Micro- and mesozooplankton in Southwest Greenland waters - Juni 1999, May and July 2000. Technical Report No. 53

1 Technical Report No. 53, 2003 Greenland Institute of Natural Resources Microand mesozooplankton in Southwest Greenland waters - June 1999, May and July 2000 2 Title: Microand mesozooplankton in Southwest Greenland waters - Juni 1999, May and July 2000 Authors: Søren A. Pedersen, Mads H. Ribergaard og Claus S. Simonsen Series:Technical Report No. 53, 2003 Publisher: Greenland Institute of Natural Resources Cover photo: Søren A. Pedersen ISBN: 87-91214-00-9 ISSN: 1397-3657 Layout: Kirsten Rydahl Printing: Oddi Printing Ltd., Reykjavik, Iceland Prints: 50 (Danish & greenlandic summaries) Reference: Pedersen, S.A, M.H. Ribergaard & C.S. Simonsen 2003. Microand mesozooplankton in Southwest Greenland waters - Juni 1999, May and July 2000. Greenland Institute of Natural resources, technical report no.53. 59 pp. Keywords: Plankton distribution, community structure, food web, ocean circulation Available from:Greenland Institute of Natural Resources P.O. Box 570 DK-3900 Nuuk Greenland Phone: +299 32 10 95 Fax: +299 32 59 57 www.natur.gl 3 Microand mesozooplankton in Southwest Greenland waters - June 1999, May and July 2000 by Søren A. Pedersen, Mads H. Ribergaard & Claus S. Simonsen Technical Report No. 53, 2003 Greenland Institute of Natural Resources 4 Planktonprøver og målinger af temperatur og saltholdighed blev indsamlet langs stationer udlagt på tværs af de vestgrønlandske fiskebanker i juni 1999, maj og juli 2000. Formålet med indsamlingerne var at undersøge udbredelsen af små dyreplanktonarter i havvandet, herunder deres udviklingsstadier, størrelser, antal og biomasser. Derudover var det formålet at sammenholde udbredelsen af dyreplanktonet med målinger af temperatur, saltholdighed og planteplankton. Havstrømmens betydning for udbredelsen af planktonet er blevet undersøgt ved hjælp af en ny havstrømsmodel for Grønland. Betydningen af små dyreplankton for kulstofomsætningen og for produktion af fisk i de frie vandmasser er blevet analyseret og sammenholdt med hvad havforskere har fundet i andre områder af Nordatlanten. Undersøgelsen konkluderer at havstrømsmodeller vil blive et nødvendigt redskab for fremtidig forskning, som ønsker øget forståelse af koblingerne mellem klima, havstrømme og økosystem forandringer, eksempelvis forandringer i produktionen af rejer og fisk. Resumé Eqikkaaneq Immap sarfaata tappiorannartut siamasissusaannut pingaaruteqarnera Kalaallit Nunaanni immap sarfaanik qarasaasiaq atorlugu ilusilersuut nutaaq atorlugu misissorneqarsimavoq. Pinngortitap kulstofimik kaaviaartitsineranut tappioraannartut uumasut mikisut pingaaruteqarnerat misissorneqarsimavoq Atlantikullu imartaata avannaani sumiiffinni allani ilisimatuut paasisimasaannut sanilliunneqarsimallutik. Silaannaap allanngorarnerata immap sarfarneranut taamatullu uumassusilinnut tamanut avatangiisaanullu sunniutigisartagaat pillugit siunissami ilisimatusartarnissani immap sarfaanik qarasaasiaq atorlugu ilusilersuummik atuisariaqartarnissaq misissuinerni matumani paasineqarpoq – soorlu kinguppannik aalisakkanillu tunisassiornermi allanngorarnerit misissuiffigineqarnerini. Kitaata ikkannersaani aalisarfiusuni avataaniittuni sineriak sinerlugu avammut sammisumik misissuiffinni tappioraannartunik misissugassanik katersuineq immallu kissassusaanik tarajoqassusaanillu uuttortaaneq junimi 1999-mi, majimi junimilu 2000-mi ingerlanneqarpoq. Katersuinernerni immami tappioraannartut mikisut siamasissusaannik misissuinissaq, tassungalu atatillugu ineriartortarnerat, angissusaat, amerlassusaat kiisalu sumiiffiit aaliajangersimasut iluini tappiorannartut amerlassusaannik misissuinissaq siunertarineqarpoq. Tamatuma saniatigut tappioraannartut immami uumasut siammasissusaat immap kissassusaanut, tarajoqassusaanut tappioraannartunullu immap naasuinut sanilliunneqarnissaat siunertarineqarpoq. 5 Abstract Plankton samples and oceanographic data were obtained during transect studies across fishing banks over the West Greenland shelf areas in June 1999, May, and July 2000. The study investigates the distributions of species, stage, size, abundance and biomass of microand mesozooplankton in relation to hydrography, phytoand protozooplankton. The role of current transport for life cycles of key plankton species is investigated using an ocean circulation model for Greenland. The role of microand mesozooplankton in carbon cycling and fish production in the pelagic food web over the southwest Greenland shelf are analyzed and related to findings from studies in other areas of the North Atlantic. Simple (or complex) food web models will not be useful for assessments of the effects of climate change on fish populations. More promising ways towards predictions of changes in fish production at higher trophic levels under climate change seems to be development of coupled bio-physical models of larval recruitment, hybrid recruitment models, and studies of indicator species. In the present study we identified the following research areas in particular relevant for understanding species distributions, current transport, and life cycles of the West Greenland micro-, mesoand meroplankton: 1) better understanding of calanoid larval dormancy, 2) species identification (e.g. nauplii of C. finmarchicus vs. C. glacialis) using genetic identification, 3) vertical migrations, and 4) trophic interactions. The ocean circulation model developed for Greenland will be useful for future research in the coupling between climate, ocean circulation and ecosystem changes. It should be further developed to treat baroclinic effects prognostic in order to describe oceanographic features like the dynamics of fronts and upwelling/downwelling of different watermasses. 6 7 1. Introduction The waters of West Greenland are dominated by the West Greenland Current, which represents a mixture of water from the East Greenland Current, the Irminger Current, and sub-Atlantic water (Buch 2000a, b). The watermass characteristics in the West Greenland Current are formed in the western Irminger Basin where the East Greenland Current and the Irminger Current meets and flowing southward side by side while mixing is taking place. As the currents round the tip of Greenland the Irminger water subduct under the Polar water and extensive missing is taking place. Hence, the marine shelf ecosystems around south Greenland are in the intermediate between cold Polar water masses of the Arctic region and temperate water masses of the Atlantic Ocean. The ocean currents that transport water from the polar and temperate regions affect the marine productivity in the shelf areas, and changes in the North Atlantic climate and ocean circulation have major impact on species distributions and fisheries yield (Pedersen & Kanneworff 1995, Jensen et al. 1999, Pedersen & Smidt 2000, Buch et al. 2003). During the last decades northern shrimp has become a dominant species for the commercial fisheries in the Northwest Atlantic (West Greenland and East Canada). At present there is no complete explanation for the increase in abundance of northern shrimp, but changes in the ocean climate is unquestionably an important factor (Buch et al. 2003). Scenarios of impacts of climate change point to a modification of the hydrographic regime in the Northwest Atlantic. Although global warming, melting ice, and changes in the thermohaline circulation may create regional lower temperatures and increased ice cover in the future in West Greenland (e.g. Serreze et al., 2000). Scenarios of changes in sea-climate imply an impact on the biological properties of the water masses including conditions that likely affect fish and shellfish recruitment. Understanding the dynamics of the lower trophic levels of the pelagic food web are one of the keys to understand changes in community structure and recruitment success for fish and shellfish (e.g. Pedersen et al. 2002). In Greenland waters the marine ecosystems of West Greenland are in terms of commercial fisheries resources the most productive and best investigated. The plankton productivity of the area is evident from the ICNAF (International Commission for the Northwest Atlantic Fisheries) Norwestlant I-III surveys in 1963 and annual surveys carried out during four decades along a number of cross-shelf transects (ICNAF 1968, Pedersen & Smidt 2000, Pedersen & Rice 2002). The main object of historic sampling programs of hydrography and plankton in West Greenland was to study the effect of the