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CITATION Bluhm, B.A., A.V. Gebruk, R. Gradinger, R.R. Hopcroft, F. Huettmann, K.N. Kosobokova, B.I. Sirenko, and J.M. Weslawski. 2011. Arctic marine biodiversity: An update of species richness and examples of biodiversity change. Oceanography 24(3):232–248, http://dx.doi.org/10.5670/ oceanog.2011.75.

COPYRIGHT This article has been published inOceanography , Volume 24, Number 3, a quarterly journal of The Oceanography Society. Copyright 2011 by The Oceanography Society. All rights reserved.

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downloaded from www.tos.org/oceanography The Changing Arctic Ocean | Special Issue on the International Polar Year (2007–2009) arctic Marine Biodiversity An Update of Species Richness and Examples of Biodiversity Change

Under-ice image from the Bering Sea. Photo credit: Miller Freeman Divers (Shawn Cimilluca)

By Bodil A. Bluhm, Andrey V. Gebruk, Rolf Gradinger, Russell R. Hopcroft, Falk Huettmann, Ksenia N. Kosobokova, Boris I. Sirenko, and Jan Marcin Weslawski

Abstract. The societal need for—and urgency of over 1,000 ice-associated protists, greater than 50 ice-associated obtaining—basic information on the distribution of Arctic metazoans, ~ 350 multicellular zooplankton species, over marine species and biological communities has dramatically 4,500 benthic protozoans and invertebrates, at least 160 macro- increased in recent decades as facets of the human footprint algae, 243 fishes, 64 seabirds, and 16 marine mammals. Endemic alter Arctic marine biodiversity. The primary goals of this and abundant species are present in all three environmental article are to present updated species inventories based on realms (sea ice, water column, and seafloor) and across phyla. focused biodiversity research over the last decade, to give The few published time series on Arctic marine biodiversity examples of emerging recent changes in diversity as indicators have detected interannual and interdecadal variability or change of environmental change, and to recommend future diversity- both in pelagic and benthic habitats, and at virtually all trophic related research areas. Species inventories across all eukaryotic levels. We identify knowledge gaps and stress the urgency to taxonomic levels now total close to 8,000 species, with several fill them. We recommend regular, strategic, and sustained thousand additional benthic species predicted to be recorded monitoring of Arctic marine biodiversity in a public, open- or discovered in the future. The currently known Arctic species access fashion in order to provide comprehensive data to inform richness estimate includes close to 2,000 phytoplankton taxa, management, conservation, and other decisions.

232 Oceanography | Vol.24, No.3 What is Biodiversity and pollutants, and tourism (ACIA, 2005; a century has produced fundamental Why Do We Care About It Johnsen et al., 2010). One of the most knowledge of marine life in the Arctic in the Arctic? visible ongoing changes is the reduc- (e.g., Sirenko, 2001; Vassilenko and Biological diversity, contracted to the tion of sea ice cover and thickness, in Petryashev, 2009; Buzhinskaja, 2011). term biodiversity, is most commonly particular during the summer months, In addition, the early explorers laid the defined as the variety of life (Gaston, reducing the habitat for ice-related flora foundation for many of the following 2010). The definition by the Convention and fauna. Concurrently, increased research projects by describing their on Biological Diversity (CBD) reads: subsurface light levels and water biotic findings in their diaries and “the variability among living organisms temperatures now occur in many regions expedition reports. from all sources including, inter alia, previously covered continuously with More recently, the Arctic Ocean terrestrial, marine and other aquatic ice (Perovich et al., 2007). The predicted Diversity project (ArcOD, 2004–2011), ecosystems and the complexes of which total loss of summer ice by mid-century, as part of the Census of Marine Life, they are part; this includes diversity and the anticipated increased human was an international collaborative effort within species, between species and presence, will alter Arctic ecosystems’ to inventory biodiversity in Arctic of ecosystems” (http://www.cbd.int/ functioning, with regional changes marine realms on a pan-Arctic scale. convention/text). in, for example, primary production, Led by authors of this article, the project In this article, we present an overview species distributions (including those of compiled historic and new data in an of organismal and ecological diversity, disease-causing taxa), and indigenous online open-access database, improved with some examples of genetic diversity subsistence use. To understand such taxonomic identification of existing of Arctic marine biota, from microbes change, biodiversity studies spanning samples, and made new collections to mammals. The primary goals are regional species lists to functional link- focused on taxonomic, regional, and twofold: to present an updated review ages between indices of diversity and habitat gaps. Legacy products include, on species inventories, here defined as ecosystems are critical. for example, the Arctic Register of numbers of species occurring per realm Various definitions exist for the Marine Species (ARMS; http://www. and broad taxonomic group, and to give marine Arctic and its boundaries, marinespecies.org/arms), which expands examples of emerging recent changes with most based on a combination of the previously most complete list by in diversity on species and community temperature, geopolitical boundaries, Sirenko (2001), both in terms of taxa levels. While other recent publications and sea ice cover. Here, we consider the and regional coverage. The majority present regional biodiversity invento- Arctic primarily as those marine regions of taxon distribution records (defined ries—including Arctic regions—in much north of Bering Strait on the Pacific side here as georeferenced location of an more detail (e.g., Archambault et al., and areas with consistent seasonal sea ice identified specimen), underlying both 2010; Carr, 2011, for Canadian waters), cover on the Atlantic side, recognizing, ARMS and related publications, are avail- we focus on the pan-Arctic macroscale however, that the literature cited does able through the Ocean Biogeographic across all habitats. We also discuss not consistently use this definition. Information System (OBIS: http://www. observed changes in Arctic biodiversity iobis.org; Figure 1) and ArcOD’s web to highlight the need for, and usefulness Recent and Ongoing portal (http://www.arcodiv.org) with of, collecting data on the distribution Arctic Marine Biodiversity microbial data housed within MICROBIS over time of individual species and Initiatives (http://icomm.mbl.edu/microbis). communities as indicators of Arctic Much of today’s marine biodiversity ArcOD also provided species pages to the environmental and ecosystem change. In research builds on the tremendous (and Encyclopedia of Life (http://www.eol.org) the Arctic, major stressors include, for ongoing) effort of dozens of taxonomists and genetic sequences to the marine example, climate change, species inva- from the Russian Federation where Barcode of Life Initiative (http://www. sions, fisheries effects, oil and gas explo- substantial emphasis on Arctic species marinebarcoding.org). The scientific ration, shipping, ocean acidification, identification and description for over network developed through ArcOD

Oceanography | September 2011 233 continues its activities—though with been published (CAFF, 2010). The hope Pacific Arctic region, which could reduced financial support—beyond 2011. is that synthesis efforts such as this will fulfill part of the CBMP goals. DBO is Currently, international teams are eventually lead to informed timely deci- suggested to include a range of biological engaged in the Arctic Biodiversity sion making for international policy, and environmental measurements, Assessment (ABA), an initiative aimed resource management, and conservation. supplemented by satellite observa- at synthesizing and assessing the status Also under the umbrella of the tions, at four key areas in the Bering, and trends of biological diversity in the Arctic Council’s Conservation of Arctic Chukchi, and Beaufort Seas with the Arctic (http://www.caff.is/aba). This Flora and Fauna (CAFF), the currently goals of detecting and tracking the initiative was created by the Arctic prepared Circumpolar Biodiversity effects of changing oceanographic Council in response to the ambitious Monitoring Plan (CBMP) is intended conditions, from microbes to mammals (though not attained) target set by to enhance and harmonize biodiversity (Grebmeier et al., 2010). the United Nations Environmental monitoring efforts (http://www.caff.is). Several large national Arctic initia- Programme (UNEP) and CBD to reduce The CBMP’s Marine Expert Monitoring tives—with international collabora- the loss of biodiversity globally by Group, co-led by Norway and the United tors—include biodiversity components 2010 (Mace et al., 2010). ABA chapters States, has developed biodiversity indica- at some level, such as ArcticNet, include terrestrial, aquatic, and marine tors along with approaches to survey a Canadian network of centers of biodiversity at organismic and ecosystem them and a strategy for implementa- excellence, and ARCTOS, an Arctic scales in addition to genetic diversity tion (e.g., Gill et al., 2011). The goal marine ecosystem research network of and ecosystem goods and services. ABA of the implemented effort is to detect Norwegian institutions. is intended to provide policymakers and biodiversity trends in the Arctic and conservation managers with a current pinpoint sources of variability or change. Environmental Settings synthesis to help guide future work and Challenges ahead include funding the The oceanographic, bathymetric, and “help ensure sustainability of Arctic efforts on a pan-Arctic scale, imple- historic characteristics of the Arctic biodiversity and communities” (http:// menting a common data structure, and that collectively shape today’s Arctic www.caff.is/aba). The ABA baseline agreeing on standard methodologies. biota with regard to its biogeographic, information aims at identifying main Various other international Arctic compositional, and regional patterns stressors, key mechanisms driving observation networks that include are presented in other articles in this change, and data gaps, and will produce biodiversity components are in the plan- special issue, and are, therefore, greatly recommendations by 2013; a shorter ning process such as the Distributed abbreviated here. Briefly, the backdrop report on biodiversity trends has already Biological Observatory (DBO) in the for the current Arctic biota is a central deep ocean that is divided into four Bodil A. Bluhm (bluhm@alaska.edu) is Research Associate Professor, School of Fisheries abyssal basins by prominent ridges and Ocean Sciences, Institute of Marine Science, University of Alaska Fairbanks, Fairbanks, surrounded by shallow—and often AK, USA. Andrey V. Gebruk is Head of Laboratory, P.P. Shirshov Institute of Oceanology, broad—shelves comprising ~ 50% of the Russian Academy of Sciences, Moscow, Russia. Rolf Gradinger is Professor, School of Arctic (Jakobsson et al., 2004; Figure 2). Fisheries and Ocean Sciences, Institute of Marine Science, University of Alaska Fairbanks, The only existing deepwater connec- Fairbanks, AK, USA. Russell R. Hopcroft is Professor, School of Fisheries and Ocean tion to the world’s ocean is through Sciences, Institute of Marine Science, University of Alaska Fairbanks, Fairbanks, AK, USA. Fram Strait. Prominent abiotic forcing Falk Huettmann is Associate Professor, Institute of Arctic Biology, University of Alaska factors include the extreme seasonality Fairbanks, Fairbanks, AK, USA. Ksenia N. Kosobokova is Leading Scientist, P.P. Shirshov of light, combined with the sea ice that Institute of Oceanology, Russian Academy of Sciences, Moscow, Russia. Boris I. Sirenko is historically covered a maximum of Department Head, Marine Laboratory, Zoological Institute, Russian Academy of Sciences, 14 million km2 in winter and a minimum St. Petersburg, Russia. Jan Marcin Weslawski is Professor, Institute of Oceanology, Polish of 7 million km2 in summer (Thomas and Academy of Sciences, Sopot, Poland. Dieckmann, 2010). The central Arctic

234 Oceanography | Vol.24, No.3 < 0.009 0.009–0.02 a 0.03–0.05 0.06–0.10 Ocean is permanently stratified owing 0.11–0.18 to seasonal ice melt and freshwater input 0.19–0.39 0.40–0.98 from huge river systems that reduce the salinity of surface waters to < 32, while deepwater salinities typically exceed 34. Inorganic nutrient concentrations exhibit strong regional gradients from high nutrient regimes (e.g., the Chukchi Sea shelf) to oligotrophic conditions (e.g., in the Beaufort Gyre; e.g., Gradinger, 2009). Abundant terrigenous sediments origi- nate in riverine discharge and coastal 1–23 24–59 erosion, or glacial erosion, while marine- b 60–112 derived organic content is greatest in 113–183 184–284 areas of high nutrient concentration and 285–434 productivity. Seafloor sediments, relevant 435–744 745–1,236 for benthic communities and demersal fishes, are typically muddy on the outer shelves and in the central basins, and coarser with sand and gravel on the inner shelves or at locations with stronger ocean currents (Naidu, 1988). Local accumulations of boulders (Dunton et al., 1982) and rocky islands like Svalbard

