CHUKCHI SEA ENVIRONMENTAL STUDIES PROGRAM 2008–2014:
BENTHIC ECOLOGY OF THE NORTHEASTERN CHUKCHI SEA
Prepared for
ConocoPhillips Company P.O. Box 100360 Anchorage, AK 99510-0360
and
Shell Exploration & Production Company 3601 C Street, Suite 1000
Anchorage, AK 99503
FINAL REPORT
Prepared by
Arny L. Blanchard
Institute of Marine Science University of Alaska Fairbanks
Fairbanks, AK 99775-7220
3
BENTHIC ECOLOGY 2008–2014:
Macrofaunal Community Structure in the northeastern Chukchi Sea
INTRODUCTION
Resources in the Chukchi Sea are of great importance to a broad variety of stakeholders, and there is renewed interest in understanding the Chukchi Sea’s environmental and biological characteristics. The heightened interest and need to understand ecosystem variability and functions has led to a number of ecosystem studies since 2007. Biological resources of primary interest include marine mammals and seabirds, and both groups include species that depend on sediment-dwelling organisms such as polychaete worms, amphipods, clams, shrimp, and crabs (Aerts et al., 2013; Blanchard et al., 2013a, b; Day et al., 2013; Gall et al., 2013; Norcross et al., 2013; Dunton et al., 2014; Schonberg et al., 2014; Whitehouse et al., 2014). Because of the importance of benthic communities as prey for higher trophic level consumers, understanding the spatial and temporal dynamics of benthic communities also contributes to understanding population dynamics of the other resources of interest. Recent studies have demonstrated the environmental complexity of the Chukchi Sea and linkages of benthic communities with hydrographic characteristics (Feder et al., 1994, 2007; Blanchard, 2014; Blanchard and Feder, 2014; Grebmeier et al., 2015). With respect to understanding sources of variability, topographic control over water circulation may have the potential to drive ecosystem-level effects through linkages of circulation variations with benthic communities that may, in turn, influence benthic predators (Blanchard et al., 2013a; Blanchard, 2014).
Benthic fauna of the northeastern Chukchi Sea and the Chukchi Sea Environmental Studies Program (CSESP) study area are diverse, abundant, and representative of northern Pacific benthic assemblages found throughout the Bering and Chukchi seas (Feder et al., 1994, 2005, 2007, 2011; Blanchard et al., 2013a, b; Blanchard, 2014). Macrofauna (animals captured with a van Veen grab and retained on a 1.0-mm-mesh sieve) within the study area include all major groups found in Alaskan waters. Macrofaunal and biomass and density of the CSESP study area are numerically dominated by polychaetes and bivalves offshore and suspension-feeding organisms such as amphipods and sand dollars nearshore (Feder et al., 1994; Blanchard et al., 2013a). Megafauna (larger benthic fauna captured in trawls and by video) are also numerous, with brittle stars, sea stars, and crabs being key members of this ecosystem component (Feder et al., 1994a; Bluhm et
4
al., 2009; Blanchard et al., 2013b; Ravelo et al., 2014). Meiofauna (very small animals passing through a 0.5-mm mesh sieve but retained on a 0.064-mm sieve) are poorly known. The most abundant permanent meiofauna are nematodes and foraminiferans, and juvenile bivalves and polychaetes are the most abundant temporary meiofauna (Hajduk, 2015). Preliminary analyses demonstrated little meiofaunal community structure, but their biomass does contribute to the carbon budget for the region. The high density and biomass of benthic fauna in the CSESP study area indicate that a large amount of seasonal production is reaching the benthos, although advected carbon from southern waters appears to be a large subsidy to locally-produced carbon (Feder et al., 1994; Dunton et al., 2005; McTigue and Dunton, 2014; Tu et al., 2015). The distributions of macrofauna appear to be spatially and temporally stable (Feder et al., 1994; Blanchard et al., 2013a; Blanchard, 2014; Blanchard and Feder, 2014), suggesting that the high interannual variability noted in the CSESP study area in 2008–2013 (Blanchard and Knowlton, 2014) presumably reflects natural ecosystem dynamics at high latitudes in the presence of ecosystem changes (Grebmeier, 2012; Frey et al., 2014; Wang et al., 2014). Sources of temporal variability may include effects from climatic factors such those indicated by sea level pressure changes in the Arctic Ocean (the Arctic Oscillation; AO; Coyle et al., 2007b; Blanchard et al., 2010; Blanchard, 2014).
It is not yet understood how the AO might influence benthic communities in the Chukchi Sea or how strong effects are. Nevertheless, regional-scale oceanographic changes elsewhere associated with climate variations (the Pacific Decadal Oscillation; PDO) are known to strongly influence benthic communities (Cloern et al., 2010). Based on associations of benthic density and richness with the PDO in Port Valdez, a subarctic glacial fjord in Alaska, (Blanchard et al., 2010), the association of benthic community characteristics with the AO in the Chukchi Sea should be expected (Coyle et al., 2007a, b; Blanchard, 2014; Grebmeier et al., 2015), particularly since greater than 30% of the species in the Chukchi Sea macrobenthic species list for the CSESP are shared between the two areas (Blanchard, 2014). Although covariance of benthic community parameters with the AO likely reflects interannual variations in water circulation, pathways for effects and their strengths need to be determined.
Investigations of carbon cycling in the Chukchi Sea demonstrate strong linkages between primary production and distributions of invertebrate fauna. The shallow water and non-synchronous timing of primary production and pelagic (water-column) grazing results in a large
5
flux of uneaten phytoplankton to the benthos and thus, to an abundant, biomass-rich, and diverse macrofaunal community (Dunton et al., 2005; Grebmeier et al., 2006; McTigue and Dunton, 2014). Consequently, interannual variability in primary production and zooplankton communities (Questel et al., 2013) may be an important source of temporal variability for benthic communities. Production by ice algae also contributes to the annual carbon budget for invertebrate communities in arctic waters, but its ecological importance needs to be established for the Chukchi Sea (Ambrose et al., 2001, 2005; Tu et al., 2015). Thus, as a covariate with climatic and oceanographic variations, the influence of interannual variability in production may contribute indirectly to population dynamics of higher-trophic-level predators dependent on benthic resources. Pelagic-benthic coupling in the Chukchi Sea may rely on advective processes, rather than local production and sinking, as the strong northward flow of water entrains particulate carbon. Thus, exports of carbon from the Bering to the Chukchi Sea are critical, but details remain poorly known (Dunton et al., 2005; Grebmeier et al., 2006).
