Biodiversity and community composition of sediment macrofauna associated with deep-sea Lophelia pertusa habitats in the Gulf of Mexico

Author's Accepted Manuscript

Biodiversity and community composition of sediment macrofauna associated with deepsea Lophelia pertusa habitats in the gulf of Mexico Amanda W.J. Demopoulos, Jill R. Bourque, Janessy Frometa

www.elsevier.com/locate/dsri

PII: DOI: Reference:

S0967-0637(14)00143-5 http://dx.doi.org/10.1016/j.dsr.2014.07.014 DSRI2383

To appear in:

Deep-Sea Research I

Received date: 7 November 2013 Revised date: 23 July 2014 Accepted date: 30 July 2014 Cite this article as: Amanda W.J. Demopoulos, Jill R. Bourque, Janessy Frometa, Biodiversity and community composition of sediment macrofauna associated with deep-sea Lophelia pertusa habitats in the gulf of Mexico, Deep-Sea Research I, http://dx.doi.org/10.1016/j.dsr.2014.07.014 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Title: Biodiversity and community composition of sediment macrofauna associated with deepsea Lophelia pertusa habitats in the Gulf of Mexico

Authors: Amanda W.J. Demopoulos a*, Jill R. Bourque b, Janessy Frometa b

Affiliations: a U.S. Geological Survey Southeast Ecological Science Center, 7920 NW 71st St, Gainesville, FL, USA; b Cherokee Nation Technology Solutions, Contracted to the U.S. Geological Survey, Southeast Ecological Science Center, 7920 NW 71st St, Gainesville, FL, USA *Corresponding author: Phone: (352) 264-3490 FAX (352) 378-4956 Email [email protected]

ABSTRACT Scleractinian corals create three-dimensional reefs that provide sheltered refuges, facilitate sediment accumulation, and enhance colonization of encrusting fauna. While heterogeneous coral habitats can harbor high levels of biodiversity, their effect on the community composition within nearby sediments remains unclear, particularly in the deep sea. Sediment macrofauna from deep-sea coral habitats (Lophelia pertusa) and non-coral, background sediments were examined at three sites in the northern Gulf of Mexico (VK826, VK906, MC751, 350-500 m depth) to determine whether macrofaunal abundance, diversity, and community composition near corals differed from background soft-sediments. Macrofaunal densities ranged

1

from 26 to 125 individuals 32 cm-2 and were significantly greater near coral versus background sediments only at VK826. Of the 86 benthic invertebrate taxa identified, 16 were exclusive to near-coral habitats, while 14 were found only in background sediments. Diversity (Fisher’s ) and evenness were significantly higher within near-coral sediments only at MC751 while taxon richness was similar among all habitats. Community composition was significantly different both between near-coral and background sediments and among the three primary sites. Polychaetes numerically dominated all samples, accounting for up to 70% of the total individuals near coral, whereas peracarid crustaceans were proportionally more abundant in background sediments (18%) than in those near coral (10%). The reef effect differed among sites, with community patterns potentially influenced by the size of reef habitat. Taxon turnover occurred with distance from the reef, suggesting that reef extent may represent an important factor in structuring sediment communities near L. pertusa. Polychaete communities in both habitats differed from other Gulf of Mexico (GOM) soft sediments based on data from previous studies, and we hypothesize that local environmental conditions found near L. pertusa may influence the macrofaunal community structure beyond the edges of the reef. This study represents the first assessment of L. pertusa-associated sediment communities in the GOM and provides baseline data that can help define the role of transition zones, from deep reefs to soft sediments, in shaping macrofaunal community structure and maintaining biodiversity; this information can help guide future conservation and management activities.

2

HIGHLIGHTS Infauna near three deep-sea coral sites in the Gulf of Mexico were characterized. Macrofaunal communities differed between near-coral and background habitats. Near-coral communities were less variable than background communities at Viosca Knoll. Taxa turnover occurred with distance from Lophelia pertusa reefs. Reef-influence on adjacent communities may be a function of habitat size. Coral-adjacent sediments support regionally distinct polychaete communities.

KEYWORDS Lophelia pertusa, sediment macrofauna, beta diversity, cold-water corals, community ecology, Gulf of Mexico

1.

Introduction Coral reefs create heterogeneous, three-dimensional structures providing niches for a

variety of species, enhancing local diversity (Wenner et al., 1983; Gratwicke and Speight, 2005), and influencing the structure and function of benthic communities found in adjacent soft sediments (Posey et al., 1992; Posey and Ambrose, 1994; Barros et al., 2001; Langlois et al., 2005, 2006). Reefs modify sediment characteristics by altering flow environments, facilitating localized sediment deposition and enhancing available organic material, all of which can affect adjacent benthos (Jumars and Nowell, 1984; Lenihan, 1999). Effects of reef proximity, often termed reef halos (e.g., Posey et al., 1992; Langlois et al., 2005), can include increased benthic diversity and abundance associated with enhanced organic input from reefs (Barros et al., 2001;

3

Danovaro et al., 2002), or decreased abundance of sediment fauna associated with increased foraging by predators utilizing the reef habitat as a refuge (Posey et al., 1992; Posey and Ambrose, 1994; Langlois et al., 2005), although both effects are often considered localized and highly variable at distances less than 10 m from the reef (Posey et al., 1992; Barros et al., 2001; Danovaro et al., 2002). Habitat fragmentation and varying patch sizes can also influence sediment community structure by altering the proportion of critical edge and transitional habitat (Harwell et al., 2011). In addition, increased three-dimensional habitat complexity has been linked to increased abundance and diversity of fauna found within a reef (Auster et al., 2005; Gratwicke and Speight, 2005; Wilson et al., 2007), which may have a corresponding effect on adjacent benthos. Despite the potential importance of adjacent sediment habitats in maintaining reef biodiversity and ecosystem functioning, the overall spatial extent of the influence of an individual reef on the surrounding substrate is still poorly understood. In cold-water environments, the globally distributed azooxanthellate scleractinian coral Lophelia pertusa is the most common reef-building species, occurring in water temperatures ranging from 4 to 12ºC and at depths ranging from 200 to 1000 m (Freiwald et al., 2004; Thiem et al., 2006). Lophelia pertusa reefs occur on topographic high points (Frederiksen et al., 1992; Rogers, 1999) where accelerated currents influence larval transport and enhance organic matter supply (Thiem et al., 2006; van Oevelen et al., 2009) facilitating coral settlement onto hard substrates. Growth of L. pertusa is estimated at 1-25mm per year (Roberts, 2002), with some reefs calculated to be >1000 years old (Rogers, 1999; Costello et al., 2005). Given their slow growth rates and vulnerability to human disturbances such as fishing, trawling (Fosså et al., 2002; Hall-Spencer et al., 2002), and oil excavating activities (Gass and Roberts, 2006), characterizing the relationship between L. pertusa and its associated fauna is needed to quantify

4

the diversity associated with reef habitats and understand deep-sea coral ecosystem function (Mortensen and Fosså, 2006) prior to disturbance. Lophelia pertusa reefs enhance local biodiversity by facilitating the colonization of sessile fauna onto coral skeletons, providing structural refuges within created microhabitats, increasing spawning habitat and nursery grounds, and enhancing available organic material (i.e., food) within the structure through enhanced sediment accumulation (e.g., Jensen and Frederiksen, 1992; Mortensen et al., 1995; Fosså et al., 2002; Raes and Vanreusel, 2005; Reed et al., 2006; Dorschel et al., 2007; Henry and Roberts, 2007; Sulak et al., 2007, 2008; BuhlMortensen et al., 2010). High fish and invertebrate diversity and abundance are associated with L. pertusa habitats in the eastern North Atlantic and Gulf of Mexico (Jensen and Frederiksen, 1992; Rogers, 1999; Costello et al., 2005; Mortensen and Fosså, 2006; Henry and Roberts, 2007; Sulak et al., 2007; Bongiorni et al., 2010). In particular, invertebrate diversity was estimated to be up to three times higher than the surrounding seabed (Henry and Roberts, 2007) and comparable to tropical coral reefs (Rogers, 1999). Beta diversity of meiofauna and macrofauna (species turnover) varied across coral habitat type, including live and dead coral, and coral rubble (Roberts et al., 2009; Bongiorni et al., 2010; Henry et al., 2010), with the highest alpha diversity found in areas dominated by mixed live and dead coral skeletons (megafauna and macrofauna, Mortensen and Fosså, 2006), dead coral skeletons (Jensen and Frederiksen, 1992) or live coral and coral rubble (meiofauna, Bongiorni et al., 2010). In contrast, low diversity and high density were associated with L. pertusa rubble at the base of coral mounds (macrofauna, Mortensen et al., 1995; Mortensen and Fosså, 2006) and significant declines in faunal abundance with distance were observed at Norwegian L. pertusa reef habitats (Jonsson et al., 2004). Much like shallowwater reefs, deep-sea coral reef size may also influence the structure of associated fauna (Jonsson

5

et al., 2004), with larger patches supporting increased abundances of omnivores and mobile organisms but decreased abundance of deposit feeders. In the northern Gulf of Mexico (nGOM), L. pertusa is found on authigenic carbonate deposits precipitated from microbial activity associated with hydrocarbon seepage (Schroeder, 2002; Formolo et al., 2004; Roberts et al., 2010a). In contrast to the NE Atlantic communities, where L. pertusa often forms large banks (e.g. Sula Ridge, >14 km in length and >30 m high) and mounds (e.g., Porcupine Seabight, 1 km in diameter and up to 100 m high) (Roberts et al., 2003), L. pertusa in the nGOM forms both large banks and mounds (up to 600 m in length; Cordes et al., 2008; Lunden et al., 2013) and less dense and scattered colonies (~1 to 2 m long and 1 to 2 m high; Brooke and Schroeder, 2007; Lunden et al., 2013) referred to as macrohabitats (Roberts et al., 2009). Lophelia. pertusa habitats in the well-studied Viosca Knoll (VK) area of the nGOM have similar temperature, salinity, and current speed regimes, but have lower dissolved oxygen content (Davies et al., 2010) and higher particle loads (Mienis et al., 2012) compared to NE Atlantic habitats. Current direction generally oscillates between eastward and westward flow along isobaths, with current speeds averaging 8 cm s-1 (Mienis et al., 2012). Ecological studies of L. pertusa habitats in the nGOM have focused on large macrofaunal (>2 mm) invertebrates and fish communities occupying and utilizing the coral matrix (Sulak et al., 2007; Cordes et al., 2008; Sulak et al., 2008; Lessard-Pilon et al., 2010), whereas no studies have assessed the infaunal communities associated with L. pertusa adjacent sediments. Using video analysis, Sulak et al. (2007) recorded diverse fish populations associated with L. pertusa habitats at two VK sites, but noted a decrease in density associated with depth. Diversity of megafaunal invertebrates based on rarefaction was significantly lower within live L. pertusa compared to soft-sediments, and significant differences in the communities were observed

