Marine Biology (2006) 149: 1577–1583 DOI 10.1007/s00227-006-0311-7

RESEARCH ARTICLE

P. Kuklinski · D. K. A. Barnes · P. D. Taylor

Latitudinal patterns of diversity and abundance in North Atlantic intertidal boulder-fields

Received: 15 November 2005 / Accepted: 24 February 2006 / Published online: 19 April 2006© Springer-Verlag 2006

Abstract In order to study taxon richness, biodiversityand abundance patterns in the North Atlantic from tem-perate latitudes through Arctic to high Arctic latitudes,we recorded the faunas (at ELWS level) colonizing 20cobbles from three sites at each of seven boulder-Weldlocalities (south-west England, 50°N; Wales, 51°N; westScotland, 56°N; Iceland, 64°N; Tromsø, 70°N; Svalbard,77°N, 79°N). Inverse correlations were found betweenlatitude and all measures of richness (species, orders, andphyla numbers) and biodiversity (S–W, P). However,these correlations were driven mostly by the consistentlyimpoverished Arctic sites; an even cline of decreasingdiversity from south to north did not exist. Multidimen-sional scaling revealed two communities, temperate–sub-arctic species-rich and high arctic species-poor. Evennessas measured by Pielou’s index was similar across all lati-tudes. Abundance data exhibited a similar trend to thespecies richness and diversity data with a signiWcant neg-ative correlation with latitude, but when Arctic datawere excluded the correlation vanished.

Introduction

The diversity of life in the sea is not geographically uni-form: some areas are much richer in taxa than others.

Interest in quantifying and understanding patterns ofbiodiversity has been a feature of ecological science formany decades and even today provokes much debate inthe primary literature. Point studies have revealed snap-shots of marine richness, often adjacent to marine bio-logical laboratories. Rigorously collected data on marinediversity still lags behind that for terrestrial environ-ments but in the last few decades patterns at the scale ofocean basins have been documented for a few taxonomicgroups (Stehli and Wells 1971; Roy et al. 1998; Boschi2000; Crame 2000; Giangrande and Licciano 2004). Nev-ertheless, major trends in species richness and organis-mal abundance generally remain poorly known and/orunexplained (Clarke 1992; Gray 2001). The current hardsubstrate communities study investigates a speciWc habi-tat across a large scale spatial gradient, focusing onchanges in richness with latitude.

There is patchy evidence for a latitudinal cline insome marine taxa in the northern hemisphere, e.g. bry-ozoans (see Clarke and Lidgard 2000). Most studiesreporting distinct latitudinal clines in the sea attributethis to a decrease in diversity from mid to high latitudesonly (e.g. Roy et al. 1998). In other taxa or habitats lati-tudinal clines are less obvious, e.g. brachiopods (Walsh1996), macroalgae (Santelices and Marquet 1998) and onsoft bottoms (Kendall and Aschan 1993). As the stron-gest gradients reported to date have concerned calcare-ous epifauna in the northern hemisphere (see Clarke1992), we designed a sampling regime to test latitudinalchanges in North Atlantic hard substratum epifaunas.

Not all habitat types occur across all latitudes. Boul-der-Welds, however, are one of the most ubiquitouscoastal habitats from high polar to tropical latitudes andare thus ideally suited for investigating latitudinal clines.Organisms inhabiting boulder-Welds are exposed toextremes of mechanical and chemical disturbance (Sousa1979). Disturbance is further ampliWed in polar regionswhere boulder-Welds are among the most disturbedaquatic habitats on Earth because of summer ice scour,intense wave action and fresh water runoV, coupled withthe freezing temperatures and ice foot during winter (see

Communicated by J.P. Thorpe, Port Erin

P. KuklinskiInstitute of Oceanology, Polish Academy of Sciences, ul.Powstancow Warszawy 55, Sopot, 81-712, Poland

Present address: P. Kuklinski (&) · P. D. TaylorNatural History Museum, Cromwell Road, London, SW7 5BD, UKE-mail: p.kuklinski@nhm.ac.ukTel.: +44-207-9426062Fax: +44-207-9425546