The 2008–2014 CSESP was a multi-disciplinary, environmental study investigating ecological conditions in the northeastern Chukchi Sea prior to oil and gas exploration. The overall research program provides information on trends in physical, chemical, and biological (including zooplankton and benthic ecology) oceanographic attributes and the acoustic environment of the Klondike, Burger, and Statoil study areas and surrounding environments. This seven-year investigation in the northeastern Chukchi Sea contributes to benchmarks for determining potential changes in the benthos due to environmental fluctuations. CSESP studies have documented the species present, species interactions, environmental and biological complexity, and temporal variations of benthic fauna in the study area (Aerts et al., 2013; Blanchard et al., 2013a, b; Day et al., 2013; Gall et al., 2013; Hannay et al., 2013; Norcross et al., 2013; Questel et al., 2013; Weingartner et al., 2013). The CSESP also contributes to building baseline databases adequate for evaluating, with confidence, long-term trends (e.g., repeated sampling at similar locations over space and time while using similar sampling methods) in macrofaunal communities of the northeast Chukchi Sea.
The broad objective of the benthic ecology component of the CSESP in 2014 was to document species composition, density, and biomass of macrofaunal communities in both nearshore and offshore habitats, and to determine associations of communities with environmental characteristics. Specifically, the 2014 study was designed to determine macrobenthic community
6
structure, sediment grain-size characteristics, isotope composition, and organic carbon concentrations in an expanded study area so that we could describe biological and environmental gradients from nearshore to offshore.
STUDY AREA AND ENVIRONMENTAL SETTING
The Chukchi Sea is a shallow body of water influenced by seasonal ice cover and by advection of southern waters derived from the Pacific Ocean entering the Arctic Ocean through Bering Strait (Weingartner et al., 2005). Feder et al. (1994) discussed in detail relevant oceanographic characteristics influencing benthic fauna. Briefly, water-masses moving into the region from the south include Anadyr Water, Bering Shelf Water, and Alaskan Coastal Water (Coachman, 1986; Weingartner et al., 2005). The northward current flow is derived from differences in sea-level height between the Pacific and Arctic oceans. This water of Pacific origin transits the Chukchi Shelf, exiting into the Arctic Ocean through Herald Valley, the Central Channel, and Barrow Canyon. Topographic variations interacting with water-masses split the northward flow into the Herald Valley, Central Channel, and Alaska Coastal branches. Interactions between topography and water currents result in complex circulation patterns around Hanna and Herald shoals (Martin and Drucker, 1997; Winsor and Chapman, 2004; Spall, 2007), both of which are prominent topographic features of the northern Chukchi Sea seafloor.
These water-masses from the south advect heat, nutrients, zooplankton, and larvae of benthic fauna into the region, contributing to the ecological characteristics of the Chukchi Sea. The shallow waters of the northeastern Chukchi Shelf (~35–45 m) prevent the establishment of in situ communities of large copepod grazers, so they must be advected to the area from the south. The resulting seasonal offset between robust seasonal primary production and the arrival and development of the zooplankton community allows much of this production to fall to the seafloor unconsumed, supporting very abundant and biomass-rich benthic assemblages (Grebmeier et al., 2006). Advection of production in nutrient-rich Bering Sea waters from the south mixed with Anadyr Water enhances secondary production in this northern region (Feder et al., 1994). In contrast, the Alaska Coastal Water (ACW) that is advected northward along the Alaska coastline is considered to be nutrient-poor, although significant benthic production occurs in sediments underneath this water-mass. Factors identified as important predictors of benthic community structure in the Chukchi Sea include sediment granulometry (e.g., percent gravel, sand, or mud)
7
and the ratio of sediment organic carbon to nitrogen (Feder et al., 1994). As a predictor, sediment granulometry is a proxy for a number of environmental features and processes, such as seafloor topography, hydrodynamics (e.g., strong currents, storm effects, ice gouging), sediment deposition, and proximity to sediment sources. Topographic control over water circulation may be a key source for spatial variations of macrofaunal communities as circulation divergences can result in greater food availability via increased deposition for deposit-feeders or within the water-column for suspension feeders (Blanchard et al., 2013a).
The CSESP study area lies 100–200 km west of the village of Wainwright, Alaska, on the northwestern coast of Alaska along the northeastern Chukchi Sea. Biological and environmental characteristics change sharply over small distances due to topography/hydrography interactions (Blanchard et al., 2013a, b; Weingartner et al., 2013). Klondike lies along a channel of northward-flowing water (called the Central Channel) and has coarse sediments, whereas Burger is an area of sluggish currents with muddy sediments. Cold, saline winter water remains longer in Burger than in Klondike, reflecting complex water movement in the former area. The persistence of the cold winter water increases stratification that helps to maintain conditions favorable for seasonal production to continue. The slow water circulation contributes to increased stratification and increased flux of carbon to the seafloor in Burger, resulting in a hotspots of biological production (Blanchard et al., 2013a, b; Blanchard and Feder, 2014; Grebmeier et al., 2015).
METHODS
Macrofaunal Sampling Methods
Sampling for macrofauna with the van Veen grab in 2014 was performed at 47 stations from August 21 to September 23 during two cruises (WWW1403 and WWW1404) in the northeastern Chukchi Sea (Fig. 1, Table 1). Macrofauna were sampled using a double van Veen grab with two 0.1-m2 adjoining grabs to collect sediments for analyzing sediment grain-size, sediment carbon concentrations, and macrofauna. Three replicate samples were collected at each station. Material collected was washed on a 1.0-mm stainless steel screen and animals preserved in a 10% formalin-seawater solution buffered with hexamine. In the laboratory, benthic organisms were identified to the lowest taxonomic resolution possible and were counted, and their wet weight was measured (protocol according to Feder et al, 1994). Sediment samples were also collected from van Veen grabs and sieved in the laboratory to determine the proportion of mud, sand, and
8
gravel (Wentworth, 1922). Sediment samples for carbon concentration were frozen aboard the ship and were processed at the Alaska Stable Isotope Facility at the University of Alaska, Fairbanks.
9
Table 1. Station information for benthic locations sampled during the 2014 CSESP survey. Intended positions (decimal-degree format). DF = DBO line station, KF = Klondike, BF = Burger, SF = Statoil, MF = nearshore station, and HS = Hanna Shoal South.
