.16 5.00 20-24/09/83 8.78 5.61 8.78 20-24/09/83 McBeth 249 93 563 1.2 18-19/09/825.29 8.39 29/09-02/10/834.98 8.74 Itirbilung 55 Itirbilung 249 435 1.2 5.8717/09/82 8.38 25-29109183 8.82 6.33 *From 0 to 5 m depth. bWithin 20 m of the bottom. Source: Trites et al., 1983; Petrie and Trites, 1984; and Syvitski et al., 1989.

forming a warmer bottom layer at the greatest depths in the TABLE 2. Distribution of sampling effort for macrobenthos during fiords (Trites, 1985). The outer shelf habitat is defined to be C.S.S. Hudson cruise 83-028 in Cambridge (CA), McBeth (MC) and those areas influenced by the Greenland Current. Itirbilung (IT)fiords, Baffin Island, Northwest Territories Mixing of arctic and Atlantic water masses occurs across a broad front extending from Padloping Island(67"N) on eastern Total Total Grab Si2tiOIl abundancea Photo Station abundancea Baffin Island to Thule on western Greenland (Fig. 1). (7TN) Benthicassociation CA MC IT (no:m-3 CAMC IT(no:m-3 The region occupied by waters of mixed arctic and Atlantic Portlundia 4 7 635698 4 origin is known as the subarctic marine zone (Dunbar, 1951). Onuphid6 2398 11 2 578 The boundary between subarctic and boreal waters is established3017Maldanid 6 4 8 3 4 3 96 at the point of farthest penetration of arctic waters (Dunbar, 1951). The marine subarctic zone extends from Scotian the Shelf Total 1019 11 12 7 3 and the Gulf of St. Lawrence to Hudson Strait and along the data were employed to calculate the relative abundanceof marine inver- coast of Baffin Island to Padloping Island. tebrate taxa in Tables 3, 5 and 7.

METHODS AND MATERIALS individuals.m-2(Table 2). Thesedata were employed to calculate the relative abundance of marine invertebrate taxa In 1983,42 grab sample stations and20 bottom camera stations reported in this study. were occupied in Cambridge, McBeth and Itirbilung fiords The marine invertebrates recovered from Cambridge, McBeth between 20 September and 1 October during C.S.S. Hudson and Itirbilung fiords have been arranged within Portlundiathe cruise 83428 (Table 2). Sample station locationsare illustrated association, the Onuphid association and the Maldanid associ- in Syvitski et al. (1989: Fig. 2, p. 235). The marine inver- ation,as designated in Syvitski et al. (1989). Organisms tebrates were recovered from the sediments retained in a singleconstituting thePortlandia, Onuphid and Maldanid associations 40 cm X 40 cm Van Veen or Shipek sampler at each grab wereranked according to their abundance based on the sample station. The shallow prodelta at the head of McBeth information presented in Syvitski et al. (1989:246-247). The Fiord was sampled witha 24 cm X 24 cm Ekman grab sampler methodof feeding employed by the various organisms operated by hand froma launch. The marine invertebrates were represented in this study was determined from information recovered from a single grabat each of7 stations at this location. presented by Barnes(1980), Fauchald andJumars (1979), Kohn Approximately 5 % of the total volume of sediment retained in (1983), and Morton (1983). Benthic invertebrates were desig- the grab samplers was removed for other analyses and the nated as carnivores, scavengers, suspension feedersor deposit remainder was seived througha 2 mm screen. Marine Organisms feeders using the classification scheme developed by Walker retained on the screen were picked onboard ship and preservedand Bambach (1974) based on this information. in formalin( 10 % formaldehyde in seawater). All the organisms identified by the present authorsare based on the examination FAUNAL COMPOSITION AND ZOOGEOGRAPHY OF of specimens recovered from the sieves. In their original study, THE FIORD BENTHIC MACROFAUNA Syvitski et al. (1989) convertedthe number of animals recovered in the grabs to individuals*m-2 (Table 2). These Portlandia Association data were employedto calculate the relative abundance of marine invertebrate taxa reported in this study. The Portlundia association occurs on soupground substrates, Underwater photographs were taken by a stereo Benthos consisting of underconsolidated mud and sand, which develop camera system triggered by a compass bearing weight. The areain areas of rapid sedimentation at the heads of McBeth and photographedwas 1.7 m X 1.2 m. In their original study, Itirbilungfiords (Dale et al., 1989) (Fig. 2). Thisbenthic Syvitski et al. (1989) identified organisms to the level of higher association is characterized by the presence and abundanceof taxa (e.g., ophiuroid echinoderms, buccinid gastropods) from PortMia arctica, maldanid polychaetes (e.g., MaMane sarsi) enlarged photographs. Identification of organisms was facilitatedand ophiuroid echinoderms (Table 3). Suspension-feeding through comparison with live specimens recovered in the bottombivalves - Hiatellu arctica, Musculus discors and Mya tmcata grab samples or with figuresin the published literature. Syvitski - are apparently restricted to the shallow water depths (less et al. (1989) counted the organisms observed in the bottom than 50 m) sampled in McBeth Fiord. The bivalve fauna in photographsand divided their numbers by twoto obtain McBeth Fiord is replaced by sabellid polychaetes, ophiuroid EASTERN BAFFIN ISLAND MARINE BENTHOS / 63

71'15' 30' 45' TABLE 3. Benthic organisms occuning within the Portlmdu aSSOciation in McBeth and Itirbiiung fiords