D. K. A. BarnesBritish Antarctic Survey N.E.R.C, High Cross, Madingley Road, Cambridge, CB3 0ET, UK

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Barnes 1999). Aspects of competition for space in boul-der-Welds vary in distinct clines from the poles to the tro-pics (Barnes 2002; Barnes and Kuklinski 2003). Across anear global gradient, Witman et al. (2004) found a strongcline of richness on rocks with latitude but included noArctic sites in their study which was restricted in its taxo-nomic resolution by the photographic techniqueemployed. In most of the studies latitudinal decline ofspecies richness towards the poles was chieXy based onregional diversity and not due to variation in local spe-cies richness (but see Witman et al. 2004). Here wemostly investigate local species richness and abundancewithin boulder-Welds along a North Atlantic latitudinaltransect from 50°N to 79°N. This study attempts toestablish the pattern of biodiversity trends from temper-ate regions to the high Arctic using a consistent method-ology, a single habitat and the same observers. Thehypothesis tested is that boulder-Weld assemblages willshow steadily decreasing taxon richness, diversity andabundance from temperate to Arctic latitudes due to fac-tors such as smaller regional species pools (e.g. Roy et al.1998; Clarke and Lidgard 2000) and increased distur-bance (Conlan et al. 1998).

Materials and methods

Study area

Seven boulder-Welds were selected for sampling along theNorth Atlantic shorelines of the west coast of Europebetween 50°N and 79°N (Fig. 1). These sites were inEngland (Lyme Regis, 50°N, 3°W), Wales (Dale, 51°N,5°W), Scotland (Oban, 56°N, 5°W), Iceland (64°N,22°W), Norway (Tromsø, 70°N, 19°E) and two on Sval-bard (Hornsund: 77°N, 15°E; Kongsfjorden: 79°N,12°E).Samples were collected in the spring and summerbetween 2002 and 2005. The sample sites were all charac-terised by mixed boulders and cobbles and had similarproWles but diVered in mean annual seawater and airtemperature, tidal amplitude, wave strength and preva-lence of ice. At all sites the cobbles and boulders com-prised hard, Wrmly cemented rocks that did not easilycrumble. The high Arctic sites at Svalbard were typicallyscoured by Xoating ice during summer months and fastice during the winter. In addition the salinity regime ofthe Svalbard sites Xuctuated seasonally, being as low as32–25 psu in June. Tidal amplitude at Svalbard is typi-cally »1 m, whereas the mean tidal amplitude may rangefrom approx. 1.1 (neap) to 3.3 m (springs) in the lowerlatitude sites. The mean summer coastal sea water tem-peratures of the Tromsø, Reykjavik and Oban sites weresimilar (12–14°C), with salinity varying little (33–34 psu).

Protocol

For all seven sites at least 20 cobbles were haphazardlycollected from each of three samples (here termed

stations, 10–100 m apart), except for Dale (Wales) whereonly 23 cobbles were gathered from one station due tologistic problems. In all cases samples were collected fromaround extreme low water spring (ELWS) level. Thenumber and identities of all colonisers were recorded tothe lowest taxonomic level possible, typically species. Forthe purpose of this study each colony of a colonial specieswas considered as one individual. In order to analyze ifsampling eVort was representative for all seven sites, spe-cies, order and phylum accumulation curves were plotted.

We calculated the following parameters: taxon rich-ness at species, order and phylum levels; two measures ofdiversity—Pielou evenness index and Shannon–WienerH’ information function (log base e); and abundance perspecies. We plotted trends in these parameters as meanvalues and standard deviations versus latitude. The rela-tive similarity of site assemblages was compared and dis-played using PRIMER software package (Clarke andGorley 2001); following fourth root transformation ofdata, Bray–Curtis similarity measures were calculated(Bray and Curtis 1957). Samples were then classiWed intogroups by hierarchical agglomerative clustering usinggroup-average linking. The inter-relationship betweensamples was mapped using the ordination techniquecalled non-metric, multidimensional scaling (nMDS).