environment on the planktonic stages of larval fish e.g. Atlantic cod (Gadus morhua) and the redfish (Sebastes marinus and S. mentella). Therefore these studies give an incomplete picture of the plankton community structure at the lower trophic levels. For example Pedersen & Smidt (2000) reports on distribution and abundances of zooplankton caught by 1 mm mesh size ring nets and a recently simplified mass balance model for the West Greenland large marine ecosystem ignores e.g. fluxes through the lower trophic levels, and the importance of the microbial loop (Pedersen & Zeller 2001). However, for many larval fish smaller organisms (< 1 mm) e.g. copepod nauplii and copepodites are main food sources and may be crucial for larval survival. The distributions and abundances of larval fish food and larval survival are determined by e.g. geographic origin, timing of production, 8 oceanographic features and current transport (Petersen 1966, Sundby 2000, Pedersen & Smidt 2000, Pedersen & Rice 2002). Research in pelagic food webs of the North Atlantic during the last century has stressed the key role of copepods, especially genus Calanus, as a direct link to the fish stocks, since copepods are dominating prey for fish larvae during their growth (e.g. Bainbridge & McKay 1968, Runge 1988, Sundby 2000). Fish and shellfish production depends on marine food web structure and functioning. However, only a small fraction of the pelagic primary production is eventually channeled up the food web to end as harvestable fish biomass (Fenchel 1988, Kiørboe 1998, 2001). Knowledge of the role of the microbial food web in the Arctic has been limited because the microbial loop in cold water ecosystems has been considered less important than at lower latitudes. Recent comprehensive investigations in Disko Bay, West Greenland, have documented that bacterioplankton and unicellular zooplankton also play a prominent role in the food web of Arctic ecosystems (Nielsen & Hansen 1995, 1999, Hansen et al. 2003). The Disko Bay marine food web is as complex as in temperate areas, and is dominated by the large calanoid copepods (Hansen et al. 1999, Madsen et al. 2001, Niehoff et al. 2002). These large grazers are key organisms in the determination of ecosystem structure and energy transfer to higher trophic levels such as fish stocks and marine mammals. In Disko Bay the three Calanus species co-occur and can contribute to more than 90% of the zooplankton biomass during spring and early summer. The behavioural adaptations of Calanus spp. to climate change may have strong effects on the food web structure, generating trophic cascades and eventually influence the fisheries (Hansen et al. 2003). Historic descriptions of zooplankton from Southwest Greenland exists: Maclellan (1967) described the annual cycle of certain calanoid species in West Greenland based on an annual study in Godthaab fjord and studies in several other West Greenland fjords at various seasons during 1942-1944. Bainbridge &d Corlett (1968) described the zooplankton of the Norwestlant I-III surveys in 1963. Pavshtiks (1968, 1972) described the species composition and the biological seasons of zooplankton in the Davis Strait based on zooplankton collections during 1962-1964. Smidt (1979) described the annual cycles of primary production and zooplankton in coastal/fjord areas of Southwest Greenland based on studies during 1955-1967. Since these descriptions little information on the structure and functioning of the plankton community exists from Southwest Greenland. In 1999 and 2000, four research cruises collected hydrographical data and plankton samples to describe species distributions and community structures of the plankton food webs in relationships with hydrographic processes (e.g. shelf break fronts) across commercially important West Greenland fishing banks (Poulsen & Reuss 2002, Pedersen et al. 2002, Munk 2002, Simonsen et al. in prep.). The present paper reports on (1) distributions of species, stage, size, abundance and biomass of microand mesozooplankton in relation to hydrography, (2) the role of current transport for life cycles of key plankton species using an ocean circulation model, and (3) the role of microand mesozooplankton in carbon cycling and fish production. Based on new information on the structure and dynamics of the pelagic food web summarized in this paper, we seek a better understanding of the coupling between climate, ocean circulation, plankton and fish/ shellfish production and suggestions for future research. The present contribution is relevant in view of the need for a long-term ecosystem-based management of natural marine resources in West Greenland and elsewhere (Jarre, 2002; Pauly et al., 2002). 9 2. Materials and Methods 2.1. Study area and sampling Sampling was carried out in June 1999, May, and July 2000 between 63°50’N and 66°50’N over the West Greenland shelf with the Greenlandic research vessels Adolf Jensen and Paamiut (Figure 1, Table 1). In May and June, sampling was performed at stations along transects crossing Fyllasand Sukkertop Bank. In July, sampling was carried further north to include stations along transects crossing Lilleand Store Hellefisk Bank using the two research vessels at the same time. In May two stations in Davis Strait and 6 coast/fjord stations were sampled in the inshore Nuuk-area (Figure 1). Depth integrated microand mesozooplankton samples of the upper 200 m (or 2 m above bottom at shallower stations) were obtained from each station shown in Figure 1. In June and in July with Paamiut, samples were collected from one vertical haul with a WP-2 net (0.58 m diameter and 50 mm mesh size) retrieved at 10 m min-1 assuming 100% filtration efficiency. In May and in July with Adolf Jensen, samples were collected using a submersible pump (900 l min-1, HOMA-H500, DIFRES-design) equipped with a conical net of 50 mm mesh size. The pump or WP-2 net were lowered to max 100 m in May and July with Paamiut and max 200m in June and July with Adolf Jensen started and retrieved to the surface at 10 m min-1. Samples were preserved in 48 % buffered formalin in seawater. At each station, and at additional stations between these (not shown in Figure 1), vertical profiles of temperature, salinity, and density were obtained with a Sea-bird SBE 9-011 sealogger CTD. Fluorescence was measured with a HydroScat2 fluorometer from HOBI-Labs, except during the cruise with Paamiut in July. The fluorescence was calibrated against fluorometrically determined chlorophyll a content in water samples collected on selected stations in May and June (Poulsen & Reuss 2002). The chl a concentrations were used as indices of phytoplankton biomass. 2.2 Plankton distribution, abundance and community structure Microand mesozooplankton were sorted and identified to the lowest possible taxon in the laboratory. Each species or taxonomic category was enumerated and length measured (Table 2). Within each copepodite stage up to 10 specimens were length measured. Abundance and length information was used to estimate the biomass as total carbon within taxonomic categories at each sampling station. Length-weight relationships (carbon content or ash-free dry weight) were obtained from the literature: Calanus (all three species) and Metridia longa from Hirche & Mumm (1992), Acartia spp. and all copepod nauplii from Berggreen et al. (1988), Pseudocalanus sp. from Klein Bretler et al. (1982), while for the smaller Period Reseach vessel Transect Gear (net mesh size) May 12-21 2000 RV Adolf Jensen 1, 3 Zooplankton pump (50µm) June 21-30 1999 RV Adolf Jensen 2, 3 WP2 (50µm) July 11-23 2000 RV Adolf Jensen 1, 4, 5 Zooplankton pump (50µm) July 12-27 2000 RV Paamiut 2, 3, 6 WP2 (50µm) Table 1. Sampling data from the four research cruises. 