6

between two sites at VK (Sulak et al., 2008). Lessard-Pilon et al. (2010) characterized megafaunal associations using photomosaics collected from L. pertusa habitats, and found communities were more similar within a site (approximately 600 m2) than among sites separated by 37 km, and identified smaller-scale site differences at distances greater than 316 m. Lophelia pertusa habitat (e.g. live, dead, rubble) had higher diversity than other nearby habitats (e.g. bacterial mats, tubeworms, sponges, other corals), and the percentage of standing dead coral was a significant determinant for the community composition at VK. Lessard-Pilon et al. (2010) hypothesized that the association of higher-order consumers with dead coral and rubble suggests the effect of the reef itself extends to the communities in the soft-sediments and rubble surrounding the coral beds. In situ collections of L. pertusa communities yielded 68 taxa (>2 mm) living within fifteen discrete L. pertusa habitats, including taxa found regionally within the nGOM slope habitats (Cordes et al., 2008). Coral-associated fauna were significantly different from nearby seep communities, although certain taxa were shared between habitats (Cordes et al., 2008). However, neither Cordes et al. (2008) nor Lessard-Pilon et al. (2010) conducted direct comparisons to the adjacent soft-sediment environment, which is almost ubiquitous in the nGOM. This paper presents new data examining macrofaunal community structure within sediments directly adjacent (within 1m) to deep-sea coral habitats. The primary objective of this study was to compare soft-sediment benthos adjacent to L. pertusa reefs to other soft-sediment habitats in the nGOM. We address the hypothesis that the habitat heterogeneity provided by biogenic structures in the deep sea influences the abundance, diversity, and composition of benthic communities in adjacent soft-sediments. We tested two null hypotheses: (1) macrofaunal abundance, taxa diversity, dominance, and feeding group assemblages in near-coral (L. pertusa)

7

sediments are not significantly different from background, non-coral soft-sediments and (2) macrofaunal polychaete family composition near corals is not significantly different from background sediments or from other soft-sediment habitats within the Gulf of Mexico region. Alternatively, because L. pertusa presence has been shown to be associated with increased organic input (Bongiorni et al., 2010) and alterations in sediment grain size (Dorschel et al., 2007), both of which have been found to alter the composition of infauna (e.g., Levin et al., 2001), we predict significant differences in sediment macrofaunal communities (e.g., composition, density, diversity) found adjacent to reefs compared to background, soft-sediments located away from reef environments.

2.

2.1.

Materials and methods

Study Locations Sediment macrofauna were collected from three sites containing L. pertusa habitats in the

nGOM in deep waters off the coast of Mississippi and Louisiana, USA (Figure 1). Two sites were in the Viosca Knoll (VK) lease area, VK826 and VK906, and the third within Mississippi Canyon (MC), MC751. Site names correspond to the Bureau of Ocean Energy Management lease block locations in which they occur. VK826 lies at the crest and flanks of a knoll with depths ranging from 430-552 m, and contains one of the largest L. pertusa habitats within the GOM (Schroeder et al., 2005; Sulak et al., 2008; Lunden et al., 2013). The coral habitat at VK826 features expansive thickets (Lunden et al., 2013) composed of living coral growing on dead coral framework covering an area of approximately 600 x 300m (Cordes et al., 2008). Seep-associated vestimentiferan tubeworms Lamellibrachia luymeysi and Seepiophila jonesi are

8

found in scattered clusters within this site (Cordes et al., 2008). VK906 is shallower, with water depths ranging from 388-432 m, and consists of a low-relief mound and ridge complex. Samples at VK906 were collected around a mound-complex of approximately 250 meters in diameter (Lunden et al., 2013) that contained densely populated live and dead L. pertusa interspersed with the black coral, Leiopathes spp (Lunden et al., 2013). MC751 is geographically separated from the VK sites by the Mississippi Canyon (MC; Bryant et al., 1990) and is characterized by numerous authigenic carbonate outcrops (e.g., Roberts et al., 2010b) and boulders surrounded by soft sediment at the head of a small canyon-like feature with depths ranging from 430-461 m. MC751 was the smallest L. pertusa habitat sampled, with the main site consisting of small, sparsely distributed patches (Lunden et al., 2013) encompassing an area of approximately 200 x 200 m, interspersed with the octocoral Callogorgia sp., anemones, and vestimentiferan tubeworms (Lunden et al., 2013). The presence of chemosynthetic tubeworms and bacterial mats confirm the existence of active seepage, and they occur in close proximity to live L. pertusa colonies. Collections at MC751 were taken near carbonate outcrops colonized by L. pertusa.

2.2.

Sampling Methods Sediment samples were collected on two cruises in 2009 aboard the NOAA ship Ronald

H. Brown (1-Sept-09 to 11-Sept-09) and the R/V Seward Johnson (18-Sept-09 to 23-Sept-09). Push cores were collected in situ near L. pertusa colonies (within 1 m) and in background softsediments ( 100 m) using the ROV Jason II and the Johnson Sea Link submersible (Figure 1, Table 1). Background sediments were defined as soft-sediments where no live or dead coral was visible. Given the patchy nature of the coral habitat at each site, background cores were collected away from the sampled coral habitat. Additional background soft-sediment cores were collected

9

with a box core (30 cm diameter) deployed from the ship. Box core collections specifically targeted soft-bottom environments identified based on sub-bottom profiling data collected prior to deployment and using the best available information for locations of deep-sea corals at the time of sampling in 2009. Thus, the distances from background sites to near L. pertusa sites provided here represent estimates. Follow-up confirmation with video footage would be required to calculate accurate distances. The absence of coral material in recovered box cores provided additional confirmation that the collections represented non-coral, soft-sediment habitat. Box cores were subsampled by inserting a single polycarbonate push core into the sediment. All push cores were 6.35 cm in diameter, except for one background core (8.26 cm diameter) collected at VK906 (Table 1, SPC). Sediment cores were sectioned vertically (0-2, 2-5, 5-10 cm) after recovery. However, not all cores penetrated to 10 cm, so for the purpose of this study, data analysis was limited to the top 5 cm fraction. Core sections were preserved whole in 8% buffered formalin solution until they were returned to the laboratory where they were stained with rose bengal and washed through a 300-μm mesh sieve. Macrofauna were sorted with a dissecting microscope and identified to the lowest practical taxonomic level, including family level for polychaetes, oligochaetes, peracarid crustaceans, and aplacophorans. Family level identification for deep-sea benthic communities has been shown to be sufficient to discriminate differences in community structure using multivariate techniques (Warwick, 1988; Narayanaswamy et al., 2003).

2.3.

Data Analysis Both alpha (within site) and beta diversity (among sites) were quantified for the habitats

sampled, and compared to the northern GOM region. Abundance of individuals and univariate

10

measures of biodiversity were analyzed using two-way analysis of variance (ANOVA) with proximity (near-coral vs. background) and site (VK906, VK826, and MC751) as factors and individual cores as replicates, followed by post-hoc test Tukey’s HSD for multiple comparisons. Abundance data were converted to number of individuals per 32cm2 to standardize among cores. Where a significant interaction between factors was detected, sites were analyzed separately using one-way ANOVA with proximity as the main effect. All data were tested for normality and heteroscedasticity using Shapiro-Wilk and Bartlett’s tests (Zar, 1999) and loge-transformed when necessary. If transformation did not achieve normality, a non-parametric Kruskal-Wallis test was used on univariate measures. Depth relationships with density were tested using Spearman’s rank correlation. A significance level of p < 0.05 was used in all tests. Univariate statistics were computed with the program R (R Development Core Team, 2011). Diversity was examined using the total number of taxa present in each core (Sp), taxa richness (d) estimated using Marglef’s index, Pielou’s evenness (J’), rarefaction analysis and Fisher’s  based on untransformed abundance data using DIVERSE in PRIMER Statistical Software version 6 (Clarke and Gorley, 2006). Rarefaction curves were plotted for each site-proximity combination. Community structure was assessed by examining the overall contribution of higher level taxa, the presence/absence of taxa among habitats, and the composition of feeding guilds. Multivariate analysis of community structure across sites and habitats was performed on squareroot transformed data using Bray-Curtis similarities in PRIMER version 6 (Clarke and Gorley, 2006). Communities were examined using a two-way analysis of similarity (ANOSIM) to simultaneously test for differences between proximity (near-coral and background habitats) across sites (MC751, VK906, VK826) and sites across proximities. Similarity of percentages (SIMPER) was used to identify the taxa responsible for discriminating between habitats and to

11

assess the variability of the communities within site-proximity combinations. Variability among Bray-Curtis similarities within site-proximity combinations was also assessed using multivariate dispersion (MVDISP), with greater variability expected in near-coral sediments due to the heterogeneous nature of these habitats. Colonial organisms (e.g., Porifera, Octocorallia and Bryozoa) often fragment and detach from the substrate during sample collection and processing. In addition, it is difficult to quantify a single individual of colonial organisms, particularly encrusting forms; consequently, only the presence and absence of these taxa were counted and these taxa were excluded from diversity calculations (, J’, and d) and multivariate community analysis. One background core from VK906 was excluded from diversity calculations (, J’, and d) due to difference in core surface area. However, data from this core were included in the rarefaction curves generated for each habitat and site. Dominance was compared by calculating the distance between dominance curves (DOMDIS) and subsequent one-way ANOSIM analysis to test for differences in dominance between near and background habitats at each site.

2.4.

Regional comparison of polychaete community structure to other nGOM softsediments To place L. pertusa sediment macrofaunal communities into a regional perspective,

polychaete communities from near-coral and background sediments (this study) were compared to published data of soft-sediment communities collected using box cores in the GOM during the Deep Gulf of Mexico Benthos program (DeGoMB) (Rowe and Kennicutt II, 2009; Wei et al., 2010; Wei et al., 2012; Carvalho et al., 2013). Polychaete families were used because the taxonomy is stable and polychaetes are the dominant group in deep-sea macrofaunal samples (Glover et al., 2008). Data from the DeGoMB study were restricted to similar depths and

12

geographic areas as the current study, equating to one site in the Mississippi Trough, MT1 (depth = 461-490 m, N=6). Univariate analysis of polychaete densities across sites was performed using one-way ANOVA; samples from the current study were first converted to individuals m-2 for comparability to the DeGoMB samples. Multivariate analysis of polychaete community structure across sites was performed on Bray-Curtis similarities based on presence/absence data to remove any effect of density differences. Additionally, polychaete family richness based on rarefaction was performed.