All data (number of species, orders and phylas, totalabundance, Pielou evenness and Shannon–Wiener H’diversity) were subjected to ANOVA with site and lati-tude as spatial factors. Parametric Pearson product-moment correlation was used to evaluate relationshipsand signiWcance between the species, order and phylum

Fig. 1 Sampling sites (L Lyme Rygies, D Dale, O Oban, I Iceland,T Tromsø, H Hornsund, K Kongsfjorden)

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richness, total abundance, Pielou evenness index andShannon–Wiener H’ diversity index, and latitude.

Results

Richness

The 383 cobbles collected were colonized by 13,183 recruitsbelonging to 99 taxa, bryozoans being the richest taxonalthough comprising only 2,371 (18%) of the recruits. Spe-cies accumulation plots for Wve sites (Lyme Regis, Oban,Tromsø, Hornsund, Kongsfjorden) approached an asymp-tote, while for two remaining sites (Dale, Iceland) accumu-lation plots were still increasing. Order and phylaaccumulations curves levelled before all the samples wereincluded. Thus the sampling appears to have been repre-sentative for study sites. The richest site was that at Dale,Wales (51°N) where 44 species were recognised. Recruitsattained maximum abundance at Tromsø in Norwaywhere 2,459 individuals were recorded. In contrast, therewas no fauna at one station from the Hornsund site inSvalbard (77°N). There were signiWcant diVerencesbetween the species richness values of the sites (ANOVA,F6=26.78, P<0.001). We found a signiWcant negative cor-relation between the number of species present and latitude(r=¡0.77, P<0.001), but visualisation of the data (Fig. 2a)showed the pattern to be strongly dependent on the impov-erished level of the high Arctic sites. On reanalysis exclud-ing data from these Svalbard sites, there was no correlationbetween species number and latitude (r=¡0.22, P<0.48).We found >10 and <45 species at stations/sites between50°N and 70°N but much lower numbers at the high Arcticsites, the boulder-Welds falling into two latitudinal group-ings: temperate–subarctic and high Arctic.

At higher taxonomic levels we found similar patternsof richness variation with latitude. At both order-(Fig. 2b) and phylum-levels (Fig. 2c) there were signiW-cant diVerences between the taxon richness values of thesites (F6>30, P<0.001 for both). There were strong neg-ative correlations between both number of orders andnumber of phyla versus latitude (r=¡0.72, P<0.001 forboth correlations). On repeating these analyses withoutthe Svalbard sites, no correlation was found (r=¡0.02,P=0.936 for both analyses). As with species level pat-terns, a higher but much more variable level of order andphylum richness was evident at temperate and subarcticcompared to high Arctic sites.

Multivariate analysis nMDS showed sites to be clus-tered into two distinct groupings at species level: highArctic and temperate-subarctic (Fig. 3). The high Arcticsamples were much more scattered in comparison to thetemperate–subarctic samples. Thus multivariate analysissupported our interpretation of variation in richnesswith latitude being stepped rather than forming asmooth cline. Multivariate analysis of order and phylumrichness with latitude showed the same split betweenhigh Arctic and temperate–subarctic sites.

Diversity

Shannon–Wiener H’ values (base e) varied between 0(Hornsund 77°N, Kongsfjorden 79°N) and 2.50 (Dale51°N) (Fig. 4). There were signiWcant diVerences betweenthe H’ diversity of sites (ANOVA, F6=6.36, P=0.001). Aswith the patterns of taxon richness described above, thespread of data was more suggestive of a stepped patternthan a smooth latitudinal cline. Although there was a sig-niWcant negative correlation (r=¡0.59; P=0.002) (Fig. 4)when all sites were included, this became non-signiWcant

Fig. 2 Mean values § SD of species (a), orders (b) and phyla (c) foreach of the sampled station (for the station at 51°N there was onlyone sample so no SD could be generated)

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(r=0.10; P=0.73) after exclusion of the high Arctic sites.We found similar patterns with negative correlations(r=¡0.57, P<0.001) at order- and phylum-level but these

too became non-signiWcant when reanalysed without thehigh Arctic data (r=0.08; P=0.79). Thus for diversity, asfor richness, low latitudes were characterised by high val-ues whereas high Arctic sites were impoverished.