16 Temperature oC. -0.8 -0.4 0.0 0.4 0.8 Depth (m) -200 -150 -100 -50 0 1 2 3 4 5 6 Salinity psu 32.8 33.2 33.6 µg Chl.a l-1 012345 Calanus finmarchicus 0.0 0.2 0.4 0.6 0.8 CI CII CIII CIV CV CVI-F Calanus glacialis 0.0 0.5 1.0 1.5 2.0 2.5 3.0 Calanus hyperboreus Ind. (x103) m-2 0.0 0.5 1.0 1.5 2.0 0 500 1000 1500 2000 Copepod eggs Copepod nauplii Station no. 0 1000 2000 3000 4000 5000 6000 Appendicularia Bivalvia Cirripedia Echinodermata Euphausiacea Gastropoda Polychaeta 0 100 200 300 400 500 600 Acartia spp. Metridia longa Microcalanus spp. Microsetella spp. Oithona similis Oncaea spp. Pseudocalanus spp. 123456 Stages of Calanus sp.: Station no.: males) on especially the deeper stations west and east of the banks. In June and July the abundance of C. finmarchicus females were lower or nil. Generally no females or males of C. glacialis and C. hyperboreus were found. However, in July few C. glacialis females were identified at stations along Tr5. The small copepod community (CI-CVI) consisted predominantly of Oithona similes and Microsetella norvegica during all sampFigure 2d Vertical profiles of temperature (°C), salinity, chlorophyll a, abundance indices of stage composition of Calanus spp., other copepods (CI-CVI), copepod eggs, nauplii, and other invertebrate larvae at coast/fjord station 1-6 in May 2000. ling times. Total abundances were at similar levels in May and June, and highest in July. In May the fjordic stations were dominated by Microsetella spp., and Pseudocalanus elongatus. Microcalanus spp. was dominant at one station on Tr3 in May. Pseudocalanus spp. occurred in high abundance at the two shallow stations nearest to shore of Tr6 in July. The abundance of both large and small copepods was exceptionally high over deep water east and west of the bank on Tr2 and west of the bank on Tr3 in July (not shown). Copepod eggs showed highest abundance in May and June, whereas copepod egg sacks were dominating in July. By number, Bivalvia larvae and relatively large copepod nauplii (> 200 µm) dominated the zooplankton community in May, whereas smaller copepod nauplii (< 200 µm) were dominating in June and July (Figure 3a, b). In July high numbers of gastropod (pteropod) larvae were found especially along Tr2 and Tr3, and tintinnids on Tr1 (Appendix Table 1g-i). By weight, the large copepodites of Calanus spp. dominated the copepod and invertebrate biomass in all sampling periods, with Pseudocalanus spp., Metridia longa, and Oithona spp. comprising most of the remaining copepod biomass (Table 3). Calanus spp., especially C. finmarchicus, became increasingly dominant from May to July with exceptionally high biomasses over the shelf slopes along Tr2 and Tr3 (Figure 4). In May, on the coast and fjord stations (St. 1-6) other copepod species Metridia longa, Pseudocalanus spp., Microsetella spp. were dominating. In May, diatoms, Thalassiosira spp. and Chaetoceros spp., dominated the biomass structure of the plankton community of the upper 100 m followed by heterotrophic flagellates, ciliates and copepods (Table 3 and 4). Conversely in June (and July) where copepods dominated over heterotrophic flagellates, ciliates, autotrophic flagellates and other invertebrate zooplankton. We have no information on the species compo- 17 Figure 3a Mean concentrations of microand mesozooplankton categories by size and sampling location in May 2000 (upper panels) and June 1999 (lower panels). Figure 3b Mean concentrations of microand mesozooplankton categories by size and sampling location in July 2000. Figure 4 Distribution and biomass (mg C m -2 ) of Calanus spp. in May 2000, June 1999 (left panels) and July 2000 (right panels). Dot sizes are graduated by square root. Note different scales between left and right panel. Tr2 June 1999 Size (µm) 50-100 101-150 151-200201-250251-300301-400401-500 >501 Ind. (x103) m-2 0 50 100 150 200 Tr3 June 1999 0 50 100 150 200 Calanus C1-6 Microset. C1-6 Oithona C1-6 Copepod eggs Copepod npl Bivalvia larvae Gastropod larvae Tintinnids Others Tr3 May 2000 Ind. (x103) m-2 0 100 200 300 400 500 600 700 Calanus C1-6 Microset. C1-6 Oithona C1-6 Copepod eggs Copepod npl Bivalvia larvae Euphausidae eggs Euphausidae larvae Others 1346 Tr1 May 2000 0 100 200 300 400 500 600 700 Fjd May 2000 Size (µm) 50-100 101-150 151-200201-250251-300301-400401-500 >501 0 100 200 300 400 500 600 700 1192 N=5 N=6 N=6 N=5 N=5 Tr6 July 2000 0 100 200 Calanus C1-6 Microset. C1-6 Oithona C1-6 Copepod eggs Copepod npl Bivalvia larvae Gastropod larvae Tintinnids Others Tr5 July 2000 0 100 200 Tr4 July 2000 0 100 200 Tr3 July 2000 Ind. (x103) m-2 0 100 200 300 400 Tr2 July 2000 0 100 200 300 400 500 600 700 800 Tr1 July 2000 Size (µm) 50-100 101-150 151-200201-250 251-300301-400 401-500 >501 0 100 200 N=5 N=6 N=5 N=4 N=10 N=5 18 sition and biomasses of phytoand protozooplankton from July, however, tintinnids were very abundant on several stations. Information about vertical distributions of microand mesozooplankton at some of the stations in May 2000 indicate that zooplankton was most abundant in the upper ~100m and at the Fjord stations between 100 and 30m (Appendix Table 2-4). However, copepod eggs and nauplii were most abundant in the upper 50 m along Tr1 and Tr3 over the shelf (Appendix Table 2b,c). Location Transects 1, 3 Transects 2,3 Transects 1-6 Fjord (St. 1-6) Sampling period May 2000 June 1999 July 2000 May 2000 Number of stations 11 10 36 6 Plankton category Mean Std Mean Std Mean Std Mean Std Copepods: C. finmarchicus 160 266 764 534 3120 5509 4 3 C. glacialis 123 114 724 480 1858 2847 14 7 C. hyperboreus 304 385 563 584 1291 3875 16 15 Acart i a s pp .14001425 Metridia longa 16 52 51 114 37 109 94 230 Microcalanus spp. 17 31 3 4 2 4 4 5 Microsetella spp. 12 10 9 12 17 275475 Oithona similis 27 21 21 21 65 74 13 7 Oncaea spp. 0 0 3 3 5 12 11 22 Pseudocal anus spp. 66 82 22 20 49 54 74 62 Copepod eggs 88 63 22 40 34 34 56 63 Copepod nauplii 413 349 27 333442226 242 Total Copepods 1229 1376 2210 1845 6513 12592 566 736 Other invertebrates: Appendicularia 16 22 24 29 7 11 4 4 Bivalvia 37 47 3 4 12 20 58 99 Cirripedia 103 190 63115 45 85 301 315 Echinodermata - - - - Euphausiacea 209 450 15 24 14 42 109 119 Gastropoda 13 33 11 19 56 95 4 7 Polychaeta 8 6 4 2 4 3 21 8 Pandalus larvae* 15 29 7 5 8 8 23 19 Total other invertebrates 401 776 127 198 146 263 520 570 *From Pedersen et al . (2002). Table 3. Mean biomass (mg C m-2) of each zooplankton category by sampling location and period. 19 Location Transects 1, 3 Transects 2,3 Fjord (St. 4) Sampling period May 2000 June 1999 May 2000 Number of stations 8 5 1 Plankton category Mean Std Mean Std Mean Std Autotrophic organisms: Flagellates < 10 µm 90 39 185 86 107 - Flagellates > 10 µm 16 23 44 64 0 - Euglenophyceae 16 45 0 0 0 - Phaeocystis pouchetii 436 341 - - 4010 - A.Dinoflagellates 44 42 37 50 83 - Ceratium arcticum 00 94209 0 - Centric diatoms 339 339 18 22 8 - Chaetoceros spp. 3567 2171 395 881 2327 - Thalassiosira spp. 4985 1792 25 53 1716 - Pennate diatoms 332 363 29 51 99 - Mesodinium rubrum 76 53 0 - Total autotrophic biomass (mg C m-2)9831342083112248349Heterotrophic organisms: Nanoflagellates < 10 µm 32 22 94 47 132 - Nanoflagellates > 10 µm 1 3 6 7 0 - Coanoflagellates 108 70 34 39 58 - A.Dinoflagellates < 20 µm 95 65 149 101 294 - A.Dinoflagellates > 20 µm 948 656 205 205 1683 - T.Dinoflagellates 136 66 32 27 107 - Ciliates < 50 µm 252 115 109 72 322 - Ciliates > 50 µm 392 363 115 61 151 - Laboea strobila 77 91 18 21 25 - Tintinnids 12 27 2 3 3 - Total heterotro p hic biomass ( m g C m-2 ) 2053 1108 763 376 2775 - Table 4. Mean biomass (mg C m-2) of phytoplankton and protozooplankton by sampling location and period. Data from Poulsen and Reuss (2002). 3.2 Plankton transport by ocean currents and effects of hydrographic features We found good agreement between the current simulations and drifter tracks of two drifters (drogue in 30 m) deployed along Tr1 in May 2000. The current model simulated hydrographic features seen in the drifter tracks – the semidurial tidal ellipses, circulation around shelf banks and a net northward flowing drift along the shelf which generally following the depth contour (Figure 5). The strength of the currents and the general cyclonic circulation in the Labrador Sea was also well modelled compared to other observations (Jacobsen et al. 2003). Modelled trajectories of particles by release locations (Tr0, Tr1 and Tr3) for two years, 1999 and 2000, were almost identical in spite of differences in the wind fields between years. Tracking of particles released in different depths (10, 30, 50 and 80 m) showed minor differences in transport patterns indicating minor effects of adding vertical behaviour to the particles (plankton). Simulations of drifters released in 30 m along Tr0, Tr1 and Tr3 across the shelf showed clear differences in the transport patterns (Figure 5). Drifters released in coastal areas and over the shelf drifted north ending in the cost or caught in eddies over the shelf banks. The westernmost drifters were either transported west to the Labrador shelf (Tr0) or north along the West Greenland shelf slope (Tr1 and Tr3). 