(Wesławski et al., 2010) can provide 1.9–6.7 isolated hard substrates, although overall c 6.8–13.0 13.1–16.9 such habitat is spatially limited. 17.0–20.5 20.6–24.3 24.4–28.3 Richness of Species in 28.4–31.9 the Three Arctic Realms 32.0–35.4 35.5–39.3 The most recent estimates of species 39.4–45.9 richness are presented in this section, organized by the three major realms of the Arctic: sea ice, pelagic (water column), and benthos (seafloor), with vertebrates in a fourth section that cuts across these realms. The degree of completeness of the species inventories Figure 1. Taxonomic records in the Arctic per 5° cell and per km2 as varies greatly across realms, taxonomic archived in the Ocean Biogeographic Information System (http:// www.iobis.org) as of October 2010. (a) Density of records (N km–2), groups, and geographic regions due to (b) observed number of taxa (S km–2), (c) estimated number of taxa in differing levels of sampling effort, ease 50 randomly chosen individuals (ES(50) km–2). One record is one taxon of capture, and actual species numbers occurrence at one location at a given time. S is a function of sampling effort reflected in N, while ES(n) is a sample-size independent proxy for present. In most cases, the underlying species richness (Magurran, 2004). An additional ~ 50,000 records are species lists are based on standardized currently in preparation by the Arctic Ocean Diversity project.

Oceanography | September 2011 235 Crabs Telmessus cheiragonus and Oregonia gracilis; bivalve Pododesmus macrochisma seasonally ice-covered seas (Gosselin Snow crab et al., 1997; Gradinger, 2009). Typically, Walley Pollock Gray whale ice algal blooms start with the availability of sufficient light for photosynthesis Black Guillemot about mid-March in the coastal sea ice Diatom zones, when meiofaunal ice algal grazers Neodenticula seminae also start appearing in high abundances (e.g., Gradinger et al., 2009). The timing of the ice algal maximum is related to the local light climate and is latest in

Ivory gull the central Arctic. Most of the algal and faunal biomass and production is present in the bottom few centimeters of the ice Killer whale where temperatures and nutrient concen- Coccolithophorite Emiliania huxleyi trations are highest and salinity is lowest (e.g., Gradinger et al., 2009). Bacteria, in contrast, can be abundant in interior ice Blue Northern Gannet sections and are active at more extreme mussel salinities (> 100) and temperatures

Diatom (< –10°C; Junge et al., 2004). Three- Neodenticula dimensional under-ice structure, seminae including sea ice pressure ridges and crevasses, provides different micro- Bathymetric and topographic tints (m) habitats for under-ice fauna and flora

–5,000 –2,500 –1,000 –100 –10 0 50 300 600 1,000 (Ambrose et al., 2005; Gradinger et al., 2010a). The under-ice metazoan fauna, Figure 2. Schematic of examples of recent change in species distributions or population size or sightings that have been attributed to global climate change (details in text). The yellow arrows show the general dominated by gammaridean amphi- direction of the species range change and end in the general area of the new occurrence, but are not pods and Arctic or polar cod, transfers meant to suggest exact pathways. For the diatom Neodenticula seminae, no arrow was drawn across particulate organic matter from the ice the Arctic Ocean since the distribution pathway is unclear according to Reid et al. (2007). Red triangles indicate increases ( ) or decreases ( ) in population numbers or sightings. After data from: Krasnov and realm to the water column through the Barrett (1997), Berge et al. (2005), Feder et al. (2005), Gilchrist and Mallory (2005), Mecklenburg et al. (2007; release of fecal pellets and as prey for 2011), Reid et al. (2007), Sirenko and Gagaev (2007), Bluhm et al. (2009), Moline et al. (2008), Ferguson (2009) fishes, seals, and whales. Most of the organic carbon produced in the sea ice system, however, is not grazed by these taxonomy as accepted in the World Sea Ice Realm ice meiofaunal and under-ice grazers Register of Marine Species (http://www. A specialized, sympagic (ice-associated) (e.g., Nozais et al., 2001) and therefore marinespecies.org). Brief introductions community lives within a brine-filled serves as an early and high-quality food outline relevant characteristics of each network of pores and channels or at the pulse for the underlying fauna both in environment and its associated commu- ice-water interface. Observed taxa include the water column and at the seafloor nities. Recent discoveries of new species viruses, archaea, bacteria, protists, and (e.g., Sun et al., 2009). in all realms and across taxa demonstrate metazoans. Ice algal productivity exhibits Pan-Arctic inventories of ice bacteria that the inventory, here the number strong regional gradients with maximum and archaea are lacking, but first studies of species per realm, region, or higher contributions of up to ~ 50% of total conducted north of Svalbard and in taxon, is still incomplete despite the primary productivity in the central the Greenland Sea catalogued over significant progress made in recent years. Arctic, and lower contributions in the 30 bacterial phylotypes dominated by

236 Oceanography | Vol.24, No.3 proteobacteria and the Cystophaga- of Amphipoda; Table 1) with partial (SS rRNA) used to delineate operational Flavobacterium group (Brinkmeyer overlap with the pelagic biota. The inven- taxonomic units (OTUs) (Lovejoy et al., et al., 2003). Recently, 22 sea ice bacterial tory remains incomplete due to the need 2011). For pelagic picoplankton, Lovejoy phylotypes were described for seasonal for live identification of several domi- et al. (2011) estimate ~ 500 OTUs ice from the Franklin Bay region (Collins nant sea ice taxa, such as rotifers and of pico-Eucarya and ~ 500 OTUs of et al., 2010). On the eukaryotic level, a acoel flatworms, and the concurrent lack Archaea per water mass (of which total of 1,027 sympagic marine single- of taxonomists working on those groups ~ 300 of each are unique to that water celled protist species were recently in the Arctic. Recently described ice- mass) for a total of ~ 4,500 OTUs in compiled for the Arctic, with separate endemic species include the first known each group, assuming 15 distinct water inventories provided for the following sympagic hydroid, Sympagohydra tuuli masses occur in the Arctic. The number marine regions: Alaska, Canada, (Piraino et al., 2008) and one of the few, of bacterial OTUs is estimated to be an Scandinavia including Greenland, and but very abundant, sympagic nematode order of magnitude higher (Table 1). the Russian Arctic (Poulin et al., 2011). species, Cryonema tenue (Tchesunov A total of 1,874 single-celled marine Diatom species (74% of all listed taxa) and Riemann, 1995). Sea ice endemic protist species have been compiled from and dinoflagellate species (13% of all species also include several prominent Arctic phytoplankton studies (Poulin listed taxa) dominated the total protist amphipods (Table 1). et al., 2011), again excluding amoebae, inventory, excluding amoebae, cili- ciliates, foraminiferans, and radiolarians. ates, foraminiferans, and radiolarians. Pelagic Realm Some of those 1,874 species also occur Melosira arctica, Fragilariopsis cylindrus, Typically, phytoplankton production in sea ice (e.g., Table 1). Poulin et al. F. oceanica, and Nitzschia frigida are begins with ice melt in April and ends (2011) argue that this number is high examples of sympagic diatoms that in early September with a growth curve compared to the most recent estimate of consistently colonize annually formed generally characterized by a single peak ~ 5,000 phytoplankton species globally sea ice, with N. frigida being a character- in primary production (Sakshaug, 2004). by Tett and Barton (1995). Taxa from istic ice-endemic species (Poulin et al., Enhanced plankton activity on the Arctic four of the six super-groups present in a 2011). Inventories of ciliates and other shelves is fueled by the seasonal retreat widely accepted eukaryote classification protozoans from sea ice are incomplete. of sea ice, allowing for the formation system were recorded for the Arctic, The description of four new ciliate of ice-edge algal blooms, with reduced and diatoms again dominated in all four species in a single study of an ice floe surface salinity increasing vertical regions (57%), followed by dinoflagel- near Svalbard (Agatha et al., 1993) and stability. During this period, the often lates (23%). Poulin et al. (2011) caution the common occurrence of suctorian large herbivorous zooplankton species that the recorded highest species rich- and peritrich ciliates on the sympagic accumulate substantial lipid reserves for ness in the Canadian Arctic and lowest amphipod Gammarus wilkitzkii (Arndt winter survival and early reproduction in the Alaskan Arctic may be biased by et al., 2005) suggest the potential for the following spring (Pasternak et al., the numbers of studies conducted, and further discovery in these taxa. 2001). Predatory zooplankton species they point out that their inventory is In addition to these protists, at least rely on continuous availability of their primarily comprised of cells > 20 μm 50 species of metazoans live within the prey, and generalists and scavengers (e.g., Table 1). Examples of fairly recently sea ice brine channels or at the ice-water show broad flexible diets (Laakmann described pelagic protist species include interface. For sea ice meiofauna, these et al., 2009). Their low metabolic rates several prasinophytes from the Canadian species include at least eight of Rotifera, at cold temperatures allow low rates of Arctic (Daugbjerg and Moestrup, 1993). three Nematoda, 11 Copepoda, four annual primary production in the central For protozoan groups not summarized Polychaeta (larvae and juveniles), and Arctic to support relatively large stocks by Poulin et al. (2011), the two most several unidentified Acoela (summa- of metazoan zooplankton. common pelagic foraminiferans are rized in Bluhm et al., 2010a). A similar Most marine microbe groups are Neogloboquadrina pachyderma and diversity of metazoan species occurs at present in the Arctic plankton, based on Globigerina quinqueloba (Carstens and the ice-water interface (e.g., 11 species the analysis of small subunit rRNA genes Wefer, 1992; Carstens et al., 1997), which

Oceanography | September 2011 237 Table 1. Species richness estimates by realms or taxon group, and examples of Arctic endemic species and species that are very abundant and typically widespread in the Arctic, based on cited references and authors’ knowledge