Cruise Station Latitude Longitude Cruise Station Latitude Longitude 1403 BF007 71.2416 -163.4087 1403 MF041 71.0751 -160.7329 1403 DF004 70.8424 -161.5430 1403 MF042 71.1900 -160.3211 1403 HS017 70.9846 -162.6649 1403 MF043 71.3041 -159.9042 1403 KF005 70.6481 -164.5003 1403 MF044 71.4172 -159.4821 1403 KF009 70.7732 -164.8751 1403 SF003 71.4956 -164.1720 1403 KF017 71.0213 -165.6389 1403 SF005 71.6215 -164.5610 1403 KF021 71.1441 -166.0280 1403 SF007 71.7465 -164.9554 1403 MF002 70.1402 -163.0479 1404 BF003 71.1135 -163.0342 1403 MF004 70.3956 -163.7651 1404 BF011 71.3690 -163.7879 1403 MF005 70.5222 -164.1304 1404 BF015 71.3526 -162.2312 1403 MF006 71.2660 -166.4217 1404 BF019 71.4824 -162.6047 1403 MF011 70.3796 -162.2843 1404 BF023 71.6113 -162.9829 1403 MF013 70.6380 -163.0002 1404 KF013 70.8976 -165.2546 1403 MF014 70.7661 -163.3651 1404 KF025 71.1462 -164.4876 1403 MF016 71.0201 -164.1090 1404 MF012 70.5091 -162.6400 1403 MF017 71.2711 -164.8722 1404 MF015 70.8935 -163.7347 1403 MF018 71.3955 -165.2612 1404 MF023 70.3884 -161.0416 1403 MF019 71.5190 -165.6552 1404 MF024 70.4622 -161.2354 1403 MF025 70.5938 -161.5857 1404 MF026 70.7247 -161.9405 1403 MF027 70.8550 -162.3003 1404 MF030 70.6266 -160.2645 1403 MF037 70.0242 -164.1507 1404 MF031 70.6935 -160.4372 1403 MF038 70.1487 -163.7699 1404 MF032 70.8267 -160.7862 1403 MF039 70.3887 -163.0221 1404 MF033 70.9592 -161.1402 1403 MF040 70.6272 -162.2571 Quality-assurance Procedures
The TigerObserver system, an integrated navigational and data-collection system, was developed for the CSESP program in 2009 to integrate data collection in the field with the ship’s navigation system in real time. This integration allows for geographic coordinates and oceanographic conditions to be linked with biological data and minimizes transcriptional errors between field notes and databases. Data managers onboard the vessel assisted scientists with onsite quality-control checks to minimize data-input errors. The TigerObserver system transcribed the data into a Microsoft® (MS) Access database. Raw datasheets from the field and laboratory are archived at the University of Alaska Fairbanks’s Institute of Marine Science (IMS).
10
Representative specimens of each taxon collected during the CSESP were archived at IMS. These voucher specimens provide records of identification of organisms sampled in the study. Although archived specimens may be sent to experts for further identification and/or verification, a complete collection will be maintained at IMS.
Quality-control procedures were followed in processing macrofaunal samples in the laboratory. The work of sorters was monitored throughout the project by a trained taxonomist. Once fully trained, a minimum of 10% of samples sorted by student employees were re-sorted to be certain that >95% of the organisms in each sample were removed. All of the work performed by junior taxonomists was checked and verified by a senior taxonomist, with verification tapering off as they approached the skill level expected for a more experienced taxonomist. Work was verified to ensure that all counts were accurate and that all organisms were correctly identified. Similar quality control procedures were applied to the weighing and data entry processes. Fauna identified in the 2008–2014 CSESP (Appendix I) were compared with the voucher collection from the 1986 investigation by Feder et al. (1994) and with current references (e.g., other benthic programs and our work in the same study area throughout the years) to ensure accuracy and consistency of identification, consistency among studies, and, to the best of our abilities, consistency with currently recognized taxonomic status. Original data forms and MS Access databases will be archived at IMS and delivered to OLF, in accordance with prescribed data management protocols. Taxonomic information was scrutinized for consistency as a further quality control check.
Statistical Methods
Trends in community composition were evaluated with both univariate and multivariate approaches. The design of the 2014 CSESP precludes comparisons among the Klondike, Burger, and Statoil study areas for benthic ecology, unlike in prior years. Too few stations were sampled in each study area to represent communities adequately or to compare to prior years’ data collections. The focus of the present study is on the broad-scale patterns of numerically dominant groups (amphipods, bivalves, echinoderms, polychaetes, and others) and between nearshore and offshore habitats. Nearshore stations are defined here as those under Alaska Coastal Water (ACW), and offshore stations are those under Bering Sea Water (BSW, including remnant winter water) in the summer. Descriptive summaries of the data provide insights into variability macrobenthos of
11
the study area and include average density, biomass, and number of taxa (sample number of taxa: average of replicates). Ecological diversity is represented by richness (total number of taxonomic categories identified). Canonical correspondence analysis (CCA) was used to test for associations between faunal community structure and environmental predictors. CCA is a direct-gradient-analysis tool that presents the portion of trend in the biological community associated with environmental regressors. The statistical program R and R library “vegan” were used for analyses (www.R-project.org). Data for all stations from the 2008–2014 CSESP studies (Fig. 2) were averaged for spatial analyses.
12
RESULTS
Environmental characteristics of the study area indicate coarser sediments nearshore and finer sediments offshore (Fig. 3). Percent sand increased and percent mud decreased with increasing distance to shore. The concentration of organic carbon in sediments increased offshore in association with increasing percent mud. The carbon stable isotope 13C was less negative offshore (indicative of marine carbon sources) and more negative nearshore (indicating terrestrial carbon sources).
13
Both benthic biomass and the density of macrofauna were higher nearshore, whereas carbon biomass was higher in many areas offshore, plus a few nearshore locations (Fig. 4). Biomass (g WW m–2) was high in the southwestern portion of the nearshore line, whereas density (ind. m–2) was highest in the northeastern portion of the line (line ML 6). Carbon biomass (g C m– 2) did not follow the same pattern as biomass, though it was higher nearshore with a peak at station ML041 along the ML 6 line.
Figure 4. Biomass (g WW m-2), carbon biomass (g C m-2), density (individuals m-2), and carbon biomass of amphipods in the CSESP study area, 2008–2014. The nearshore transect line ML 6 is indicated on the biomass map.
14
The carbon biomass of amphipods was high at a few nearshore locations (e.g., the 2009– 2010 mammal-feeding stations) but otherwise was low (Fig. 4). Dominant gammarid amphipods in the area of high biomass include the family Ampeliscidae (Ampelisca and Byblis) as well as
Protomedeia spp.
Bivalve carbon biomass was high offshore, with only one station of high biomass inshore, reflecting highly variable distributions (Fig. 5). Dominant bivalves in the CSESP study area include the small bivalves Ennucula tenuis and Nuculana pernula and the larger bivalves
Figure 5. Carbon biomass (g C m-2) of bivalves, echinoderms, polychaetes, and other fauna in the CSESP study area, 2008–2014. The nearshore transect line ML 6 is indicated on the bivalve-biomass map.