20 Figure 5 Model calculated mean current velocity, April-October 2000, in 30 m over the Southwest Greenland shelf (left panel), and model calculated tracks of particles released in 30 m on May 12 2000 along three transects across the shelf (Tr0, Tr1, and Tr3) (right panel). Additional marks on the calculated particle tracks in panel B indicated position on July 12 and the tracking was stopped on September 12. 21 4.1 Plankton distributions, stage development and life cycles The upper 200 m during May, June, and July were dominated by Polar water, which is characterized by temperatures below 0°C (increasing to 3–5°C in the surface layer during summer) and salinities below 34.4 (Buch 2000). A hydrographic frontal zone between cold Polar water and warmer mixed shelf water over the bank was most clearly seen in June on the western part of Tr3 (Figure 2b). In May and July, fronts were difficult to identify across transects. Vertical lines were clearly seen between warmer and less saline water in the surface layers and near the coast due to freshwater runoff. The coarse spatial and temporal resolution of hydrographical data measurements makes detection of the small scale frontal processes difficult. Fronts may only occur periodically within the sampled areas. We found no clear relationship between zooplankton abundance and water mass characteristics. In May and June, chlorophyll a was concentrated in the relatively cold Polar water mass. During the spring bloom in May the phytoplankton biomass (92 ± 45 mg C m -3 ) was dominated by diatoms of Thalassiosira spp. and Chaetoceros spp. (Poulsen & Reuss 2002). In June, a post-bloom situation prevailed on most of Tr3 resulting in a very low phytoplankton biomass (2 ± 1 mg C m -3) (Poulsen & Reuss 2002). Peak phytoplankton biomasses (30 mg C m -3) were found at the western part of Tr3 where diatoms of Chaetoceros spp. dominated (Figure 2b). In July pronounced subsurface concentrations of chlorophyll a were observed in the upper 50 m of the water column on Tr1, Tr4, and Tr5. The phytoplankton composition of these subsurface blooms was not investigated, but diatoms probably dominated (Nielsen & Hansen 1999). In all cases the blooms extent down to the depth of the upper thermocline. The onset of the seasonal phytoplankton development (spring bloom) begin in Southwest Greenland in April and it is delayed from south to north due to e.g. later increase in day-length and withdraw of the West-Ice covering the Baffin Bay and Davis Strait during winter (Pavshtiks 1968, 1972, Jensen et al. 1999, Head et al. 2000). However, duration and extent of the ice cover are related to climatic conditions, and, consequently, onset and development of the spring bloom vary from year to year. After the spring bloom, only minor blooms develop, caused by intrusions of nutrients due to temporal mixing of the surface water (Nielsen & Hansen 1999). We found weak relationships between chlorophyll a concentrations and zooplankton abundance. High copepod and invertebrate abundances coincided with high chl a concentrations, which may indicate increased growth and survival in high productive areas. The three species of large copepods Calanus finmarchicus, C. glacialis, and C. hyperboreus were dominating in terms of biomass. There was a general increasing biomass of the three Calanus species and especially of C. finmarchicus from May to July as individuals and populations gain weight and developed. According to Pavshtiks (1968, 1972) C. finmarchicus stage CVI-females was the most abundant mesozooplankton over the West Greenland Shelf in April. From April to July the progeny of the spawning C. finmarchicus females in this region gradually develops to copepodid stages IV and V, which by July became dominant in terms of biomass. C. finmarchicus, brought to West Greenland following the Irminger Water, 4. Discussion 22 probably spawns first, and then the local C. finmarchicus population, which has overwintered in the costal waters spawns. This aspect, however, requires further study (Pavshtiks 1972). According to Pavshtiks (1972) it is quite probable that in the deep central part of the Davis Strait the first spawning also refers to C. finmarchicus from the Irminger Water and that the forms which have overwintered in the deep waters of the strait spawn later. Because it is known that this area is inhabited by several populations of Calanus which differ in body size and in spawning periods these questions can be resolved by a more detailed study of the morphology of Calanus in Davis Strait (Pavshtiks 1972). According to Pavshtiks (1972), the C. finmarchicus population which spawns in May on the Greenland shelf in the southern part of Davis Strait consists of small females (average length of cephalothorax 2.6-2.8 mm) and the females that spawn somewhat later in the deep basin of the Labrador Sea are larger (2.9-3.0 mm). The spawning of the latter population starts in June and continues during July and part of August. In July, the spawning of C. finmarchicus continued very actively in the waters of the West Greenland current off southern Greenland, leading to an extremely large increase in the numbers of juveniles 5,182 ind. m-3 (Pavshtiks 1972). The females of C. finmarchicus which spawned in August and September in the northern part of Davis Strait were larger (3.2-3.4 mm) and apparently belong to a separate population (Pavshtiks 1972). In May, in this study, there was about equal abundance of the three Calanus species with stage CI being dominating in C. finmarchicus and C. glacialis, whereas CII dominated over CI in C. hyperboreus. Females of C. finmarchicus were abundant, whereas no females of C. glacialis or C. hyperboreus were observed. In Disko Bay in 1996, the maximum abundance of females of C. finmarchicus, C. glacialis, and C. hyperboreus in June was 6,498, 1,446, and 1,131 ind. m–2, respectively (Niehoff et al. 2002). In the present study the maximum female abundance of C. finmarchicus was 3,458 ind. m–2 in May, however, very high abundances of CIV and CV of all three Calanus species was observed in July. The abundance and demographic structure indicate that the three species of Calanus have developed from CI-CII to CIV-CV between the sampling in May and July. In Disko Bay, the life cycle of C. finmarchicus was deduced to be 1 year and at least 2 year for C. glacialis and C. hyperboreus (Madsen et al. 2001). C. finmarchicus, C. glacialis, and C. hyperboreus, reproduce successfully in Disko Bay (Niehoff et al. 2002). However, their reproductive cycles were considerably different with respect to the timing of final gonad maturation and spawning. The three Calanus species have evolved different reproductive strategies to adapt to the seasonal phytoplankton development (Niehoff et al. 2002). C. finmarchicus in Disko Bay outnumbers both C. glacialis and C. hyperboreus by up to a factor of three throughout the year, indicating that this species can reproduce and recruit successfully in ecosystems strongly influenced by polar conditions (Madsen et al. 2001, Niehoff et al. 2002). At Svalbard and in the marginal ice zone of the Barents Sea in northeast Atlantic, Scott et al. (2000) and Falk-Petersen et al. (1999) found C. finmarchicus to have a 1 year life cycle, C. glacialis 1-2 year life cycle, and C. hyperboreus a 3-5 year life cycle. These generation times seems to fit for Calanus in southwest Greenland waters. However, based on only three sampling periods in this study it is difficult to deduce the development and life cycles of the three Calanus species, because one has to take into account e.g. advection by currents and mixing of different populations over the southwest Greenland shelf (Pavshtiks 1972). The stage composition of the species in plankton samples reflects the reproductive cycles and e.g. time/duration/intensity of spawning, stage development times, migrations, advections and survival/mortality. We found high numbers of Calanus nauplii, low numbers of Calanus copepodites in 23 stage CI mainly, few females of C. finmarchicus, no females of C. glacialis or C. hyperboreus in the coast and fjord samples in May. We hypothesize that the young Calanus stages have drifted into the fjord from offshore areas. Smidt (1979) found some zooplankton species to occur mainly in the inner fjord regions, while others mainly occur closer to Davis Strait, and are uniformly distributed. Among the copepods, Pseudocalanus spp., Metridia longa, Oncaea borealis and Microsetella norvegica were most frequent in the inner fjord regions, while species of Calanus and Microcalanus were mainly or exclusively found in costal regions. Maclellan (1967) found few young stages of Calanus in the inner fjord and suggests the progeny from the fjord population may have been advected out of the fjord with the runoff melt water. It seems therefore likely that e.g. the Calanus spp. populations in the fjord are sustained by inflow from offshore and coastal populations. 