3.

3.1.

Results

Macrofaunal abundance, diversity, composition, and structure Macrofaunal abundance per core ranged from 26 to 125 individuals 32 cm-2 (Figure 2,

Table 2). Depth was not a significant determinant of macrofaunal density (Spearman correlation;  = 0.279; p = 0.122). There was a significant interaction effect between site and proximity (Two-way ANOVA; F2,26 = 4.971; p = 0.0149); consequently, sites were evaluated individually. Densities were significantly higher in near-coral sediments at VK826 (Figure 2, Table 2, Wilcoxon; W = 2; p = 0.0294). In contrast, the opposite trend was observed at MC751, where macrofaunal densities near coral were lower than in background sediments, although this pattern was not significant (One-way ANOVA; F1,5= 4.867; p = 0.0785). No significant proximity effect was detected for macrofaunal densities at VK906 (One-way ANOVA; F1,12 = 0.157; p = 0.698). There was a significant interaction for macrofaunal diversity (Fisher’s , Table 1) and evenness (J’, Table 1) among sites and proximity (Fisher’s , F2,25 = 5.328, p = 0.049; J’, F2,25 = 3.442, p = 0.011). Comparisons between near and background habitats within sites revealed

13

significantly higher diversity and evenness within near-coral sediments only at MC751 (Fisher’s , F1,5 = 7.33, p = 0.042; J’, F1,5 = 7.68, p = 0.039). However, there was no significant difference in taxon richness (d) among sites (d; F2,25 = 0.559; p = 0.581) or proximity (d; F1,25 = 0.979; p = 0.332). Taxa dominance in both habitats was high, with 6 of 74 taxa from near-coral sediments and 7 of 70 taxa found in background sediments comprising 50% of the total macrofaunal abundance; but this pattern varied among sites as follows. At VK906, near-coral habitats exhibited significantly higher dominance of taxa, estimated by DOMDIS (ANOSIM; R = 0.367; p = 0.022). However, dominance in background sediments was similar to near-coral sediments at both VK826 (ANOSIM; R = - 0.066; p = 0.591) and MC751 (ANOSIM; R = 0.333; p = 0.086). A total of 86 taxa from 12 phyla including 70 families was identified from the 32 cores collected; 74 taxa were present in near-coral sediments and 70 taxa from background sediments (Table 2). Of these, 66% occurred in both habitats, while 34% occurred only in either the nearcoral or background sediments. Of the habitat-specific taxa (31), most were rare occurrences, represented by only 1 or 2 individuals (22 of 31). Very few taxa represented > 3 individuals that were unique to a particular habitat. For example, taxa found exclusively in L. pertusa sediments included Macrostylidae (Isopoda), Sphyrapodidae (Tanaidacea: Apseudomorpha) and Ophiuroidea, while abundant taxa (> 3 individuals) found only in background sediments included a different suite of peracarid crustaceans: Ampeliscidae (Amphipoda), Colletteidae (Tanaidacea: Tanaidomorpha), and Aoridae (Amphipoda). Taxon richness estimated by the rarefaction curves (Figure 3) varied among sites, but because the curves do not reach an asymptote, results indicate that the full communities had not been sampled at any of the sites or habitat types. Background sediments at VK906 and VK826 were more taxon rich than nearcoral sediments, while near-coral sediments were more taxa rich at MC751.

14

Polychaetes were the dominant taxa in all near-coral and background sediments (Figure 4), and represented a greater proportion of the total macrofauna within near-coral sediments (6272%) than in background sediments (53-66%). In contrast, background sediments had a greater proportion of crustaceans (17-40%) than near-coral sediments (9-16%). Deposit feeders dominated all samples, representing greater than 70% of the community in all sediments (Supplementary Figure A1). Near-coral sediments at MC751 and VK906 had greater densities and higher proportions of filter feeders than background sediments (MC751: 2% and 0.5%; VK906: 6% and 2%, near and background respectively). VK826 had higher contributions of omnivores in background sediments (15% vs. 7%) while MC751 had more in near-coral sediments (20% vs. 14%). NMDS and ANOSIM analyses revealed significant differences between macrofaunal assemblages found in near-coral and background soft sediments (Figure 5). Community structure was significantly different both among sites (Two-way ANOSIM; R = 0.592; p = 0.001) and proximity (near vs. background, Two-way ANOSIM; R = 0.497; p = 0.001). Infaunal assemblages from VK906 and VK826 were more similar to each other (Pairwise ANOSIM; R = 0.493; p = 0.001), having a lower R value than either were to MC751 (VK906 Pairwise ANOSIM; R = 0.771; p = 0.002; VK826 Pairwise ANOSIM; R = 0.724; p = 0.002). SIMPER analyses revealed highly dissimilar communities between the two habitat types, with near-coral and background communities the least similar at VK826 (mean similarity=38%), followed by VK906 (mean similarity=40%), and most similar at MC751 (mean similarity=42%). Communities in near-coral sediments were less variable than those from background sediments at VK826 as indicated by the higher mean similarity among replicate cores (near=56% vs. background=35%) and lower relative dispersion near corals (0.61) compared to background

15

sediments (1.70). Lower variability in the near-coral communities was also present at VK906 (mean similarity: near=48% vs. background=42%; relative dispersion: near=1.08 vs. background=1.36). In contrast, near-coral sediment communities exhibited higher variability at MC751 (mean similarity: near=43% vs. background=59%; relative dispersion: near=1.41 vs. background=0.38). Across all sites, SIMPER analysis indicated Oweniidae, Maldanidae, Tubificidae, and Gastropoda accounted for 19% of the dissimilarity between near-coral and background sediments, but their relative abundance between near-coral and background sediments varied among sites. In near-coral sediments, SIMPER analysis indicated the polychaete family Oweniidae contributed most to site differences. Mean densities of Oweniidae at VK826 were nearly two times higher than those at VK906 and 17 times higher than those found at MC751 (Table 2), representing 5-10% of the dissimilarity among the sites. Other groups that contributed to the dissimilarity among near-coral sites were Fauveliopsidae (3-5%), Gastropoda (2-5%), Bivalvia (3-4%), and Maldanidae (3-7%), which had higher abundances at the VK sites, while Paraonidae (3-4%) and Spionidae (1-3%) were higher at MC751. In background sediments, the amphipod family Ampeliscidae contributed most to the observed community differences between both VK sites and MC751. While Ampeliscidae were present in high densities at MC751 (Table 2), they were absent from both VK906 and VK826, representing 7-8% of the among-site dissimilarity. Paraonidae and Spionidae had higher abundances in background habitats at MC751 and were responsible for 3-4% of the dissimilarity among sites. Several taxa that were not present in background sediment samples at MC751 represented > 2% of the dissimilarity with VK906 and VK826, including Gastropoda, Maldanidae, Munnopsidae, Cossuridae, and Orbiniidae.

16

3.2.

Regional comparison to GOM soft-sediment polychaete communities Regional NMDS analysis revealed that polychaete families at sites containing L. pertusa

habitats are distinct communities in the nGOM (Figure 6). Polychaete densities from near coral and background habitats sampled in this study (5,371-26,856 ind. m-2) were significantly higher than those from nearby soft-sediment environments examined in the DeGoMB study (MT1, 1,787-4,027 ind. m-2, One-way ANOVA, F1,32 = 45.013, p<0.001, Rowe and Kennicutt II, 2009; Carvalho et al., 2013). Both near-coral and background sites at VK906, VK826, and MC751 hosted polychaete communities that were significantly different from the closest DeGoMB site, MT1 (Pairwise ANOSIM, R 0.635, p < 0.012). Polychaete family composition was most similar between near-coral and background sediments (47%, this study). In contrast, near-coral and MT1 polychaete family composition was the least similar (38%), while the similarity between background communities (this study) and MT1 had intermediate values (44%). Within site similarity was highest at MT1 (79%). Polychaete families accounting for the highest amount of dissimilarity were more common at MT1 (Capitellidae, Dorvilleidae, Glyceridae, Lumbrineridae, Nephtyidae, Pilargidae, and Trichobranchidae), but were rare or absent from near-coral and background habitat (this study), possibly due to the higher surface area sampled with the box core (0.17 m2) versus the push core (0.0032 m2). These families represent a range of feeding guilds, including deposit feeders, carnivores, and omnivores. Two deposit-feeding polychaete families, Oweniidae and Fauveliopsidae, were frequently found in near-coral habitats (18 of 19 cores) but were absent at MT1. Multivariate dispersion was much higher among near coral and background samples (0.842-1.85, this study) than among MT1 samples (0.242). Taxon richness based on rarefaction [ES(385)] indicated that both near-coral (31 families) and background (32 families) sediments had higher polychaete diversity than MT1 (20 families,

17

Supplementary Figure S2). A total of 36 polychaete families was identified within near-coral and background L. pertusa sediments, while only 30 were observed at MT1.

4.