Number of Abundant and/or Taxon/realm Species endemic to the Arctic Key reference(s) species/taxa widespread species Diatoms Nitzschia frigida, Melosira arctica, Chaetoceros furcillatus, Single-celled 2,106 Thalassioria nordenskioeldii, eukaryotes in Diatoms Melosira arctica and (1,027 sympagic, Fragilariopsis oceanica, F. cylindrus, Poulin et al., 2011 phytoplankton Nitzschia frigida 1,875 pelagic) and Cylongrotheca closterium, and sea ice Dinoflagellate Protoperidinium pellucidum Hydroid Sympagohydra tuuli; nematodes Theristus melnikovii, Unidentified Acoela; copepod Cryonema tenue, and C. crissum; nauplii; amphipods Gammarus Sea ice fauna At least 50 Bluhm et al., 2010a amphipods Gammarus wilkitzkii, wilkitzkii, Apherusa glacialis, Apherusa glacialis, Onisimus Onisimus nanseni, and O. glacialis nanseni, and O. glacialis Copepods Calanus hyper- Copepods Spinocalanus elon- boreus, C. glacialis, Metridia gatus, S. horridus, Paraeuchaeta longa, Oithona similis, Oncaea polaris, Scaphocalanus polaris, and borealis, and Paraeuchaeta Kosobokova et al., Zooplankton 354 Lucicutia pseudopolaris; Cnidarians glacialis; chaetognaths Parasagitta 2011 Rhabdoon reesi and Rudjakovia elegans, Eukrohnia hamata, plicata; larvacean Fritillaria polaris and Homoeonema platygonon; amphipod Themisto libellula Platysiphon verticillatus, Jonssonia Agarum clathratum, Desmarestia Wilce, 1990, 2009, pulvinata, Chukchia pedicel- aculeate, Ectocarpus siliculosus, and recent work; Seaweeds ~ 160 lata, C. endophytica, Kallymenia Saccharina latissima, Polyshiphonia Mathieson et al., schmitzii, and Leptophytum arctica, Odonthalia dentate, and 2010 arcticum Ulva intestinalis Brittle star Ophiocten sericeum; Amphipod Onisimus caricus, amphipods Ampelisca eschrichti Sirenko, 2001; bryozoan Alcyonidium disciforme; and Anony nugax; bivalve Macoma Piepenburg et al., Zoobenthos ~ 4,600 holothuroids Elpidia belyaevi, calcarea; polychaetes Eteone longa, 2011; Rogacheva, E. heckeri, E. glacialis, and Aglaophamus malmgreni, and 2007, 2011 Kolga hyalina Lumbrineris fragilis Artediellus scaber, Arctogadus Boreogadus saida, Arctogadus Mecklenburg et al., glacialis, Paraliparis bathybius, glacialia, Gymnocanthus tricuspis, 2011, and Fish 243 Rhodichtys regina, Lycodes frigidus, Myoxocephalus scorpius, M. quadri- pers. comm., and L. adolfi cornis, and Lycodes polaris February 16, 2011 Ivory gull, thick-billed murre, Glaucous and Iceland gull; Arctic Dovekie, Kittlitz’s murrelet, horned Huettmann et al., Seabirds 64 tern; parasitic and long-tailed puffin, Heuglin’s Gull, and various 2011 jaeger seabird subspecies Polar bear; narwhal, beluga, and Huntington and Marine 16 bowhead whales; walrus; ringed Ringed seal; bearded seal Moore, 2008; Kovacs mammals seal; bearded seal et al., 2011

238 Oceanography | Vol.24, No.3 occur even in the central Arctic. Two zooplankton (~ 340; DeBroyer and (versus pelagic) origin of the species additional species are reported from the Danis, 2011; DeBroyer, pers. comm., (Wulff et al., 2009). Nonetheless, pennate Russian shelves (Sirenko, 2001), while February 21, 2011). Arctic crusta- diatoms, such as species of the genera subarctic species are bound to the warm ceans comprise the dominant group Navicula, Nitzschia, and Pinnularia, water inflow regions. At least 40 pelagic (218 species) with Copepoda as the appear to dominate the taxonomic Radiolaria occur in Arctic waters largest order (161 species), followed by composition (e.g., Horner and Schrader, (Sirenko, 2001), with Amphimelissa the Cnidaria (76 species). The inventory 1982; Glud et al., 2002), with some setosa being dominant in near-surface is now assumed to be nearly complete species thriving both on the sediment waters of the Chukchi, Beaufort, Barents, with the exception of the deeper-water and in the sea ice. Iceland, and Greenland Seas (Itaki et al., layers in the basins, where both unre- In addition to microalgae, macroalgae 2003). For other pelagic taxa such as corded and new species continue to be can be abundant in shallow waters naked Amoeba and Ciliata, the species found (Figure 3). Examples of those where suitable substrate occurs. inventory remains poorly studied, species include very small copepods in About 160–210 seaweed species have although at least 75 species of pelagic the family Discoidae (Andronov and been recorded in the Arctic to date ciliates are known for the Russian Kosobokova, 2011), a jellyfish found to (Wilce, 1994; Archambault et al., 2010; Seas (Sirenko, 2001). be rather common based on remotely Mathieson et al., 2010; Sirenko et al., Metazoan zooplankton communi- operated vehicle (ROV) imagery 2010). Forty percent are brown algae ties are much better characterized, (Raskoff, 2010), and several yet unde- (phaeophytes), and 30% each are red being highly structured by depth in scribed ctenophores (Figure 3). Only (rhodophytes) and green (chlorophytes) the central Arctic, with no zoogeo- 15–20% of all zooplankton species are algae (Mathieson et al., 2010). Fewer graphical barrier apparent between endemic to the Arctic (e.g., Kosobokova than 20 of these seaweeds are considered the Eurasian and Canadian basins et al., 2011; Table 1). COI sequences, Arctic endemics (Wilce, 1990, and recent (Kosobokova et al., 2011). Diversity so-called barcodes, for over 40 Arctic work of Wilce). An example of a recently indices in that study increased with plankton species accurately discrimi- described species is Chukchia pedicellata, depth to a maximum within the Atlantic nated and identified known species a minute brown alga growing on blades Water layer (i.e., 500–1,000 m depth), of 10 taxa of Arctic holozooplankton, of the kelp Saccharia latissima (Wilce followed by a decrease in the deepest and as yet suggest no cryptic species et al., 2009). Macroalgal species richness strata. Pacific and Atlantic expatriates (Bucklin et al., 2010; sequences available is much lower than in other regions of account for basin-scale differences in in GenBank; barcoding of additional the globe, except for the Antarctic, with the community composition of (only) species is ongoing). regional latitudinal and longitudinal the upper-layer zooplankton. Regionally, differences attributed to factors such zooplankton communities tend to be Benthic Realm as availability of coastal rocky habitat, structured by the distribution of water Although mostly neglected in primary salinity, and ice scouring (Wiencke et al., masses as traced by temperature and production estimates, benthic diatom 2007; Mathieson et al., 2010). salinity characteristics (e.g., Wassmann photosynthesis may be more impor- Benthic bacteria contribute signifi- et al., 2006; Błachowiak-Samołyk, 2008; tant than previously assumed. For cantly to the degradation of organic Hopcroft et al., 2010). example, these algae accounted matter at the seafloor, and also serve The current inventory of meta- for 16% of the total primary produc- as a food source. Over 450 clones of zoan holozooplankton is just over tion in a Greenlandic fjord (Glud et al., benthic bacteria were obtained from 350 species (Sirenko et al., 2010), with 2002). An inventory of Arctic benthic Pacific-Arctic Ocean sediments, nearly 200 species largely restricted microalgae, however, has not yet been including members of the α, γ, and to the shelves and 174 listed from the compiled on a pan-Arctic scale, with δ-Proteobacteria, Acidobacteria, central basins (Kosobokova et al., 2011). regionally published diatom species Bacteroidetes, and Actinobacteria (Li This number is very similar to the lists from sediment cores considered et al., 2009). First assessments of viral current species estimate for Antarctic inconclusive with regard to the benthic and fungal communities have only

Oceanography | September 2011 239 recently begun. For example, in the Kara by a few oligochaete and amphipod shallow areas, while that of Atlantic Sea, 46 different species of Zygomycota, taxa (Weslawski et al., 1993). The global affinity occurs both on the shelves Ascomycota, and anamorphic fungi distribution of benthic biomass (Wei and in the deep sea across the entire representing 24 genera were found in et al., 2010) shows comparatively high Arctic (recent work of author Gebruk 18 seafloor cores (Bubnova, 2010). Four benthic biomass on some Arctic shelves and Alexander Mironov, P.P. Shirshov new fungi species isolated from Arctic that provides major feeding grounds for Institute, Moscow). Regional differences driftwood beached in Svalbard (Pang mammals and sea birds (e.g., Grebmeier in diversity appear to be more prominent et al., 2011) suggest room for discovery et al., 2006a; Oppel and Huettmann, on the shelves than in the deep sea with in this taxon. 2010). Metazoan community abundance, no distribution barrier effect apparent Most benthic faunal communities biomass, and species richness tend from the mid-Arctic ridges (Bluhm et al., depend on food supplied from the water to decrease with water depth with no 2011; Piepenburg et al., 2011). column, with sediment and water mass mid-depth peak in species richness, For Arctic macro- and megaben- characteristics being additional promi- contrary to other regions and to Arctic thic shelf fauna (excluding fishes), nent environmental forcing factors. In zooplankton distribution (e.g., Bluhm Piepenburg et al. (2011) listed nearshore habitats, ice scouring and low et al., 2011). Modern Arctic fauna of 2,636 species (with a predicted total or variable salinity results in reduced Pacific affinity is most prominent on number of 3,900–4,700 species) with species richness and biomass, dominated the Chukchi Sea shelf and in nearby highest species numbers for crustaceans (847 taxa), closely followed by annelids (668 taxa). By region, species numbers

Figure 3. Examples of were highest in the Barents Sea. An undescribed and recently updated inventory of deep-sea (> 500 m) described Arctic species: benthos (including protists and meio- (a) the sea cucumber Elpidia belyaevi (Rogacheva, fauna) yielded 1,125 taxa (1,240 when 2007), (b) the bristle worm including the Greenland-Iceland- Terebellides irinae (Gagaev, Norwegian Seas; Bluhm et al., 2011). 2009), (c) an undescribed harpacticoid copepod crus- This species list is more than 400 taxa taceans of the genus Cervi, greater than the previous one by Sirenko (d) an undescribed ctenophore (2001) and is again dominated by crusta- of the genus Bathyctena, and (e) the moss animal ceans (366 taxa), followed by foraminif- Septentriopora karasi (Kuklinski erans, annelids, and nematodes. About and Taylor, 2008). Photo credits: (a) A. Rogacheva, P.P. Shirshov 60% of the deep-sea taxa overlapped Institute, Russia, (b) B. Bluhm, with shelf taxa (Bluhm et al., 2011). University of Alaska Fairbanks, Combining the above shelf and deep-sea USA, (c) T. Kihara, German Biodiversity Institute, Germany, taxon lists with Sirenko’s 2001 list, the (d) K. Raskoff, Monterey total known benthic species richness is Peninsula College, USA, on the order of ~ 4,600. This number is (e) P. Kuklinski, Institute of Oceanology, Poland not vastly different from the known and verified ~ 5,800 benthic invertebrate taxa currently listed in the Antarctic Register of Marine Species (DeBroyer and Danis, 2011; DeBroyer, pers. comm., February 21, 2011). The endemism rate in the Arctic benthos is significantly lower on the Arctic shelves than the > 50% rate