4.2 Plankton current transport and retention We found unusual high abundance and biomass of copepods and invertebrates at stations over deep water on Tr2 and Tr3 in July 2000, which was an order of magnitude higher than other transects. The area crossed by Tr2 is an important summer feeding area for baleen whales, mainly humpback whale (Megaptera novaeangliae), which supports the findings of exceptional high plankton densities here (Finn Larsen, DIFRES, Charlottenlund, Denmark, pers. comm.). Special hydrographical features in this area may cause plankton aggregations. As the northward drifting West Greenland Current meets Sukkertop Deep and pass west of Tovqussaqand Sukkertop Bank it produces complex gyres and circulation patterns in Sukkertop Deep and along the bank slopes which may aggregate zooplankton. Further north along Tr5, Munk (2002) found plankton aggregations and juvenile fish feeding in a hydrographic frontal zone indicating the importance of fronts for biological production and fish recruitment. The drifter tracks of two drifters deployed in May 2000 along Tr1 and our drifter simulations also indicated complex ocean circulation patterns over the shelf north of 64°N at the same locations. Hydrographic features, fronts and eddies may act as barriers to plankton transport or contribute to plankton retention - processes which is important for species and plankton distributions (e.g. Sinclair 1988, Sournia 1994, Hannah et al. 2000, Munk et al. 2003). In West Greenland larval drift by surface currents is assumed to be essential for the fish and shellfish recruitment to downstream fishing areas and fjords, whereas larval retention may dominate in other areas (Pedersen & Rice 2002, Pedersen et al. 2002, Ribergaard et al. 2003). Ribergaard et al. (2003) simulated particle transport from four release areas along West Greenland and they showed that after 100 days about 80% of the particles were located over the West Greenland shelf between 64°N and 67°N and about 20% were located on the Canadian Labrador shelf and in the Davis Strait at depths > 1,000 m. Of the latter 20 % most were released south of 63°N. Hence particles from the southern release areas were transported the longest distances, while particles from release area between 64°N and 67°N were transported relatively short distances. The northward floating West Greenland Current has a strong effect on species composition, community structure, food web dynamics and hence ecosystem productivity. Plankton animals of different geographic origin occur in the survey area. As the individual life cycle of plankton increases in time the importance of the advection term increases and for e.g. C. finmarchicus with a life cycle of several months, the advection term may become very important (Sundby 2000). Microand mesozooplankton in the survey area e.g. Calanus spp. seems to be drifted to the area from South or East Greenland. Head et al. (2000) found high concentrations and productivity of C. finmarchicus in southwest Greenland. It seems likely that C. finmarchicus populations over the West Greenland shelf to a large extent is su- 24 Figure 6 Simplified schematic representation of community structure (biomass in mg C m-2), carbon and nutrient flow through the lower trophic food web during the spring-bloom period in May 2000 (A) and the postbloom period in June 1999 (B). DIM=dissolved inorganic material (C, Ca, Si, N, P..), POM=particulate organic material, and DOM=dissolved organic material. A - Spring bloom period: 0-~100m, mg C m -2 May 12-21 2000 Other invertebrates  Heterotrophic Dinoflagellates  Ciliates   Heterotrophic Nanoflagellates  Bacteria " Phytoplankton >11 µm  Phytoplankton <11 µm  ',0 320 " '20 " 6HGLPHQWDWLRQ " B - Post-bloom period: 0-~100m, mg C m -2 June 21-30 1999 (July 11-27 2000) Other invertebrates  Heterotrophic Dinoflagellates  Ciliates  Copepods   Heterotrophic Nanoflagellates  Phytoplankton >11 µm  Phytoplankton <11 µm  Bacteria " 320 " '20 " 6HGLPHQWDWLRQ " ',0 Copepods 25 stained from the main C. finmarchicus distribution area south of Greenland and that the variability in advectional transport to West Greenland have strong implications for e.g. Atlantic cod recruitment (Sundby 2000). Today the West Greenland cod population is at a very low level as several other Atlantic fish species. However, during the warmer period in 1950‘s and 1960‘s with higher biological production several fish populations was large and productive in Southwest Greenland, especially the commercially most important Atlantic cod (Pedersen & Smidt 2000, Pedersen & Rice 2002, Wieland & Hovgaard 2002). During the 1950s and 1960s large numbers of Atlantic cod larvae and other fish larvae were transported from southwest Greenland spawning grounds to the Labrador shelf to recruit to populations here. 4.3 Vertical flux, carbon cycling and fish production During the May survey phytoplankton (diatoms) dominated the plankton community structure of the upper ~100 m whereas during June (and July) heterotrophic organisms were dominating (Figure 6). The shift in the phytoplankton community from a spring-bloom to a post-bloom community was most likely due to nutrition limitation of the phytoplankton (Paulsen & Reuss 2002). The dominance of small autotrophic flagellates in June suggested reliance upon recycled nutritions in the euphotic zone. The spring-bloom protozooplankton and the heterotrophic nanoflagellate (HNAN) biomass were comparable to biomass reported from Disko Bay (Nielsen & Hansen 1995), however the June post-bloom biomasses of protozooplankton and HNAN were lower than earlier reported. Poulsen & Reuss (2002) suggest that the low June protozooplankton and HNAN biomasses were due to the absence of phytoplankton subsurface blooms and the associated decrease in food availability. The microbial food web most likely played an important role in carbon cycling as indicated by the large standing stocks of primarily bacteriovorous HNAN especially during the post-bloom situation in June. We have no information on bacterial biomass from this study. However, Hansen et al. (2003) report the bacterial biomass to vary between 40 and 150 mg C m-3 during summer (during spring-bloom and post-bloom periods) in Disko Bay, which is at the same level as the autotrophic biomass during the spring-bloom in May. In Disko Bay, Nielsen & Hansen (1995) found an increase in bacterial production after the phytoplankton bloom but no increase in HNAN most probably due to grassing by planktonic ciliates. According to Paulsen and Reuss (2002) it seems unlikely that the low biomass of small autotrophic flagellates presented in June would be able to fuel a bacterioplankton community large enough to sustain the heterotrophic biomass present. However, DOM produced during the bloom may be the resource the bacterioplankton are utilizing during the post-bloom situation in June, which in turn is passed up the food web (Poulsen & Reuss 2002). We found Calanus spp. to be dominating the copepod biomass in all sampling periods. In May and June the three Calanus species were of about equal biomass, but in July C. finmarchicus was dominating. These findings are similar to findings from the Disko Bay area (Nielsen & Hansen 1995, Hansen et al. 1999, 2003). In May the phytoplankton biomass and production was able to sustain the heterotrophic plankton community but not in June (or July) during the post-bloom situation (Figure 6). In the latter situation copepod feeding must have been supplemented or dominated by heterotrophic food e.g. ciliates and heterotrophic dinoflagellates (Hansen et al. 1999). From a study of microzooplankton grazing of phytoplankton in the Barents Sea during early summer Verity et al. (2002) conclude that it may be that, except during the peak of the vernal bloom, microzooplankton are a major food source for mesozooplankton in the Barents Sea, and the importance of topdown influences on community structure and ecosystem function may be a general 32 Sournia, A. 1994. Pelagic biogeography and fronts. Prog. Oceanog. 