Discussion Lophelia pertusa-associated sediments in the nGOM support macrofaunal communities

that are distinct from non-coral soft sediment environments, consistent with hypotheses 1 and 2. Similar observations have been made in shallow-water reefs, where discrete communities were present at distances less than 10 m from the reef, with high variability observed at single sampling locations (Barros et al., 2001). To a degree, our results are consistent with faunal community patterns associated with deep-sea corals found in the NE Atlantic and central Mediterranean (Jonsson et al., 2004; Henry and Roberts, 2007; Bongiorni et al., 2010). Background communities in the NE Atlantic and central Mediterranean exhibited higher variability than coral-associated habitats, including increased relative dispersion and decreased similarities (Jonsson et al. 2004; Henry and Roberts, 2007; Bongiorni et al., 2010), consistent with the patterns observed in background sediments at the two VK sites (this study). However, Henry and Roberts (2007) reported increased diversity and decreased dominance on L. pertusa mounds, primarily due to enhanced diversity of epifauna encrusting dead coral skeleton. In contrast, there was no general across-site pattern in macrofaunal diversity or community dominance (this study), which may be a result of taxonomic resolution (family vs. species-level identification), low sample size, and/or rarity of encrusting epifaunal taxa on sediments adjacent to L. pertusa due to the lack of available hard substrate (dead skeleton). Variability in macrofaunal densities and community composition among near-coral and background habitats may be due to one or more site-specific factors. Densities of soft-sediment

18

macrofauna in the GOM have been shown to decrease with distance from the coast and with depth along the Louisiana slope (Pequegnat et al., 1990; Rowe and Kennicutt II, 2009; Wei et al., 2010). However, regional peaks in infaunal densities have been observed in both macrofaunal (Rowe and Kennicutt II, 2009; Wei et al., 2012) and meiofaunal communities (Baguley et al., 2006) in the northeast GOM at depths ranging 450-1900 m. While each of the study sites occupied slightly different depth ranges (Table 1), there was no significant relationship between depth and macrofaunal density in this study. VK and MC are geographically separated by the Mississippi Canyon, a deep-water feature that may influence faunal zonation in the GOM (Wei et al. 2010). In addition, the physiographic topography differed between VK and MC, with VK reefs situated on topographic highs, while MC sites occupy a slope flank at the head of a canyon (Lunden et al., 2013). Macrofaunal community composition was more similar between VK906 and VK826 than either were to MC751 located >170 km away, perhaps because the two VK sites are geographically closer together (37 km) and are topographically similar. Similar regional patterns in L. pertusa megafaunal communities were observed by Lessard-Pilon et al. (2010) where communities within VK were significantly different from other regions west of the Mississippi Canyon. Lastly, the presence of chemosynthetic communities at VK826 and MC751 is indicative of highly variable geochemical conditions that can influence sediment macrofaunal density, composition, and diversity (e.g., Levin et al 2003). However, the degree to which the seep environment shapes near-coral sediment geochemistry and associated infauna remains unknown. Habitat size may be another factor influencing the among-site variability in macrofaunal densities and community composition near corals. Qualitatively, the three sites represent a range of L. pertusa habitat sizes; VK826 contains the largest continuous reef, VK906 colonies are of

19

intermediate size, and MC751 contains a collection of small colonies (Lunden et al., 2013). Macrofaunal densities were significantly higher near L. pertusa habitat at VK826 (largest coral habitat), while infaunal densities near VK906 corals were intermediate between VK826 and MC751, and did not differ from background sediments (intermediate habitat size). MC751 had the lowest macrofaunal densities near coral and the smallest habitat size. In contrast, background densities did not vary significantly across sites (Figure 2). These density patterns or “haloes” in proximity to L. pertusa may be a function of reef size, where the influence of the small individual colonies present at MC751 on adjacent sediment communities may be correspondingly small. However, our sampling effort at the two VK sites was more extensive than at MC751, and without additional replicates, our assessment of MC751 is limited. Mortensen et al. (1995) found no relationship with bioherm size and megafaunal density or diversity for eastern Atlantic coral mounds, suggesting patterns are more likely the result of microhabitat composition and current direction. In contrast, increased habitat complexity and size have been shown to correspond to increased macrofaunal densities in cold-seep communities (Bergquist et al., 2003; Cordes et al., 2010) and were hypothesized to influence the biodiversity of meiofaunal communities associated with deep-sea corals (Bongiorni et al., 2010). Correlation of biotic variables (e.g., abundance, diversity, dominance) to quantitative estimates of reef size would help resolve the effect of reef habitat size on adjacent sediment macrofaunal communities. Macrofaunal densities in near-coral habitats presented here are comparable to enhanced densities reported near other heterogeneous deep-sea communities, including cold-seeps (16,174 individuals m-2, depth 1,420m; Demopoulos et al., 2012) and microbial mats (20,961 individuals m-2, depth = 3290m; Levin and Mendoza, 2007), as well as soft-sediments at the head of Mississippi Canyon (21,663 individuals m-2, depth = 482-676m, Wei et al., 2012). Comparisons

20

were limited to studies that used analogous methods to examine deep-sea sediment macrofauna in the GOM (Levin and Mendoza, 2007; Rowe and Kennicutt II, 2009; Demopoulos et al., 2012). Densities in both near-coral and background L. pertusa sites (overall mean: 17,941 individuals m-2; this study) were higher than macrofaunal densities in the remaining deep GOM as a whole (362 to 6172 individuals m-2) excluding the head of the Mississippi Canyon (Wei et al., 2012). Site-specific variations in habitat heterogeneity (e.g., Cordes et al., 2010) and possibly food availability may be driving the high densities of benthic infauna near the L. pertusa habitats. To our knowledge, there are no comparable published results for sediment macrofauna adjacent to other L. pertusa locations (<1 m) in the Gulf of Mexico or elsewhere. Both near-coral and background habitats exhibited high taxon dominance, with polychaetes representing the community dominant in all habitats sampled, typical for deep-sea sediments in general (Levin and Gooday, 2003). Macrofaunal community structure is influenced by food availability, sediment and organic matter flux, and flow regime (Levin et al., 2001; Carvalho et al., 2013). Lophelia pertusa reefs can facilitate localized organic matter accumulation; for example, sediment deposition at VK826 has been reported to range from 1.24.7 g m-2 d-1 and organic carbon flux of 4-6.5 mg m-2 d-1 (Davies et al., 2010; Mienis et al., 2012), with fresh organic matter deposited from surface waters. The high dominance and abundance of deposit-feeders observed near L. pertusa and background habitats may represent a community response from this fresh food source. However, deposit feeders dominate most deepsea soft sediments, so their presence here could also be indicative of the flow environment and/or other environmental factors including grain size. While it was not possible to collect separate cores to analyze for sediment characteristics due to sampling restrictions during this study, additional analysis of sediment parameters, including particle size, organic carbon content and

21

nitrogen, would help identify the potential environment characteristics driving high dominance in these communities. The sample area and replication for this study was limited as illustrated by the rarefaction curves (Figures 3 and A2). Small sample sizes may account for the high frequency of rare taxa encountered, and it is expected that with each additional sample collected and analyzed from coral habitats, estimates of taxon richness will correspondingly increase. However, despite the small total sampling area in near-coral (0.06 m2) and background habitats (0.04 m2), polychaete family richness was higher and six additional polychaetes families were collected in this study as compared to the larger area sampled at MT1 (1.0 m2) (Rowe and Kennicutt II, 2009), further suggesting the enhanced diversity associated with coral habitats extends into adjacent sediments. Cordes et al. (2008) suggested that fauna occupying L. pertusa habitats are not unique, but are composed of different proportions of taxa from the general population in the GOM. In support of this hypothesis, 66% of the infaunal families found in near-coral and background sediments were the same (this study). Although species-level information is lacking for these collections and the shared families may represent different species, the similarity in the diversity and number of taxa shared suggests a high degree of overlap between the habitats. Although the size class for identified macrofauna and megafauna from Cordes et al. (>2mm, 2008) was greater than the present study (> 0.3 mm), 13 of the 15 polychaete families reported from L. pertusa habitats in Cordes et al. (2008) were present in near-coral and background sediments from this study, suggesting high taxon redundancy between the coral and adjacent sediments, at least at the family level. In contrast, polychaete communities associated with L. pertusa sediments were significantly different from other non-coral deep-sea habitats in the GOM. Levin and Mendoza (2007) reported only seven polychaete families near cold seep microbial mat and pogonophoran

22

communities in the Florida Escarpment, while 36 were collected near L. pertusa habitat in this study. The combination of high polychaete densities with distinct community structure that differed from rest of the GOM supports the hypothesis that the L. pertusa reef environment affects not only adjacent sediments, but that its influence may extend beyond the local environment. The sediment “apron” (Freiwald and Wilson, 1998) around the L. pertusa may represent an important transition zone from coral-dominated to fine-sediment dominated habitats. The significant difference in the community composition among near-coral and background sediments (ANOSIM comparisons) indicates that taxa turnover occurs at some distance away from the reef ( 100 m). However, with 66% of taxa shared among near-coral and background sediments (this study), full taxonomic turnover may occur at distances greater than were sampled. While quantifying the spatial scales of macrofaunal taxa turnover with proximity to L. pertusa reefs was beyond the scope of this study, replicate sampling along linear transects at standard distances away from the reef would clarify the pattern of taxa turnover and refine the spatial extent of L. pertusa’s influence on adjacent environments. Further sampling, including in situ collections of coral matrix samples similar to Cordes et al. (2008), followed by sieving with a 300 μm sieve, will help further identify taxa overlap and microhabitat niche specialization found within the coral matrix, the adjacent sediment apron, and background soft sediments, and provide direct comparisons between GOM L. pertusa communities with those from the NE Atlantic (e.g., Henry and Roberts, 2007). The unique sediment communities associated with L. pertusa habitats described here may be important to consider in the context of conserving the biodiversity of vulnerable deep-sea coral ecosystems, although the direct functional relationship between the coral habitat and

23

adjacent sediments has yet to be determined. Maintaining the diversity of coral habitats, including adjacent sediments, is central to the overall health of these systems because deep-sea biodiversity is exponentially correlated with high and efficient ecosystem functioning (Danovaro et al., 2008). Although background sediments were collected away from coral habitats, they exhibited significantly different polychaete communities than observed in any other softsediments in the GOM. These results suggest that the influence of L. pertusa reefs and the environmental characteristics that shape these reefs, on surrounding sediments may be spatially extensive. Further taxonomic resolution is likely to result in additional separation of communities in near-coral sediments from the regional populations. Future conservation efforts and ecosystem-based management of L. pertusa habitats may need to consider a site-specific approach, given that community composition is highly localized, similar to results found by Lessard-Pilon et al. (2010). Deep-sea coral habitats are being recognized worldwide for conservation and protection from human activities due to their value to biodiversity (Davies et al., 2007). This study provides baseline data that can help test hypotheses regarding the role of transition zones, from deep reefs to soft sediments, in shaping overall community structure and maintenance of biodiversity.

4.1

Conclusions In summary, this study presents new data on the macrofauna residing in L. pertusa

sediments compared to nearby and regional soft-sediment communities. Lophelia pertusa associated sediments support distinct macrofaunal communities both within a site and within the nGOM region, with site-specific factors such as hydrodynamics, food availability, and habitat size potentially influencing benthic macrofaunal community structure. Lophelia pertusa reefs

24

create transition zones, linking the reef environment to adjacent soft sediments. While we found some degree of taxonomic overlap between near-coral and background habitat assemblages, the full spatial extent of reef influence on adjacent sediments has yet to be quantified. As deep-sea corals are extremely sensitive to anthropogenic and natural disturbance (Fosså et al., 2002; HallSpencer et al., 2002; Auster et al., 2005; White et al., 2012; Fisher et al. 2014), this study provides baseline information on deep-sea coral sediment-associated communities in the GOM that can be used to help inform future deep-sea coral research, monitoring activities, and conservation strategies.