Mean RelativeMean 75O- 75O Benthic rank abundanceb Life grab samplesabundance* (96) Feedingmodehabit Bivalvia PortMia arcticu 1.8 43.3 InfaunalDeposit feeder 74O 74O portMia 30' - 30' (Hitchcock) Axznopsida orbiculata (G.O. Sars) 3.0 3.0 Infaunal Deposit feeder Macoma calcarea (Gmelin) 3.2 1.1 Infaunal Deposit feeder N I Nucula belloti Adams 3.4 0.3 Infaunal Deposit feeder 69'- 69: 45 ntyasira gouldi 45' (Philippi)* Infaunal Deposit feeder Mya truncata (Lilltl6) 3.3 0.6 Infaunal Suspension feeder ntracia sp. * InfaunalSuspension feeder Hiatella arctica 3.0 6.3 EpifaunalSuspension feeder 30' - 30' Musculus discors (Li.m6)$* 3.3 2.5 EpifaunalSuspension feeder Penploma abyssonun Bush* Infaunal Carnivore Gastropoda Cylichna cf. occulata Mighels 69'- and Adams* Epifaunal Carnivore 15' Polychaeta Maldanidae Maldane sarsi Malmgren* InfaunalDeposit feeder Unidentified maldanid U polychaetes 1.8 42.6 InfaunalDeposit feeder Ampharetidae 6S0 30' Amphicteis st-? sundevalli 0PORTIANDIA MALDANIDONUPHID (Malmgren)* InfaunalSuspension feeder Nephthyidae FIG. 2. Map illustrating the distribution of benthic invertebrate associations Nephthys ciliato identified by Syvitski et al. (1989) within Cambridge, McBeth and Itirbilung (Miiller)* Motile Carnivore fiords. Note thatthe PortWa association occurs at the fiord head in McBeth Oweniidae and Itirbilung fiords but is replaced by the Onuphid association inCambridge Owenia jiuifonnis Fiord. The Maldanid associationoccurs farther seawards andat greater depths delle Chiaje* InfaunalDeposit feeder Sabellidae than the other two benthic associations. Unidentified sabellid echinoderms and buccinid gastropods in Itirbilung Fiord. The polychaetes InfaunalDeposit feeder Echinodermata Porthndia association in McBeth Fiord includes species charac- Ophiuroid teristic of Porthndia and Macomu-Astarte associations that echinoderms 3.3 0.4 EpifaunalDeposit feeder inhabitmud and sand substrates associated with seasonally Anthoma variable, shallow surface waters in the Canadian Arctic and Actinians truncata, (anemones) Epifaunal Carnivore Greenland: Portlmdia arctica, Macoma calcarea, Mya """""""""""~"""""" Hiatella arctica and Musculus discors (Table 4). In eastern RelativeMean Greenland fiordsPortlandia arctica occurs in great abundance Bottom rank abundance Life in association with Macoma calcarea, Astarte borealis and photographs abundance (96) habit Feeding mode Gastropoda Hiatella arctica at depths of5-40 m; in Franz Joseph Fiord the Buccinum sp. 3.0 0.4 Epifaunal Carnivore presence ofPorthndia arctica in theMacoma-Astarte associa- Polychaeta tion is restricted to the inner fiord (Thorson, 1933), as is the Sabellid situation in McBeth Fiord.In J$rgen Brginlund Fiord, however, polychaetes 2.9 2.5 SuspensionfeederInfaunal Portlandia arctica is present in the Macoma-Astarte associa- Echinodermata Ophiuroid tion throughout the length of the fiord (Schigitte, 1989). echinoderms 1 .o 95.8 EpifaunalDepositfeeder Soupground substrates grade into softground substrates over Anthozoa distances of 1-5 km from the fiord head (Dale et al., 1989). Actinians Softground substrates, composedof variable portions of mud, (anemones) 3 .O 0.9 Epifaunal Carnivore sand and gravel, occur in areas characterized by moderate to *Those species recorded for the first time in these fiords. low sedimentation rates, which allow for gradual dewatering $Identified as Modiolaria sp. in Syvitski et al., 1989. "Mean rank abundance = sum of the ranksltotal number of samples. of the sediment and the developmentof firmer substrates. The bRelative abundance = (number of individuals for a taxodtotal number of Onuphid association is consistently associated with gravel on individuals) X 100%. 64 / A.E. AITKEN and J. FOURMER

sofiground substrates, while the Maldanid association occurs of Macoma-Astarte associations that occur at 50-300 m depth on substrates largely free of gravel. on theBaffin Island continental shelf. Dacridiumvitreum, Myriochele heeri, maldanidpolychaetes and agglutinated Onuphid Association foraminifera are abundant in an oweniid polychaete association The Onuphid association occurs at the head of Cambridge occurring at 50-250 m depth in Eclipse Sound. YoMiella spp., Fiord and on the outer sill in Itirbilung Fiord (Fig. 2). This Aximpsidu orbiculata, Dacridium vitreumand Qvhiura robusta benthicassociation is characterized by thepresence and occur abundantly in the Bathyarca glacialis-Astarte crenata abundance of onuphid polychaetes(e.g., Nothria conchylega), association recorded from 45 to 200 m depth in Keiser Franz maldanid polychaetes, the bivalves YoMiella intennedia and Joseph Fiord in East Greenland. Yoldiella lenticula, ophiuroid echinoderms and agglutinated The presence ofChws islandica in the nearshore habitatof foraminifera (Table5). The species composition of the Onuphid northern Baffin Island is of considerable zoogeographic interest. association resembles thatof a variety of benthic invertebrate Its presence in the SAFE collections records a substantial range associationsinhabiting mud, sand and gravel substrates extension for this species in the eastern Canadian Arctic. A associated with arctic waters (Table 4). Macoma calcarea, single live specimen ofChlamys islandicawas recovered from Yoldiella spp. and Ophiura robusta are characteristic species 19 m depth at the head of Cambridge Fiord (station CAFE;

TABLE 4. Benthic invertebrateassociations present within Baf!in Island fiords on the Baffin Island continental shelf and East within Greenland fiords

1. BaffinIslandfiords Bafh IslandShelf - nearshoreassociations GreenlandEast fiords Itirbilung Fiord, Frobisher Bay Scott Inlet EclipseSound, Keiser Franz Joseph Keiser Franz Joseph McBeth Fiord LancasterSound, Fiord, Scoresby Sound Fiord, Scoresby Sound NW Baffin Island Portlandia association Portlandia association Macoma-AstartePortlandia association Macoma association association Portlandia arctica Astarte borealis Portlandia arctica Astarte borealisPortlandia arctica Macoma calcarea Musculus discors Hiatella arctica ntyasira spp. Astartemontagui Myriotrochus rinki Macoma moesfa Mya truncata Mya truncata Macoma moesfa Astarte borealis Hiatella arctica Macoma calcarea Macoma calcarea Astarte montagui Macoma calcarea Musculus discors Mya truncata Astarte elliptica Maldanid polychaetes Ophiacantha bidentata Musculus niger Mya truncata Ophiopus arcticus Nuculana minuta Hiatella arctica Nichomache Ophiura robusta Musculus discors lumbricalis Nephtys spp. Myriotrochus rinki iocten sericeum ?Lpu[us cawlatus Depth(m): 5-40 30-75 5-20 15-50 1040 5-45 Substrate:Sandy mud Sandy mud Muddy sand MudSilty sand Muddy sand Source:Syvitski et al., 1989; Wacasey et al., Thomson et al., 1986 Thomson et al., 1986Spirck, 1933; Thorson,1933, 1934; Aitken and Fournier 1979,1980 Thorson,1934 Bertelsen,1937 (this study) 2. Baffii IslandfiordsBaffinIslandShelf -associations shelfinner Greenland East fiords CambridgeHudsonFiord,EclipseStrait,Sound,EclipseSound, Keiser Franz Joseph Itirbilung FiordFiord Inlet ScottDavisSound,Lancaster Strait NW Baffin Bay Onuphid association Macoma-Astarte Oweniid association Bathyarca-Astarte association cremta association Macoma calcarea Astarte striata Macoma calcarea Dacridium vitreum Bathyarca glacialis Nucula belloti Macoma calcarea Astarte montagui Ophiocten sericeum Astarte crenata Yoldiella spp. ntyasira gouldi Hiatella arm'ca Ophiura sarsi Yoldiella spp. Axinopsida orbiculata Nuculana pernula Margarites sp. Mynochele spp. Axinopsida orbiculata Dacridium vitreum Yoldiella lucida Lepeta caeca Nephtys Ciliata i'hyasira gouldi Ophiacantha bidentata Lepeta caeca Ophiura robusta Maldane sarsi Dacridium vitreum Ophiura robusta Ophiura robusta Ophiocten sericeum Agglutinated Delectopecten foraminifera greenlandicus Gorgonocephalus Ophiopholis aculeata Strongylocentrotus Lepeta caeca arcticus droebachiensis Nothria conchylega Strongylocentrotus Strongylocentrotus droebachiensis droebachiensis Maldanid polychaetes Agglutinated Scoloplos armiger Ophiura robusta foraminifera Depth (m): 100-560 100-300 50-250 50-250 45-200 Substrate: Sandy mud, gravel Sandy mud, gravelly Muddy sand Muddy sand Mud Sand Source: Syvitski et al., 1989; Stewart et al., 1985 Thomson,1982 Thomson,1982 Spiirck,1933; Aitken and Fournier Thorson, 1933 (this study) (continued on next page) EASTERN BAFFIN ISLAND MARINE BENTHOS / 65