34: 109-120. Storm, L. & S.A. Pedersen 2003. Development and drift of northern shrimp larvae (Pandalus borealis) at West Greenland. Marine Biology. Publiced on-line. Sundby, S. 2000. Recruitment of Atlantic cod stocks in relation to temperature and advection of copepod populations. Sarsia 85: 277-298. Turner, J.T., H. Levinsen, T.G. Nielsen & B.W. Hansen 2001. Zooplankton feeding ecology: Grazing on phytoplankton and predation on protozoans by copepod and barnacle nauplii in Disko Bay, West Greenland. Marine Ecology Progress Series 221: 209-219. Uye, S. 1982. Length-weight relationships of important zooplankton from the inland sea of Japan. Journal of the Oceanographical Society of Japan 38: 149-158. Verity, P.G., P. Wassmann, M.E. Frischer, M.H. Howard-Jones & A. Allen 2002. Grazing of phytoplankton by microzooplankton in the Barents Sea during early summer. Journal of Marine Systems, 38: 109-123. Werner, F.E., B.R. Mackenzie, R.I. Perry, R.G. Lough, C.E. Naimie, B.O. Blanton & J.A. Quinlan 2001. Larval trophodynamics, turbulence, and drift on Georges Bank: A sensitivity analysis of cod and haddock. Sci. Mar., 65: 99115. Wieland, K. & H. Hovgaard 2002. Distribution and Drift of Atlantic Cod (Gadus morhua) Eggs and Larvae in Greenland Offshore Waters. J. Northw. Atl. Fish. Sci. 30: 6176. 33 Station no. 1234 56 Zooplankton category Stage\Depth (m) 200-0 155-0 185-0 200-0 90-0 35-0 Copepoda egg sacks 6588 36890 42160 2635 eggs 34255 187086 321471 18445 42160 5270 $FDUWLDORQJLUHPLV CVI-male 2635 nauplii 1318 28985 100130 15810 &DODQXVILQPDUFKLFXV CI 82 21 309 144 638 576 CII 144 62 82 62 185 CIII 21 103 124 CIV 21 CVI-female 62 &DODQXVJODFLDOLV CI 309 350 556 741 1215 1956 CII 82 185 226 309 103 782 CIII 165 165 185 82 CIV 82 &DODQXVK\SHUERUHXV CI 144 124 62 638 391 226 CII 247 247 721 659 165 CIII 185 144 &DODQXV sp. nauplii 5270 5270 31620 36890 105400 10540 0HWULGLDORQJD CVI-female 3953 0LFURFDODQXVSXVLOOXV CI 5270 CV 2635 CVI-female 5270 2635 nauplii 42160 42160 0LFURVHWHOODQRUYHJLFD CI-VI28985 31620 73780 42181 274041 7905 2LWKRQDVLPLOLV CI 5270 21080 CII 5270 CIII 2635 CV 2635 2635 CVI-female 5270 5270 10540 10540 21080 5270 CVI-male 10540 5270 2LWKRQD sp. nauplii 18445 26350 36890 13175 548082 76415 2LWKRQDVSLQLURVWULV CVI-female 2635 2QFDHDERUHDOLV CI-5 2635 42160 10540 CVI-female 2635 42160 CVI-male 1318 10540 63240 3VHXGRFDODQXVHORQJDWXV CVI-female 2635 3VHXGRFDODQXVPLQXWXV CI 11858 84320 5270 CII19763 10540 21080 CIII 9223 CIV CVI-female 2635 5270 2635 3VHXGRFDODQXV sp.nauplii 52700 76415 163371 181816 779963 39525 Bivalvia larvae 334646 353091 943334 21080 5291101 39525 Chaetognatha ( ( XNURKQLDKDPDWD )21 &LUULSHGLDFLSULV nauplii 1318 55335 42160 150196 147561 289851 Decapoda larvae 62 185 473 62 62 Echinodermata larvae 5270 28985 21080 10540 42160 5270 Euphausidae eggs 6588 5270 68510 7905 36890 nauplii 1318 42160 41 21080 5270 )ULWLOODULDERUHDOLV 2635 5270 2LNRSOHXUD sp. 5270 Gastropoda larvae 21080 5270 Hyperiidae 21 Pisces eggs 21 Polychaeta larvae 31620 15810 15810 63240 Appendix Table 1a. Abundance of zooplankton categories (ind. m-2) at sampling stations, fjord and coast, May 2000 (Pump, 50µm net). 34 Table 1b. Abundance of zooplankton categories (ind. m-2) at sampling stations, Transect 1, May 2000 (Pump, 50µm net). Station no. 123456 Zooplankton category Stage\Depth (m) 100-0 60-0 30-0 60-0 100-0 100-0 Copepoda egg sacks 10540 5270 10540 36890 17128 eggs 569162 42160 7905 695643 216071 61923 $FDUWLDORQJLUHPLV CI 2635 CVI-female 2635 nauplii 2635 115940 27668 &DODQXVILQPDUFKLFXV CI 7411 2429 3129 1441 1400 412 CII 659 165 206 206 494 CIII 1153 206 288 329 CIV 329 CV 1482 82 165 CVI-female 3458 412 659 &DODQXVJODFLDOLV CI 15810 2223 4735 1894 2017 2141 CII 4776 782 576 576 1153 2553 CIII 494 165 412 618 1318 CIV 1647 247 247 CV 165 41 82 247 &DODQXVK\SHUERUHXV CI 5435 576 1400 782 1112 823 CII 9717 1976 906 1688 3417 4529 CIII 329 371 618 700 247 CV 659 &DODQXV sp. nauplii 126481 13175 76415 63240 15810 0HWULGLDORQJD CVI-male 41 1318 0LFURFDODQXVSXVLOOXV CII 2635 CVI-female 5270 1318 CVI-male 5270 1318 nauplii 2635 0LFURVHWHOODQRUYHJLFD CI-VI 21080 2635 5270 21080 21080 9223 nauplii 2635 2LWKRQDVLPLOLV CI 5270 7905 31620 10540 1318 CII 3953 CIII 2635 1318 CV 5270 2635 CVI-female 7905 10540 21080 21080 15810 CVI-male 2635 2635 10540 5270 9223 nauplii 168641 36890 5270 147561 42160 10540 2QFDHDERUHDOLV CI-5 2635 21080 1318 3VHXGRFDODQXVHORQJDWXV CVI-female 21080 3VHXGRFDODQXVPLQXWXV CI 2635 CII 1318 CIII 1318 CVI-female 1318 3 VHXGRFDODQXV sp.nauplii 548082 65875 65875 548082 173911 71145 Bivalvia larvae 105400 300391 226611 779963 785233 150196 &LUULSHGLDFLSULV nauplii 126481 7905 26350 31620 31620 54018 Decapoda larvae 82 247 Echinodermata larvae 2635 21080 Euphausidae eggs 2635 52700 21080 nauplii 329 82 42160 6588 )ULWLOODULDERUHDOLV 42160 10540 2635 10540 1318 Gastropoda larvae 7905 5270 63240 Hyperiidae 988 82 41 247 Ostracoda ( &RQFRHFLDHOHJDQV )329 Polychaeta larvae 21080 5270 5270 35 Table 1c. Abundance of zooplankton categories (ind. m-2) at sampling stations, Transect 3, May 2000 (Pump, 50µm net). Station no. 12 34 5 Zooplankton category Stage\Depth (m) 100-0 100-0 100-0 45-0 100-0 Copepoda egg sacks 21080 10540 42160 10540 42160 eggs 126481 94860 316201 10540 484842 $ FDUWLD spp. nauplii 10540 &DODQXVILQPDUFKLFXV CI 5682 2100 1029 329 371 CII 1729 659 329 679 206 CIII 576 288 41 21 1112 CIV 535 CV 329 CVI-female 1976 206 206 659 CVI-male 82 &DODQXVJODFLDOLV CI 9799 4076 3953 2964 1647 CII 2059 1976 906 391 329 CIII 2635 618 700 309 1276 CIV 659 247 288 CV 165 &DODQXVK\SHUERUHXV CI 5188 329 1276 226 329 CII 7246 1359 1647 62 782 CIII 2223 371 988 3088 CV 82 165 1318 &DODQXV sp.nauplii 274041 63240 63240 52700 21080 (XFKDHWDQRUYHJLD CIII 21080 CVI-female 21080 0LFURFDODQXVSXVLOOXV CI 42160 CII 21080 CIII 21080 CIV 21080 CV 21080 CVI-female 10540 21080 21080 nauplii 21080 0LFURVHWHOODQRUYHJLFD CI-VI21080 63240 21080 42160 2LWKRQDVLPLOLV CI 10540 CII 10540 CV 21080 CVI-female 21080 10540 84320 10540 21080 CVI-male 10540 21080 nauplii 189721 42160 105400 84320 3 VHXGRFDODQXV spp. CV 10540 10540 CVI-female 21080 21080 nauplii 653483 179181 252961 305661 210801 Bivalvia larvae 21080 1960448 642943 3014452 &LUULSHGLDFLSULV nauplii 10540 21080 21080 Echinodermata larvae 10540 10540 Euphausidae eggs 10540 42160 316201 nauplii 105400 21080 larvae 329 )ULWLOODULDERUHDOLV 21080 21080 Hyperiidae 329 Polychaeta larvae 21080 21080 10540 36 Table 1d. Abundance of zooplankton categories (ind. m-2) at sampling stations, Davis Strait, May 2000 (Pump, 50µm net). Station no. D1 D2 Zooplankton category Stage\Depth (m) 100-0 100-0 Copepoda egg sacks 21080 21080 eggs 189721 274041 &DODQXVILQPDUFKLFXV CI 6135 9717 CII 988 6258 CIII 288 823 CIV 329 CV 165 CVI-female 1359 494 &DODQXVJODFLDOLV CI 9017 22727 CII 2347 5105 CIII 329 1482 CIV 988 &DODQXVK\SHUERUHXV CI 1318 6423 CII 1441 10211 CIII 1688 2141 CV 371 165 CVI-female 41 &DODQXV sp. nauplii 147561 316201 0HWULGLDORQJD CVI-female 21080 0LFURFDODQXVSXVLOOXV CIII 21080 21080 CVI-female 21080 nauplii 42160 0LFURVHWHOODQRUYHJLFD CI-VI 21080 2LWKRQDVLPLOLV CI 21080 42160 CIII 21080 2LWKRQD sp. nauplii 84320 84320 2LWKRQDVSLQLURVWULV CVI-female 21080 2QFDHDERUHDOLV CI-5 21080 3VHXGRFDODQXV spp. nauplii 316201 1117244 6FROHFLWKULFHOOD sp. CVI-female 21080 Bivalvia larvae 42160 63240 &LUULSHGLDFLSULV 21080 Euphausidae nauplii 21080 larvae 63240 )ULWLOODULDERUHDOLV 42160 21080 Hydromedusae 329 Ostracoda 329 37 Table 1e. Abundance of zooplankton categories (ind. m-2) at sampling stations, Transect 2, June 1999 (WP2, 50µm net). Station no. 12345 Zooplankton category Stage\Depth (m) 200-0 100-0 100-0 40-0 200-0 Copepoda egg sacks 4527 1358 2264 566 eggs 11771 2716 3169 1585 2264 &DODQXVILQPDUFKLFXV CI 3622 6338 4980 792 6791 CII 4527 905 2716 1471 15393 CIII 4527 4074 5433 1924 12223 CIV 1811 3169 3169 1471 2716 CV 905 905 4980 340 CVI-female 453 &DODQXVJODFLDOLV CI 2716 4527 2716 226 14940 CII 3622 4074 5433 340 5433 CIII 13582 7696 9960 113 CIV 6338 3622 4527 CV 1811 1358 226 453 CVI-male 905 &DODQXVK\SHUERUHXV CI 1811 905 1811 2264 CII 4527 2716 6791 CIII 8149 1811 2264 CIV 905 4527 5885 CV 453 &DODQXV sp. nauplii 21731 6791 6791 1358 30332 (XFDODQXVHORQJDWXV CV 905 0HWULGLDORQJD CIII 905 CVI-female 905 0LFURFDODQXVSXVLOOXV CII 453 CIII 453 0LFURVHWHOODQRUYHJLFD CI-VI 9960 8149 12676 2716 8149 2LWKRQDVLPLOLV CI 905 905 1471 2264 CII 6338 905 3169 2264 6338 CIII 3622 2264 1811 905 8602 CIV 5433 1811 453 679 5885 CV 453 905 1245 5433 CVI-female 1811 1811 453 2037 4074 CVI-male 905 905 1811 1019 6791 2LWKRQD sp. nauplii 176561 15393 10413 15506 5433 2LWKRQDVSLQLURVWULV CVI-female 905 CVI-male 453 2QFDHDERUHDOLV CI-5 12676 6791 3169 13582 CVI-female 