Polychaete assemblages of the northwestern Ross Sea shelf: worming out the environmental drivers of Antarctic macrobenthic assemblage composition

Climate change has ecosystem-wide cascading effects. Little is known, however, about the resilience of Arctic marine ecosystems to environmental change. Here we quantify and compare large-scale patterns in rocky intertidal biomass, coverage and zonation in six regions along a north-south gradient of temperature and ice conditions in West Greenland (60-72°N). We related the level and variation in assemblage composition, biomass and coverage to latitudinal-scale environmental drivers. Across all latitudes, the intertidal assemblage was dominated by a core of stress-tolerant foundation species that constituted >95% of the biomass. Hence, canopy-forming macroalgae, represented by Fucus distichus subsp. evanescens and F. vesiculosus and, up to 69 °N, also Ascophyllum nodosum, together with Semibalanus balanoides, occupied >70% of the vertical tidal range in all regions. Thus, a similar functional assemblage composition occurred across regions, and no latitudinal depression was observed. The most conspicuous difference in species composition from south to north was that three common species (the macroalgae Ascophyllum nodosum, the amphipod Gammarus setosus and the gastropod Littorina obtusata) disappeared from the mid-intertidal, although at different latitudes. There were no significant relationships between assemblage metrics and air temperature or sea ice coverage as obtained from weather stations and satellites, respectively. Although the mean biomass decreased >50% from south to north, local biomass in excess of 10 000 g ww m-2 was found even at the northernmost site, demonstrating the patchiness of this habitat and the effect of small-scale variation in environmental characteristics. Hence, using the latitudinal gradient in a space-for-time substitution, our results suggest that while climate modification may lead to an overall increase in the intertidal biomass in north Greenland, it is unlikely to drive dramatic functional changes in ecosystem structure in the near future. Our dataset provides an important baseline for future studies to verify these predictions for Greenlands intertidal zone.

Download Full-text

Macroinvertebrates and Microbes (Archaea, Bacteria) Offer Complementary Insights into Mine-Pit Lake Ecology

Mine Water and the Environment ◽

10.1007/s10230-019-00647-9 ◽

2019 ◽

Vol 39 (3) ◽

pp. 589-602 ◽

Cited By ~ 1

Author(s):

Melanie L. Blanchette ◽

Richard Allcock ◽

Jahir Gonzalez ◽

Nina Kresoje ◽

Mark Lund

Keyword(s):

Water Chemistry ◽

Environmental Drivers ◽

Sediment Chemistry ◽

Lake Ecosystem ◽

Pit Lake ◽

Lake Ecosystems ◽

Assemblage Composition ◽

Management Actions ◽

Pit Lakes ◽

Broad Objective

Abstract The broad objective of this research was to determine the environmental drivers of macroinvertebrate and microbial assemblages in acidic pit lakes. This is important because pit lake ecosystem development is influenced by prevailing environmental characteristics. Three lakes (Stockton, Kepwari, WO5H) within a larger pit-lake district in Collie, Western Australia were surveyed for spatial variability of benthic macroinvertebrate and microbe (Archaea, Bacteria) assemblage composition as well as potential environmental drivers (riparian condition, aquatic habitat, sediments, and aquatic chemistry) of assemblages. With the exception of sediment chemistry, biophysical variables were significantly different across lakes and reflected riparian condition and groundwater chemistry. Microbial assemblages in pit lakes were significantly different across lakes and correlated with water chemistry, particularly metals in Lake WO5H. However, the most abundant microbes were not readily identified beyond class, making it difficult to speculate on their ecological function. Macroinvertebrate assemblage composition and species richness were also significantly different across all lakes, and in Lake WO5H (a lake with low pH and high metal concentrations), taxa were correlated with benthic organic matter as well as water chemistry. Results indicated that despite poor water quality, input of nutrients from terrestrial leaf litter can support or augment pit lake ecosystems. This is a demonstration of the concept that connection of pit lakes to catchments can positively affect aquatic ecosystems, which can inform management actions for remediation.