15
Astarte borealis, Cyclocardia crassidens, Macoma calcarea, and Serripes laperousii. The large bivalve Mya, a preferred prey of walrus, was rarely captured during the study period due to limitations of the van Veen grab.
The carbon biomass of echinoderms was high on the southwestern end of the nearshore line ML 6 (Fig. 5). The high carbon biomass nearshore reflected the high numbers of the sand dollar Echinarachnius parma, but other echinoderms in the study area included the brittle stars
Amphiodia craterodmeta, Ophiura maculata, and Ophiura sarsi; the sea cucumbers Cucumaria
spp., Ocnus glacialis, Psolus fabricii, and P. phantapus; and the sea urchin Strongylocentrotus droebachiensis.
Polychaete carbon biomass was high primarily offshore, although high carbon biomass also occurred on the northeastern end of the nearshore line ML 6 (Fig. 5). Dominant polychaetes over the study period include family Maldanidae (particularly Maldane sarsi), family Cirratulidae,
Galathowenia oculata, Nephtys spp. (N. brachycephala, N. paradoxa, N. caeca, and/or N. punctata), and Scoletoma spp.
Carbon biomass of other taxa was variable, but a high point occurred at station MF041 along the nearshore line ML 6, and was due to a high biomass of cnidarians (sea anemones and the soft coral Gersemia rubiformis; Fig. 5). Other numerically dominant benthic fauna in the study area included the crabs Chionoecetes opilio and Hyas coarctatus; the peanut worm Golfingia margaritacea; the urochordates Boltenia ovifera, Chelyosoma orientale, Styela rustica, and
Halocynthia aurantium; and in some areas, the echiuran (spoon worm) Echiurus echiurus alaskanus.
Multivariate ordination of the biological and environmental data was conducted with canonical correspondence analysis (CCA). CCA attempts to reduce or “map” data with many dimensions to two or three dimensions and then performs a regression using environmental predictors to generate a new data set, which become CCA axes that can be plotted and interpreted. CCA captures only that portion of structure in a biological data matrix directly associated with the regression predictor variables. The position of fauna or stations on the map represent the association with the regressors as well as with other fauna and stations. Two faunal groups that are positioned close together on the plot are interpreted as having a similar response to the environmental regressors, and two stations plotted close together are similar with respect to
16
environmental characteristics. The position of faunal groups and stations relative to the arrows for each environmental predictor variable also indicate associations with regressors. The length of an arrow for a predictor variable indicates the strength of correlation with the CCA axes, and the direction indicates which axis a variable is most highly correlated with.
The CCA of the CSESP biological data indicates strong associations with sediment grain-size characteristics and water depth. Percent sand and water depth are correlated with Axis 1 (-0.42 and 0.45; Fig. 6a), whereas percent gravel and sand are moderately correlated with Axis 2 (0.34 and 0.37). The spoon worm Echiura and sand dollars (Echar) are associated with shallow waters (the groups are positioned opposite from the arrow for depth); sea urchins (Ech) and isopods (Iso) are associated with deep waters and coarse sediments; chitons (Pla), sea cucumbers (Cukes), and sea squirts (Uro) are associated with gravel; and ostracods (Ostr) and sea stars (Ast) are associated with fine sediments, higher organic carbon, and marine carbon sources (opposite the arrow for % Sand and associated with OC). Offshore stations are deeper and have finer sediments, more OC, and less-negative 13C values (indicative of marine carbon sources) than nearshore stations do (Fig. 6b).
17
Figure 6. Canonical correspondence analysis of higher taxonomic orders of benthic fauna, 2008–2014. The ordination plots present the association of (a) faunal groups and (b) stations with environmental characteristics. Tables on the figure present faunal groups and their labels (bottom) and the correlations of environmental variables with axes (Fig. 6a, left).
18
DISCUSSION
Environmental gradients, oceanographic and geochemical characteristics, and biological communities of the northeastern Chukchi Sea are driven in part by interactions between seafloor geomorphology and water movements. Topographic control of water circulation plays a defining role for benthic community characteristics in particular. A portion of the Burger study area lays in a trough (a submerged watershed draining towards Barrow Canyon) to the south of Hanna Shoal. Weingartner et al. (2013) documented higher water temperature and salinity values in Klondike, southwest of Hanna Shoal than in Burger in 2008–2011, reflecting slower circulation and flows transporting winter water into Burger from the north. In association with deeper water depths and a persistence of winter water, the benthic macrofaunal community in Burger has higher density and biomass of benthic fauna than Klondike does, reflecting covariances with oceanographic conditions (Faulkner et al., 1994; Weingartner et al., 2005; Blanchard et al., 2013a, b; Weingartner et al., 2013; Blanchard and Feder, 2014). Feder et al. (1994) also noted high biomass at stations closest to what is now the Burger study area.
The broad covariance between biological and environmental characteristics is reflected in the changes in benthic community characteristics from nearshore to offshore habitats. Environmental/biological covariances reflect the processes controlling food (particulate organic carbon) quality, how that food is delivered (deposited vs. suspended), and the quantity of food that is available, rather than direct effects of covariates alone. Thus, the dominance of suspension-feeding animals nearshore indicates the presence of suspended carbon where currents are stronger, whereas the dominance of deposit-feeding organisms in muddy sediments reflects a covariance with carbon deposition. As in prior years, the current study demonstrates that spatially-structured benthic communities reflect the extensive environmental complexity in this region (Blanchard and Knowlton, 2013a, b; Blanchard et al., 2013a, b) and that, in general, sediment characteristics and water depth are the strongest predictors of community structure, in this case reflecting the control of seafloor topography over current flow.