71'1 1.5 'N, 75'02.5'W). This record extends the range of this molluscs southwards along the Baffin Island coast. It is most species 700km northward from Cumberland Sound, the approx- probable that the live specimenof Chlamys islandica, sampled imate present northern limit of Chlamys islandica in eastern at the head of Cambridge Fiord, is derived from a relict popu- Canadian waters, where large populations inhabit depths greaterlation isolated during the southward retreat of subarctic molluscs than 30 m (Dale et al., 1989). described above. Marine molluscs with subarctic affinities have been collected New bathymetric records for the eastern Canadian Arctic frompostglacial marine sediments throughout the eastern are recorded for the bivalvesDacridium vitreum and Yoldiella Canadian Arctic, indicating a greater extension of subarctic lenticula amongthe organisms constituting the Onuphid waters into Davis Strait and BaffinBay in theearly and middle association (Table 6). Holocene than at present (Andrews, 1972; Andrews et al., MaManid Association 1981). Miller (1980) noted the time-transgressive natureof the incursion of subarctic waters along the eastern Baffin Island The Maldanid association occurs on muddy sand substrates coast.Subarctic molluscs, notably Astarte striata, Chlamys throughout the central and outer portions of all three fiords islandica and Mytilus edulis, expanded their range during the (Fig.2). This benthicassociation is characterized by the period ca. 10 000-8000 a BP. Diverse macrofaunal assemblages, presence and abundance of maldanid(e.g., Asychis biceps) and containingsuch subarctic water mass indicator species as sabellid (e.g., Myxicola infundibulum) polychaetes, ophiuroid chlumys islandica and Mytilus edulis, are observed in Holocene echinoderms, elasipod holothurians, the bivalves Axinopsida marine deposits as old as 9725 f 120 a BP (QC-450; Miller, orbiculata and Bathyarca glacialis, sea anemones and aggluti- 1979) in FrobisherBay (63'N), 8750 f 100 a BP (GSC-2508; nated foraminifera (Table 7). The species composition of the Miller, 1979) on northern Hall Peninsula (65'N), 8230 f 160 Maldanid association resembles that of a variety of benthic a BP (Gak-3090; Andrews andMiller, 1972) in Narpaing Fiord invertebrate .associations inhabiting mud and sand substrates (6TN), 8190 f 120 aBP (Y-1705; Andrews and Drapier, 1%7) associated with Atlantic waters (Table Bathyarca4). glacialis, inInugsuin Fiord (6YN) and 7780 f 115a BP (SI-2620; Astarte crenuta, Gorgonocephalus arcticus and Ophiopleura Andrews, 1976) at Cape Hunter, Buchan Gulf(71'N) along the borealis are characteristic species of the Bathyarca-Astarte eastern Baffin Island coast. crenuta association recorded from40 to 550m depth in Scoresby Ameliorated marine climates persisted throughout the intervalSound, East Greenland. Two benthic associations, characterized ea. 5500-3000a BP, culminating with the appearance of by theabundance of Bathyarca spp., recordedfrom the Macomabalthica in postglacial marine deposits on eastern continental shelfof Baffin Island are analogous to the Maldanid Baffm Island (Andrews, 1972). Subsequent deterioration theof association: a Bathyarca raridentata association developed on mdrine climate of Baffin Bay coincided with the expansion of mud substrates at 250-500 m depth in Lancaster Sound, and a glaciers on Baffin Island over the last 3000 years (Andrews, Bathyarca pectunculoides-Astartecrem association developed 1972; Miller, 1973; Dyke, 1979) and the retreat of subarctic onmud substrates at 300-700 m depthin Davis Strait. TABLE 4. Continued

3. Baffi Island fiords Baffii Island Shelf - outer shelf associations East Greenlandfiords CambridgeLancasterStraitFiord,Davis Sound,Lancaster Sound, Scoresby SoundKeiserFranz Joseph McBeth Fiord, McBeth SoundNWScoresby Baffi Fiord, Bay BayNW Baffin Itirbilung Fiord Maldanid associationMaldanid Bathyarca association Praxillura-Go&ngia Bathyarca-Astarte Foraminifera association crenata associationassociation Astarte crenata Astarte crenataBathyarca mridentata oohiacanthabidentata Bathvarca~-nlucialis Agglutinated Gaminifera Bathyarca glacialis BathyarcaPraxillella gracilis Pmxillum sp. Astarte crenataYoldiella figida pectunculoides Axinopsidaorbiculuta Nucula delphinodonta Nothria conchylega Nucula tenuis Yoldiella lenticula Yoldiellaintennedia Nothriu conchylega Asychis biceps Nothria conchylega Ctediscus crispatus

Yoldiella lenticula GoUfingia Gorgonocephalus Asychis biceps ' margaritacea arcticusmargaritacea Ophiacantha bidentata Ophwpleum borealis Axinopsida orbiculata Ophiopleum borealis Agglutinated lhyasira gouldi foraminifera Gorgonocephalus arcticus

Elasipod holothurians Asychis biceps Agglutinated foraminifera Depth (m): 255-750 300-700 250-500 250-500 40-550 50-780 Substrate:Sandy mud Mud Mud Coarse silt, fine sand Mud Mud Source: Syvitski et al., 1989; Stewart et al., 1985 Thomson,1982 Thomson,1982 Thorson,1934 Spiirck,1933; Aitken and Fournier Thorson,1934 (this study) 66 / A.E. AITKEN and J. FOURNIER

TABLE 5. Benthic organisms occurring within the Onuphid association in Cambridge and Itirbilung fiords