1811 453 4074 CVI-male 1811 2QFDHDERUHDOLV CI-5 679 3OHXURPDPPDUREXVWD CIII 453 3VHXGRFDODQXVHORQJDWXV CI 4980 CII 905 CV 453 226 CVI-female 113 3VHXGRFDODQXVPLQXWXV CV 905 453 CVI-female 905 905 453 3VHXGRFDODQXV sp.nauplii 453 5885 38 Table 1f. Abundance of zooplankton categories (ind. m-2) at sampling stations, Transect 3, June 1999 (WP2, 50µm net). Station no. 12345 Zooplankton category Stage\Depth (m) 200-0 100-0 100-0 40-0 200-0 Bivalvia larvae 73341 40292 53421 1471 4074 &LUULSHGLDFLSULV 5433 3622 1358 Echinodermata larvae 35312 9054 7244 679 4527 Euphausidae eggs 905 larvae 905 453 )ULWLOODULDERUHDOLV 2716 1358 3622 2LNRSOHXUD sp. tail 29879 15845 4527 792 3622 Gastropoda larvae 32596 11318 6791 340 5433 Hydromedusae 57 453 57 28 Hyperiidae 1811 453 Ostracoda (&RQFRHFLDREWXVDWD )905 Polychaeta larvae 6338 3169 2716 905 Table 1e (continued). Abundance of zooplankton categories (ind. m-2) at sampling stations, Transect 2, June 1999 (WP2, 50µm net). Station no. 12345 Zooplankton category Stage\Depth (m) 200-0 200-0 100-0 45-0 200-0 Copepoda eggs 398396 554130 35765 6055 12563 nauplii 557752 554131 82395 24446 17656 $FDUWLDORQJLUHPLV CIV 4 CV 14 14 CVI-female 14 14 CVI-male 11 14 $FDUWLD sp. CI 156 11 4 7 CII 99 4 11 4 CIII 42 18 28 11 CIV 42 25 18 14 CV 14 7 18 CVI-female 28 21 21 CVI-male 14 7 14 4 &DODQXVILQPDUFKLFXV CI 24447 16298 5206 1188 3622 CII 6338 28974 13129 5999 9054 CIII 2264 18562 13808 8432 16298 CIV 2264 11771 10865 2547 10865 CV 2264 4980 2490 509 2716 CVI-female 453 453 453 57 damaged 4527 170 &DODQXVJODFLDOLV CI 5433 57 CII 7244 905 CIII 1811 1811 679 CIV 905 4980 1132 1188 2264 CV 453 1358 2037 566 2264 Continued..... 39 Table 1f (continued). Abundance of zooplankton categories (ind. m-2) at sampling stations, Transect 3, June 1999 (WP2, 50µm net). &DODQXVK\SHUERUHXV CI 6791 CII 1811 CIII 2716 2264 57 453 CIV 453 2264 1358 CV 453 226 damaged 3169 (XFKDHWDQRUYHJLD CIV 905 0HWULGLD sp. CI 57 453 CV 1811 453 CVI-female 1358 453 0LFURFDODQXV sp. CI 1358 226 CII 453 905 226 CIII 1358 905 226 CIV 905 453 905 CV 905 1358 CVI-female 2716 3622 1132 4074 damaged 905 0LFURVHWHOOD sp. CI 453 CIV 1811 1811 905 1358 CV 23089 3169 2490 113 9960 CVI-female 10413 905 3678 20372 CVI-male 4980 226 905 damaged 1358 679 113 2LWKRQDVLPLOLV CI 14487 15393 6791 2547 14034 CII 9507 13129 6338 1471 14940 CIII 6791 17203 7017 1075 9054 CIV 4074 11318 8149 1245 8602 CV 15393 15845 8375 2207 19467 CVI-female 3622 13582 453 57 453 CVI-male 23541 4301 1302 17656 damaged 2264 16751 3622 679 1358 2QFDHD sp. CI 1358 CII 9507 57 CIII 5433 905 CIV 11318 1358 1811 57 CV 10413 905 1358 1811 CVI-female 453 1811 57 905 CVI-male 1358 6338 1132 57 1358 damaged 905 1811 226 57 3VHXGRFDODQXV spp. CI 4980 3622 1585 170 1811 CII 4074 2716 1358 113 1811 CIII 1811 3622 1132 396 3169 CIV 1811 453 113 1358 CV 453 453 226 226 2716 CVI-female 453 170 damaged 453 453 57 6FROHFLWKULFHOOD sp. CVI-female 453 Station no. 12345 Zooplankton category Stage\Depth (m) 200-0 200-0 100-0 45-0 200-0 Continued..... 40 Table 1f (continued). Abundance of zooplankton categories (ind. m-2) at sampling stations, Transect 3, June 1999 (WP2, 50µm net). Station no. 12345 Zooplankton category Stage\Depth (m) 200-0 200-0 100-0 45-0 200-0 Appendicularia 48894 37123 2264 255 226 Bivalvia larvae 224549 16751 13016 1938 22862 Chaetognatha 453 113 &LUULSHGLDFLSULV 16298 7696 679 141 792 Cnidaria 1811 85 Echinodermata larvae 18109 6791 2037 85 453 Euphausidae larvae 21731 2717 283 113 Foraminifera 105031 453 679 226 Gastropoda larvae 105031 34859 1245 141 566 Hyperiidae 14 113 Invertebrata larvae 3622 113 453 Polychaeta larvae 16298 6338 2830 71 2490 5K\QFKRFSLOLGLXP 14 Siphonophora 905 Gastropoda (Thecosomata) 453 3282 Unidentified invertebrates 1811 28 41 Table 1g. Abundance of zooplankton categories (ind. m-2) at sampling stations, Transect 1, July 2000 (Pump, 50µm net). Station no. 12345 Zooplankton category Stage\Depth (m) 200-0 75-0 35-0 200-0 100-0 Copepoda egg sacks 15905 22132 4497 21814 14295 eggs 3976 20657 12206 14115 3899 $FDUWLDORQJLUHPLV CI 1475 CII 738 CVI-female 321 nauplii 2566 &DODQXVILQPDUFKLFXV CI 663 4426 6416 650 CII 3976 8853 1285 12832 650 CIII 5964 11066 5133 2599 CIV 5302 8853 13474 5848 CV 9278 5164 642 14757 3899 CVI-female 1325 642 &DODQXVJODFLDOLV CI 663 1925 CII 663 CIII 1988 2213 642 650 CIV 1325 642 2599 CV 1325 5774 2599 &DODQXVK\SHUERUHXV CI 650 CII 642 CIII 1988 1283 CIV 1325 738 7058 3249 CV 738 1283 &DODQXV sp.nauplii 12591 11066 1927 5774 650 &HQWURSDJHVKDPDWXV nauplii 642 0HWULGLDORQJD CIII 650 CVI-female 663 0LFURFDODQXVSXVLOOXV CI 1283 CIII 1283 CVI-female 5133 CVI-male 1283 nauplii 1325 0LFURVHWHOODQRUYHJLFD CI-VI 9278 28772 7067 10266 33789 nauplii 738 6424 10266 31190 2LWKRQDVLPLOLV CI 13254 14755 16703 14115 10397 CII 19881 14755 7709 7699 9097 CIII 10603 8853 2570 6416 6498 CIV 13254 5902 5782 6416 12996 CV 38436 16230 10279 14115 11696 CVI-female 21206 11804 8351 11549 12996 CVI-male 2651 4426 1285 1283 2599 nauplii 249171 156402 71309 137301 72777 2QFDHDERUHDOLV CVI-female 1325 2951 1285 3850 1949 CVI-male 5964 3689 1927 6416 2599 CI-5 1988 738 1285 6416 3VHXGRFDODQXVHORQJDWXV CI 663 642 CIII 1325 CIV 1325 1283 1300 CV 663 1475 3208 1300 CVI-female 650 CVI-male 642 Continued..... 48 Table 1k (continued). Abundance of zooplankton categories (ind. m-2) at sampling stations, Transect 5, July 2000 (Pump, 50µm net). 3VHXGRFDODQXVHORQJDWXV CVI-male 683 CI 1397 331 CII 629 CIV 629 CV 301 CVI-female 659 3VHXGRFDODQXVPLQXWXV CI 1397 1025 659 CII 683 659 CIII 342 CIV 629 1397 CV 1886 4192 1025 301 3VHXGRFDODQXV sp.nauplii 4401 1397 683 3954 301 6FROHFLWKULFHOOD sp. CVI-female 659 Station no. 123456 Zooplankton category Stage\Depth (m) 200-0 155-0 185-0 200-0 90-0 35-0 Station no. 123456 Zooplankton category Stage\Depth (m) 200-0 155-0 185-0 200-0 90-0 35-0 $JODQWKDGLJLWDOH 21 Amphipoda 21 Bivalvia larvae 13833 18165 36218 1318 2979 15648 Chaetognatha (6DJLWWD sp.) 330 &LUULSHGLDFLSULV 5030 1397 342 1318 2648 40473 Decapoda larvae 21 Echinodermata larvae 5659 32138 2733 1977 993 301 Euphausidae eggs 2515 1397 659 903 larvae 1258 2795 342 Gastropoda larvae 71678 67070 2392 1324 3310 Pteropoda (/LPDFLQD sp.) 44 1367 659 703 Hydromedusae 629 1397 662 Hydrozoa actinula 1397 903 Isopoda 342 2LNRSOHXUD sp. 1258 1397 683 1977 1986 Polychaetalarvae 9431 11178 1708 1977 1204 Rotatoria 3912 Protozoa (Tintinnidae) 1886 659 662 903 49 Table 1l. Abundance of zooplankton categories (ind. m-2) at sampling stations, Transect 6, July 2000 (WP2, 50µm net). Station no. 12345 Zooplankton category Stage\Depth (m) 100-0 100-0 100-0 40-0 50-0 Copepoda egg sacks 7244 6338 13129 14487 eggs 3622 28974 3622 nauplii 5433 spermato 23541 $FDUWLDORQJLUHPLV CIII 453 CVI-female 3622 nauplii 905 3622 &DODQXVILQPDUFKLFXV CI 453 2264 1811 CII 905 1811 1358 1811 CIII 4527 2716 1811 1811 CIV 3622 4074 1811 CV 13582 4074 1811 3622 10865 &DODQXVJODFLDOLV CI 453 453 CII 905 905 453 CIII 2716 2716 453 CIV 1811 905 905 1811 1811 CV 3622 2264 4980 1811 3622 &DODQXVK\SHUERUHXV CV 1811 &DODQXV sp.nauplii 7244 0LFURFDODQXVSXVLOOXV CI 905 CV 453 nauplii 2264 3622 0LFURVHWHOODQRUYHJLFD CI-VI 9054 10413 6791 14487 9054 nauplii 8602 2LWKRQDVLPLOLV CI 8149 4527 12223 3622 5433 CII 16298 6338 10865 10865 5433 CIII 13582 4074 11318 5433 7244 CIV 17203 7244 15393 3622 3622 CV 18109 11318 20825 9054 5433 CVI-female 4527 9960 11771 18109 12676 CVI-male 1811 1811 1358 1811 2LWKRQD sp. nauplii 149398 78773 51157 170223 81490 2LWKRQDVSLQLURVWULV CVI-female 2716 2QFDHDERUHDOLV CI-5 4527 905 1811 CVI-male 905 3OHXURPDPPDUREXVWD CI 1811 3VHXGRFDODQXV spp. CI 453 3622 3622 CII 905 5433 CIII 1811 5433 CIV 5433 7244 CV 1811 905 7244 3622 CVI-female 905 10865 CVI-male 453 nauplii 2716 16298 12676 Appendicularia 2264 5433 Bivalvia larvae 6338 24900 15845 153925 251713 Chaetognatha ((XNURKQLDKDPDWD )28 28 &LUULSHGLDFLSULV larvae 4527 453 1811 nauplii 1358 39839 9054 Continued..... 50 Decapoda larvae 1811 Echinodermata larvae 8149 2264 1811 Euphausidae larvae 2716 )ULWLOODULDERUHDOLV 905 2264 7244 10865 2LNRSOHXUD sp. 3622 8602 4980 12676 14487 Gastropoda larvae 44367 21731 10865 43461 18109 /LPDFLQDKHOLFLQD 113 1811 Hydromedusae 905 905 Mysidacea 1811 Polychaeta larvae 1811 2264 453 Scyphomedusae 905 Station no. 12345 Zooplankton category Stage\Depth (m) 100-0 100-0 100-0 40-0 50-0 Table 1l (continued). Abundance of zooplankton categories (ind. m-2) at sampling stations, Transect 6, July 2000 (WP2, 50µm net). 