High nutrient and particulate-organic-carbon (POC) loads in the BSW may increase secondary benthic production in the Chukchi Sea (Feder et al., 1994; Dunton et al., 2005). Based on apparent pelagic–benthic coupling, Grebmeier et al. (1988) proposed that lower benthic productivity and biomass occurred under the ACW (with the lower nutrient quality than the BSW), although Feder et al. (1994, 2005, 2007) found this pattern to be inconsistent. Feder suggested that
19
the mixing of water-masses and the advection of carbon northward may subsidize areas of high productivity in the Chukchi Sea. The high biomass of amphipods in marine-mammal feeding areas and the high carbon biomass of various groups nearshore in the present study also indicate high benthic productivity under ACW (Feder et al., 1994; Blanchard et al., 2013a; Blanchard and Feder, 2014; Schonberg et al., 2014; Grebmeier et al., 2015). The effect of increased water flow into marine canyons is an increase in the flow of POC past suspension feeders, enhancing benthic productivity, even underneath otherwise carbon-depleted waters (De Leo et al., 2010). Feder et al. (1994, 2005, 2007) identified additional sites where biomass and/or density were exceptionally high underneath the ACW; all were associated with topographic-driven variations in water-circulation. Several of these areas of high biomass under the ACW are associated with key vertebrate resources, including eiders and gray whales, indicating that regions affected by hydrographic features and changes (polynyas, convergences, canyons, etc.) are among the most highly significant marine habitats in the Chukchi Sea (Feder et al., 1994; Feder et al., 2007; Blanchard and Feder, 2014; Schonberg et al., 2014; Grebmeier et al., 2015) Tu et al. (2015) found that food webs in the offshore CSESP study areas were marine based, whereas Blanchard and Knowlton (2013b, 2014) found indications of terrestrial carbon sources nearshore, as in the present study. Overall, the substantial spatial differences in faunal communities indicate ecologically-significant variations in carbon sources, processes delivering food to benthic fauna, food webs, and ecosystem functioning.
ACKNOWLEDGMENTS
We thank ConocoPhillips Company and Shell Exploration & Production Co. for funding this study and providing the opportunity for conducting the research. The project was managed by Olgoonik Fairweather LLC. We thank the crews of the M/V Bluefin (2008) and M/V Westward Wind (2009–2014), the marine technicians, and Aldrich Offshore Services for assistance and logistic support as well as the students and research technicians who assisted with the project. Tama Rucker, Erin May, and Jessica Reitano assisted with laboratory processing of the 2014 samples, and Sioned Sitkiewicz and Ann Knowlton led the field-sampling teams.
20
REFERENCES
Aerts, L.A.M., McFarland, A.E., Watts, B.H., Lomac-MacNair, K.S., Seiser, P.E., Wisdom, S.S., Kirk, A.V., Schudel, C.A., 2013. Marine mammal distribution and abundance in an offshore sub-region of the northeastern Chukchi Sea during the open-water season. Continental Shelf Research 67, 116-126.
Ambrose, W.G., Clough, L.M., Tilney, P.R., Beer, L., 2001. Role of echinoderms in benthic remineralization in the Chukchi Sea. Marine Biology 139, 937-949.
Ambrose, W.G., Jr., von Quillfeldt, C., Clough, L.M., Tilney, P.V.R., Tucker, T., 2005. The sub-ice algal community in the Chukchi sea: large- and small-scale patterns of abundance based on images from a remotely operated vehicle. Polar Biology 28, 784-795.
Blanchard, A.L., 2014. Variability of macrobenthic diversity and distributions in Alaskan sub-Arctic and sub-Arctic marine systems with application to worldwide sub-Arctic Systems. Marine Biodiversity, 1-15.
Blanchard, A.L., Feder, H.M., 2014. Interactions of habitat complexity and environmental characteristics with macrobenthic community structure at multiple spatial scales in the northeastern Chukchi Sea. Deep Sea Research Part II: Topical Studies in Oceanography 102, 132-143.
Blanchard, A.L., Feder, H.M., Hoberg, M.K., 2010. Temporal variability of benthic communities in an Alaskan glacial fjord, 1971-2007. Marine Environmental Research 69, 95-107.
Blanchard, A.L., Knowlton, A.L., 2013a. Chukchi Sea Environmental Studies Program, 2008-2011: Benthic ecology of the northeastern Chukchi Sea. Final report to ConocoPhillips Co., Shell Expolration and Produiction Co. and Statoil USA E&P. Institute of Marine Science, University of Alaska Fairbanks Fairbanks, AK, p. 190.
Blanchard, A.L., Knowlton, A.L., 2013b. Chukchi Sea Environmental Studies Program, 2008-2012: Benthic ecology of the northeastern Chukchi Sea. Final report to ConocoPhillips Co., Shell Expolration and Produiction Co. and Statoil USA E&P. Institute of Marine Science, University of Alaska Fairbanks Fairbanks, AK, p. 143.
Blanchard, A.L., Knowlton, A.L., 2014. Chukchi Sea Environmental Studies Program, 2008-2013: Benthic ecology of the northeastern Chukchi Sea. Final report to ConocoPhillips Co., Shell Expolration and Produiction Co. and Statoil USA E&P. Institute of Marine Science, University of Alaska Fairbanks Fairbanks, AK, p. 52.
Blanchard, A.L., Parris, C.L., Knowlton, A.L., Wade, N.R., 2013a. Benthic ecology of the northeastern Chukchi Sea. Part I. Environmental characteristics and macrofaunal community structure, 2008–2010. Continental Shelf Research 67, 52-66.
Blanchard, A.L., Parris, C.L., Knowlton, A.L., Wade, N.R., 2013b. Benthic ecology of the northeastern Chukchi Sea. Part II. Spatial variation of megafaunal community structure, 2009–2010. Continental Shelf Research 67, 67-76.
Bluhm, B.A., Iken, K., Hardy, S.M., Sirenko, B.I., Holladay, B.A., 2009. Community structure of epibenthic megafauna in the Chukchi Sea. Aquatic Biology 7, 269-293.
Cloern, J.E., Hieb, K.A., Jacobson, T., Sansó, B., Di Lorenzo, E., Stacey, M.T., Largier, J.L., Meiring, W., Peterson, W.T., Powell, T.M., Winder, M., Jassby, A.D., 2010. Biological
21
communities in San Francisco Bay track large-scale climate forcing over the North Pacific. Geophysical Research Letters 37, L21602.
Coachman, L., 1986. Advection and mixing on the Bering–Chukchi Shelves. Component A. Advection and mixing of coastal water on high latitude shelves. ISHTAR, 1-42.
Coyle, K.O., Bluhm, B., Konar, B., Blanchard, A., Highsmith, R.C., 2007a. Amphipod prey of gray whales in the northern Bering Sea: Comparison of biomass and distribution between the 1980s and 2002–2003. Deep Sea Research Part II: Topical Studies in Oceanography 54, 2906-2918.
Coyle, K.O., Konar, B., Blanchard, A., Highsmith, R.C., Carroll, J., Carroll, M., Denisenko, S.G., Sirenko, B.I., 2007b. Potential effects of temperature on the benthic infaunal
community on the southeastern Bering Sea shelf: Possible impacts of climate change. Deep Sea Research Part II: Topical Studies in Oceanography 54, 2885-2905.