Acknowledgements Thank you to C. Charles (USGS), the Bureau of Ocean Energy and Management (BOEM), including G. Boland, the crews of the NOAA Ship Ron Brown, ROV JASON group (WHOI), JSL Seward Johnson (HBOI), S.W. Ross, E. Cordes, C. Fisher, T. Shank, and collaborations with the BOEM contracted scientists from TDI Brooks. Additionally, special thanks go out to K. Kovacs, J. McClain-Counts, A. Quattrini, J. Lunden, C. Kellogg, C. Morrison, and G. Brewer for assistance at sea and thoughtful discussions during the preparation of this manuscript. Many thanks go to the anonymous reviewers whose comments greatly improved the manuscript. Funding was provided to A. Demopoulos from the USGS Terrestrial, Freshwater, and Marine Environments Program through the Outer Continental shelf study Lophelia II: Rigs, Reefs, and Wrecks. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

Appendix A. Supporting information

25

Supplementary data associated with this article can be found in the online version.

References Auster, P., Freiwald, A., Roberts, J.M., 2005. Are deep-water corals important habitats for fishes? In: Freiwald, A., Roberts, J.M. (Eds.), Cold-water Corals and Ecosystems. Springer-Verlag, Berlin Heidelberg, pp. 747-760. Baguley, J.G., Montagna, P.A., Hyde, L.J., Kalke, R.D., Rowe, G.T., 2006. Metazoan meiofauna abundance in relation to environmental variables in the northern Gulf of Mexico deep sea. Deep Sea Research Part I: Oceanographic Research Papers 53 (8), 1344-1362. Barros, F., Underwood, A.J., Lindegarth, M., 2001. The influence of rocky reefs on structure of benthic macrofauna in nearby soft-sediments. Estuarine, Coastal and Shelf Science 52 (2), 191-199. Bergquist, D.C., Andras, J.P., McNelis, T., Howlett, S., van Horn, M.J., Fisher, C.R., 2003. Succession in Gulf of Mexico cold seep vestimentiferan aggregations: The importance of spatial variability. Marine Ecology-Pubblicazioni Della Stazione Zoologica Di Napoli I 24 (1), 31-44. Bongiorni, L., Mea, M., Gambi, C., Pusceddu, A., Taviani, M., Danovaro, R., 2010. Deep-water scleractinian corals promote higher biodiversity in deep-sea meiofaunal assemblages along continental margins. Biological Conservation 143 (7), 1687-1700. Brooke, S., Schroeder, W.W., 2007. State of Deep Coral Ecosystems in the Gulf of Mexico Region: Texas to the Florida Straights. In: Lumsden, S.E., Hourigan, T.F., Bruckner, A.W., Dorr, G. (Eds.), The State of Deep Coral Ecosystems of the United States. NOAA Technical Memorandum CRCP-3, Silver Spring, Maryland 20910, pp. 271-306.

26

Bryant, W.R., Bryant, J.R., Feeley, M.H., Simmons, G.R., 1990. Physiographic and bathymetric characteristics of the continental slope, northwest Gulf of Mexico. Geo-Marine Letters 10 (4), 182-199. Buhl-Mortensen, L., Vanreusel, A., Gooday, A.J., Levin, L.A., Priede, I.G., Buhl-Mortensen, P., Gheerardyn, H., King, N.J., Raes, M., 2010. Biological structures as a source of habitat heterogeneity and biodiversity on the deep ocean margins. Marine Ecology 31 (1), 21-50. Carvalho, R., Wei, C.-L., Rowe, G., Schulze, A., 2013. Complex depth-related patterns in taxonomic and functional diversity of polychaetes in the Gulf of Mexico. Deep Sea Research Part I: Oceanographic Research Papers 80, 66-77. Clarke, K.R., Gorley, R.N., 2006. PRIMER v6: User Manual/Tutorial. PRIMER-E, Plymouth, UK. Cordes, E.E., Cunha, M.R., Galeron, J., Mora, C., Olu-Le Roy, K., Sibuet, M., Van Gaever, S., Vanreusel, A., Levin, L.A., 2010. The influence of geological, geochemical, and biogenic habitat heterogeneity on seep biodiversity. Marine Ecology 31, 51-65. Cordes, E.E., McGinley, M.P., Podowski, E.L., Becker, L., Lessard-Pilon, S., Viada, S.T., Fisher, C.R., 2008. Coral communities of the deep Gulf of Mexico. Deep-Sea Research I 55, 777-787. Costello, M., McCrea, M., Freiwald, A., Lundälv, T., Jonsson, L., Bett, B., Weering, T., Haas, H., Roberts, J., Allen, D., Freiwald, A., Roberts, J.M., 2005. Role of cold-water Lophelia pertusa coral reefs as fish habitat in the NE Atlantic. In: Freiwald, A., Roberts, J.M. (Eds.), Cold-water Corals and Ecosystems. Springer-Verlag, Berlin Heidelberg, pp. 771805. Danovaro, R., Gambi, C., Dell'Anno, A., Corinaidesi, C., Fraschetti, S., Vanreusel, A., Vincx,

27

M., Gooday, A.J., 2008. Exponential decline of deep-sea ecosystem functioning linked to benthic biodiversity loss. Current Biology 18 (1), 1-8. Danovaro, R., Gambi, C., Mazzola, A., Mirto, S., 2002. Influence of artificial reefs on the surrounding infauna: analysis of meiofauna. ICES Journal of Marine Science: Journal du Conseil 59 (suppl), S356-S362. Davies, A.J., Duineveld, G.C.A., van Weering, T.C.E., Mienis, F., Quattrini, A.M., Seim, H.E., Bane, J.M., Ross, S.W., 2010. Short-term environmental variability in cold-water coral habitat at Viosca Knoll, Gulf of Mexico. Deep-sea research. Part I, Oceanographic research papers 57 (2), 199-212. Davies, A.J., Roberts, J.M., Hall-Spencer, J., 2007. Preserving deep-sea natural heritage: Emerging issues in offshore conservation and management. Biological Conservation 138, 299-312. Demopoulos, A.W.J., Kovacs, K.M., Gualtieri, D., 2012. Macrofaunal community structure and sediment environmental characteristics in three seep ecosystems. In: Ross, S.W., Demopoulos, A.W.J., Kellogg, C.A., Morrison, C.L., Nizinkski, M.S., Ames, C.L., Casazza, T.L., Gualtieri, D., Kovacs, K., McClain, J.P., Quattrini, A.M., Roa-Varon, A.Y., Thaler, A.D. (Eds.), Deepwater Program: Studies of Gulf of Mexico Lower Continental Slope Communities Related to Chemosynthetic and Hard Substrate Habitats. U.S. Geological Survey, pp. 35-44. Dorschel, B., Hebbeln, D., Foubert, A., White, M., Wheeler, A.J., 2007. Hydrodynamics and cold-water coral facies distribution related to recent sedimentary processes at Galway Mound west of Ireland. Marine Geology 244 (1–4), 184-195. Fisher, C., Demopoulos, A.W.J., Cordes, E.E., Baums, I., White, H., Bourque, J.R., 2014. Deep-

28

sea coral communities as indicators of ecosystem-level impacts resulting from the Deepwater Horizon oil spill. Bioscience, accepted. Formolo, M.J., Lyons, T.W., Zhang, C., Kelley, C.A., Sassen, R., Horita, J., Cole, D.R., 2004. Quantifying carbon sources in the formation of authigenic carbonates at gas hydrate sires in the Gulf of Mexico. Chemical Geology 205, 253-264. Fosså, J.H., Mortensen, P.B., Furevik, D.M., 2002. The deep-water coral Lophelia pertusa in Norwegian waters: distribution and fishery impacts. Hydrobiologia 471 (1), 1-12. Frederiksen, R., Jensen, A., Westerberg, H., 1992. The distribution of the scleractinian coral Lophelia Pertusa around the Faroe Islands and the relation to internal tidal mixing. Sarsia 77 (2), 157-171. Freiwald, A., Fosså, J.H., Grehan, A., Koslow, T., Roberts, J.M., 2004. Cold-water coral reefs. UNEP-WCMC, Cambridge, UK 84. Freiwald, A., Wilson, J.B., 1998. Taphonomy of modern deep, coldǦtemperate water coral reefs. Historical Biology 13 (1), 37-52. Gass, S.E., Roberts, J.M., 2006. The occurrence of the cold-water coral Lophelia pertusa (Scleractinia) on oil and gas platforms in the North Sea: Colony growth, recruitment and environmental controls on distribution. Marine Pollution Bulletin 52 (5), 549-559. Glover, A.G., Smith, C.R., Mincks, S.L., Sumida, P.Y.G., Thurber, A.R., 2008. Macrofaunal abundance and composition on the West Antarctic Peninsula continental shelf: evidence for a sediment 'food bank' and similarities to deep-sea habitats. Deep Sea Research Part II 55, 2491-2501. Gratwicke, B., Speight, M.R., 2005. Effects of habitat complexity on Caribbean marine fish assemblages. Marine Ecology Progress Series 292, 301-310.