51 Table 2a. Abundance of zooplankton categories (ind. m-3) at sampling stations, fjord and coast, May 2000 (Pump, 50µm net). Station no. 1234 56 Zooplankton category Stage\Depth (m) 30-0 60-30 100-60 30-0 60-30 100-60 30-0 60-30 100-60 60-30 100-60 30-0 60-30 100-60 30-0 60-30 100-60 Copepoda egg sacks 218 492 901 14 109 41 14 102 41 92 82 55 410 eggs 1584 519 2622 833 1625 2704 1147 2622 1147 533 594 150 133 1557 41 Acartia longiremis CI 82 CVI-female 55 14 27 55 CVI-male nauplii 164 82 109 205 737 218 1475 819 137 82 300 109 82 Calanus finmarchicus CI 1 3 1 1 4 1 36333719 CII 1 3 3 1 2 7 3 6 CIII 1 1 3 2 1 1 1 1 3 CIV CV 1 2 CVI-female 1 CVI-male 1 Calanus glacialis CI 755111079584661251145 CII 199 4 16333 23312 CIII 1 3 6 4 1 1 1 1 3 CIV 1 CV 1 CVI-female 1 Calanus hyperboreus CI 375 233952 431219 CII 1 3 22 2 3 1 4 12 7 12 3 12 9 CIII 121 614311 Calanus sp. nauplii 191 82 573 41 68 246 137 382 205 150 123 55 102 246 109 82 Metridia longa. CV 2 CVI-female 1 3 164 Microcalanus pusillus CI CV CVI-female 55 41 14 nauplii 27 20 41 492 382 205 82 51 246 82 Microsetella norvegica CI-VI 1338 737 3113 89 68 410 601 710 451 218 225 246 451 1147 27 328 328 CI-VI Oithona similis CI 7 27 CII 14 14 20 CIII 55 27 14 CIV 27 20 82 27 CV 27 82 27 27 14 27 31 246 CVI-female 137 218 655 14 82 27 164 82 41 20 96 41 410 109 164 CVI-male 55 218 737 27 27 14 52 Table 2a (continued). Abundance of zooplankton categories (ind. m ) at sampling stations, fjord and coast, May 2000 (Pump, 50µm net). Station no. 1234 56 Zooplankton category Stage\Depth (m) 30-0 60-30 100-60 30-0 60-30 100-60 30-0 60-30 100-60 60-30 100-60 30-0 60-30 100-60 30-0 60-30 100-60 Oithona sp.nauplii 137 61 246 1311 82 655 369 266 451 461 2212 696 382 655 Oithona spiniros. CVI-female Oncaea borealis CI-V 137 328 82 218 41 14 61 297 164 CVI-female 20 410 CVI-male 1274155154 328 27 55 Pseudocalanus elongatus CVI-female Pseudocalanus minutus CI 246 628 492 27 82 205 82 328 55 CII 819 1038 2785 82 41 55 31 246 82 CIII 82 20 27 CIV 55 355 246 27 CV 27 27 82 14 CVI-female 27 82 41 27 246 82 CVI-male 1 82 Pseudocalanus sp.nauplii 1420 983 1720 533 1720 3113 1994 1912 1475 1147 1086 1283 1352 3605 806 546 328 Station no. 1234 56 Zooplankton category Stage\Depth (m) 30-0 60-30 100-60 30-0 60-30 100-60 30-0 60-30 100-60 60-30 100-60 30-0 60-30 100-60 30-0 60-30 100-60 Bivalvia larvae 2048 10623 10241 676 983 11224 5134 9722 3932 2581 4875 2294 860 9995 2198 6882 5079 Chaetognatha (Eukrohnia hamata )10 2 Cirripedia cipris nauplii2782259 1393 683 109 1024 396 533 314 236 164 1898 7155 3236 Decapoda larvae 4 2 1 1 5 2 5 2 3 2 1 2 5 3 Echinodermata larvae 164 300 328 171 314 492 164 492 492 109 102 137 51 328 96 82 Euphausidae eggs 218 137 82 48 96 164 191 164 82 150 82 109 41 273 164 nauplii 191 55 164 164 218 164 164 102 27 larvae 11 1 Fritillaria borealis 27 164 Gastropoda larvae 27 109 Hydromedusae 1 Hyperiidae 2 11 Oikopleura sp. 82 Ostracoda (Concoecia spin. )1 Pisces eggs 1 Polychaeta larvae 27 27 7 27 573 164 109 205 96 61 68 396 492 82 Protozoa (Tintinnidae) 55 55 61 164 -3 53 Table 2b. Abundance of zooplankton categories (ind. m-3) at sampling stations,Transect 1, May 2000 (Pump, 50µm net). Station no. 12345 6 Zooplankton category Stage\Depth (m) 50-0 100-50 200-10 0 60-0 30-0 60-0 100-0 50-0 100-0 Copepoda egg sacks 41 176 176 176 369 131 171 eggs 29362 3146 328 703 264 11594 2161 1180 619 $FDUWLDORQJLUHPLV CI 88 CVI-female 88 nauplii 88 1932 262 277 %UDG\LGLVLPLOLV CVI-female 1 &DODQXVILQPDUFKLFXV CI 60 70 1 40 104 24 14 16 4 CII 3 15 137 2185 CIII 16 1 1 3 3 10 3 CIV 5 CV 1 2 CVI-female 46 7 1 4 7 &DODQXVJODFLDOLV CI 110 228 3 37 158 32 20 47 21 CII 12 9 8 131910124526 CIII 31 1 3 3 7 6 18 13 CIV 29 4 2 2 CV 1 122 CVI-female 4 &DODQXVK\SHUERUHXV CI 52 25 4 10471311 6 8 CII 56 34 1 33 30 28 34 63 45 CIII 30 6 0 6 10 7 8 2 CV 15 38 &DODQXV sp. nauplii 1049 1311 220 2547 1054 158 197 0HWULGLDORQJD CIII 1 CVI-male 0 13 0LFURFDODQXVSXVLOOXV CII 41 26 CV 74 33 CVI-female 262 49 53 13 CVI-male 16 53 13 nauplii 262 320 33 26 0LFURVHWHOODQRUYHJLFD CI-VI 25 229 CI-VI 44 176 351 211 92 nauplii 88 2LWKRQDVLPLOLV CI 90 88 264 527 105 13 CII 262 8 40 CIII 44 33 13 CV 262 176 33 26 CVI-female 1049 524 16 132 351 351 211 328 158 CVI-male 262 448817653 98 92 2LWKRQD sp. nauplii 5243 2097 533 615 176 2459 422 66 105 2LWKRQDVSLQLURV CVI-female 16 CVI-male 16 2QFDHDERUHDOLV CI-V 49 44 211 13 3VHXGRFDODQXVHORQJDWXV CVI-female 3VHXGRFDODQXVPLQXWXV CI 44 CII 13 CIII 13 CVI-female 262 13 3 VHXGRFDODQXV sp.nauplii 22022 6816 295 1098 2196 9135 1739 950 711 Bivalvia larvae 4195 1311 33 5007 7554 12999 7852 2556 1502 Chaetognatha ( ( XNURKQLDKDPDWD )1 &LUULSHGLDFLSULV nauplii 262 132 878 527 316 786 540 Decapoda larvae 1 1 2 54 Echinodermata larvae 262 8 88 211 Euphausidae eggs 1049 44 878 295 211 nauplii 703 66 66 larvae 4 1 1 )ULWLOODULDERUHDOLV 176 88 105 98 13 Gastropoda larvae 1049 8 132 176 1054 66 Hyperiidae 8 1 0 2 2LNRSOHXUD sp. 33 Ostracoda (&RQFRHFLDHOHJDQV ) (XFKDHWDQRUYHJLD CIII 2 CIV 1 Polychaeta larvae 16 176 262 53 Protozoa (Tintinnidae) 33 Station no. 123456 Zooplankton category Stage\Depth (m) 50-0 100-50 200-10 0 60-0 30-0 60-0 100-0 50-0 100-0 Table 2b (continued). Abundance of zooplankton categories (ind. m-3) at sampling stations,Transect 1, May 2000 (Pump, 50µm net). 55 Table 2c. Abundance of zooplankton categories (ind. m-3) at sampling stations, Transect 3, May 2000 (Pump, 50µm net). Station no. 12345 Zooplankton category Stage\Depth (m) 50-0 100-50 50-0 100-50 50-0 100-50 45-0 50-0 100-50 Copepoda egg sacks 262 524 557 234 524 197 eggs 9438 2359 2884 3670 9438 229 234 6292 786 $FDUWLDORQJLUHPLV CVI-male 262 nauplii &DODQXVILQPDUFKLFXV CI 121 88 35 36 22 16 7 6 9 CII 41 23 6 19 5 8 15 8 1 CIII 6 31 4 16 8 1 0 15 2 CIV CV 18 9 5 CVI-female 96 49 12 7 1 6 17 15 CVI-male &DODQXVJODFLDOLV CI 188 186 57 90 34 25 66 14 6 CII 45 51 28 35 12 9 9 39 1 CIII 51 35 5 8 17 2 7 18 5 CIV 8 2 24 3 CV CVI-female 4 &DODQXVK\SHUERUHXV CI 115 25 16 11 4 1 5 6 1 CII 158 96 20 25 15 5 1 15 4 CIII 23 33 1 15 5 14 22 18 CV 1 1 7 &DODQXV sp.nauplii 4195 3146 6554 1049 3670 262 1171 (XFKDHWDQRUYHJLD CIII CVI-female 0LFURFDODQXVSXVLOOXV CI CII CIII CIV CV 66 197 CVI-female 262 98 147 CVI-male 49 0LFURFDODQXVS\JPDHXV CVI-female 33 0 LFURFDODQXV sp. nauplii 524 262 524 262 0LFURVHWHOODQRUYHJLFD CI-VI 1049 1049 786 524 197 786 82 CI-VI 468 2LWKRQDVLPLOLV CI 262 262 262 33 CII 234 CV 262 524 66 CVI-female 786 262 786 524 164 234 524 CVI-male 1049 262 33 234 180 2LWKRQD sp  nauplii 2097 3932 786 524 1049 524 1874 1049 328 2LWKRQDVSLQLURV CVI-female 229 2QFDHDERUHDOLV CI-V 262 262 131 3VHXGRFDODQXVHORQJDWXV CVI-female 3VHXGRFDODQXVPLQXWXV CI 262 CV 234 CVI-female 1049 262 98 524 3VHXGRFDODQXV sp.nauplii 18876 12846 8651 3408 1573 1278 6792 3146 475 Bivalvia larvae 1573 2359 34605 4981 14288 17565 737 &LUULSHGLDFLSULV nauplii 262 524 1311 Echinodermata larvae 234 262 Euphausidae eggs 262 1344 5505 610 nauplii 786 524 2342 262 larvae 4 )ULWLOODULDERUHDOLV 1049 1049 524 468 524 Gastropoda larvae 262 Hyperiidae Polychaeta larvae 234 56 Table 2d. Abundance of zooplankton categories (ind. m-3) at sampling stations, Davis Strait, May 2000 (Pump, 50µm net). Station no. D1 D2 Zooplankton category Stage\Depth (m) 100-0 200-100 100-0 200-100 Copepoda egg sacks 211 139 211 115 eggs 1897 107 2740 786 &DODQXVILQPDUFKLFXV CI 61 3 97 5 CII 10 1 63 0 CIII 3 0 8 CIV 3 CV 2 2 CVI-female 14 1 5 &DODQXVJODFLDOLV CI 90 4 227 6 CII 23 2 51 1 CIII 3 0 15 0 CIV 10 1 CV 0 &DODQXVK\SHUERUHXV CI 13 2 64 5 CII 14 102 1 CIII 17 1 21 4 CV 4 2 CVI-female 0 &DODQXV sp. nauplii 1476 3162 66 0HWULGLDORQJD CIII 3 CIV 1 CV 66 CVI-female 211 82 CVI-male 1 0LFURFDODQXVSXVLOOXV CII 74 CIII 211 211 CIV 66 CV 57 49 CVI-female 123 211 16 nauplii 721 422 180 0LFURVHWHOODQRUYHJLFD CI-VI 211 164 2LWKRQDVLPLOLV CI 211 422 CII 82 CIII 211 CIV 57 CV 131 CVI-female 74 nauplii 843 582 843 705 2LWKRQDVSLQLURV CVI-female 211 41 82 2QFDHDERUHDOLV CI-V 211 66 3VHXGRFDODQXVPLQXWXV CVI-female 57 66 CVI-male 41 3VHXGRFDODQXV sp.nauplii 3162 229 11172 475 6FROHFLWKULFHOOD sp. CV 49 CVI-female 8 211 (XFKDHWDQRUYHJLD CII 5 CIII 3 37 CIV 8 Bivalvia larvae 422 188 632 66 Chaetognatha ((XNURKQLDKDPDWD )4 G 57 &LUULSHGLDFLSULV nauplii 211 82 Cyclopoida CVI-female 2 33 Echinode larvae 41 49 Euphausidae nauplii 632 66 larvae 211 82 )ULWLOODULDERUHDOLV 422 211 Hydromedusae 3 Hyperiidae 49 Ostracoda (&RQFRHFLDHOHJDQV )4 Ostracoda 2 3 Station no. D1 D2 Zooplankton category Stage\Depth (m) 100-0 200-100 100-0 200-100 Table 2d (continued). Abundance of zooplankton categories (ind. m-3) at sampling stations, Davis Strait, May 2000 (Pump, 50µm net).