Day, R.H., Weingartner, T.J., Hopcroft, R.R., Aerts, L.A.M., Blanchard, A.L., Gall, A.E., Gallaway, B.J., Hannay, D.E., Holladay, B.A., Mathis, J.T., Norcross, B.L., Questel, J.M., Wisdom, S.S., 2013. The offshore northeastern Chukchi Sea, Alaska: A complex high-latitude ecosystem. Continental Shelf Research 67, 147-165.
De Leo, F.C., Smith, C.R., Rowden, A.A., Bowden, D.A., Clark, M.R., 2010. Submarine canyons: hotspots of benthic biomass and productivity in the deep sea. Proceedings of the Royal Society B: Biological Sciences 277, 2783-2792.
Dunton, K.H., Goodall, J.L., Schonberg, S.V., Grebmeier, J.M., Maidment, D.R., 2005. Multi-decadal synthesis of benthic-pelagic coupling in the western arctic: role of cross-shelf advective processes. Deep Sea Research Part II: Topical Studies in Oceanography 52, 3462-3477.
Dunton, K.H., Grebmeier, J.M., Trefry, J.H., 2014. The benthic ecosystem of the northeastern Chukchi Sea: An overview of its unique biogeochemical and biological characteristics. Deep Sea Research Part II: Topical Studies in Oceanography 102, 1-8.
Faulkner, K.K., MacDonald, R.W., Carmack, E.C., Weingartner, T., 1994. The potential of barium as a tracer of arctic water masses, in: Muench, R., Johannessen, O. (Eds.), The Polar Oceans and their Role in Shaping the Global Environment, Geophysical Monograph 85. American Geophysical Union, pp. 63-76.
Feder, H.M., Iken, K., Blanchard, A.L., Jewett, S.C., Schonberg, S., 2011. Benthic food web structure in the southeastern Chukchi Sea: an assessment using δ13C and δ15N analyses. Polar Biology 34, 521-532.
Feder, H.M., Jewett, S.C., Blanchard, A., 2005. Southeastern Chukchi Sea (Alaska) epibenthos. Polar Biology 28, 402-421.
Feder, H.M., Jewett, S.C., Blanchard, A.L., 2007. Southeastern Chukchi Sea (Alaska) macrobenthos. Polar Biology 30, 261-275.
Feder, H.M., Naidu, A.S., Jewett, S.C., Hameedi, J.M., Johnson, W.R., Whitledge, T.E., 1994. The northeastern Chukchi Sea: benthos-environmental interactions. Marine Ecology Progress Series 111, 171-190.
22
Frey, K.E., Maslanik, J.A., Kinney, J.C., Maslowski, W., 2014. Recent variability in sea ice cover, age, and thickness in the Pacific Arctic region, in: Grebmeier, J., Maslawski, W. (Eds.), The Pacific Arctic Region Ecosystem Status and Trends in a Rapidly Changing Environment. Springer, Dordrecht, pp. 31-63.
Gall, A.E., Day, R.H., Weingartner, T.J., 2013. Structure and variability of the marine-bird community in the northeastern Chukchi Sea. Continental Shelf Research 67, 96-115.
Grebmeier, J.M., 2012. Shifting patterns of life in the Pacific Arctic and sub-Arctic Seas. Annual Review of Marine Science 4, 63-78.
Grebmeier, J.M., Bluhm, B.A., Cooper, L.W., Danielson, S.L., Arrigo, K.R., Blanchard, A.L., Clarke, J.T., Day, R.H., Frey, K.E., Gradinger, R.R., Kędra, M., Konar, B., Kuletz, K.J., Lee, S.H., Lovvorn, J.R., Norcross, B.L., Okkonen, S.R., 2015. Ecosystem characteristics and processes facilitating persistent macrobenthic biomass hotspots and associated benthivory in the Pacific Arctic. Progress in Oceanography 136, 92-114.
Grebmeier, J.M., Cooper, L.W., Feder, H.M., Sirenko, B.I., 2006. Ecosystem dynamics of the Pacific-influenced Northern Bering and Chukchi seas in the Amerasian Arctic. Progress In Oceanography 71, 331-361.
Hajduk, M.M., 2015. Influence of complexity and disturbance on meiofauna in the northeastern Chukchi Sea, GPMSL. University of Alaska Fairbanks, Fairbanks, AK, p. 19.
Hannay, D.E., Delarue, J., Mouy, X., Martin, B.S., Leary, D., Oswald, J.N., Vallarta, J., 2013. Marine mammal acoustic detections in the northeastern Chukchi Sea, September 2007–July 2011. Continental Shelf Research 67, 127-146.
Martin, S., Drucker, R., 1997. The effect of possible Taylor columns on the summer ice retreat in the Chukchi Sea. Journal of Geophysical Research 102, 10473–10482.
McTigue, N.D., Dunton, K.H., 2014. Trophodynamics and organic matter assimilation pathways in the northeast Chukchi Sea, Alaska. Deep Sea Research Part II: Topical Studies in
Oceanography 102, 84-96.
Norcross, B.L., Raborn, S.W., Holladay, B.A., Gallaway, B.J., Crawford, S.T., Priest, J.T., Edenfield, L.E., Meyer, R., 2013. Northeastern Chukchi Sea demersal fishes and associated environmental characteristics, 2009–2010. Continental Shelf Research 67, 77-95.
Questel, J.M., Clarke, C., Hopcroft, R.R., 2013. Seasonal and interannual variation in the planktonic communities of the northeastern Chukchi Sea during the summer and early fall. Continental Shelf Research 67, 23-41.
Ravelo, A.M., Konar, B., Trefry, J.H., Grebmeier, J.M., 2014. Epibenthic community variability in the northeastern Chukchi Sea. Deep Sea Research Part II: Topical Studies in
Oceanography 102, 119-131.
Schonberg, S.V., Clarke, J.T., Dunton, K.H., 2014. Distribution, abundance, biomass and
diversity of benthic infauna in the Northeast Chukchi Sea, Alaska: Relation to environmental variables and marine mammals. Deep Sea Research Part II: Topical Studies in Oceanography 102, 144-163.
Spall, M.A., 2007. Circulation and water mass transformation in a model of the Chukchi Sea. Journal of Geophysical Research 112, doi:10.1029/2005JC002264.
23
Tu, K.L., Blanchard, A.L., Iken, K., Horstmann-Dehn, L., 2015. Small-scale spatial variability in benthic food webs in the northeastern Chukchi Sea. Marine Ecology Progress Series 528, 19-37.