In contrast, evenness varied little between sites. Pie-lou’s evenness index values varied from 0 (Hornsund77°N, Kongsfjorden 79°N) to 0.91 (Kongsfjorden 79°N)(Fig. 4). No signiWcant diVerence was found in species-level evenness between sites (ANOVA, F6=1.04;P=0.43). There was correspondingly no correlationbetween Pielou’s evenness at species-level and latitude(r=0.10; P=0.62). Similar results were obtained atorder- and phylum-levels (r=¡0.05; P=0.80).

Abundance

Of the 13183 individuals recorded on cobbles from theboulder-Welds, nearly half (5,100) were polychaetes withbryozoans being the second most numerous group(2,141 colonies). Echinoderms were the least well repre-sented phylum (5 individuals). Abundance values variedfrom 0 (Hornsund 77°N) to 2,288 (Tromsø 70°N) indi-viduals per sample. The scale of variability (shown asstandard deviation on Fig. 5) was lowest at Kongsfjor-den (79°N) and highest at Tromsø (70°N). There weresigniWcant diVerences in faunal abundance between sites(ANOVA, F6=7.12, P=0.006). A general trend wasapparent of decreasing abundance with increasing lati-tude (Fig. 5). This was conWrmed by a strong negativesigniWcant correlation (r=¡0.74, P<0.001). However,faunal abundance at one site, Tromsø, was anomalouswith respect to the general trend. Mean epifaunal abun-dance was very high (1,027 ind./station) and much morevariable (range from 239 to 2,288 ind./sample) atTromsø than the other sites. Reanalysis of the trendwithout the Tromsø data revealed a stronger negativecorrelation (r=¡0.88; P<0.001) between abundanceand latitude.

Fig. 3 Multidimensional scaling (nMDS) based on Bray–Curtissimilarities calculated from fourth-rooted transformed speciesabundance data

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Fig. 4 Shannon–Wiener H’ diversity index § SD (a) and Pielouevenness index § SD (b) for all sampled stations

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Discussion

Spatial patterns of marine epifaunal richness and diversity

Half a century of sampling species (as well as generic andfamilial) richness across a range of diVerent higher taxahas lead to the establishment of a prevailing paradigm ofrichness with respect to latitude. Broadly, richness is con-sidered to decrease from tropics to poles in both terres-trial and marine realms (e.g. Stehli and Wells 1971;Kaufman and Willig 1998; Roy et al. 1998; Crame 2000;Gaston and Blackburn 2000; Clarke 1992; Valdovinoset al. 2003). Many workers have considered this latitudi-nal cline in richness to be of great importance and haveoVered explanations for the pattern (e.g. see Allen et al.2002). However, there is still a need to establish whethersuch a pattern actually exists before attempting toexplain it. The supposed latitudinal richness cline ismuch more apparent in the northern hemisphere thanthe south, and also in certain taxa and environmentsthan in others (see Clarke 1992; Gray 2001). The currentstudy, in contrast to most of the literature, controls forhabitat, sampling eVort, area, collecting method andapparatus, and observer, and includes high polar lati-tudes. Potential sources of error in our study could bedriven by too narrow a scale of investigation or too low asampling eVort.