M ean RelativeMean RelativeMean abundanceb Life Benthic rank abundanceb Life abundanceb Benthicrank Benthic rankLife abundanceb mab samles abundancea ( 56) Feedinghabitmode grab samDlesabundancea ( % ) Feedinehabitmode Bivalvia Capitellidae Astarte crenata Notomastus (Gray)* Infaunal Suspension feeder latericeus Sars* InfaunalDeposit feeder Astarte striata Lumbrineridae (Leach) 3.8 0.3 Infaunal Suspension feeder Lumbrineris Periploma fragilis abyssorurn Bush* Infaunal Suspension feeder (Muller)* CarnivoreMotile Bathyarca Oweniidae glacialis (Gray) 3.8 0.3 Epifaunal Suspension feeder Myriochele heeri Chlamys islandica Malmgren* InfaunalDeposit feeder (Muller) Epifaunal Suspension feeder Owenia fusiformis Dacridium vitreum delle Chiaje* InfaunalDeposit feeder (Moiler)$* 3.7 0.6 Epifaunal Suspension feeder Spionidae Musculus discors Luonice cirrata (Linne)* Epifaunal Suspension feeder sars* InfaunalDeposit feeder Axinopsida Echinodermata orbiculata Ophiuroidea (G.O. Sars) 3.5 2.7 Infaunal Deposit feeder Ophiacantha Macoma calcarea bidentata (Gmelin) 3.6 1.5 Infaunal Deposit feeder (Retzius)* EpifaunalDeposit feeder Macoma loveni Ophiura robusta (Steenstrup) (Ayres)* EpifaunalDeposit feeder Jensen* Infaunal Deposit feeder Ophiura sarsi Nucula belloti (Luke@* EpifaunalDeposit feeder Adams 3.5 1.8 Infaunal Deposit feeder Unidentified Nuculana pernula ophiuroid costigera khe* Infaunal Deposit feeder echinoderms 3.7 2.5 EpifaunalDeposit feeder PortMa arctica 3.8 0.3 Infaunal Deposit feeder Sipunculida portlandia Phascolion strombi (Hitchcock) Wontag)* InfaunalDeposit feeder Thyasira gouldi Agglutinated (Philippi)* Infaunal Deposit feeder foraminifera 3.3 11.4 EpifaunalDeposit feeder Yoldiella spp. $ 3.2 7.6 Infaunal Deposit feeder *wgw (G.O. Sars) 3.8 0.3 Infaunal Carnivore Gastropoda Bottom Lepeta caeca DhotoeraDhs (Miiller)* Epifaunal Browser Gastropoda Buccinum sp. 4.5 0.03 EpifaunalScavenger Polychaeta Polychaeta Onuphidae Onuphid Nothria conchylega polychaetes 1.5 97.8 Epifaunal Scavenger (S@* Epifaunal Scavenger Sabellid polychaetes 5.2 0.02 Infaunal Suspension feeder Unidentified onuphid Echinodermata polychaetes 1.6 32.0 Epifaunal Scavenger Gorgonocephalus Maldanidae arciicus (Leach) 3.7 0.11 EpifaunalSuspension feeder Nichomache Ophiuroid lumbricalis echinoderms 2.7 1.8 EpifaunalDeposit feeder (Fabricius)* Infaunal Deposit feeder Bryozoa Petaloproctus Unidentified longissima bryozoans0.03 4.7 EpifaunalSuspension feeder Anvidsson* Infaunal Deposit feeder Porifera Praxillura Unidentified longissima sponges 4.8 0.02 EpifaunalSuspension feeder Arwidsson* Infaunal Deposit feedex Unidentified Anthozoa maldanid Actinians polychaetes 2.1 35.3 Infaunal Deposit feeder (anemones) 3.0 0.19 EpifaunalCarnivore Sabellidae Pennatulaceans Euchone analis (sea pens) 4.7 0.01 EpifaunalCarnivore Alcyonaceans pWe?* Infaunal Suspension feeder Unldentlfied (soft. coral) 4.8 0.02 EpifaunalCarnivore sabellid Arthropoda polychaetes 3.5 3.3 Infaunal Suspension feeder Pycnogonids 5.0 0.03 EpifaunalCarnivore " *Those species recorded for the first time in these fiords. #Identified as Modiolaria sp. in Syvitski et al., 1989. $Both Yoldiella intermedia (M. Sars) and YoMiella lenticula (MBller) were identified in the grab samples; both are recorded for the Fit time in these fiords. 'Mean rank abundance = sum of the rariks/total number of samples. bRelative abundance = (number of individuals for a taxodtotal number of individuals) X 100%. EASTERN BAFFIN ISLAND MARINE BENTHOS / 67

TABLE 6. New bathymetric records for marine invertebrates in the eastern Canadian Arctic

Previous records Species Stationa North latitude West longitude Depth (m) hpth (m) source Dacridium vitreum (Maller) CA 2.2 71' 19.4' 74" 46.2' 292 31 Ellis, 1960 CASi113.571" 42.1 ' 74" 23.6 ' 255 BiologicalArctic77-245Station,1980 3 1-733 Wacasey el al., 1979, 1980 Nuculana pernula (Miiller) IT 2.1 69" 25.3' 68" 51.2' 310 1909Greig, 4-40 20-50 Ellis, 1960 35, 245 ArcticBiological Station, 1980 30-73Wacasey et al., 1979, 1980 145, 292 Stewart et al., 1985 Ophiopleuraborealis MC 2.0 69" 33.5' 69' 40.2' 320 450- 160 (Danielssen and Koren) and (Danielssen 1932 0 Mortensen,