29

Hall-Spencer, J.M., Allain, V., Fosså, J.H., 2002. Trawling damage to northeast Atlantic ancient coral reefs. Proceedings: Biological Sciences 269 (1490), 507-511. Harwell, H.D., Posey, M.H., Alphin, T.D., 2011. Landscape aspects of oyster reefs: Effects of fragmentation on habitat utilization. Journal of Experimental Marine Biology and Ecology 409, 30-41. Henry, L.A., Davies, A.J., Roberts, J.M., 2010. Beta diversity of cold-water coral reef communities off western Scotland. Coral Reefs 29 (2), 427-436. Henry, L., Roberts, J.M., 2007. Biodiversity and ecological composition of macrobenthos on cold-water coral mounds and adjacent off-mound habitat in the bathyal Porcupine Seabight, NE Atlantic. Deep-Sea Research I 54, 654-672. Jensen, A., Frederiksen, R., 1992. The fauna associated with the bank-forming deep-water coral Lophelia Pertusa (Scleractinaria) on the Faroe Shelf. Sarsia 77 (1), 53-69. Jonsson, L.G., Nilsson, P.G., Floruta, F., Lundalv, T., 2004. Distributional patterns of macroand megafauna associated with a reef of the cold-water coral Lophelia pertusa on the Swedish west coast. Marine Ecology Progress Series 284, 163-171. Jumars, P.A., Nowell, A.R.M., 1984. Fluid and Sediment Dynamic Effects on Marine Benthic Community Structure. American Zoologist 24, 45-55. Langlois, T.J., Anderson, M.J., Babcock, R.C., 2005. Reef-associated predators influence adjacent soft-sediment communities. Ecology 86 (6), 1508-1519. Langlois, T.J., Anderson, M.J., Babcock, R.C., 2006. Inconsistent effects of reefs on different size classes of macrofauna in adjacent sand habitats. Journal of Experimental Marine Biology and Ecology 334 (2), 269-282. Lenihan, H.S., 1999. Physical-biological coupling on oyster reefs: how habitat structure

30

influences individual performance. Ecological Monographs 69 (3), 251-275. Lessard-Pilon, S.A., Podowski, E.L., Cordes, E.E., Fisher, C.R., 2010. Megafauna community composition associated with Lophelia pertusa colonies in the Gulf of Mexico. Deep Sea Research Part II: Topical Studies in Oceanography 57 (21–23), 1882-1890. Levin, L., Etter, R.J., Rex, M.A., Gooday, A.J., Smith, C.R., Pineda, J., Stuart, C.T., Hessler, R.R., Pawson, D., 2001. Environmental influences on regional deep-sea species diversity. Annual Revue of Ecology, Evolution, and Systematics 32, 51-93. Levin, L., Gooday, A.J., 2003. The deep Atlantic Ocean. In: Tyler, P.A. (Ed.), Ecosystems of the World Volume 28: Ecosystems of the Deep Ocean. Elsevier, Amsterdam, pp. 111-178. Levin, L.A., Ziebis, W., Mendoza, G.F., Growney, V.A., Tryon, M.D., Brown, K.M., Mahn, C., Gieskes, J., Rathburn, A.E., 2003. Spatial heterogeneity of macrofauna at northern California methane seeps: influence of sulfide concentration and fluid flow. Marine Ecology Progress Series 265, 123-139. Levin, L.A., Mendoza, G.F., 2007. Community structure and nutrition of deep methane-seep macrobenthos from the North Pacific (Aleutian) margin and the Gulf of Mexico (Florida Escarpment). Marine Ecology 28, 131-151. Lunden, J.J., Georgian, S.E., Cordes, E.E., 2013. Aragonite saturation states at cold-water coral reefs structured by Lophelia pertusa in the northern Gulf of Mexico. Limnology and Oceanography 58 (1), 354-362. Mienis, F., Duineveld, G.C.A., Davies, A.J., Ross, S.W., Seim, H., Bane, J., van Weering, T.C.E., 2012. The influence of near-bed hydrodynamic conditions on cold-water corals in the Viosca Knoll area, Gulf of Mexico. Deep-Sea Research Part I-Oceanographic Research Papers 60, 32-45.

31

Mortensen, P., Fosså, J.H., 2006. Species diversity and spatial distribution of invertebrates on deep-water Lophelia reefs in Norway. Proceedings of the 10th International Coral Reef Symposium Okinawa, 1849-1868. Mortensen, P.B., Hovland, M., Brattegard, T., Farestveit, R., 1995. Deep water bioherms of the scleractinian coral Lophelia pertusa (L.) at 64° n on the Norwegian shelf: Structure and associated megafauna. Sarsia 80 (2), 145-158. Narayanaswamy, B.E., Nickell, T.D., Gage, J.D., 2003. Appropriate levels of taxonomic discrimination in deep-sea studies: species vs family. Marine Ecology Progress Series 257, 59-68. Pequegnat, W.E., Gallaway, B.J., Pequegnat, L.H., 1990. Aspects of the ecology of the deepwater fauna of the Gulf of Mexico. American Zoologist 30 (1), 45-64. Posey, M.H., Ambrose, W.G., 1994. Effects of proximity to an offshore hard-bottom reef on infaunal abundances. Marine Biology 118 (4), 745-753. Posey, M.H., Vose, F.E., Lindberg, W.J., 1992. Short-term responses of benthic infauna to the establishment of an artificial reef. In: Cahoon, L.B. (Ed.), Diving for Science - 1992. Proceedings of the American Academy of Underwater Science 12th Annual Symposium. American Academy of Underwater Sciences, Costa Mesa, CA, pp. 125-131. R Development Core Team, 2011. R: A language an environment for statistical computing. . R Foundation for Statistical Computing, Vienna, Austria. Raes, M., Vanreusel, A., 2005. The metazoan meiofauna associated with a cold-water coral degredation zone in the Porcupine Seabight (NE Atlantic). In: Freiwald, A., Roberts, J.M. (Eds.), Cold-water Corals and Ecosystems. Springer-Verlag, Berlin Heidelburg. Reed, J.K., Weaver, D.C., Pomponi, S.A., 2006. Habitat and fauna of deep-water Lophelia

32

pertusa coral reefs off the southeastern U.S.: Blake Plateau, Straits of Florida, and Gulf of Mexico. Bulletin of Marine Science 78 (2), 343-375. Roberts, H.H., Feng, D., Joye, S.B., 2010a. Cold-seep carbonates of the middle and lower continental slope, northern Gulf of Mexico. Deep Sea Research Part II: Topical Studies in Oceanography 57 (21–23), 2040-2054. Roberts, H.H., Shedd, W., Hunt Jr, J., 2010b. Dive site geology: DSV ALVIN (2006) and ROV JASON II (2007) dives to the middle-lower continental slope, northern Gulf of Mexico. Deep Sea Research Part II: Topical Studies in Oceanography 57 (21–23), 1837-1858. Roberts, J.M., 2002. The occurrence of the coral Lophelia pertusa and other conspicuous epifauna around an oil platform in the North Sea. Underwater Technology: The International Journal of the Society for Underwater 25 (2), 83-92. Roberts, J.M., Davies, A.J., Henry, L.A., Dodds, L.A., Duineveld, G.C.A., Lavaleye, M.S.S., Maier, C., van Soest, R.W.M., Bergman, M.J.N., Huhnerbach, V., Huvenne, V.A.I., Sinclair, D.J., Watmough, T., Long, D., Green, S.L., van Haren, H., 2009. Mingulay reef complex: an interdisciplinary study of cold-water coral habitat, hydrography and biodiversity. Marine Ecology Progress Series 397, 139-151. Roberts, J.M., Long, D., Wilson, J.B., Mortensen, P.B., Gage, J.D., 2003. The cold-water coral Lophelia pertusa (Scleractinia) and enigmatic seabed mounds along the north-east Atlantic margin: are they related? Marine Pollution Bulletin 46 (1), 7-20. Rogers, A.D., 1999. The biology of Lophelia pertusa (Linnaeus 1758) and other deep-water reefforming corals and impacts from human activities. International Review of Hydrobiology 84 (4), 315-406. Rowe, G.T., Kennicutt II, M.C. (Eds.), 2009. Northern Gulf of Mexico continental slope habitats

33

and benthic ecology study: Final report, U.S. Dept. of the Interior, Minerals Management Service, Gulf of Mexico OCS Region, New Orleans, LA. Schroeder, W.W., 2002. Observations of Lophelia pertusa and the surficial geology at a deepwater site in the northeastern Gulf of Mexico. Hydrobiologia 471 (1), 29-33. Schroeder, W.W., Brooke, S.D., Olson, J.B., Phaneuf, B., McDonough III, J.J., Etnoyer, P., 2005. Occurrence of the deep-water Lophelia pertuse and Madrepora oculata in the Gulf of Mexico. In: Freiwald, A., Roberts, J.M. (Eds.), Cold-water Corals and Ecosystems. Springer-Verlag, Berlin Heidelberg, pp. 297-307. Sulak, K.J., Brooks, R.A., Luke, K.E., Norem, A.D., Randall, M., Quaid, A.J., Yeargin, G.E., Miller, J.M., Harden, W.M., Caruso, J.H., Ross, S.W., 2007. Demersal fishes associated with Lophelia pertusa coral and hard-substrate biotopes on the continental slope, northern Gulf of Mexico. Bulletin of Marine Science 81 (Supplement 1), 65-92. Sulak, K.J., Randall, M.T., Luke, K.E., Norem, A.D., Miller, J.M., 2008. Characterization of northern Gulf of Mexico deepwater hard bottom communities with emphasis on Lophelia coral - Lophelia reef megafaunal community structure, biotopes, genetics, microbial ecology, and geology. USGS Open-File Report 2008-1148. Thiem, O., Ravagnan, E., Fossa, J.H., Berntsen, J., 2006. Food supply mechanisms for coldwater corals along a continental shelf edge. Journal of Marine Systems 60 (3-4), 207-219. van Oevelen, D., Duineveld, G., Lavaleye, M.S.S., Meinis, F., Soetaert, K., Heip, C., 2009. The cold-water coral community as a hot spot for carbon cycling on continental margins: A food-web analysis from Rockall Bank (north Atlantic). Limno. Oceanogr. 54 (6), 18291844. Warwick, R.M., 1988. Analysis of community attributes of the macrobenthos of

34

Frierfjord/Langesundfjord at taxonomic levels higher than species. Marine Ecology Progress Series 46, 167-170. Wei, C.L., Rowe, G.T., Escobar-Briones, E., Nunnally, C., Soliman, Y., Ellis, N., 2012. Standing stocks and body size of deep-sea macrofauna: Predicting the baseline of 2010 Deepwater Horizon oil spill in the northern Gulf of Mexico. Deep-Sea Research Part IOceanographic Research Papers 69, 82-99. Wei, C.L., Rowe, G.T., Fain Hubbard, G., Scheltema, A.H., Wilson, G.D.F., Petrescu, I., Foster, J.M., Wicksten, M.K., Chen, M., Davenport, R., Soliman, Y., Wang, Y., 2010. Bathymetric zonation of deep-sea macrofauna in relation to export of surface phytoplankton production. Marine Ecology Progress Series 399, 1-14. Wenner, E.L., Knott, D.M., Van Dolah, R.F., Burrell Jr, V.G., 1983. Invertebrate communities associated with hard bottom habitats in the South Atlantic Bight. Estuarine, Coastal and Shelf Science 17 (2), 143-158. White, H.K., Hsing, P.-Y., Cho, W., Shank, T.M., Cordes, E.E., Quattrini, A.M., Nelson, R.K., Camilli, R., Demopoulos, A.W.J., German, C.R., Brooks, J.M., Roberts, H.H., Shedd, W., Reddy, C.M., Fisher, C.R., 2012. Impact of the Deepwater Horizon oil spill on a deep-water coral community in the Gulf of Mexico. Proceedings of the National Academy of Sciences 109 (50), 20303-20308. Wilson, S.K., Graham, N.A.J., Polunin, N.V.C., 2007. Appraisal of visual assessments of habitat complexity and benthic composition on coral reefs. Marine Biology 151 (3), 1069-1076. Zar, J.H., 1999. Biostatistical analysis. Prentice Hall, Upper Saddle River, NJ.