Wang, J., Eicken, H., Yu, Y., Bai, X., Zhang, J., Hu, H., Wang, D.-R., Ikeda, M., Mizobata, K., Overland, J.E., 2014. Abrupt climate changes and emerging ice-ocean processes in the Pacific Arctic Region and the Bering Sea, in: Grebmeier, J., Maslawski, W. (Eds.), The Pacific Arctic Region Ecosystem Status and Trends in a Rapidly Changing Environment. Springer, Dordrecht, pp. 65-99.
Weingartner, T., Aagaard, K., Woodgate, R., Danielson, S., Sasaki, Y., Cavalieri, D., 2005. Circulation on the north central Chukchi Sea shelf. Deep Sea Research Part II: Topical Studies in Oceanography 52, 3150-3174.
Weingartner, T., Dobbins, E., Danielson, S., Winsor, P., Potter, R., Statscewich, H., 2013. Hydrographic variability over the northeastern Chukchi Sea shelf in summer-fall 2008–2010. Continental Shelf Research 67, 5-22.
Wentworth, C.K., 1922. A Scale of Grade and Class Terms for Clastic Sediments. Journal of Geology 30, 377-392.
Whitehouse, G.A., Aydin, K., Essington, T., Hunt, G., Jr., 2014. A trophic mass balance model of the eastern Chukchi Sea with comparisons to other high-latitude systems. Polar Biology 37, 911-939.
Winsor, P., Chapman, D.C., 2004. Pathways of Pacific water across the Chukchi Sea: A numerical model study. Journal of Geophysical Research: Oceans 109.
25
APPENDIX I
27 PORIFERA CNIDARIA HYDROZOA ANTHOZOA Actiniidae Edwardsiidae Edwardsia spp. Halcampoididae Haloclavidae Halcampidae Halcampa crypta Nephtheidae Gersemia rubiformis NEMERTEA ANNELIDA POLYCHAETA Polynoidae Bylgides sarsi Bylgides promamme Arcteobia anticostiensis Enipo canadensis Enipo chuckchi Enipo gracilis Enipo torelli Eunoe depressa Eunoe nodosa Eunoe oerstedi Eunoe clarki Gattyana amondseni Gattyana ciliata Gattyana cirrhosa Harmothoe beringiana Harmothoe extenuata Harmothoe imbricata Hesperonoe adventor Parahalosydna krassini Pholoidae/Sigalionidae Pholoe minuta Phyllodocidae Phyllodoce groenlandica Eteone flava Eteone longa Eteone pacifica Eteone spetsbergensis Hesionidae Nereimya aphroditoides
28 Syllidae Proceraea cornuta Typosyllis alternata Typosyllis pigmentata Exogone spp. Exogone naidina Nereidae Nereis spp. Nephtyidae Nephtys ciliata Nephtys caeca Nephtys punctata Nephtys longosetosa Nephtys paradoxa Sphaerodoridae Sphaerodorum papillifer Sphaerodoropsis minuta Sphaerodoropsis sphaerulifer Glyceridae Glycera capitata Goniadidae Glycinde wireni Onuphidae Paradiopatra parva Eunicidae Lumbrineridae Scoletoma spp. Scoletoma fragilis Arabellidae Drilonereis spp. Dorvilleidae Orbiniidae Scoloplos armiger Leitoscoloplos pugettensis Paraonidae Aricidea spp. Levinsenia gracilis Apistobranchidae Apistobranchus ornatus Spionidae Dipolydora spp. Polydora spp. Prionospio steenstrupi Spio cirrifera Spiophanes bombyx Pygospio elegans
29 Marenzelleria wireni Magelonidae Magelona longicornis Trochochaetidae Trochochaeta carica Trochochaeta multisetosa Chaetopteridae Phyllochaetopterus spp. Cirratulidae Cirratulus cirratus Chaetozone setosa Cossuridae Cossura pygodactylata Flabelligeridae Brada inhabilis Brada villosa Brada nuda Flabelligera affinis Flabelligera mastigophora Diplocirrus longisetosus Scalibregmatidae Scalibregma californicum Scalibregma inflatum Opheliidae Travisia forbesi Travisia pupa Ophelia limacina Ophelina groenlandica Ophelina acuminata Sternaspidae Sternaspis scutata Capitellidae Capitella capitata Heteromastus filiformis Notomastus latericeus Mediomastus spp. Barantolla americana Maldanidae Maldane sarsi Nicomache lumbricalis Petaloproctus borealis Petaloproctus tenuis Axiothella catenata Praxillella gracilis Praxillella praetermissa Rhodine bitorquata
30 Rhodine loveni Oweniidae Owenia fusiformis Myriochele heeri Galathowenia oculata Sabellariidae Idanthyrsus saxicavus Pectinariidae Pectinaria granulata Pectinaria hyperborea Ampharetidae Amage spp. Ampharete arctica Ampharete goesi Ampharete acutifrons Ampharete crassiseta Ampharete finmarchica Ampharete vega Lysippe labiata Asabellides sibirica Terebellidae Amphitrite cirrata Neoamphitrite groenlandica Nicolea zostericola Thelepus cincinnatus Thelepus setosus Artacama proboscidea Lanassa nordenskioldi Lanassa venusta venusta Lysilla loveni Axionice maculata Laphania boecki Proclea emmi Proclea graffii Trichobranchidae Terebellides kobei Terebellides reishi Terebellides stroemi Trichobranchus glacialis Sabellidae Chone infundibuliformes Chone duneri Chone magna Chone mollis Euchone analis Euchone incolor
31 Bispira crassicornis Laonome kroeyeri Parasabella media Serpulidae OLIGOCHAETA MOLLUSCA GASTROPODA Lepetidae Lepeta caeca Trochidae Margarites giganteus Margarites costalis Solariella obscura Solariella varicosa Turbinidae Moelleria costulata Rissoidae
Alvania spp. (possibly Frigidoalvania cruenta)
Cingula spp. Turritellidae Tachyrhynchus erosus Tachyrhynchus reticulatis Epitonidae Boreascala greenlandica Trichotropidae Trichotropis spp. Ariadnaria borealis Neoiphinoe kroyeri Neoiphinoe coronata Velutinidae Limneria undata Capulidae Naticidae Cryptonatica affinis Lunatia pallida Muricidae Boreotrophon clathratus Boreotrophon truncatus Nodulotrophon coronatus Buccinidae Aulacofusus brevicauda Aulacofusus herendeenii Buccinum plectrum Buccinum polare Colus herendeenii Colus hypolispus