Our data reveal a clear poleward decrease in localrichness and diversity (at multiple taxonomic levels,Fig. 2), but not a smooth cline. As with other data fromspeciWc taxa (Roy et al. 1998) or habitats (Witman et al.2004), poleward decrease is dependent on the depressedlevel of the Arctic biota. When high Arctic data wereexcluded from our analysis we found no signiWcant cor-relation between richness (or diversity) and latitude. Thepattern instead shows two distinct diversity levels, onedue to the rich temperate–subarctic community and theother to the impoverished Arctic community. This two-level richness was supported over a smooth cline modelby nMDS (see Fig. 3). Ellingsen and Gray (2002) investi-gating richness patterns along the Norwegian continen-tal shelf also found no evidence for a cline fromtemperate to low Arctic regions (across a latitudinalrange of 56°N–71°N). In further contrast to the general-ised poleward decrease of taxa, Barnes (2005) found thatrichness of communities, similar to those in the currentstudy, slightly increased from southern temperate topolar latitudes (across a latitudinal range of 54°S–68°S).

Factors inXuencing species richness and diversitywithin temperate–subarctic communities are diYcult toidentify. Among the sites here investigated there arediVerences in, for example, tidal height and air and sea-water temperatures, but these are not a pronouncedcause of data variability. Ellingsen and Gray (2002) alsofound that for the Norwegian continental shelf faunathere was either no or little relationship between diver-sity and measured environmental factors. We, therefore,

probed for diVerences on a higher scale, between temper-ate–subarctic and Arctic environments.

Published literature (e.g. Pianka 1966; Rosenzweig1995; Roy et al. 1998; Allen et al. 2002; Willig et al. 2003)contains many hypotheses explaining latitudinal gradi-ents of taxon richness. Factors such as competition, pre-dation, time, climate stability, regional species pool andproductivity have been suggested as relevant to a rich-ness-latitude relationship. For example Dauvin et al.(1994) did not Wnd a gradient with latitude among forsoft bottom polychaetes in the Northeast Atlantic. Whenthey excluded stations below 700 m depth, higher diver-sity was observed at 55°N–80°N than in the latitudesbetween 45°N and 55°N, which is in contrast to manyexisting studies. Biological and ecological adaptationswithin this taxon was one of their explanations of theobserved pattern. Taylor and Taylor (1977) showed asteady decrease in predatory gastropod species fromArctic regions to latitudes around 43°N. They concludedthat the lower number of predatory species found at midlatitudes could be due to greater temperature Xuctua-tions found in shallow waters at these latitudes. Theseexamples show the complexity of factors which coulddrive species richness. Very often local diversity reXectsthe richness of the regional species pool (Cornell andKarlson 1996; Witman et al. 2004). Rex et al. (1997)investigated diversity of deep-sea prosobranch gastro-pods and showed a clear latitudinal diversity gradientfrom the equator to 77°N in the North Atlantic. Theirdata were positively related to regional diversity. Otherpublished data conWrm that the regional species pool canbe low (for well-studied taxa) in the Arctic (e.g. Roy et al.1998; Clarke and Lidgard 2000). A major explanatoryfactor is undoubtedly that the Arctic is geologicallyyoung and still in the process of colonization (Dayton1990; Dunton 1992). In the case of the Svalbard archipel-ago, there is evidence that the regional species pool issmaller than that of Norway (Brattegard and Holte1997; Gulliksen et al. 1999), correlating with smallershelf area, greater isolation, and lower solar energy input(see Roy et al. 1998; Allen et al. 2002). Hypothesesexplaining regional diversity are relevant to the interpre-tation of our data because of the ‘downstream’ eVect ofgamma diversity on alpha diversity.