35

Figure captions Fig. 1. Sampling sites in the northern Gulf of Mexico, including MC751 (a), VK906 (b), and VK826 (c) with solid black squares representing near-coral locations and open squares representing background locations and DeGoMB site MT1 (Rowe & Kennicutt II 2009). Bathymetric contours are at 10 m intervals.

Fig. 2. Mean (± 1 S.E.) density of macrofauna (> 300Pm) in near-coral and background soft sediments at MC751, VK906, and VK826, Gulf of Mexico. The symbol “*” indicates statistical significance at p < 0.05.

Fig. 3. Rarefaction curves showing richness of macrofauna based on number of individuals (Coleman Rarefaction) from near-coral and background habitats at MC751, VK906, and VK826.

Fig. 4. Proportion of taxa based on mean macrofaunal densities of major taxonomic groups in near-coral and background sediments at each site, including the polychaete families: Maldanidae, Oweniidae, Paraonidae, Spionidae, and Syllidae. The Other group includes the following taxa: Halacaridae, Pycnogonida, Cnidaria (Anthozoa, Hydrozoa), Echinodermata (Ophiuroidea, Holothuroidea), Nemertea, Platyhelminthes, Sipuncula, Echiura, Tunicata, and Chaetognatha.

Fig. 5. Non-metric multidimensional scaling results of macrofaunal assemblages from nearcoral (solid black symbols) and background (open symbols) sediments at MC751, VK906 and VK826, based on square-root transformed Bray-Curtis similarities. Each point represents the data from one core. The stress value measures how well the 2-dimensional plot represents the

36

multidimensional distances among the data; values < 0.20 are considered to yield a useful 2dimensional representation of the data (Clarke & Warwick 2001).

Fig. 6. Non-metric multidimensional scaling results of polychaete assemblages near Lophelia pertusa and in background sediments at MC751, VK906, and VK826 (this study), and the Deep Gulf of Mexico Benthos program (DeGoMB) site MT1 (Rowe & Kennicutt II 2009, Wei et al. 2010), based on Bray-Curtis similarities of presence/absence data. Each point represents the data from one core. The circle represents among sample similaries of 79% for MT1.

Supplementary Figure A1. Percent composition of macrofaunal feeding guilds in near-coral and background sediments at each site. Taxa included in each feeding guild are detailed in Table 2.

Supplementary Figure A2. Rarefaction curves showing richness of polychaete families based on number of individuals (Coleman Rarefaction) from near-coral and background habitats (this study) and DeGoMB site MT1 (Rowe & Kennicutt II 2009, Wei et al. 2010).

37

Table 1. Locations, depths, gear used, and diversity measures for the samples collected in this study. PC = Push cores (6.35 cm); SPC = Large push cores (8.26 cm); BC = Box cores subsampled with push cores (6.35 cm). Sp = Total number of identified taxa; Fisher’s  = Fisher’s diversity index; J’ = Pielou’s evenness; d = Margalef’s index of species richness. Numbers in parentheses correspond to ± 1 standard error. Diversity calculations for VK906 Background excluded SPC. Site MC 751

VK 906

Habitat

No. of Samp les

Ge ar

Dive/ Stn

Latitu de

Nearcoral

3

PC

464

28.19 37

Backgro und

2

PC

464

28.19 87

1

BC

27

28.19 69

1

BC

28

28.19 68

3

PC

465

29.06 96

3

PC

465

29.06 92

3

PC

473

29.06 90

3

PC

465

29.06 73

1

SP C

3725

29.06 91

1

BC

33

29.07 27

3

PC

466

29.15 78

2

PC

466

29.15 82

2

PC

467

29.15 87

Nearcoral

Backgro und

VK 826

Nearcoral

Longit ude 89.798 8 89.801 0 89.798 8 89.799 9 88.377 1 88.377 6 88.377 1 88.380 2 88.376 1 88.378 1 88.016 2 88.016 8 88.010

Dep th (m)

S p

Fisher's 

440

3 2

15. 62

(2.1 1)

0.9 4

(0.0 1)

4.6 4

(0.2 6)

431

3 4

10. 47

(0.6 0)

0.8 5

(0.0 3)

4.4 1

(0.2 2)

4 9

8.0 9

(1.1 3)

0.8 6

(0.0 2)

3.7 8

(0.3 5)

4 5

12. 24

(2.8 1)

0.8 9

(0.0 1)

4.9 2

(0.9 1)

5 2

10. 52

(1.5 7)

0.8 1

(0.0 2)

4.6 7

(0.3 3)

J'

d

429

427

388

393

392

432

393

418

475

470 480

38

4 Backgro und

1

BC

62

29.17 01

1

BC

63

29.17 07

1

BC

72

29.16 77

1

BC

74

29.17 08

88.013 3 88.012 3 88.013 2 88.011 3

470

4 9

12. 21

(1.2 5)

0.8 7

(0.0 1)

4.5 8

(0.3 2)

461

472

458

39

Table 2. Mean macrofaunal densities for individual taxa, total density per core (individuals per 32 cm2), and total density (individuals per m2) with standard errors (in parentheses) for nearcoral and background habitats at MC751, VK906, and VK826, and feeding guild designation for each taxa. D=Deposit feeder; C=Carnivore; O=Omnivore; F=Filter feeder. SITE PROXIMITY ANNELIDA

Feed ing Guil d -

MC 751 Backgrou Near nd 21. (1. 28. (3.4 0 5) 0 ) 19. (2. 27. (3.2 7 2) 5 ) (0.5 - 0.5 ) (0. (0.3 0.7 3) 0.8 )

POLYCHAETA

-

Acrocirridae

D

Ampharetidae

D

Amphinomidae

C

-

-

Capitellidae

D

-

Cirratulidae

D

1.3

Cossuridae

D

0.3

Chrysopetalidae

C

0.3

(0. 7) (0. 3) (0. 3)

Dorvilleidae

O

-

Eunicidae

O

Fauveliopsidae

-

VK 906 Backgrou Near nd 43. (4.2 33. (6.1 7 ) 1 ) 39. (4.2 28. (3.8 8 ) 1 ) (0.6 (0.1 0.9 ) 0.1 ) (0.5 (0.5 2.6 ) 1.2 )

(0.3 ) (0.5 )

0.1

-

-

2.1

-

-

-

-

-

-

0.3

-

-

-

-

0.2

D

-

-

-

-

3.6

Flabelligeridae

D

-

-

-

-

0.3

Glyceridae

C

-

-

O

0.3

1.3

Lumbrineridae

O

-

-

0.5

(0.3 ) (0.5 )

0.2

Hesionidae

(0. 3)

0.2

Lacydoniidae

D

-

-

-

0.7

Maldanidae

D

0.7

-

-

2.2

Nephtyidae

C

0.3

(0. 7) (0. 3)

-

Nereididae

O

-

-

0.5

(0.3 )

Nerillidae

D

-

-

-

0.3 0.8

-

0.3

0.2

(0.2 ) (0.1 ) (1.2 ) (0.3 ) (0.1 ) (0.9 ) (0.2 ) (0.1 ) (0.2 ) (0.1 ) (0.7 ) (0.7 )

0.4 1.2 2.1 0.8 0.4

(0.2 ) (0.7 ) (1.5 ) (0.8 ) (0.4 )

VK 826 Backgrou Near nd 58. (7.8 30. (8.0 3 ) 8 ) 57. (7.9 29. (7.1 4 ) 8 ) (0.5 - 0.5 ) (0.3 (0.3 0.3 ) 0.5 ) (0.4 (0.3 0.4 ) 0.3 ) (0.3 - 0.3 ) (1.0 (1.5 1.4 ) 1.5 ) (0.5 - 0.5 ) (0.1 0.1 ) - (0.4 (0.3 0.7 ) 0.3 ) (0.1 (0.3 0.1 ) 0.3 ) (1.3 (1.3 2.3 ) 1.3 )

-

-

-

-

-

(0.6 ) (0.2 ) (0.2 ) (1.1 )

-

(0.3 )

0.3

-

-

0.8

-

(2.3 )

1.5 0.3

0.7 0.4 0.2 2.2

0.3

9.0

-

-

-

-

-

-

-

(0.4 )

-

(0.4 )

-

(0.2 )

0.7

0.6

1.7

0.3

-

(0.3 ) (0.3 ) (0.8 ) (1.0 ) (0.3 )

-

-

-

-

40

Onuphidae

O

1.7

Opheliidae

D

1.0

Orbiniidae

D

-

Oweniidae

D

1.3

Paraonidae

D

3.3

Pilargidae

C

Pholoidae

(0. 9) (0. 6)

(0.5 )

0.4

-

-

0.3

-

(0.3 ) (1.2 ) (0.3 )

1.1 12. 1

0.8

(0. 9) (1. 3)

0.3

-

-

0.5

C

-

-

-

Polynoidae

C

-

-

Sabellariidae

F

-

Sabellidae Scalibregmatida e

F

0.7

(0. 3)

D

-

-

Serpulidae

F

-

Sigalionidae

C

0.3

Spionidae

D

3.7

Syllidae

O

2.7

(0. 3) (0. 3) (1. 5)

Terebellidae Trichobranchida e

D

-

D

1.0

OLIGOCHAETA

-

1.3

Tubificidae

D

1.3

ARTHROPODA

-

5.7

-

-

-

0.5 21. 3 11. 8

-

-

-

0.3

Aoridae

D

-

-

1.0

Ampeliscidae

D

-

-

9.3

Ampilochidae

D

-

-

-

Ampithoidae

O

-

-

0.3

Caprellidae

-

-

-

Lysianassidae

C

-

-

AMPHIPODA Unknown Gammaroidea

(0. 6) (0. 9) (0. 9) (1. 5)

6.0

1.0

(0.2 ) (0.3 ) (0.6 ) (3.1 ) (0.4 )

0.3 0.1 1.2 4.2 2.0

(0.2 ) (0.1 ) (0.4 ) (2.1 ) (0.9 )

0.4 0.7 0.4 23. 0 2.9

-

-

-

-

0.4

-

-

-

-

0.1

-

-

-

-

0.2

-

(0.3 )

-

0.1

1.2

-

-

0.2

-

1.8

(0.5 ) (0.8 ) (0.1 )

0.2

(0.2 ) (0.2 ) (1.3 ) (0.4 ) (1.1 )

-

-

(0.6 ) (0.2 ) (1.1 )