240 Oceanography | Vol.24, No.3 estimated for the Arctic deep sea Vertebrates and Chernova, 1995). COI sequences (Vinogradova, 1997). This number, Fishes occur in all three realms of the obtained for 165 species from the Arctic however, should be viewed cautiously, Arctic, with the highest species rich- region and adjacent waters permitted and likely as inflated, because of glob- ness in the benthic and demersal fishes discrimination of all sequenced species, ally inadequate investigation of the (87%) versus the pelagic fishes (13%) supporting the separation of several deep seafloor. In the Arctic deep sea, (Catherine Mecklenburg, California species and the synonomy of several for example, half of the taxa found in Academy of Sciences, pers. comm., other species whose taxonomic status analysis of ~ 6,000 records only occurred February 16, 2011). Habitat prefer- has been debated (Mecklenburg et al., at one or two locations (Bluhm et al., ence in these bottom-oriented fishes 2011). Fishes with Arctic, predominantly 2011). Recently, new Arctic benthic is primarily driven by sediment type, Arctic, or Arctic–boreal distributions species were described from a broad bottom salinity, and bottom temperature, composed 41% of the 242 species in range of taxa and regions, for example while water-column temperature and the region, while the remainder were a pan-Arctic deep-sea sea cucumber salinity characterize ichthyoplankton considered boreal, predominantly (Rogacheva, 2007), three mollusks from distribution patterns much like they boreal, or widely distributed species. the Chukchi Sea shelf (Chaban, 2008; influence zooplankton communities New Arctic fish species continued to Sirenko, 2009), several polychaetes from (e.g., Norcross et al., 2010). Two fish be described in the first decade of this the Canada Basin (e.g., Gagaev, 2009), species, Arctic and polar cod, are closely century, for example, Lycodes paamiuti and several bryozoans and a hydroid associated with Arctic sea ice where they (Møller, 2001) and Careproctus kidoi from a well-investigated Svalbard fjord serve as energy transmitters from the sea (Knudsen and Møller, 2008). New (e.g., Ronowicz and Schuchert, 2007; ice system to higher trophic level preda- studies continue to change the inven- Kuklinski and Taylor, 2008; Figure 3). tors (e.g., Lønne and Gabrielsen, 1992). tory, with, for example, resurrection of Publicly available sequence data such Many temperate fishes are intolerant to the North Pacific spiny dogfish, Squalus as COI barcodes for over 330 (with more the low temperatures of bottom waters in suckleyi, from synonymy in S. acanthias in progress) of Arctic benthic inverte- ice-covered regions, and thus the sea ice (Ebert et al., 2010), raising the count to brate species (http://www.boldsystems. extent with its interannual and decadal- 243 species (Catherine Mecklenburg, org) are beginning to be applied to scale variability reasonably corresponds California Academy of Sciences pers. biogeographic and other questions. For in spatial extent to the (hence, also comm., February 16, 2011). The reason example, recent molecular studies docu- variable) boundary between Arctic and for the overall low species richness of ment the presence of numerous cryptic subarctic demersal and benthic fish Arctic fish fauna is thought to be related species and identify locations of Arctic communities (Wyllie-Echeverria and to the relatively young evolutionary age glacial and periglacial marine refugia for Wooster, 1998; Mecklenburg et al., 2011). of the Arctic habitat. a range of taxa (summarized in Hardy An updated Arctic fish inven- Arctic seabirds are dependent on et al., 2011). Barcode sequences for shelf tory contains 242 species (excluding marine resources from the Arctic for species of polychaetes and echinoderms 12 likely synonyms) distributed among all or most of their energy require- have also revealed high population 45 families, with sculpins (Cottoidei: ments while they are in the region connectivity across the Arctic as well 72 species) and eelpouts (Zoarcoidei: (Gaston, 2004). A total of ~ 450 bird as connectivity to both the Atlantic and 55 species) accounting for more than species are known to breed or have Pacific faunas. The degree of gene flow half of all species (Mecklenburg et al., bred in the Arctic region as defined by differs, however, between taxa, with, for 2011). Thirty-one species are listed as CAFF (CAFF, 2001; Zoeckler, in press). instance, greater gene flow over larger diadromous and the remaining species Of these, 256 species have significant spatial scales in echinoderms than in as marine. The authors note that their populations in the Arctic, and 175 are polychaetes (Carr, 2010; Corstophine, list of species reflects significant changes water related. The Seabird Working 2010; Hardy et al., 2011). in taxonomy and increased knowledge Group of CAFF identified 64 Arctic of species geographic distributions since seabird species (Petersen et al., 2008; previous compilations (e.g., Andriashev Zoeckler, in press), about 16 species of

Oceanography | September 2011 241 which have circumpolar distributions. of some species (references cited in spans result in less seasonally modulated Uncertainty on the subspecies level and O’Corre-Crowe, 2008), while data on abundance and distribution that inte- taxonomic splitting (see Huettmann metapopulations, species culture, and grate changes over longer time periods et al., 2011, for a taxonomic crosswalk of population size and structure of other (e.g., Blacker, 1957). As an example, 27 pelagic seabird species) affect not only species are sparse (Kovacs et al., 2011). the benthic community structure in the species richness estimates but also Analysis of molecular data from multiple Kongsfjorden (Svalbard) varied with the specific conservation and risk assess- studies on seven Arctic marine mammal phases of the North Atlantic Oscillation ments. Species that forage on the open species suggests that small and isolated and its local manifestations between ocean are mostly alcids, gulls, skuas, subarctic populations tend to have lower 1980 and 2003 (Beuchel et al., 2006). and terns (e.g., Huettmann et al., 2011). genetic diversity than larger Arctic To date, most of the observed changes Other taxa tied to marine food webs populations (O’Corre-Crowe, 2008). are near the Arctic margins rather than are sea ducks, as well as the species-rich Behavioral aspects, widely recognized to in the central Arctic (Figure 2), but it shorebirds, loons, some geese, cranes, be essential for defining marine mammal remains unclear whether this is a bias and most Arctic raptors, including owls population structures, are still virtually from higher observation density in and ravens. It should be noted that many unstudied for most species. subarctic areas or is due to truly larger terrestrial and coastal birds of the Arctic environmental changes in those areas. can often be found on the sea ice, and Recent Changes in At the lowest trophic level, increased crossing oceans. Many Arctic seabirds Biodiversity and Biomass ice-free conditions extend the distribu- are connected with southern areas by A proper assessment of changes in biodi- tion of Atlantic phytoplankton species seasonal migrations (Huettmann et al., versity requires solid baselines on species northward. An example is Emiliania 2011), for example, the Arctic tern, occurrences, abundance, and biomass. huxleyi that now occurs along the some skuas, and jaegers travel between To date, however, only a few time northern sector of the western Eurasian the Arctic and Antarctic, and the sooty series of biological variables have been shelves (Hegseth and Sundfjord, 2008; shearwater and Wilson’s storm petrels collected in the Arctic, and for a limited Figure 2). The recent occurrence of migrate between New Zealand/Chile and number of taxa and regions; nonetheless, the North Pacific planktonic diatom the North Pacific, including Alaska, as they demonstrate substantial interannual Neodenticula seminae in the North well as the North Atlantic. and interdecadal variability or change in Atlantic (Figure 2) is also interpreted The life cycles, distribution, and pelagic and benthic habitats at virtually as an effect of climate warming (Reid migration patterns of many Arctic all trophic levels. Changes include shifts et al., 2007), presumably by transport marine mammals are also intricately in distribution ranges (Figure 2), and/or in a pulse of Pacific water through the coupled to the seasonal pattern of sea ice biomass and trophic cascades (examples Canadian Arctic Archipelago and/or melt and formation (e.g., Moore et al., outlined below), but also—primarily Fram Strait. At intermediate trophic 2000). A total of 16 marine mammals investigated in mammal species—vari- levels, switches from long-lived, slow- occur in the Arctic: nine species are ances in body condition, reproductive growing Arctic benthic species to faster- ice-associated year-round with an addi- output, or diet (examples in Kovacs et al., growing temperate species in Svalbard tional seven species occurring season- 2011; Wassmann et al., 2011). The largest reflect increasing water temperatures ally or occasionally (Huntington and number of reported changes are for (e.g., Weslawski et al., 2010). Similarly, Moore, 2008). Eight of the 16 species marine mammals and seabirds, where northern range extensions in some are cetaceans and seven are seals, plus studies often tend to focus on individual epifaunal crabs, chitons, and bivalves in the polar bear. Arctic foxes are regularly species and populations rather than the Chukchi Sea (Sirenko and Gagaev, observed far out on sea ice but have not communities and ecosystems as a whole. 2007) and community-wide northward been classified as marine mammals. Within the invertebrates, documented distribution shifts of fish in the Bering Recent diversity-related research on distribution shifts are more numerous in Sea (Mueter and Litzow, 2008) are tied to Arctic marine mammals has focused on the benthic realm than the pelagic realm warming water. The reappearance of the delineating genetic population structure because the typically longer benthic life blue mussel in Svalbard after a thousand

242 Oceanography | Vol.24, No.3 years of absence appears to be a direct the sea ice that provides critical foraging most sensitive to climate change, based consequence of a warmer environ- habitat for the species retreated earlier on population size, geographic range, ment (Berge et al., 2005; Figure 2). The and farther offshore. Other species such habitat specificity, diet diversity, migra- contraction of the distribution center as Skuas, Horned and Tufted Puffin, tion, site fidelity, sensitivity to changes of female snow crab to the north in the some gull species, and the otherwise in sea ice, sensitivity to changes in the Bering Sea (Ohrensantz et al., 2004) temperate Northern Gannets seem trophic web, and maximum population and a probable increase of that species to have moved north, with the latter growth potential (Laidre et al., 2008). in the Chukchi Sea (Bluhm et al., 2009; species now breeding in the White Sea While changes in species distribution Figure 2) might eventually influence the (e.g., Krasnov and Barrett, 1997; Piatt ranges appear primarily tied to water distribution of the commercial fishery. and Kitaysky, 2002). temperatures, changes in biomass (other At still higher trophic levels, examples Marine mammals have frequently than those related to harvests) result of population changes include declines of been suggested as “ecosystem sentinels” from a combination of shifts in energy seabird numbers such as those of nesting because they integrate change across flow or benthic-pelagic coupling, and ivory gulls (a species strongly associated trophic levels as well as large areal environmental conditions. For example, with sea ice) in the Canadian Arctic by and temporal scales (Moore, 2008). the biomass of jellyfish increased in as much as 80% relative to the 1980s Distribution changes in Arctic pinnipeds the Bering Sea throughout the 1990s, (Gilchrist and Mallory, 2005). Sabine’s and cetaceans have been linked to ice followed by a biomass collapse in 2000, Gull and Kittlitz’s Murrelet populations extent and ice availability plus related with subsequent stabilization (Brodeur have dropped, and Thick-billed Murres factors (e.g., Kovacs et al., 2011). To give et al., 2008). These dynamics were have been declining for several decades only a few examples from the growing linked to ice cover, wind mixing, and (CAFF, 2010). Other southern species body of literature, northward expan- sea surface temperatures as well as prey seem to increase northerly; for example, sions are recorded for the Pacific gray availability, specifically juvenile walleye declines of various populations of king whale in the Chukchi and Beaufort Seas pollock and zooplankton. Associated and common eiders in the Beaufort Sea (e.g., Moore, 2008) and for orcas in the phytoplankton communities switched between 1976 and 1996 have also been Canadian Arctic (e.g., Ferguson, 2009). between coccolithophore blooms in documented, with yet undetermined Other populations, in contrast, such as warmer years and diatoms in colder causes (Suydam et al., 2000). Spectacled bowhead whales in the Chukchi and years (Stockwell et al., 2001). Emerging eiders nesting in southwest Alaska Beaufort Seas, have been rather stable trends with regard to benthic inver- declined by 96% between the early 1970s with regard to their distribution (George tebrate biomass are not coherent and and the early 1990s and stabilized after- et al., 2004). Population size has changed include (1) decreasing infaunal and/ ward at those low levels (e.g., Petersen in some populations (summarized by or amphipod biomass in the northern et al., 2000), while trends in the large O’Corre-Crowe, 2008) with declines and Bering Sea (Moore et al., 2003; Dunton Siberian spectacled eider breeding popu- distribution changes, for example, in et al., 2005; Grebmeier et al., 2006b; lations remain unknown. A 30+ year many polar bear (Aars et al., 2006) and Coyle et al., 2007), (2) increased time series on seabirds of Cooper Island, some walrus populations (Born, 2005), epifaunal biomass in the northern Bering off the coast of Arctic Alaska, demon- but increasing numbers can be seen and southern Chukchi Seas (Feder et al., strated the arrival and successful nesting in other populations such as western 2005; Hamazaki et al., 2005; Bluhm et al., of black guillemots and later horned Arctic bowhead whales between 1979 2009), and (3) no change of infaunal puffins (Divoky, 1982) at the island when and 2001 (George et al., 2004). Other biomass in yet other areas such as a the environment had warmed enough documented changes in seals and whales High Arctic fjord (Renaud et al., 2007). to provide sufficient snow-free days for include shifts in prey composition and The examples of biomass decrease could laying eggs and raising chicks (Moline declines in body condition and repro- perhaps be interpreted in support of et al., 2008). Beginning in the 1990s, the ductive success (e.g., reviewed by Kovacs the prediction that the current benthos- number of breeding pairs of black guil- et al., 2011). The hooded seal, polar favoring pelagic-benthic coupling lemots declined again, possibly because bear, and narwhal are regarded as the will shift toward a pelagic-dominated