32 Liomesus spp. Neptunea ventricosa Neptunea communis Neptunea borealis Neptunea heros Plicifusus kroeyeri Pyrulofusus deformis Retifusus roseus Volutopsius spp. Cancellariidae Admete solida Admete viridula Conidae (Mangelidae) Oenopota elegans Oenopota excurvatas Oenopota impressa Oenopota pyramidilis Obesotoma simplex Propebela turricula Propebela arctica Propebela nobilis Propebela pingelii Curtitoma incisula Curtitoma novajasemljensis Pyramidellidae Odostomia spp. Cylichnidae Cylichna occulta Cylichna alba Diaphanidae Diaphana minuta Haminoeidae Haminoea vesicula Retusidae Retusa obtusa Calyptraeidae Crepidula spp. NUDIBRANCHIA OPISTHOBRANCHIA POLYPLACOPHORA Leptochitonidae Leptochiton spp. Ischnochitonidae Stenosemus albus Mopaliidae
33 Amicula vestita BIVALVIA Nuculidae Ennucula tenuis Nuculanidae Nuculana pernula Nuculana minuta Yoldiidae Yoldia hyperborea Yoldia myalis Yoldia seminuda Portlandia spp. Mytilidae Crenella decussata Musculus niger Musculus discors Musculus glacialis Pectinidae Chlamys behringiana Lucinidae Parvilucina tenuisculpta Thyasiridae Adontorhina cyclia Axinopsida serricata Thyasira flexuosa Ungulinidae Diplodonta aleutica Lasaeidae Neaeromya compressa Mysella planata Kurtiella tumida Carditidae Cyclocardia crebricostata Cyclocardia crassidens Cyclocardia ovata Astartidae Astarte montagui Astarte borealis Cardiidae
Ciliatocardium ciliatum ciliatum Serripes groenlandicus Serripes laperousii Tellinidae Macoma calcarea Macoma brota Macoma moesta
34 Tellina bodegensis Veneridae Liocyma fluctuosa Nutricola lordi Myidae Mya arenaria Mya psuedoarenaria Mya truncata Hiatellidae Hiatella arctica Pandoridae Pandora glacialis Lyonsiidae Lyonsia arenosa Periplomatidae Periploma aleuticum Thraciidae Thracia spp. Lampeia adamsi ARTHROPODA PYCNOGONIDA CRUSTACEA Balanomorpha Balanidae Balanus crenatus Balanus glandula OSTRACODA CUMACEA Lampropidae Lamprops spp. Lamprops quadriplicata Leuconidae Leucon spp. Leucon nasica Eudorella emarginata Eudorella groenlandica Eudorellopsis integra Eudorellopsis biplicata Diastylidae Diastylis bidentata Diastylis paraspinulosa Diastylis sulcata Ektondiastylis robusta Nannastacidae Campylaspis papillata
35 Cumella spp. TANAIDACEA ISOPODA Antarcturidae Pleuroprion murdochi Idoteidae Synidotea bicuspida Synidotea muricata Tecticepidae Tecticeps alascensis Tecticeps c.f. renoculis Munnidae Munna spp. Paramunnidae Pleurogonium spinosissimum AMPHIPODA Odiidae Odius carinatus Ampeliscidae Ampelisca macrocephala Ampelisca birulai Ampelisca erythrorhabdota Ampelisca eschrichti Byblis gaimardi Byblis robusta Byblis frigidis Byblis pearcyi Byblis breviramas Haploops laevis Argissidae Argissa hamatipes Corophiidae Crassicorophium crassicorne Ischyroceridae Ericthonius spp. Dexaminidae Guernea nordenskioldi Eusiridae Eusirus cuspidatus Pontogeneia spp. Rhachotropis oculata Gammaridae Maera loveni Melita dentata Uniciolidae Uniciola leucopis
36 Haustoriidae Eohaustorius eous Pontoporeiidae Monoporeia affinis Pontoporeia femorata Priscillina armata Isaeidae Cheirimedeia spp. Photis spp. Photis vinogradovi Protomedeia spp. Ischyroceridae Ischyrocerus spp. Ischyrocerus latipes Lysianassidae Anonyx spp. Hippomedon spp. Guernea nordenskioldi Orchomene spp. Paratryphosites abyssi Uristidae Centromedon spp. Melphidippidae Oedicerotidae Aceroides latipes Bathymedon spp. Monoculodes spp. Westwoodilla caecula Epimeriidae Paramphithoe polyacantha Phoxocephalidae Harpiniopsis kobjakovae Harpiniopsis gurjanovae Harpiniopsis serrata Paraphoxus oculatus Grandifoxus acanthinus Grandifoxus vulpinus Grandifoxus nasuta Pleustidae Pleustes panoplus Pleustomesus medius Podoceridae Dyopedos arcticus Stenothoidae Synopiidae Syrrhoe crenulata
37 Tiron bioculata Caprellidae DECAPODA ANOMURA Lithodidae Paralithodes platypus Oregoniidae Chionoecetes opilio Hyas coarctatus Paguroidea Paguridae Labidochirus splendescens Pagurus rathbuni Pagurus trigonocheirus Pagurus capillatus BRACHYURA Pinnotheridae Pinnixa spp. SIPUNCULA Golfingiidae Golfingia margaritacea Phascoliidae Phascolion strombus ECHIURA Echiuridae
Echiurus echiurusalaskanus
CEPHALORHYNCHA Priapulidae Priapulus caudatus BRACHIOPODA BROZOA Alcyonidiidae Alcyonidium disciforme Alcyonidium gelatinosum Alcyonidium pedunculatum ECHINODERMATA ASTEROIDEA Goniopectinidae Ctenodiscus crispatus Echinasteridae Henricia sp. Henricia tumida Asteriidae Leptasterias groenlandica Leptasterias arctica Leptasterias polaris
38 Urasterias lincki Pterasteridae Pteraster obscurus ECHINOIDA Strongylocentrotidae Strongylocentrotusdroebachiensis HOLOTHUROIDEA Chiridotidae Chiridota sp. Cucumariidae Cucumaria sp. Ocnus glacialis Myriotrochidae Myriotrochus rinkii Psolidae Psolus fabricii Psolus phantapus OPHIUROIDEA Ophiuridae Ophiura maculata Ophiura sarsi Stegophiura nodosa Ophiactidae Ophiopholis aculeata Amphiuridae Amphiodia craterodmeta Amphiura sundevalli Unioplus sp. Gorgonocephalidae Gorgonocephalus arcticus Gorgonocephalus eucnemis CHORDATA ASCIDIACEA Pyuridae Boltenia echinata Boltenia ovifera Boltenia villosa Halocynthia aurantium Corellidae Chelyosoma orientale Styelidae Styela coriacea Styela rustica Pelonaia corrugata cf. Cnemidocarpa sp. Didemnidae