(0.2 ) (0.1 ) (0.3 )

0.3

10. 3 3.8 0.8 0.5 0.5

(1.6 ) (0.6 ) (0.5 ) (0.3 ) (0.3 ) (0.3 ) (5.4 ) (5.6 ) (0.3 ) (0.6 ) (5.2 )

3.9 2.8 0.2 3.9 3.9 5.2 0.6

(1.9 ) (1.9 ) (1.9 ) (0.3 )

0.4 0.2

4.3 2.3 2.0 5.0 5.0 10. 5 2.2

-

-

-

-

-

0.4

-

-

-

(0.3 )

-

-

0.3

-

-

-

-

-

-

-

0.1

-

-

-

-

-

(2.5 ) (2.5 ) (2.1 ) (0.7 )

0.3 0.3 0.1

0.1 0.1 7.9 3.6 0.6 0.9 0.9 12. 9 2.1

(0.2 ) (0.3 ) (0.4 ) (4.2 ) (1.5 ) (0.2 ) (0.1 ) (0.3 ) (0.2 ) (0.1 ) (0.1 ) (0.1 ) (1.7 ) (0.9 ) (0.4 )

0.3 0.3 0.8 0.8 3.5

(0.3 ) (0.3 ) (0.8 ) (0.5 ) (1.9 )

-

-

-

(0.3 ) (0.3 ) (0.5 )

0.3 0.3 0.5 -

-

-

(0.3 ) (3.9 ) (0.9 ) (0.8 )

0.3 9.3 4.8 0.8

(0.3 ) (0.3 ) (2.0 ) (0.8 )

-

1.0

1.0

7.8 2.5

(1.0 ) (1.0 ) (1.3 ) (1.0 ) (0.3 ) (0.3 )

(0.2 )

-

-

0.3

-

-

0.3

(0.2 )

-

-

-

-

-

-

-

-

(0.1 )

-

-

-

-

-

(0.3 )

-

-

-

-

-

0.3

41

(0.1 ) (0.1 ) (0.1 ) (0.1 ) (1.4 ) (0.2 )

2.0

-

-

0.2

-

-

-

-

0.4

(0.4 )

-

-

-

-

-

0.8

-

(0.5 ) (0.5 ) (0.6 )

0.9

(0.4 )

-

-

-

(0.9 ) (0.3 ) (0.3 )

0.1

-

-

0.1

-

-

-

0.6

-

-

-

D

-

-

1.0

(0.4 )

-

-

-

-

-

0.1

D

-

-

-

-

0.1

Melitidae Phoxocephalida e

O

-

-

-

-

-

-

0.8

Podoceridae

-

-

-

0.3

Stilipedidae

-

-

ISOPODA Desmosomatida e

-

4.0

D

3.0

(1. 2) (0. 6)

Hyssuridae

D

-

-

-

-

Ischnomesidae

D

-

-

-

Janiridae

D

-

Macrostylidae

D

0.3

Munnopsidae

D

0.7

(0. 3) (0. 7)

Paramunnidae

D

-

-

0.3

Nannastacidae

D

0.3

TANAIDACEA Unknown Paratanaoidea

-

0.7

(0. 3) (0. 3) (0. 7)

-

-

-

-

Apseudidae

-

-

-

1.0

Agathotanaidae Armaturatanais sp

D

-

-

D

-

-

Colletteidae

D

-

Leptocheliidae

D

0.3

Leptognathiidae

D

0.3

(0. 3) (0. 3)

Pseudotanaidae

D

-

-

Sphyrapodidae

-

-

Tanaellidae

D

Typhlotanaidae

CUMACEA

MYSIDA Mysidae

3.0 3.0

0.8 0.8 5.3

2.8 0.3 0.3

(0.5 ) (0.3 ) (0.4 ) (0.4 )

0.2 0.1 0.1 0.1 2.7 0.6

(0.3 ) (0.9 )

1.4

(0.4 )

1.9

(0.6 )

2.0

-

-

-

-

-

-

-

(1.3 ) (0.5 ) (0.2 )

-

(1.5 ) (1.5 )

-

(0.9 ) (0.3 )

3.8

0.4 0.3 0.8

6.9 4.1 -

(0.4 )

0.1

(0.2 ) (0.6 )

1.9

-

0.7

2.0 0.3

(0.1 )

-

-

-

(1.0 ) (0.4 )

0.3

(0.3 )

1.5

-

-

-

-

-

-

-

-

-

0.3

-

(0.7 )

-

-

-

-

0.2

-

-

0.8

-

(0.1 )

0.2

(0.9 ) (0.1 ) (0.3 ) (0.1 ) (0.6 )

0.3

4.2

(1.2 ) (0.2 ) (0.4 ) (0.2 ) (0.2 ) (0.4 ) (0.2 )

1.7

0.9 -

(0.9 )

0.2

(0.5 )

1.3

(0.1 ) (0.6 )

-

0.5

1.0

(0.4 )

3.6 0.1 0.6 0.1 0.9 0.3 0.1 0.3

(0.2 ) (0.1 ) (0.3 )

-

-

-

(0.7 ) (0.1 ) (0.1 )

-

-

-

-

-

-

(0.1 ) (0.1 )

-

-

1.1

-

-

0.1

-

-

0.1

2.5 0.3 0.3

(0.6 ) (0.3 ) (0.3 ) (1.0 ) (0.3 ) (0.3 )

-

-

-

(0.3 ) (0.3 ) (0.3 )

0.5 0.5 0.5 -

-

-

(0.5 )

0.5 -

-

-

-

-

-

42

CIRRIPEDIA

-

-

-

-

-

-

-

0.1

Scalpellidae

F

-

-

0.7

C

0.7

0.1

PYCNOGONIDA

-

-

-

-

-

0.1

Callipallenidae

C

-

-

1.0

(0.8 )

0.1

-

GASTROPODA

D

0.3

BIVALVIA

D

0.3

6.0

APLACOPHORA Chaetodermatid ae Prochaetoderma tidae

-

0.3

D

0.3

(0. 6) (0. 3) (0. 3) (0. 3) (0. 3)

(0.1 ) (0.1 ) (0.1 ) (0.1 ) (1.8 ) (1.2 ) (0.8 )

0.1

-

(0.3 ) (0.3 )

-

ARACHNIDA

(0. 3) (0. 3)

D

-

-

Halacaridae

MOLLUSCA

0.5 0.5

1.3 1.3

(0.8 )

0.1

7.6 4.2 3.3

(0.1 ) (0.1 )

-

-

-

-

-

(0.1 ) (0.1 )

-

(0.5 ) (0.5 )

-

-

0.1

-

(0.2 ) (0.2 ) (2.7 ) (1.6 ) (1.8 ) (0.2 )

0.1

0.2 0.2 8.0 1.8

-

-

-

-

(1.6 ) (0.6 ) (1.2 ) (0.2 )

-

(1.7 ) (0.9 ) (1.2 ) (0.3 )

5.7 1.6 3.9

-

-

-

0.2

-

-

-

-

-

-

-

-

-

0.2

-

-

-

-

0.1

F F

-

-

-

-

0.1 -

(0.1 ) (0.1 ) -

Hydrozoa BRYOZOA PORIFERA ECHINODERMAT A

F F F

-

P

-

P P

-

0.2 P P

-

1.0

-

-

-

-

-

-

0.3

Holothuroidea

D

0.3

-

-

-

-

-

-

-

Ophiuroidea

O

0.7

-

0.7

(0.1 )

-

C

0.2

SIPUNCULA

D

1.3

(0.3 ) (0.3 )

-

NEMERTEA

(0. 6) (0. 3) (0. 3) (0. 7) (0. 9)

-

-

1.0

ECHIURA PLATYHELMINTH ES

D

-

(0.2 ) (0.4 ) (0.2 )

O

1.0

CHORDATA

-

Tunicata

CNIDARIA Anthozoa Octocorallia

CHAETOGNATHA Total number of ind. per 32cm²

0.5 0.3

0.1

0.2 -

(0. 6)

-

-

-

-

0.2

-

-

-

-

-

-

-

-

-

-

-

F

-

-

-

-

-

C

31. 7

(0.1 ) (4.3 )

-

(2. 8)

51. 3

(7.2 )

0.1 56. 8

(0.2 )

0.5

-

-

(0.2 ) (0.2 )

0.5

0.3 0.3 0.4 0.1 0.3 P

0.3 0.6 1.6

(0.2 ) (0.2 ) (0.1 ) (0.2 ) (0.2 ) (0.2 ) (0.2 ) (0.4 )

4.5 1.8 2.5 0.3 0.3 0.8 0.3 P 0.5 P 0.3 0.3 0.3 0.5

(0.3 ) (0.5 ) (0.3 ) (0.5 ) (0.3 ) (0.3 ) (0.3 ) (0.5 )

-

-

-

-

-

-

-

-

-

-

0.1

-

-

-

-

0.1

(0.1 ) (0.1 )

-

-

(9.3 )

79. 9

(9.7 )

44. 8

53. 3

(8.2 )

43

Total number of ind. m-²

-

100 05

(90 0)

161 93

(22 83)

179 39

(13 49)

168 26

(29 34)

252 31

(30 60)

141 39

(25 81)

44

Percent Composition

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

MC751 Near

MC751 Background

VK906 Near

VK906 Background

VK826 Near

VK826 Background

Deposit Feeder

Carnivore

Omnivore

Filter Feeder

Macrofaunal Composition (%)

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

MC751 Near

MC751 Background

VK906 VK906 Near Background Site/Proximity

VK826 Near

VK826 Background

Other Groups

Mollusca

Crustacea

Oligochaeta

Other Polychaeta

Syllidae

Spionidae

Paraonidae

Oweniidae

Maldanidae

Number of Families/Groups 0

10

20

30

40

50

60

0

100

200 300 400 Number of Individuals

500

MC751 Near MC751 Background VK906 Near VK906 Background VK826 Near VK826 Background 600

Individuals 32-cm2 0

10

20

30

40

50

60

70

80

90

100

MC751

Near-coral Background

VK906 Site

VK826

*

Number of Polychaete Families

0

5

10

15

20

25

30

35

40

0

500

1000

1500 2000 Number of Individuals

2500

3000

3500

Background

Near

MT1

Figure1

Figure5

2D Stress: 0.04

MC751 2D Stress: 0.14

VK906 2D Stress: 0.12

VK826

Figure6

79%

2D Stress: 0.23

MC-751 Near MC-751 Background VK-906 Near VK-906 Background VK-826 Near VK-826 Background MT1

SiteProximity