Oceanography | September 2011 243 system (e.g., Carroll and Carroll, 2003; as pelagic ciliates or benthic microalgae. 8,000 eukaryotic species (i.e., excluding Grebmeier et al., 2006b). Regionally, On higher trophic levels, including Eubacteria and Archaea). Cautious however, biomass changes can also be seabirds and marine mammals, gaps still estimates predict that several thousand evidence of spatial community-wide exist in the knowledge of species distri- benthic invertebrate species still remain shifts, specifically northward displace- butions and population numbers, as well to be recorded (Bluhm et al., 2011; Carr, ment as documented in the Bering Sea as their temporal trends, sensitivities, 2011; Piepenburg et al., 2011). It is clear (Mueter and Litzow, 2008). and reasons for change (other than a that Arctic ecosystems will be subjected human role per se) (Huettmann et al. to a variety of pressures in the future Knowledge Gaps 2011; Kovacs et al., 2011). (e.g., ACIA, 2005; Johnsen et al., 2010), Arctic regions contain a complex Regional gaps still exist in the deep and prediction of future Arctic “species variety of habitats, most of which are sea, in particular at depths over 1,000 m, richness” in time and space is compli- difficult to access. Despite a recent despite considerable sampling effort in cated by an interplay of factors capable increase in overall interest and research the past decade (e.g., Soltwedel et al., of either increasing or decreasing the effort, observational gaps still remain 2005; Bluhm et al., 2011). Of the shelf overall species richness in the coming for some geographic areas (Figure 1a), seas, the East Siberian Sea is prob- decades (Weslawski et al., 2011). Species taxa, and habitats. The decades-long ably the most understudied in terms richness can increase, for example, when lack of interest and the logistical chal- of biodiversity, although an intense northward-advected boreal species mix lenges posed by filling these gaps are study by the Zoological Institute in St. with Arctic residents, and when peren- now leading to uncertainties about Petersburg is ongoing. Large gaps also nial algae and associated fauna replace the biodiversity patterns (Figure 1b) exist in the vast area of the Canadian seasonal communities in previously ice- and the extent of ongoing changes. Arctic Archipelago (Carr, 2011) and scoured nearshore areas (Vermeij and Compiling information on the status northern Greenland, both of which still Roopnarine, 2008; Weslawski et al., 2008, quo and making informed predic- remain heavily ice-covered. Examples 2011). Species richness can decrease tions into the future require open data of underexplored habitats include through habitat homogenization and sharing in online data systems, as, for the deep-sea ridge systems spanning increasing sedimentation associated example, outlined in the data policy of thousands of kilometers across the with glacial melt and increased river the International Polar Year 2007–2009 Arctic as well as special features such as runoff, and when biota associated with and followed by some of its projects pockmarks and seamounts. In the sea multiyear ice loses its habitat (e.g., Kędra (e.g., Bluhm et al., 2010b), with regret- ice realm, pressure ridge biodiversity et al., 2010; Weslawski et al., 2011). tably overall weak compliance to date studies are only now starting to emerge Species richness might even stay stable (Carlson, 2011). (Hop and Pavlova, 2008; Gradinger et al., if, for example, southern species replace Incomplete species/OTU lists are 2010b), although this habitat may play functionally similar Arctic species, or clearly largest in the microbial realm, an increasingly important role in light because existing adaptations to season- including fungi. For the bacteria and of the diminishing ice cover. Ironically, ally low food availability, variable archaea, diversity estimates are largely while nearshore habitats have been temperatures, and other factors might based on the scaling of a limited number extensively studied, they are typically buffer Arctic biota against some degree of observations (Lovejoy et al., 2011). only well investigated in the vicinity of of change (Pertsova and Kosobokova, The recent inventory of marine pelagic field stations and not at broader scales 2010; Weslawski et al., 2011). and sea ice unicellular eukaryotes that capture the full range of habitat Species richness, therefore, may not (Poulin et al., 2011) demonstrated the types and heterogeneities. be the most desirable single metric with largest gap in knowledge to be in the which to evaluate biodiversity changes, diversity of small cells (< 20 μm), which Outlook and should be considered along with represented less than 20% of their Recent updates of Arctic species many other metrics. The competi- assessment; however, their effort did inventories across all taxonomic levels tion of Arctic endemics and primarily not include lesser-known groups such demonstrate the presence of close to Arctic-distributed biota with temperate

244 Oceanography | Vol.24, No.3 taxa is inevitable, and is expected (if ACIA. 2005. Arctic Climate Impact Assessment. Bluhm, B.A., K. Iken, S.L. Mincks, B.I. Sirenko, and Cambridge University Press, Cambridge, 1,042 pp. B.A. Holladay. 2009. Community structure of not already observed; see above) to Agatha, S., M. Spindler, and N. Wilbert. 1993. Ciliated epibenthic megafauna in the Chukchi Sea. Aquatic lead to the reduction of “typical” Arctic Protozoa (Ciliophora) from Arctic sea ice. Acta Biology 7:269–293, http://dx.doi.org/10.3354/ Protozoologica 32:261–268. ab00198. populations, species, communities, and/ Ambrose, W.G. Jr., C. von Quillfeldt, L.M. Clough, Bluhm, B.A., D. Watts, and F. Huettmann. 2010b. Free or habitat (e.g., Weslawski et al., 2008; P.V.R. Tilney, and T. Tucker. 2005. The sub-ice database availability, metadata and the Internet: algal community in the Chukchi Sea: Large- and An example of two high latitude components CAFF, 2010). The examples of ongoing small-scale patterns of abundance based on of the Census of Marine Life. Pp. 233–244 in changes on species and communities images from a remotely operated vehicle. Polar Spatial Complexity, Informatics and Wildlife Biology 28:784–795, http://dx.doi.org/10.1007/ Conservation. F. Huettmann and S.A. Cushman, levels demonstrate the value and neces- s00300-005-0002-8. eds, Springer, Tokyo. sity of related surveys that are systematic Andriashev, A.P., and N.V. Chernova. 1995. Brinkmeyer, R., K. Knittel, J. Juergens, H. Weyland, Annotated list of fishlike vertebrates and fish of R. Amann, and E. Helmke. 2003. Diversity and and methodologically comparable in the Arctic seas and adjacent waters. Journal of structure of bacterial communities in Arctic nature. Such surveys are required on Ichthyology 35:81–123. versus Antarctic pack ice. Applied Environmental Andronov, V.N., and K.N. Kosobokova. 2011. Microbiology 69:6,610–6,619, http://dx.doi. both regional and pan-Arctic scales to New species of small, bathypelagic calanoid org/10.1128/AEM.69.11.6610-6619.2003. detect change and inform both short- copepods from the Arctic Ocean: Brodskius Born, E.W. 2005. An assessment of the effects of arcticus sp. nov. (Tharybidae) and three new hunting and climate on walruses in Greenland. term and long-term conservation and species of Pertsoviusgen nov. (Discoidae). PhD thesis, University of Oslo, Oslo. management plans. As stressed also Zootaxa 2,809:33–46. Brodeur, R.D., M.B. Decker, L. Ciannelli, J.E. Purcell, Archambault, P., P.V.R. Snelgrove, J.A.D. Fisher, N.A. Bond, P.J. Stabeno, E. Acuna, and by CAFF (2010) and UNEP, these J.-M. Gagnon, D.J. Garbary, M. Harvey, G.L. Hunt Jr. 2008. Rise and fall of jellyfish in the plans should include identifying and E.L. Kenchington, V. Lesage, M. Levesque, eastern Bering Sea in relation to climate regime C. Lovejoy, and others. 2010. From sea to sea: shifts. Progress in Oceanography 77:103–111, http:// protecting biologically important marine Canada’s three oceans of biodiversity. PLoS dx.doi.org/10.1016/j.pocean.2008.03.017. areas (Johnsen et al., 2010; Huettmann ONE 5(8):e12182, http://dx.doi.org/10.1371/ Bubnova, E.N. 2010. Fungal diversity in journal.pone.0012182 bottom sediments of the Kara Sea. Botanica and Hazlett, 2010). Arndt, C.E., G. Fernandez-Leborans, L. Seuthe, Marina 53:595–600, http://dx.doi.org/10.1515/ J. Berge, and B. Gulliksen. 2005. Ciliated epibionts BOT.2010.063. on the Arctic sympagic amphipod Gammarus Bucklin, A., R.R. Hopcroft, K.N. Kosobokova, Acknowledgments wilkitzkii as indicators for sympago-benthic L.M. Nigro, B.D. Ortman, R.M. Jennings, and We are indebted to the Ocean Biogeo- coupling. Marine Biology 147:643–652, http:// C.J. Sweetman. 2010. DNA barcoding of Arctic dx.doi.org/10.1007/s00227-005-1599-4. Ocean holozooplankton for species identi- graphic Information System, in partic- Berge, J., G. Johnsen, F. Nilsen, B. Gulliksen, and fication and recognition. Deep-Sea Research ular E. Vanden Berghe, for preparing D. Slagstad. 2005. Ocean temperature oscillations Part II 57:40–48, http://dx.doi.org/10.1016/​ enable reappearance of blue mussel Mytilus edulis j.dsr2.2009.08.005. the maps in Figure 1. We appreciate the in Svalbard after 1000 years of absence. Marine Buzhinskaja, G., ed. 2011. Illustrated Keys to Free- comments made on a previous version Ecology Progress Series 303:167–175, http://dx.doi. Living Invertebrates of Eurasian Arctic Seas org/10.3354/meps303167. and Adjacent Deep Waters, vol. 2. Nemertea, of this article by C.W. Mecklenburg Beuchel, F., B. Gulliksen, and M.L. Carroll. 2006. Cephalorhyncha, Oligochaeta, Hirudinida, (fish section), J.M. Grebmeier, and an Long-term patterns of rocky bottom macro- Pogonophora, Echiura, Sipuncula, Phoronida, and benthic community structure in an Arctic fjord Brachiopoda. Alaska Sea Grant, University of anonymous reviewer. Thanks are due (Kongsfjorden, Svalbard) in relation to climate Alaska Fairbanks, Fairbanks, AK. to T. Kihara, P. Kuklinski, K. Raskoff, variability (1980–2003). Journal of Marine CAFF (Conservation of Arctic Flora & Fauna). 2001. Systems 63:35–48, http://dx.doi.org/10.1016/​ Arctic Flora and Fauna: Status and Conservation. and A. Rogacheva for use of their j.jmarsys.2006.05.002. Edita Helsinki, 278 pp. photographs. We gratefully acknowl- Blacker, R. 1957. Benthic animals as indicators of CAFF. 2010. Arctic Biodiversity Trends 2010: Selected hydrographic conditions and climatic change Indicators of Change. CAFF International edge the support of the Alfred P. Sloan in Svalbard waters. Fishery Investigations, Secretariat, Akureyri, Iceland, 121 pp. Foundation (grant number 2009-6-1), series 2, 20(10):1–59. Carlson, D. 2011. A lesson in sharing. Nature 469:293, Błachowiak-Samołyk, K. 2008. Contrasting http://dx.doi.org/10.1038/469293a. with special thanks to its visionary vice- zooplankton communities (Arctic vs. Atlantic) Carr, C.M. 2010. The Polychaeta of Canada: Exploring director, J. Ausubel. This publication is in the European Arctic Marginal Ice Zone. diversity and distribution patterns using DNA Oceanologica 50:363–389. barcodes. MSc Thesis, University of Guelph, part of the Census of Marine Life’s Arctic Bluhm, B.A., A.G. Ambrose Jr., M. Bergmann, Guelph, Ontario. Ocean Diversity project synthesis. L.M. Clough, A.V. Gebruk, C. Hasemann, K. Iken, Carr, C.M. 2011. Polychaete diversity and distri- M. Klages, I.R. MacDonald, P.E. Renaud, and bution patterns in Canadian marine waters. others. 2011. Diversity of the Arctic deep-sea Marine Biodiversity, http://dx.doi.org/10.1007/ References benthos. Marine Biodiversity 41:87–107, http:// s12526-011-0095-y. Aars, J., N.F. Lunn, and A.E. Derocher, eds. 2006. dx.doi.org/10.1007/s12526-010-0078-4. Carroll, M.L., and J. Carroll. 2003. The Arctic Seas. Polar Bears: Proceedings of the 14th Working Bluhm, B., R. Gradinger, and S. Schnack-Schiel. 2010a. Pp. 127–156 in Biogeochemistry of Marine Systems. Meeting of the IUCN/SSC Polar Bears Specialist Sea ice meio- and macrofauna. Pp. 357–393 in K.D. Black and G.B. Shimmield, eds, CRC Press, Group, June 20–24, 2005, Seattle,Washington, USA. Sea Ice. D. Thomas and G. Dieckmann, eds, Wiley- Boca Raton, FL. International Union for Conservation of Nature, Blackwell, New York. Cambridge, MA.