MacArthur (1972) suggested that there should be nodiVerence in sample species (local) richness between lowand high latitudes. Some recent studies have corrobo-rated this suggestion (Clarke and Lidgard 2000; Elling-sen and Gray 2002). Consequently the results weobtained for the study sites at 50°N–70°N are not sur-prising. The high Arctic sites were, however, much lowerin diversity. Besides the smaller Arctic species pool incomparison to lower latitudes, this impoverishment isprobably explained also by the high frequency and inten-sity of disturbance by strong wind and wave action andice scour such that macrobiotic assemblages have littletime to develop to the stage beyond pioneers (see Conlanet al. 1998; Gutt 2001). Comparable Antarctic assem-blages aVected by iceberg scour also tend to be species

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poor (Arntz et al. 1994; Brown et al. 2004 but see Barnesand Brockington 2003). High levels of disturbance in theArctic are also reXected in the apparent lack of intertidalspecialists. Intertidal boulder-Weld colonizers largely aresourced from more stable subtidal populations nearby(Kuklinski and Barnes 2005). In contrast, we found thatintertidal boulder-Weld communities at lower latitudesinclude specialist species, such as the bryozoan Umbon-ula littoralis Hastings. It seems likely that at a criticallevel of disturbance, boulder-Weld communities areunable to support their own stable communities and aredependent on nearby subtidal populations for replenish-ment. Our results suggest that the number of speciescoexisting in local boulder-Weld communities in the highArctic is controlled by physical disturbance, while thetemperate–subarctic may be inXuenced more by biologi-cal interactions (e.g. larval dispersal strategies, popula-tion dynamics). The examples of deep-sea prosobranchgastropods indicates that species richness of stable envi-ronments will depend more on the regional species pool(Rex et al. 1997), while in more dynamic environments itwill be more dependent on factors operating at a localscale.

Spatial patterns of abundance

In general our abundance data did show a decreasewith latitude but variations in within-site variabilitywas the most striking feature. Within-site variabilitywas notably high at Tromsø compared to elsewhere.Weslawski et al. (1993) observed high variability in bio-mass at the km scale in W. Spitsbergen (Isfordenregion) but our high Arctic samples showed uniformlylow levels of abundance. The low levels of high Arcticintertidal abundance reported here are typical of thosereported from Arctic and Antarctic intertidal zones (seeBarnes and Brockington 2003). Abundance at the otherisolated island study site, Iceland, was also low, butsome of the samples at Tromsø were similar. However,replicate samples within 10 m of low abundance sam-ples at Tromsø contained abundant macrobiota.Clearly processes acting at small spatial scales are par-ticularly important in governing diversity levels (asthey are in the patchy ice scoured subtidal zone of polarregions) at this site. Part of the explanation for the highvariability at Tromsø may be its transitional positionbetween essentially temperate and true Arctic regionsthat are strongly inXuenced by seasonal ice and relatedoceanographic factors. Older literature has suggestedthat numbers of individuals should be similar at lowand high latitudes (e.g. Klopfer and MacArthur 1960).Our data found no support for this uniformity. Fur-thermore, intertidal boulder-Weld assemblages in thehigh Canadian Arctic are similarly impoverished(DKAB personal observation). The retreat of coastalsnow and ice predicted over the next several decadesshould, however, drastically increase the time high lati-tude intertidal sites are available for colonisation.

Conclusions

Patterns of biodiversity, evenness and abundance arequite distinct along NW European shores. No consistentcline of North Atlantic coastal biodiversity could bedetected in local diversity levels of sessile biotas on cob-bles from intertidal boulder-Welds across the NW Euro-pean latitudes (50°N–79°N) covered by this study.However signiWcant correlations between latitude andtaxonomic richness and diversity were detected at species-, order-, and phylum-level. These were driven by the twohigh Arctic sites being highly impoverished relative tolower latitude sites at 70°N and further south. Neither oftwo paradigms—that point richness changes little or thatthere is a strong latitudinal cline—are supported by ourdata. Overall there are two very diVerent communitieswith contrasting levels of richness and diversity—a spe-cies-rich temperate–subarctic community and a species-poor high Arctic community. Despite this, evenness var-ied little with latitude. Animal abundance showed someevidence for a latitudinal cline, but we found anoma-lously high variability amongst the Tromsø samples.Lower regional diversity in the Arctic may contribute tothe impoverishment of sessile biotas, but factors operat-ing at a local scale may be more important in explainingthe patterns found. In particular, low local diversity in theArctic is likely governed by extreme levels of disturbance.