Tetilla sp. CASill3.1 71" 41.5' 74" 15.0' 397 < 150 Dale et al., 1989 Yoldiella lenticula (Moller) CA 1.5 71" 14.0' 74" 57.0' 262 192 Wagner,1964 CA 1.7 71" 15.0' 74' 54.0' 310 1980Lubinsky, 10-130 CA 4.1 71" 25.5' 74O 45.7' 520 MC 4.1 69" 36.6' 69" 44.5' 549 IT 6.0 68" 52.7' 66" 24.5' 502 aThe location of the various stations within the three fiords is illustrated in Syvitski et al., 1989. CA = CambridgeFiord; MC = McBethFiord; IT = ItirbilungFiord. Ophiacantha bidentataand Asychis biceps are represented abun- trophic structure, basedon organism feeding habits,of various dantly in a polychaete-sipunculid association developedon fine benthic associations inhabitingeastern Baffin Island and Green- sandsubstrates at 250-500 m depthin Lancaster Sound. land fiords is presented in Table 8. Deposit-feeding taxa are Axinopsida orbiculata, Yoldiella spp., Asychis biceps and wellrepresented in the fiord benthic associations and are agglutinatedforaminifera are characteristicspecies of the the most abundant taxa composing the benthic macrofauna of Foraminifera association recorded from 50 to 780 m depth in Cambridge, McBeth and Itirbilung fiords. The foraging activities East Greenland fiords. ofmobile deposit-feeding taxa, notably nuculanid bivalves New bathymetric records in the eastern Canadian Arcticare (Portlandia, Yoldiella, Nuculana and Nucula), ophiuroid recordedfor .the bivalves Nuculana pernula and Yoldiella echinodermsand holothurians, and scavenging, tubiculous lenticula, the ophiuroid echinodermOphiopleura borealis and onuphid polychaetes contribute to the vigorous reworking of the sponge Tetilla sp. among the organisms constituting the fiord bottom sediments (Gilbert, 1982) and may influence the Maldanid association (Table 6). structure of benthic communities. Changes in sediment fabric The three fiords lie fully within the marine arctic zone as produced by the feeding and locomotory activities of mobile defined by Dunbar (195 1); hence it is not surprising that45 of benthic organisms contribute to enhanced resuspension and the 52 species recorded in this study inhabit arctic waters. Of deposition of sediment and mortalityof sessile andor tubiculous these 45 organisms, 11 are restricted to arctic waters:Portlundia organisms(Brenchley, 1981; Wilson, 1981; Thayer, 1983). arctica portMia, Cuspidaria glacialis, Dacridium vitreum, Dale et al. (1989) noted that low abundances of sessile tubiculous Macoma loveni, masira gouldi, Yoldiellaintemdia, Yoldiella polychaetes and cerianthid anemones were associated with high lenticula, Astarte crenata, Bathyarca glacialis, Ophiopleura densities of ophiuroid echinoderms on soupground substrates borealis and Periploma abyssorum. The remaining 34 species in Baffh Island fiords. possess a broad tolerance to higher temperatures and salinities Sessile, suspension-feeding organisms associated with hard and inhabit the marine subarctic zone as well. Many common arctic marine invertebrates are includedthis in group of panarctic substrates are restricted largely to fiord walls andsills, environ- organisms: Axinopsida orbiculata, Buccinum spp., Macoma ments characterized by low rates of sedimentation and/or strong calcarea, Musculus discors, Mya truncata, Nucula belloti, currents (Dale et al., 1989; Syvitski, 1989). The presence of Nuculana pernula, Ophiacantha bidentata, Ophiura sarsi and ice-rafted debris (e.g., gravel, boulders) on the fiord bottom ntyaSira gouldi. Subarctic and cosmopolitan speciesare poorly (Gilbert, 1984) provides these organisms with suitable substrates represented in the macrofaunas of the fiords.Chlumys islundica, for attachment in otherwise unsuitable softground substrates. Astarte striata, Astarte montagui and Myxicola infundibulum These hard substratesare readily colonizedby a varietyof taxa are amongthe subarctic organisms inhabiting the fiords; associatedwith hard substrates: Gorgonocephalus arcticus, cosmopolitan organisms inhabiting the fiords are represented ascidians, bryozoans andsponges, creating the "faunal islands" by Hiatella arctica, Maldane sarsi and Owenia fusiformis. described by Dale et al. (1989). The data presentedin Table 8 indicate that the total number ECOLOGY OF THE FIORD BENTHIC MACROFAUNA of marineinvertebrate taxa andthe proportion of carnivorous/scavenging taxa constituting the east Greenland The interactionof fiord macrofaunal organisms with bottom fiord benthos are greater than in the three Baffin Island fiords substrates and withone another can be examined through trophic examined in this study. The differences in diversity and trophic analysis (Walker and Bambach,1974). One method of describ- structure may be attributed to the greater varietyof gastropod, ing the trophic structure of benthic associations employs the polychaete, crustacean and asteroid echinoderm taxa recorded feeding habits of organisms (Scott, 1978). A comparison of the from Greenland fiords, Many of these invertebratesare motile, 68 / A.E. AITKEN and J. FOURNIER

TABLE 7. Benthic organisms occurring within the Maldanid association in Cambridge, McBeth and Itirbilung fiords

Mean Relative Mean Relative Benthic rank abundanceb Life Benthic rank abundanceb Life grab samplesabundance' (%) Feedingmodehabit grab Samples abundancea (%) habit Feeding mode Bivalvia Echinodermata Axinopsida Holothuroidea orbiculata Elasipod (G.O. Sars) 3.6 11.8 InfaunalDeposit feeder holothurians 4.1 0.7 EpifaunalDepositfeeder Nuculn belbti OpMuroidea (Adam 4.1 1.o InfaunalDeposit feeder Ophiacantha Macoma calcarea bidentata (Gmelin) 4.3 1.o Infaunal Deposit feeder (Retzius)* EpifaunalDeposit feeder Nucuhpernuh Ophiopleura costigera Leche InfaunalDeposit feeder borealis lltyasira gouU (Danielssen and (Philippi)* InfaunalDeposit feeder Koren)* EpifaunalDeposit feeder Yoldiella intermedia Ophiura robusta (M.Sars)* InfaunalDeposit feeder (Ayres)* EpifaunalDeposit feeder Yokiiella lenticula Unidentified (Moiler)* Infaunal Deposit feeder ophiuroid Astarte spp. 8 4.1 0.9 InfaunalSuspension feeder echinoderms 4.2 0.5 EpifaunalDeposit feeder Periploma abyssorum Bush* InfaunalSuspension feeder Ascidiacea Bathyarca glacialis Ciona intestinalis (Gray) 3.8 2.4 EpifaunalSuspension feeder (Linn6) EpifaunalSuspension feeder Dacridium vitreum Porifera (M6ller)* EpifaunalSuspension feeder Tetilln sp.* EpifaunalSuspension feeder Musculus dscors &inn6) * EpifaunalSuspension feeder Priapulida cuspidaria glacialis Priapulus caudatus (G.O. Sam) 4.2 0.7 Infaunal Carnivore Lamarck* Motile Carnivore Agglutinated Gastropoda foraminifera 3.2 41.5 Epifaunal Deposit feeder Lepeta caeca (Muller)*$ EpifaunalBrowser Natica clausa (Broderip and Sowerby)* Epifaunal Carnivore Bottom Polychaeta photographs Maldanidae Gastropoda Asychis biceps Buccinum spp. 4.6 0.7 EpifaunalScavenger Deposit feeder Sari* Infaunal Polychaeta Pmillella gracilis Onuphid SarS* Infaunal Deposit feeder polychaetes 4.3 6.2 Epifaunal Scavenger Unidentified Sabellidpolychaetes 3.8 3.3 Infaunal Suspension feeder maldanid polychaetes 2.1 24.2 Infaunal Deposit feeder Echinodermata Onuphidae Holothuroidea Nothria conchylega Elasipod (Sars)* Epifaunal Scavenger holothurians 4.1 5.3 feederEpifaunalDeposit Unidentified Ophiuroidea onuphid Ophiuroid polychaetes 4.3 0.2 Epifaunal Scavenger echinoderms 1.7 77.3 Epifaunal Dewsit feeder Sabellidae Gorgonocephalus Mjxicolu arcticus Leach 4.8 3.7 EpifaunalSuspension feeder infundibulum .Ascidicea~~ ~.~" (Renier)* Infaunal Suspension feeder Unidentified Unidentified ascidians 5.2 0.1 SuspensionEpifaunal feeder sabellid polychaetes 3.4 10.2 Infaunal Suspension feeder Porifera Capitellidae Unidentified Notomastus sponges 5.3 0.1 Epifaunal Suspensionfeeder latericeus Sars* Infaunal Deposit feeder Anthozoa Scalibregmidae Actinians Polyphysia crassa (anemones) 3.5 2.4 Epifaunal Carnivore (oersted)* Motile Carnivore Pennatulaceans 5.2 0.2 Epifaunal Carnivore Unidentified (sea pens) ampharetid ArthroDoda polychaetes Infaunal " Suspension feeder4.4 PycnOgonids 0.6 Epifaunal Carnivore *Species recorded for the first time in these fiords. $"he species of Astarte have been identified in the collections: Asrarte borealis(Schumacher), Astarte monragui (Dillwyn) and Astarte crema (Gray), which is recorded for the first time in Cambridge Fiord. $4 single empty shell was collected. 'Mean rank abundance = sum of the ranksltotal number of samples. bRelative abundance = (number of individuals for a taxodtotal number of individuals) X 100%. EASTERN BAFFM ISLAND MARINE BENTHOS / 69