Oceanography | September 2011 245 Carstens, J., D. Hebbeln, and G. Wefer. 1997. Ferguson, S.H. 2009. Killer whales on the rise in the Chukchi Seas in the Amerasian Arctic. Progress Distribution of planktic foraminifera at the Canadian Arctic. The Circle 4:20–23. in Oceanography 71:331–361, http://dx.doi. ice margin in the Arctic (Fram Strait). Marine Gagaev, S.Y. 2009. Terebellides irinae sp. n.: A new org/10.1016/j.pocean.2006.10.001. Micropaleontology 29:257–269, http://dx.doi. species of the genus Terebellides (Polychaeta, Grebmeier, J.M., J.E. Overland, S.E. Moore, E.V. Farley, org/10.1016/S0377-8398(96)00014-X. Terebellidae) from the Canada Basin of the Arctic E.C. Carmack, L.W. Cooper, K.E. Frey, J.H. Helle, Carstens, J., and G. Wefer. 1992. Recent distribu- Ocean. Russian Journal of Marine Biology 35:73–75, F.A. McLaughlin, and S.L. McNutt. 2006b. A tion of planktonic foraminifera in the Nansen http://dx.doi.org/10.1134/S1063074009060042. major ecosystem shift in the northern Bering Sea. Basin, Arctic Ocean. Deep-Sea Research Gaston, A.J. 2004. Seabirds: A Natural History. Yale Science 311:1,461–1,464, http://dx.doi.org/10.1126/ Part A 39:S507–S524, http://dx.doi.org/10.1016/ University Press, London, 224 pp. science.1121365. S0198-0149(06)80018-X. Gaston, K.J. 2010. Biodiversity. Pp. 27–44 in Grebmeier, J.M., S.E. Moore, J.E. Overland, Chaban, E.M. 2008. Opisthobranchiate mollusca Conservation Biology for All. J.S. Sodhi and K.E. Frey, and R.R. Gradinger. 2010. of the orders Cephalaspidea, Thecosomata and P.R. Ehrlich, eds, Oxford University Press. Biological response to recent Pacific Arctic Gymnosomata (Mollusca, Opisthobranchia) of the George, J.C., J. Zeh, R. Suydam, and C. Clark. sea ice retreats. Eos, Transactions, American Chukchi Sea and the Bering Strait. Pp. 149–162 2004. Abundance and population trend Geophysical Union 91:161–162, http://dx.doi. in Fauna and Zoogeography of Benthos of the (1978–2001) of western arctic bowhead org/10.1029/2010EO180001. Chukchi Sea. B.I. Sirenko and S.V. Vassilenko, eds, whales surveyed near Barrow, Alaska. Marine Hamazaki, T., L. Fair, L. Watson, and E. Brennan. 2005. Explorations of the Fauna of the Seas 61(69). Mammal Science 20:755–773, http://dx.doi. Analyses of Bering Sea bottom-trawl surveys in Collins, R.E., G. Rocap, and J.W. Deming. 2010. org/10.1111/j.1748-7692.2004.tb01191.x. Norton Sound: Absence of regime shift effect on Persistence of bacterial and archaeal communities Gilchrist, H.G., and M.L. Mallory. 2005. Declines epifauna and demersal fish. ICES Journal of Marine in sea ice through an Arctic winter. Environmental in abundance and distribution of the ivory gull Science 62:1,597–1,602, http://dx.doi.org/10.1016/​ Microbiology 12:1,828–1,841. (Pagophila eburnea) in Arctic Canada. Biological j.icesjms.2005.06.003. Corstorphine, E.A. 2010. DNA barcoding of echino- Conservation 121:303–309, http://dx.doi. Hardy, S.M., C.M. Carr, M. Hardman, D. Steinke, derms: Species diversity and patterns of molecular org/10.1016/j.biocon.2004.04.021. E. Corstorphine, and C. Mah. 2011. Molecular evolution. MSc Thesis, University of Guelph, Gill, M.J., K. Crane, R. Hindrum, P. Arneberg, diversity of Arctic fauna: Genetic tools provide Guelph, Ontario. I. Bysveen, N.V. Denisenko, V. Gofman, A. Grant- new insights in taxonomy and biogeography of Coyle, K.O., B.A. Bluhm, B. Konar, A. Blanchard, Friedman, G. Gudmundsson, R.R. Hopcroft, marine organisms. Marine Biodiversity 41:195–210, and R.C. Highsmith. 2007. Amphipod prey and others. 2011. Arctic Marine Biodiversity http://dx.doi.org/10.1007/s12526-010-0056-x. of gray whales in the northern Bering Sea: Monitoring Plan (CBMP-Marine Plan). Final Draft, Hegseth, E.N., and A. Sundfjord. 2008. Intrusion and Comparison of biomass and distribution between Circumpolar Biodiversity Monitoring Program, blooming of Atlantic phytoplankton species in the the 1980s and 2002–2003. Deep-Sea Research Environment Canada, 174 pp. high Arctic. Journal of Marine Systems 74:108–119, Part II 54:2,906–2,918, http://dx.doi.org/10.1016/​ Glud, R.N., M. Kühl, F. Wenzhöfer, and S. Rysgaard. http://dx.doi.org/10.1016/j.jmarsys.2007.11.011. j.dsr2.2007.08.026. 2002. Benthic diatoms of a high Arctic fjord Hop, H., and O. Pavlova. 2008. Distribution and Daugbjerg, N., and Ø. Moestrup. 1993. Four new (Young Sound, NE Greenland): Importance biomass transport of ice amphipods in drifting species of Pyramimonas (Prasinophyceae) from for ecosystem primary production. Marine sea ice around Svalbard. Deep-Sea Research arctic Canada including a light and electron micro- Ecology Progress Series 238:15–29, http://dx.doi. Part I 55:2,292–2,307, http://dx.doi.org/10.1016/​ scopic description of Pyramimonas quadrifolia sp. org/10.3354/meps238015. j.dsr2.2008.05.023. nov. European Journal of Phycology 28:3–16, http:// Gosselin, M., M. Levasseur, P.A. Wheeler, R.A. Horner, Hopcroft, R.R., K.N. Kosobokova, and A.I. Pinchuk. dx.doi.org/10.1080/09670269300650021. and B.C. Booth. 1997. New measurements 2010. Zooplankton community patterns in the DeBroyer, C., and B. Danis. 2011. How many species of phytoplankton and ice algal produc- Chukchi Sea during summer 2004. Deep-Sea in the Southern Ocean? Towards a dynamic tion in the Arctic Ocean. Deep-Sea Research Research Part II 57:27–39, http://dx.doi. inventory of the Antarctic marine species. Part II 44:1,623–1,644, http://dx.doi.org/10.1016/ org/10.1016/j.dsr2.2009.08.003. Deep-Sea Research Part II 58:5–17, http://dx.doi. S0967-0645(97)00054-4. Horner, R., and G.C. Schrader. 1982. Relative contri- org/10.1016/j.dsr2.2010.10.007. Gradinger, R. 2009. Sea-ice algae: Major contributors butions of ice algae, phytoplankton, and benthic Divoky, G.J. 1982. The occurrence and behavior to primary production and algal biomass in the microalgae to primary production in nearshore of nonbreeding Horned Puffins at Black Chukchi and Beaufort Seas during May/June 2002. regions of the Beaufort Sea. Arctic 35:485–503. Guillemot colonies in northern Alaska. Wilson Deep-Sea Research Part II 56:1,201–1,212, http:// Huettmann, F., and S. Hazlett. 2010. Changing the Bulletin 94:356–358. dx.doi.org/10.1016/j.dsr2.2008.10.016. Arctic: Adding immediate protection to the equa- Dunton, K.H., J.L. Goodall, S.V. Schonberg, Gradinger, R., B.A. Bluhm, R.R. Hopcroft, A. Gebruk, tion. Alaska Park Science 8:95–96. J.M. Grebmeier, and D.R. Maidment. 2005. K.N. Kosobokova, B. Sirenko, and J.M. Węsławski. Huettmann, F., Y. Artukhin, O. Gilg, and Multi-decadal synthesis of benthic-pelagic 2010a. Chapter 10. Marine life in the Arctic. G. Humphries. 2011. Predictions of 27 pelagic coupling in the western Arctic: Role of cross- Pp. 183–202 in Life in the World’s Ocean: Diversity, seabird distributions using public environmental shelf advective processes. Deep-Sea Research Distribution, Abundance. A. McIntyre, ed., variables, assessed with compiled colony data: A Part II 52:3,462–3,477, http://dx.doi.org/10.1016/​ Wiley-Blackwell. first digital IPY and GBIF Open Access synthesis j.dsr2.2005.09.007. Gradinger, R., B.A. Bluhm, and K. Iken. 2010b. Arctic platform. Marine Biodiversity 41:141–179, http:// Dunton, K.H., E.K. Reimnitz, and S. Schonberg. 1982. sea ice ridges: Safe havens for sea ice fauna during dx.doi.org/10.1007/s12526-011-0083-2. An Arctic kelp community in the Alaskan Beaufort periods of extreme ice melt? Deep-Sea Research Huntingon, H.P., and S.E. Moore. 2008. Assessing Sea. Arctic 35:465–484. Part II 57:86–95, http://dx.doi.org/10.1016/​ the impacts of climate change on Arctic marine Ebert, D.A., W.T. White, K.J. Goldman, j.dsr2.2009.08.008. mammals. Ecological Applications 18:S1–S2, http:// L.J.V. Compagno, T.S. Daly Engel, and R.D. Ward. Gradinger, R., M.R. Kaufman, and B.A. Bluhm. dx.doi.org/10.1890/06-0282.1. 2010. Resurrection and redescription of Squalus 2009. The pivotal role of sea ice sediments Itaki, T., M. Ito, H. Narita, N. Ahagon, and H. Sakai. suckleyi (Girard, 1854) from the North Pacific, for the seasonal development of near-shore 2003. Depth distribution of radiolarians from with comments on the Squalus acanthias subgroup Arctic fast ice biota. Marine Ecology Progress the Chukchi and Beaufort Seas, western Arctic. (Squaliformes: Squalidae). Zootaxa 2,612:2,2­40. Series 394:49–63, http://dx.doi.org/10.3354/ Deep-Sea Research Part I 50:1,507–1,522, http:// Feder, H.M., S.C. Jewett, and A. Blanchard. 2005. meps08320. dx.doi.org/10.1016/j.dsr.2003.09.003. Southeastern Chukchi Sea (Alaska) epiben- Grebmeier, J.M., L.W. Cooper, H.M. Feder, and Jakobsson, M., A. Grantz, Y. Kristoffersen, and thos. Polar Biology 28:402–421, http://dx.doi. B. Sirenko. 2006a. Ecosystem dynamics of R. Macnab. 2004. Physiography and bathymetry org/10.1007/s00300-004-0683-4. the Pacific-influenced Northern Bering and of the Arctic Ocean. Pp. 1–6 in The Organic Carbon Cycle in the Arctic Ocean. R. Stein and R. MacDonald, eds, Springer, Berlin.