Acknowledgments We would like to thank several people withoutwhom this study would not have been possible: Jan Marcin Weslaw-ski, Wojtek Walkusz, Kit Kovac, Haakon Hop, Joanne Porter andAdam Hughes. We also grateful to two anonymous reviewers forcomments leading to an improved manuscript. The study has beencompleted thanks to the Wnancial support to one of us (PK) from theEU Marie Curie programme BRYOARC.

References

Allen AP, Brown JH, Gillooly JF (2002) Global biodiversity, bio-chemical kinetics, and the energetic-equivalence rule. Science297:1545–1547

Arntz WE, Brey T, Gallardo AV (1994) Antarctic zoobenthos. Oce-anogr Mar Biol 32:241–304

Barnes DKA (1999) The inXuence of ice on polar near shore ben-thos. J Mar Biol Assoc UK 79:401–407

Barnes DKA (2002) Polarization of competition increases with lati-tude. Proc R Soc Lond B 269:2061–2069

Barnes DKA (2005) Changing chain: past, present and future of theScotia Arc’s and Antarctica’s shallow benthic communities. SciMar 69:65–89

Barnes DKA, Brockington S (2003) Zoobenthic biodiversity, bio-mass and abundance at Adelaide Island, Antarctica. Mar EcolProg Ser 249:145–155

Barnes DKA, Kuklinski P (2003) High polar spatial competition: ex-treme hierarchies at extreme latitude. Mar Ecol Prog Ser 259:17–28

Boschi EE (2000) Biodiversity of marine decapod brachyurans ofthe Americas. J Crustacean Biol 20:337–342

Brattegard T, Holthe T (1997) Distribution of marine, benthic mac-ro-organisms in Norway. A tabulated catalogue. Preliminaryedition. Research report No. 1991–1 Directorate for nature man-agement, Trondheim, Norway, pp 409

1583

Bray JR, Curtis JT (1957) An ordination of the upland forest com-munities of southern Wisconsin. Ecol Monogr 27:325–349

Brown KM, Fraser KPP, Barnes DKA, Peck LS (2004) Links be-tween the structure of an Antarctic shallow-water communityand ice-scour frequency. Oecologia 141:121–129

Clarke A (1992) Is there a latitudinal diversity cline in the sea?Trends Ecol Evol 7:286–287

Clarke KR, Gorley RN (2001) PRIMER v5: user manual/tutorial,Plymouth:PRIMER—E

Clarke A, Lidgard S (2000) Spatial patterns of diversity in the sea:bryozoan species richness in the North Atlantic. J Anim Ecol69:799–814

Conlan KE, Lenihan HS, Kvitek RG, Oliver JS (1998) Ice scour dis-turbance to benthic communities in the Canadian high Arctic.Mar Ecol Prog Ser 166:1–16

Cornell HV, Karlson RH (1996) Species richness of reef-building coralsdetermined by local and regional processes. J Anim Ecol 65:233–241

Crame JA (2000) Evolution of taxonomic diversity gradients in themarine realm: evidence from the composition of recent bivalvefaunas. Paleobiology 26:188–214

Dauvin JC, Kendall M, Paterson G, Gentil F, Jirkov I, Sheader M,de Lange M (1994) An initial assessment of polychaete diversityin the Northeastern Atlantic Ocean. Biodivers Lett 2:171–181

Dayton PK (1990) Polar benthos. In: Smith WO (ed) Polar oceanog-raphy, Academic, London, pp 6 31–685

Dunton KH (1992) Arctic biogeography: the paradox of the marinebenthic fauna and Xora. Trends Ecol Evol 7:183–189

Ellingsen KE, Gray JS (2002) Spatial patterns of benthic diversity: isthere a latitudinal gradient along the Norwegian continentalshelf? J Anim Ecol 71:373–389