TABLE 8. Trophiccomposition of variousbethnic invertebrate TABLE 9. Summary of the marine invertebrate species recorded for associations inhabiting eastern Baffin Island an3 eastern Greenland the first time in Cambridge, McBeth and Itirbilung fiords, Baffin Island, fiords (the numberof taxa in each categoryis presented in the table)' Northwest Territories

Trophic category Benthic association D eposit Suspension Carnivores/Suspension Deposit Portlandia OnuphidMaldanid BenthicassociationBrowsersfeeders scavengers Bivalvia Portlandiag 10 6 0 5 Astarte crenata (Gray) X X Portlandia*3 5 0 3 Dacridium vitreum (Moller) X X Macoma 23calcarea* 33 4 37 Macoma loveni (Steenstrup) Jensen X Musculus discors (Linn6) X X X 11 1 9 Onuphid5 1 17 11 Nucukma pernula costigera Lxhe X Bathyarca glacialis- Periploma abyssonun Bush X X X Astarte crenata* Astarte 20 2815 1 Thmcia sp. X Thyasira gouldi (Phillipi) X X X Maldanidg13 18 0 10 Yoldiella intermedia (M. Sars) X X Bathyarca glacialis- Yoldiella lenticula (Moller) X X Astarte crenata* Astarte 20 2815 1 Foraminifera* 25 9 0 20 Gastropoda Cylichna cf. occulata 'The trophicterminology follows Walkerand Barnbach (1974). Datafor Mighels and Adams X invertebrate taxa occurring within each benthic associationare taken from the Lepeta caeca (Miiller) followine sources: Baffin Island fiords- 6 Svvitski et al.. 1989: Aitken and X Foumie;(this study); Greenland fiords -" *-Spiirck, 1933; Thorson, 1933, Natica clausa (Broderip and Sowerby) X 1934; Bertelsen, 1937. Polychaeta carnivorous/scavenging organisms that occur less abundantly Amphicteis sundevalli Malmgren X Asychis biceps Sars X in the fiord benthos and hencemay be underrepresented in the Euchune analis (Kroyer) X Baffin Island benthos due to thesmall samples recovered at each Laonice cirrata Sars X station in the three fiords (see Methods and Materials). Lumbrineris fmgilis (Muller) X Maldane sarsi Malmgren X Myriochele heeri Malmgren X SUMMARY Myxicola infundibulum (Renier) X Nephthys Ciliata (Miiller) X Syvitski et ul. (1989) identified three macrofaunal associa- Nichomuche lumbricalis (Fabricius) X tions in Cambridge, McBeth and Itirbilung fiords; proceeding Nothria conchylega (Sars) X X seawards from the headsof the fiords theseare the PortZundiu Notomastus latericeus Sars X X association (mean depth55 m), the Onuphid association (mean Owenia fusiformis delle Chiaje X X Petaloprmtus longissima Anvidsson X depth 272 m) and the Maldanid association (mean depth4 18 m) . Polyphysia crassa (Oersted) X The present study has demonstrated that the species compositionPmillella gracilis Sars X of each of these macrofaunal associations is broadly similar to Pradlura longissimu Arwidsson X thatof macrofaunal associations occurring over the same Echinodermata bathymetric range on similar substrates along the continental Ophiuroidea shelfof eastern Baffin Island and in the fiords of eastern Ophiacantha bidentata (Retzius) X X Greenland. The similarityof benthic macrofaunal associations Ophiopleura borealis (Danielssen and along the eastern coastsof Baffin Island and Greenland reflects Koren) X Ophiura robusta (Ayres) X X the broad distribution of arctic and panarctic species in polar Ophiura sarsi (Lutken) X and subarctic waters. Ascidiacea Ciona intestidis (Lid) X CONCLUSIONS Porifera Thirtyeight species of marine invertebrates have been added Tetilla sp. X to the benthic macrofauna described previously as inhabiting Cambridge, McBeth and Itirbilung fiords (Table 9), bringing Priapulida Priqulus caudatus Lamarck thepresent total to 52 species: 22 bivalves, 4 gastropods, X 5 echinoderms, 17 polychaetes and 4 minor taxa.'A number of Sipunculida taxa, including ascidians, bryozoans, elasipod holothurians, Phascolion strombi Wontam)-I X pennatulaceans, pycnogonids and sponges, were observed in bottom photographs but were not recovered in benthic grab Future expeditions to this region must devote sufficient time samples.Curtis (1972) recorded 68 speciesof polychaetes for a dedicated five-replicate grab benthic sampling program, inhabiting depthsas great as 100 m in Hare Fiord and Tanquary as recommended by Holme and McIntyre(1984), to adequately Fiord, Ellesmere Island. Daleet al. (1989) recorded 145 species quantify the fiord benthos. of benthic marine invertebrates in Pangnirtung Fiord, Baffin Thefeeding and locomotory activities of mobileand/or Island: 25 bivalves, 30 gastropods, 32 polychaetes, 25 echino- deposit-feeding organisms play an important role in structuring derms and 33 other taxa. It is apparent that the present study themarine benthos inhabiting unconsolidated substrates by of Baffin Island fiord macrobenthos underestimates the diversity altering the physical propertiesof marine sediments (Thayer, of benthic organisms inhabiting these estuarine environments. 1983). The inverse relation between the abundance of motile 70 / A.E. AITKEN and J. FOURNIER