246 Oceanography | Vol.24, No.3 Johnsen, K.I., B. Alfthan, L. Hislop, and J.F. Skaalvik, Magurran, E.M. 2004. Measuring Biological Diversity. Oppel, S., and F. Huettmann, 2010. Using a Random eds. 2010. Protecting Arctic Biodiversity. United Blackwell Publishing, Malden, MA, 256 pp. Forest model and public data to predict the distri- Nations Environment Programme, GRID-Arendal, Mathieson, A.C., G.E. Moore, and F.T. Short. 2010. bution of prey for marine wildlife management. Norway. Available online at: http://www.grida.no A floristic comparison of seaweeds from James Pp. 151–163 in Spatial Complexity, Informatics, (accessed July 20, 2011). Bay and three contiguous northeastern Canadian and Wildlife Management. S.A. Cushman and Junge, K., H. Eicken, and J.W. Deming. 2004. Bacterial Arctic sites. Rhodora 112:396–433, http://dx.doi. F. Huettmann, eds, Springer, http://dx.doi. activity at –2 to –20°C in Arctic wintertime sea ice. org/10.3119/09-12.1. org/10.1007/978-4-431-87771-4_8. Applied Environmental Microbiology 70:550–555, Mecklenburg, C.W., P.R. Møller, and D. Steinke. 2011. Orensanz, J., B. Ernst, D.A. Armstrong, P. Stabeno, and http://dx.doi.org/10.1128/AEM.70.1.550-557.2004. Biodiversity of Arctic marine fishes: Taxonomy and P. Livingston. 2004. Contraction of the geographic Kędra, M., M. Włodarska-Kowalczuk, and zoogeography. Marine Biodiversity 41:109–140, range of distribution of snow crab (Chionoecetes J.M. Węsławski. 2010. Decadal change in macro- http://dx.doi.org/10.1007/s12526-010-0070-z. opilio) in the Eastern Bering Sea: An environ- benthic soft-bottom community structure in Mecklenburg, C.W., D.L. Stein, B.A. Sheiko, mental ratchet? CalCOFI Report 45:65–79. a high Arctic fjord (Kongsfjorden, Svalbard). N.V. Chernova, T.A. Mecklenburg, and Pang, K.-L., R.K.K. Chow, C.-W. Chan, and Polar Biology 33:1–11, http://dx.doi.org/10.1007/ B.A. Holladay. 2007. Russian-American long-term L.L.P. Vrijmoed. 2011. Diversity and physiology s00300-009-0679-1. census of the Arctic: Benthic fishes trawled in of marine lignicolous fungi in Arctic waters: Knudsen, S.W., and P.R. Møller. 2008. Careproctus the Chukchi Sea and Bering Strait, August 2004. A preliminary account. Polar Research 30, http:// kidoi, a new Arctic species of snailfish (Teleostei: Northwestern Naturalist 88:168–187, http://dx.doi. dx.doi.org/10.3402/polar.v30i0.5859. Liparidae) from Baffin Bay. Ichthyological org/10.1898/1051-1733(2007)88[168:RLCOTA]​ Pasternak, A., E. Arashkevich, K. Tande, and Research 55:175­–182, http://dx.doi.org/10.1007/ 2.0.CO;2. T. Falkenhaug. 2001. Seasonal changes in feeding, s10228-007-0034-x. Moline, M.A., N.J. Karnovsky, Z. Brown, G.J. Divoky, gonad development and lipid stores in Calanus Kosobokova, K.N., H-J. Hirche, and R.R. Hopcroft. T.K. Frazer, C.A. Jacoby, J.J. Torres, and finmarchicus and C. hyperboreus from Malangen, 2011. Patterns of zooplankton diversity through W.R. Fragser. 2008. High latitude changes in northern Norway. Marine Biology 138:1,141–1,152, the depths of the Arctic’s central basins. Marine ice dynamics and their impact on polar marine http://dx.doi.org/10.1007/s002270100553. Biodiversity 41:29–50, http://dx.doi.org/10.1007/ ecosystems. Annals of the New York Academy of Perovich, D.K., S.V. Nghiem, T. Markus, and s12526-010-0057-9. Sciences 1,134:267–319, http://dx.doi.org/10.1196/ A. Schweiger. 2007. Seasonal evolution and Kovacs, K.M., S. Moore, C. Lydersen, and annals.1439.010. interannual variability of the local solar energy J.E. Overland. 2011. Impacts of changing sea ice Møller, P.R. 2001. Redescription of the Lycodes absorbed by the Arctic sea-ice–ocean system. conditions on Arctic marine mammals. Marine pallidus species complex (Pisces, Zoarcidae), with Journal of Geophysical Research 112, C03005, Biodiversity 41:181–194, http://dx.doi.org/10.1007/ a new species from the Arctic/North Atlantic http://dx.doi.org/10.1029/2006JC003558. s12526-010-0061-0. Ocean. Copeia 2001:972–996, http://dx.doi. Pertsova, N.M., and K.N. Kosobokova. 2010. Krasnov, Y.V., and R.T. Barrett. 1997. The first record org/10.1643/0045-8511(2001)001[0972:ROTLPS] Interannual and seasonal variation of the popula- of North Atlantic Gannets Morus bassanus 2.0.CO;2. tion structure, abundance, and biomass of the breeding in Russia. Seabird 19:54–57. Moore, S.E. 2008. Marine mammals as ecosystem Arctic copepod Calanus glacialis in the White Sea. Kuklinski, P., and P.D. Taylor. 2008. Arctic species sentinels. Journal of Mammology 89:534–540, Oceanology 50:531–541, http://dx.doi.org/10.1134/ of the cheilostome bryozoan Microporealla, with http://dx.doi.org/10.1644/07-MAMM-S-312R1.1. S0001437010040090. a redescription of the type species. Journal of Moore, S.E., D.P. DeMaster, and P.K. Dayton. 2000. Petersen, A., D. Irons, T. Anker-Nilssen, Y. Artukhin, Natural History 42:2,893–2,906, http://dx.doi. Cetacean habitat selection in the Alaskan Arctic R. Barrett, D. Boertmann, C. Egevang, org/10.1080/00222930802126904. during summer and autumn. Arctic 53:432–447. M.G. Gavrilo, G. Gilchrist, M. Hario, and others. Laakmann, S., M. Kochzius, and H. Auel. 2009. Moore, S.E., J.M. Grebmeier, and J.R. Davies. 2003. 2008. Framework for a Circumpolar Arctic Seabird Ecological niches of Arctic deep-sea copepods: Gray whale distribution relative to forage habitat Monitoring Network. CAFF CBMP Report Vertical partitioning, dietary preferences and in the northern Bering Sea: Current condi- No. 15. CAFF International Secretariat, Akureyri, different trophic levels minimize inter-specific tions and retrospective summary. Journal of Iceland, 67 pp. competition. Deep-Sea Research Part I 56:741–756, Zoology 81:734–742, http://dx.doi.org/10.1139/ Petersen, M.R., J.B. Grand, and C.P. Dau. 2000. http://dx.doi.org/10.1016/j.dsr.2008.12.017. z03-043. Spectacled eider: Somateria fischeri. A. Poole and Laidre, K.L., I. Stirling, L. Lowry, Ø. Wiig, Mueter, F.J., and M.A. Litzow. 2008. Sea ice retreat F. Gill, eds, The Birds of North America Inc., M.P. Heide-Jørgensen, and S. Ferguson. 2008. alters the biogeography of the Bering Sea conti- no. 57, Philadelphia, PA, 24 pp. Quantifying the sensitivity of arctic marine nental shelf. Ecological Applications 18:309–320, Piatt, J.F., and A.S. Kitaysky. 2002. Tufted Puffin: mammals to climate-induced habitat change. http://dx.doi.org/10.1890/07-0564.1. Fratercula cirrata. The Birds of North America Ecological Applications 18:S97–S125, http://dx.doi. Naidu, A.S. 1988. Marine surficial sediments. Online, A. Poole, ed., Cornell Laboratory of org/10.1890/06-0546.1. Section 1.4 in Bering, Chukchi and Beaufort Seas: Ornithology, Ithaca, NY. Available online at: http:// Li, H., Y. Yu, W. Luo, Y. Zeng, and B. Chen. 2009. Coastal and Ocean Zones Strategic Assessment Data bna.birds.cornell.edu/bna/species/708 (accessed Bacterial diversity in surface sediments from the Atlas. NOAA Strategic Assessment Branch, Ocean June 21, 2011). Pacific Arctic Ocean. Extremophiles 13:233–246, Assessment Division, Washington, DC. Piepenburg, D., P. Archambault, W.G. Ambrose Jr., http://dx.doi.org/10.1007/s00792-009-0225-7. Norcross, B.L., B.A. Holladay, M.S. Busby, and A. Blanchard, B.A. Bluhm, M.L. Carroll, K. Conlan, Lønne, O.J., and G.W. Gabrielsen. 1992. Summer diet K.L. Mier. 2010. Demersal and larval fish assem- M. Cusson, H.M. Feder, J.M. Grebmeier, and of seabirds feeding in sea-ice-covered waters near blages in the Chukchi Sea. Deep-Sea Research others. 2011. Towards a pan-Arctic inventory of Svalbard. Polar Biology 12:685–692. Part II 57:57–70, http://dx.doi.org/10.1016/​ the species diversity of the macro- and mega- Lovejoy, C., E. Pierre, P.E. Galand, and D.L. Kirchman. j.dsr2.2009.08.006. benthic fauna of the Arctic shelf seas. Marine 2011. Picoplankton diversity in the Arctic Ocean Nozais, C., M. Gosselin, C. Michel, and G. Tita. Biodiversity 41:51–70, http://dx.doi.org/10.1007/ and surrounding seas. Marine Biodiversity 41:5–12, 2001. Abundance, biomass, composition and s12526-010-0059-7. http://dx.doi.org/10.1007/s12526-010-0062-z. grazing impact of the sea-ice meiofauna in Piraino, S., B.A. Bluhm, R. Gradinger, and F. Boero. Mace, G.M., W. Cramer, S. Diaz, D.P. Faith, the North Water, northern Baffin Bay. Marine 2008. Sympagohydra tuuli gen. nov. and sp. nov. A. Larigauderie, P. Le Prestre, M. Palmer, Ecology Progress Series 217:235–250, http://dx.doi. (Cnidaria: Hydrozoa) a cool hydroid from the C. Perrings, R.J. Scholes, M. Walpole, and org/10.3354/meps217235. Arctic sea ice. Journal of the Marine Biological others. 2010. Biodiversity targets after O’Corre-Crowe, G.M. 2008. Climate change and the Association of the United Kingdom 88:1,637–1,641, 2010. Current Opinion in Environmental molecular ecology of Arctic marine mammals. http://dx.doi.org/10.1017/S0025315408002166. Sustainability 2:1–6, http://dx.doi.org/10.1016/​ Ecological Applications 18:S56–S76. j.cosust.2010.03.003.