Gaston KJ, Blackburn TM (2000) Pattern and process in macroecol-ogy. Blackwell, Oxford

Giangrande A, Licciano M (2004) Factors inXuencing latitudinalpattern of biodiversity: an example using Sabellidae (Annelida,Polychaeta). Biodivers Conserv 13:1633–1646

Gray JS (2001) Antarctic marine benthic biodiversity in a world-wide latitudinal context. Polar Biol 24:633–641

Gulliksen B, Palerud R, Brattegaard T, Sneli J (1999) Distribution ofmarine benthic macroorganisms at Svalbard (including Bear Is-land) and Jan Mayen. Research report for DN 1999 4. Director-ate for nature management, Trondheim, pp 148

Gutt J (2001) On the direct impact of ice on marine benthic commu-nities, a review. Polar Biol 24:553–564

Kaufmann DM, Willig MR (1998) Latitudinal patterns of mamma-lian species richness in the New World: the eVects of samplingmethod and faunal group. J Biogeogr25:795–805

Kendall MA, Aschan M (1993) Latitudinal gradients in the struc-ture of macrobenthic communities: a comparison of Arctic, tem-perate and tropical sites. J Exp Mar Biol Ecol 172:157–169

Klopfer PH, MacArthur RH (1960) Niche size and faunal diversity.Amer Nat 94:293–300

Kuklinski P, Barnes DKA (2005) Bryodiversity on coastal bouldersat Spitsbergen. In: Moyano J, Cancino J, Wase-Jackson PN (eds)Bryozoan studies 2004. Balkema, Abingdon, pp 161–172

MacArthur RH (1972) Geographical ecology: patterns in the distri-bution of species. Harper and Row, New York

Pianka ER (1966) Latitudinal gradient in species diversity: a reviewof concepts. Am Nat 910:33–46

Rex MA, Etter RJ, Stuart CT (1997) Large-scale patterns of speciesdiversity in the deep-sea benthos. In: Ormond RFG, Gage JD,Angel MV (eds) Marine biodiversity. Patterns and processes.Cambridge University Press, Cambridge, pp 94–121

Rosenzweig ML (1995) Species diversity in space and time. Cam-bridge University Press, Cambridge

Roy K, Jablonski D, Valentine JW, Rosenberg G (1998) Marine lat-itudinal diversity gradients: tests of causal hypotheses. Proc NatlAcad Sci USA 95:3699–3702

Santelices B, Marquet PA (1998) Seaweeds, latitudinal diversity pat-terns, and the rapoport’s rule. Divers Distrib 4:71–75

Sousa WP (1979) Disturbance in marine intertidal boulder Welds: thenonequilibrium maintenance of species diversity. Ecology60:1225–1239

Stehli FG, Wells JW (1971) Diversity and age patterns in hermatypiccorals. Syst Zool 20:115–126

Taylor JD, Taylor CN (1977) Latitudinal distribution of predatorygastropods on the eastern Atlantic shelf. J Biogeogr 4:73–81

Valdovinos C, Navarrete SA, Marquet PA (2003) Mollusk speciesdiversity in the Southeastern PaciWc: why are there more speciestowards the pole? Ecography 26:139–144

Walsh JA (1996) No second chances? New perspectives on bioticinteractions in post-palaeozoic brachiopod history. In: CooperP, Jin J (eds) Brachiopods. Balkema, Rotterdam, pp 281–288

Weslawski JM, Wiktor J, Zajaczkowski M, Swerpel S (1993) Inter-tidal zone of Svalbard 1. Macroorganism distribution and bio-mass. Polar Biol 13:73–79

Willig MR, Kaufman DM, Stevens RD (2003) Latitudinal gradientsof biodiversity: pattern, process, scale, and synthesis. Annu RevEcol Evol Syst 34:273–309

Witman JD, Etter RJ, Smith F (2004) The relationship between re-gional and local species diversity in marine benthic communi-ties: a global perspective. Proc Natl Acad Sci USA 101:15644–15669