ophiuroid echinoderms and sessile tubiculous polychaetes and DUNBAR, M.J. 1951. &tern arctic waters. Bulletinof the Fisheries Research cerianthid anemoneson soupground substrates described by Dale Board of Canada No. 88. et al. (1989) in Baffin Island fiords suggests that bioturbation DYKE, AS. 1979. Glacialand sea-level history of southwestern Cumberland Peninsula, Baffin Island, N.W.T., Canada. Arctic and Alpine Research may influence benthic community structure. Physical disturbance 11:179-202. of Baffin Island fiord sediments by motile and/or deposit-feedingELLIS, D.V. 1960. Marine infaunal benthos in arctic North America. Montreal: organisms has been observed in box cores (Gilbert,1982) and Arctic Institute of North America, Technical Paper No. 5. on bottom photographs (Syvitski et al., 1989). The role of FAUCHALD, K., and JUMARS, P. 1979. The dietof worms: A study of poly- commonmarine invertebrates such as nuculanidbivalves, chaete feeding guilds. Oceanography and Marine Biology, Annual Review 17~193-284. ophiuroid echinoderms and onuphid polychaetes in structuring FISSEL, D.B., LEMON, D.D., andBIRCH, J.R. 1981.The physical the marine benthos of arctic fiords remainsto be investigated. oceanographyof western Baffin Bayand Lancaster Sound. Ottawa: Department of Indian and Northern Affairs. Environmental Studies 25. GADE, H.G., LAKE, R.A., LEWIS, E.L., andWALKER, E.R. 1974. ACKOWLEDGEMENTS Oceanography of an arctic bay. Deep-sea Research 21547-571. GILBERT,R. 1978. Observations on oceanography and sedimentationat The work of A.E. Aitken was supported by the Natural Sciences Pangnirtung Fiord, Baffin Island. Maritime Sediments 14:l-9. and EngineeringResearch Council ofCanada through operating grants -. 1982. Contemporary sedimentary environments on Baffin Island, and a postdoctoral fellowship. Dr. John A. Allen and Dr. R.J.A. N.W.T., Canada: Glaciomarine processesin fiords of eastern Cumberland Atkinson, University MarineBiological Station at Millport, Cumbrae, Peninsula. Arctic and Alpine Research 14:l-12. -. 1983. Sedimentary processesof Canadian Arcticfjords. Sedimentary Scotland,provided access to the materialexamined in thisstudy. Geology 36:147-175. Dr. Edward Grainger, Fisheries and Oceans Canada, Institut Maurice -. 1984. Coarse particles in the sediments of Cambridge, McBeth and Lamontagne, confirmed the identification of the echinoderms. Iris Itirbilung fiords. In: Syvitski, J.P.M., compiler. Sedimentology of Arctic Hardy of the Geological Survey ofCanada, Bedford Institute of Fjords Experiment: HU 83-028 andHU 82-031 Data Report, Vol. 2. Canadian Oceanography, and Luci BossB, Fisheries and Oceans Canada, Institut Data Report of Hydrography and Ocean Sciences No. 28:9-1 to 9-25. Maurice Lamontagne, provided assistance in retreiving oceanographic GRAINGER, E.H. 1954. Polychaetous annelids of Ungava Bay, Hudson Strait, data and library research respectively. Diane Gradowski and Keith Frobisher Bay and Cumberland Sound. Journal of the Fisheries Research Bigelow prepared the text figures. Dr. James Syvitski, coordinator for Board of Canada 11507-528. the SAFE project, has donated the invertebrate specimens examined . 1955. Echinoderms of Ungava Bay, Hudson Strait, Frobisher Bay and Cumberland Sound.Journal of theFisheries Research Board of Canada for this study to the permanent collections of the Canadian Museum 12~899-916. of Nature, Ottawa. The content of the paper has been improved through GREIG, J.A. 1909. Brachiopodsand molluscs with a supplement to the the constructive reviews of thejournal referees, Dr. G.V. Winter and echinoderms. Report of the 2nd Norwegian Arctic Expedition in“Fram”: the Dr. A.G.Lewis. 1898-1902, No. 20. Kristiania, Norway: Videnskab-SelskabetI Kristiania. HOLME, N.A., and McINTYRE, A.D. 1984. Methods for the studyof marine benthos. 2nd ed. Blackwells: Oxford. International Biological Programme REFERENCES Handbook No. 10. KOHN, A.J. 1983. Feeding biologyof gastropods. In: Saleuddin, A.S.M., and AITKEN, A.E., RISK, M.J., and HOWARD, J.D. 1988. Animal-sediment Wilbur, K.M., eds. The mollusca. Vol. 5, Part 2, Physiology. New York: relationships on a subarctic intertidal flat: PangnirtungFiord, Baffin Island, Academic Press. 2-63. Canada. Journal of Sedimentary Petrology 58:969-978. LUBINSKY, I. 1980. Marine bivalve molluscs of the Canadian central and ANDREWS, J.T. 1972. Recent and fossil growth rates of marine bivalves, eastern arctic: Faunal composition and zoogeography. Canadian Bulletinof Canadian Arctic, and Late Quaternary arctic marine environments. Fisheries and Aquatic Sciences No. 207. Palaeogeography, Palaeoclimatology, Palaeoecology 11: 157-176. MACPHERSON, E. 1971. The marine molluscs of arctic Canada. National -. 1976. Radiocarbon date list ID: Baffin Island, N.W.T., Canada. Museums of Canada, Publications in Biological Oceanography No. 3. Boulder: Institute of Arctic and Alpine Research, University of Colorado. MEUNCH, R.D. 1971. The physical oceanographyof the northern BaffinBay Occasional Paper No. 21. region. Washington, D.C.: Arctic Institute of North America. BaffinBay - ANDREWS, J.T., and DRAPIER, L. 1967. Radiocarbondates obtained through North Water Project. Scientific Report 1. Geographical Branch fieldobservations. Geographical Bulletin9: 115-162. MILLER, G.H. 1973.Late Quaternary glacialand climatic history of northern ANDREWS, J.T., and MILLER, G.H. 1972. The Quaternary of northern Cumberland Peninsula, Baftin Island,N.W.T., Canada. Quatemary Research Cumberland Peninsula, eastBarn Island, N.W.T. PartX: Radiocarbon date 3~561-583. list. Arctic and Alpine Research 4:261-277. . 1979. Radiocarbon date list IV: Baffin Island, N.W.T., Canada. ANDREWS, J.T., MILLER, G.H., NELSON, A.R., MODE, W.N., and Boulder: Institute of Arctic and Alpine Research, University of Colorado. LOCKE, W.W., III. 1981. Quaternary near-shore environments on eastern Occasional Paper No. 29. Baffin Island.In: Mahaney, W.C., ed. Quaternary Paleoclimate. Norwich: -. 1980. Late Foxe glaciation of southern Baffin Island,N.W.T., Canada. GOBooks. 13-44. Geological Society of America Bulletin 91 :399-405. ARCTICBIOLOGICAL STATION. 1980. A marine biologicalstudy of MORTENSEN, Th. 1932. TheGodthaab Expedition 1928. Echinoderms. Brevoort Harbour and nearby waters of eastern Baffin Island. Canadian Meddelelser om Gr$nland 79(2): 1-64. Maunscript Report of Fisheries and Aquatic Sciences No. 1557. MORTON, B. 1983. Feeding and digestion in Bivalvia.In: Saleuddin, A.S.M., BAILEY, W.B. 1957. Oceanographic features of the Canadian Archipelago. and Wilbur, K.M., eds. The mollusca. Vol. 5, Part 2, Physiology. New Journal of the Fisheries Research Board of Canada 14:731-769. York: Academic Press. 65-147. BARNES, R.D. 1980. Invertebrate zoology. Philadelphia: Saunders NIELSEN, T.K., and OlTESEN-HANSEN, N.-E. 1980. Mixing and exchange CollegelHolt, Rinehart and Winston. processes in a small west Greenland sillfjord. In: Freeland, H.J., Fanner, BERTELSEN, E. 1937. Contributions to the animal ecology of the fiords of D.M., and Levings, C.D., eds. Fjord oceanography. New York: Plenum Angmagssalik and Kangerdlugssuaq in east Greenland. Meddelelser om Press. 219-225. Gdnland 108(3):1-38. PERKIN, R.G., and LEWIS, E.L. 1978. Mixing in an arctic fjord. Journal BRENCHLEY, G.A. 1981. Disturbance andcommunity structure: An of Physical Oceanography 82373-880. experimental study of bioturbation in marine soft-bottom environments. PETRIE, W.M., andTRITES, R.W. 1984. Synoptic oceanopmphy. In: Syvitski, Journal of Marine Research 39:767-790. J.P.M., compiler. Sedimentology of ArcticFjords Experiment: HU 83-028 CURTIS, M.A. 1972. Depth distribution of benthic polychaetesin two fiords and HU 82-031 Data Report, Vol.2. Canadian Data Report of Hydrography on Ellesmere Island, N.W.T. Journal of the Fisheries Research Board of and Ocean Sciences No. 28:2-1 to 2-133. Canada 29:1319-1327. SCHIOTTE, T. 1989. Marine mollusca from J$rgen Br$nlund Fjord, north DALE, J.E., AITKEN, A.E., GILBERT, R., andRISK, M.J. 1989. Greenland,including the descriptionof Diaphana vedelsbyae n.sp. Macrofauna of Canadian arctic fjords. Marine Geology 85:331-358. Meddelelser om Gr$nland, Biosciences 28: 1-24. EASTERN BAFFIN ISLAND MARINE BENTHOS / 71