Oceanography | September 2011 247 Poulin, M., N. Daugbjerg, R. Gradinger, L. Ilyash, multidisciplinary investigations at a deep-sea, Wesławski, J.M., M.A. Kendall, M. Włodarska- T. Ratkova, and C. von Quillfeldt. 2011. The pan- long-term observatory in the Arctic Ocean. Kowalczuk, K. Iken, M. Kędra, J. Legezynska, and Arctic biodiversity of marine phytoplankton and Oceanography 18(3):46–61. M.K. Sejr. 2011. Arctic fjord and coastal macroben- sea-ice unicellular eukaryotes: A first-attempt Stockwell, D.A., T.E. Whitledge, S.I. Zeeman, thic biodiversity. Marine Biodiversity 41:71–86. assessment. Marine Biodiversity 41:13–28, http:// K.O. Coyle, J.M. Napp, R.D. Brodeur, A.I. Pinchuk, Węsławski, J.M., S. Kwaśniewski, and L. Stempniewicz. dx.doi.org/10.1007/s12526-010-0058-8. and G.L. Hunt. 2001. Anomalous condi- 2008. Warming in the Arctic may result in Raskoff, K.A. 2010. Bathykorus bouilloni: A new genus tions in the south-eastern Bering Sea, 1997: the negative effects of increased biodiversity. and species of deep-sea jellyfish from the Arctic Nutrients, phytoplankton and zooplankton. Polarforschung 78:105–108. Ocean (Hydrozoa, Narcomedusae, Aeginidae). Fisheries Oceanography 10:99–116, http://dx.doi. Wesławski, J.M., J. Wiktor Jr., and L. Kotwicki. 2010. Zootaxa 2361:57–67. org/10.1046/j.1365-2419.2001.00158.x. Increase in biodiversity in the arctic rocky littoral, Reid, P.C., D.G. Johns, M. Edwards, M. Starr, Sun, M.-Y., L.M. Clough, M.L. Carroll, J. Dai, Sorkappland, Svalbard, after 20 years of climate M. Poulin, and P. Snoeijs. 2007. A biological conse- W.G. Ambrose Jr., and G.R. Lopez. 2009. Different warming. Marine Biodiversity 40:123–130. quence of reducing Arctic ice cover: Arrival of the responses of two common Arctic macrobenthic Wesławski, J.M., J. Wiktor, M. Zajączkowski, and Pacific diatom Neodenticula seminae in the North species (Macoma balthica and Monoporeia S. Swerpel. 1993. Intertidal zone of Svalbard. Atlantic for the first time in 800,000 years. Global affinis) to phytoplankton and ice algae: Will 1. Macroorganism distribution and biomass. Polar Change Biology 13:1,910–1,921, http://dx.doi. climate change impacts be species specific? Biology 13:73–108. org/10.1111/j.1365-2486.2007.01413.x. Journal of Experimental Marine Biology and Wiencke, C., M.N. Clayton, I. Gomez, K. Iken, Renaud, P.E., M. Włodarska-Kowalczuk, H. Trannum, Ecology 376:110–121, http://dx.doi.org/10.1016/​ U.H. Lüder, C.D. Amsler, U. Karsten, D. Hanelt, B. Holte, J.M. Weslawski, S. Cochrane, S. Dahle, j.jembe.2009.06.018. K. Bischof, and K. Dunton. 2007. Life strategy, and B. Gulliksen. 2007. Multidecadal stability of Suydam, R.S., D.L. Dickson, J.B. Fadely, and ecophysiology and ecology of seaweeds in benthic community structure in a high-Arctic L.T. Quakenbush. 2000. Population declines of polar waters. Review in Environmental Science glacial fjord (van Mijenfjord, Spitsbergen). Polar King and Common eiders of the Beaufort Sea. and Biotechnology, http://dx.doi.org/10.1007/ Biology 30:295–305, http://dx.doi.org/10.1007/ Condor 102:219–222, http://dx.doi.org/10.1650/​ s11157-006-9106-z. s00300-006-0183-9. 0010-5422(2000)102[0219:PDOKAC]​2.0.CO;2. Wilce, R.T. 1990. Role of the Arctic Ocean as a bridge Rogacheva, A.V. 2007. Revision of the Arctic Tchesunov, A.V., and F. Riemann. 1995. Arctic sea between the Atlantic and Pacific Oceans: group of species of the family Elpidiidae ice nematodes (Monhysteroidea) with descrip- Fact and hypothesis. Pp. 323–348 in Evolutionary (Elasipodida, Holothuroidea). Marine tions of Cryonemacrassum gen. n. sp. n. and Biogeography of the Marine Algae of the North Biology Research 3:376–396, http://dx.doi. C. tenue. Nematologica 41:35–50, http://dx.doi. Atlantic. D.J. Garbary and G.R. South, eds, org/10.1080/17451000701781880. org/10.1163/003925995X00035. Springer-Verlag. Rogacheva, A.V. 2011. Taxonomy and distribution Tett, P., and E.D. Barton. 1995. Why are there about Wilce, R.T. 1994. The Arctic subtidal as habitat for of the genus Kolga Danielssen and Koren, 1879 5000 species of phytoplankton in the sea? Journal macrophytes. Pp. 89–91 in Seaweed Ecology and (Elpidiidae, Holothuroidea, Echinodermata). of Plankton Research 17:1,693–1,704, http://dx.doi. Physiology. C.S. Lobban and P.J. Harrison, eds, Journal of the Marine Biological Association of org/10.1093/plankt/17.8.1693. Cambridge University Press, Cambridge. the United Kingdom, http://dx.doi.org/10.1017/ Thomas, D., and G. Dieckmann, eds. 2009. Sea Ice: An Wilce, R.T., P.M. Pedersen, and S. Sekida. 2009. S0025315411000427. Introduction to its Physics Chemistry Biology and Chukchi pedicellata gen. et sp. nov. and Ronowicz, M., and P. Schuchert. 2007. Halecium Geology. Wiley-Blackwell, New York, NY, 416 pp. C. endophytica nov. comb., Arctic endemic arcticum (Cnidaria: Hydrozoa), a new species of Vassilenko, S.V., and V.V. Petryashov, eds. 2009. brown algae (Phaeophyceae). Journal hydroid from Spitsbergen. Zootaxa 1,549:55–62. Illustrated Keys to Free-Living Invertebrates of Phycology 45:272–286, http://dx.doi. Sakshaug, E. 2004. Primary and secondary produc- of Eurasian Arctic Seas and Adjacent Deep org/10.1111/j.1529-8817.2008.00631.x. tion in the Arctic Seas. Pp. 57–82 in The Organic Waters, vol. 1. Rotifera, Pycnogonida, Cirripedia, Wulff, A., K. Iken, M.L. Quartino, A. Al-Handal, Carbon Cycle in the Arctic Ocean. R. Stein and Leptostraca, Mysidacea, Hyperiidea, Caprellidea, C. Wiencke, and M.N. Clayton. 2009. Biodiversity, R. MacDonald, eds, Springer, Berlin. Euphausiacea, Dendrobranchiata, Pleocyemata, biogeography and zonation of marine benthic Sirenko, B.I. 2001. List of species of free-living Anomura, and Brachyura. Alaska Sea Grant, micro- and macroalgae in the Arctic and Antarctic. invertebrates of Eurasian Arctic seas and adjacent University of Alaska Fairbanks, 192 pp. Botanica Marina 52:491–507, http://dx.doi. deep waters. Explorations of the Fauna of the Vermeij, G.J., and P.D. Roopnarine. 2008. The coming org/10.1515/BOT.2009.072. Seas 51:1–129. Arctic invasion. Science 321:780–781, http://dx.doi. Wyllie-Echeverria, T., and W.S. Wooster. 1998. Sirenko B.I. 2009. The prosobranchs of the gastro- org/10.1126/science.1160852. Year to year variations in Bering Sea ice cover pods (Mollusca, Gastropoda, Prosobranchia) of Vinogradova, N.G. 1997. Zoogeography of the and some consequences for fish distributions. the Chukchi Sea and Bering Strait, their species abyssal and hadal zones. Advances in Marine Fisheries Oceanography 7:159–170, http://dx.doi. composition and distribution. Explorations of the Biology 32:326–387, http://dx.doi.org/10.1016/ org/10.1046/j.1365-2419.1998.00058.x. Fauna of the Seas 64(72):104–153. S0065-2881(08)60019-X. Zoeckler, C. 2011. In press. Chapter 9: Status, Sirenko, B.I., and S.Y. Gagaev. 2007. Unusual abun- Wassmann, P., C.M. Duarte, S. Agusti, and threat and protection of Arctic waterbirds. In dance of macrobenthos and biological invasions M.K. Sejr. 2011. Footprints of climate change Protection of the Three Poles. F. Huettmann, ed., in the Chukchi Sea. Russian Journal of Marine in the Arctic marine ecosystem. Global Springer Japan. Biology 33:355–364, http://dx.doi.org/10.1134/ Change Biology 17:1,235–1,249, http://dx.doi. S1063074007060016. org/10.1111/j.1365-2486.2010.02311.x. Sirenko, B.I., C. Clarke, R.R. Hopcroft, F. Huettmann, Wassmann, P., M. Reigstad, T. Haug, B. Rudels, B.A. Bluhm, and R. Gradinger, eds. 2010. The M.L. Carroll, H. Hop, G.W. Gabrielsen, Arctic Register of Marine Species (ARMS) Compiled S. Falk-Petersen, S.G. Denisenko, E. Arashkevich, by the Arctic Ocean Diversity (ArcOD) Project. and others. 2006. Food webs and carbon flux in the Available online at: http://www.marinespecies.org/ Barents Sea. Progress in Oceanography 71:232–287, arms (accessed February 12, 2011). http://dx.doi.org/10.1016/j.pocean.2006.10.003. Soltwedel, T., E. Bauerfeind, M. Bergmann, Wei, C.-K., G.T. Rowe, E. Escobar-Briones, A. Boetius, N. Budaeva, E. Hoste, N. Jaeckisch, T. Soltwedel, M.J. Caley, Y. Soliman, F. Huettmann, K. von Juterzenka, J. Matthiessen, V. Mokievsky, F. Qu, Z. Yu, and others. 2010. Global patterns E.-M. Nöthig, and others. 2005. HAUSGARTEN, and predictions of seafloor biomass using random forests. PLoS ONE 5(12):e15323, http://dx.doi. org/10.1371/journal.pone.0015323.

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