SCOTT, R.W. 1978. Approaches to trophic analysis of paleocommunities. THORSON, G. 1933. Investigations on shallow water animal communities in kthaia 11:l-14. the Franz Joseph Fjord (east Greenland) and adjacent waters. Meddelelser SPARCK, R. 1933. Contributions to the animal ecology ofthe Franz Joseph om Grdnland lOO(2):l-70. Fjord and adjacent waters. Meddelelser om Wnland 100(1):1-40. -.1934. Contributions to the animal ecology of the Scoresby Sound Fjord STEWART, P.L., POCKLINGTON, P., and CUNJAK, R.A. 1985. Distri- complex (east Greenland). Meddelelser om Glprnland lOO(3):l-67. bution, abundanceand diversity of benthic macroinvextebmtes on Canadianthe TRITES, R.W. 1985. Oceanographic reconnaissance of selected Baffin Island continental shelf andslope of southern Davis Strait and Ungava Bay.Arctic fjords. 14th Arctic Workshop,Bedford Institute of Oceanography, Dartmouth, 38:281-291. Nova Scotia, Canada. Geological Surveyof Canada, Open File122354-58. SYVITSKI, J.P.M. 1989. On the deposition of sediment in glacier-influenced TRITES, R. W., PETRIE, W.M., HAY, A.E., and DeYOUNG, B. 1983. fjords: Oceanographic controls. Marine Geology 85:301-330. Synecoceanography. In: Syvitski, J .P.M., and Blakeney , C .P., compilers. SYWTSKI, J.P.M., and SCHAFER, C.T.1985. sedimentologyof Arctic Fjords Sedmmtology of Arctic Fjords Experiment:HU 82431 Data Report, Vol. 1. Experiment (SAFE): Project introduction. Arctic 38:264-270. Canadian Data Report of Hydrography and Ocean Sciences No. 12:2-1to SYWTSKI, J.P.M., B'iJRRELL, D.C., and SKEI, J.M. 1986. Fjords: Processes 2-129. and products. New York: Springer-Verlag. WACASEY, J.W., ATKINSON, E.G., and GLASSPOLE, L. 1979. Zoobenthos SYVITSKI, J.P.M., FARROW, G.E., ATKINSON, R.G.A., MOORE, P.G., data from upper Frobisher Bay,1%7-1973. Canadian Data Report of Fisheries andANDREWS, J.T. 1989. BaffinIsland fiord macrobenthos:Bottom and Aquatic Sciences No. 164. WACASEY, J.W., ATKINSON, E.G., and GLASSPOLE,L. Zoobenthos communities and environmental significance. Arctic 42:232-247. 1980. THAYER, C.W. Sediment-mediatedbiological disturbance and the data from inshore stations of upper Frobisher Bay, 1969-1976.Canadian 1983. Data Report of Fisheries and Aquatic Sciences No. 205. evolution ofmarinebenthos. In: TEVESZ, M.J., and McCALL, P.L., eds. WAGNER, F.J.E. 1964. Faunal report II, Marine geology program, Polar Biotic interactions in recent and fossil benthic communities. New York: Continental Shelf Project, Isachsen, Districtof Franklin. Geological Survey Plenum Press. 479-625. of Canada Report, Bedford Institute of Oceanography 64-1. THOMSON, D.H. 1982. Marine benthos in theeastern Canadian High Arctic: WALKER, K.R., and BAMBACH, R.K. 1974. Feeding by benthic inverte- Multivariate analysis of standing crop and community structure. Arctic brates: Classification and terminologyfor paleoecological analysis. Lethaia 35~61-74. 7~67-78. THOMSON, D.H., MARTIN, C.M., and CROSS, W.E. 1986. Identification WILSON, W.H., Jr. 1981. Sediment-mediated interactions ina densely and characterizationof arctic nearshore benthic habitats. Canadian Technical populated infaunal assemblage:The effects of the polychaete Abarenicola Report of Fisheries and Aquatic Sciences No. 1434. pacifica. Journal of Marine Research 39:735-748.