Download Full-text

Thermohaline variability and Antarctic bottom water formation at the Ross Sea shelf break

Deep Sea Research Part I Oceanographic Research Papers ◽

10.1016/j.dsr.2011.07.002 ◽

2011 ◽

Vol 58 (10) ◽

pp. 1002-1018 ◽

Cited By ~ 33

Author(s):

Giorgio Budillon ◽

Pasquale Castagno ◽

Stefano Aliani ◽

Giancarlo Spezie ◽

Laurie Padman

Keyword(s):

Bottom Water ◽

Ross Sea ◽

Shelf Break ◽

Antarctic Bottom Water ◽

Water Formation ◽

Bottom Water Formation ◽

Ross Sea Shelf

Download Full-text

Macrobenthic communities of the north-western Ross Sea shelf: links to depth, sediment characteristics and latitude

Antarctic Science ◽

10.1017/s0954102010000489 ◽

2010 ◽

Vol 22 (6) ◽

pp. 793-804 ◽

Cited By ~ 25

Author(s):

V.J. Cummings ◽

S.F. Thrush ◽

M. Chiantore ◽

J.E. Hewitt ◽

R. Cattaneo-Vietti

Keyword(s):

Ross Sea ◽

Fine Sand ◽

Sediment Characteristics ◽

Explanatory Variables ◽

The North ◽

Biogenic Habitat ◽

Community Variability ◽

North Western ◽

Western Ross Sea ◽

Ross Sea Shelf

AbstractIn early 2004 the Victoria Land Transect project sampled coastal north-western Ross Sea shelf benthos at Cape Adare, Cape Hallett, Cape Russell and Coulman Island from 100–500 m deep. We describe the benthic macrofaunal assemblages at these locations and, to assess the use of seafloor sediment characteristics and/or depth measures in bioregionalizations, determine the extent to which assemblage compositions are related to measured differences in these factors. Percentages of fine sand and silt, the ratio of sediment chlorophyllato phaeophytin, and depth were identified as important explanatory variables, but in combination they explained only 17.3% of between-location differences in assemblages. Consequently, these variables are clearly not strong determinants of macrofaunal assemblage structure. Latitudeper sewas not a useful measure of community variability and change. A significant correlation between both number of individuals and number of taxa and sediment phaeophytin concentration across locations suggests that the distribution of the benthos reflects their response to seafloor productivity. A number of factors not measured in this study have probably influenced the structure and function of assemblages and habitats. We discuss the implications of the results to marine classifications, and stress the need to incorporate biogenic habitat complexity into protection strategies.

Download Full-text

Composition, abundance and stratification of soft-bottom macrobenthos from selected areas of the Ross Sea shelf (Antarctica)

Polar Biology ◽

10.1007/s003000050372 ◽

1999 ◽

Vol 21 (6) ◽

pp. 347-354 ◽

Cited By ~ 35

Author(s):

M. C. Gambi ◽

S. Bussotti

Keyword(s):

Ross Sea ◽

Soft Bottom ◽

Ross Sea Shelf

Download Full-text

Benthic hydroids (Cnidaria, Hydrozoa) from the Ross Sea (Antarctica) collected by the New Zealand Antarctic expedition BioRoss 2004 with RV Tangaroa

Zootaxa ◽

10.11646/zootaxa.4293.1.1 ◽

2017 ◽

Vol 4293 (1) ◽

pp. 1 ◽

Cited By ~ 2

Author(s):

ÁLVARO L. PEÑA CANTERO

Keyword(s):

New Species ◽

New Zealand ◽

New Records ◽

Ross Sea ◽

Beam Trawl ◽

Generic Level ◽

Marine Communities ◽

Genus Level ◽

Antarctic Expedition ◽

Ross Sea Shelf

During the New Zealand BioRoss 2004 survey, with RV Tangaroa, sampling of marine communities on the Ross Sea shelf was undertaken. Samples were obtained employing several sampling gears (Van Veen grab, epibenthic sled, rough bottom trawl, and beam trawl). Among the numerous benthic samples obtained, a large and important collection of hydroids was present. Sixty-one species, four of them new to science (Monocoryne antarctica sp. nov., Halecium tangaroa sp. nov., Staurotheca gracilis sp. nov. and Symplectoscyphus densus sp. nov.) have been recorded. Oswaldella blanconae sp. nov. is also described. “Anthoathecata” are represented by ten species belonging to the families Bougainvilliidae, Candelabridae, Clathrozoellidae, Hydractiniidae, Eudendriidae and Tubulariidae. Leptothecata are dominant, with 51 species belonging to the families Campanulariidae, Campanulinidae, Lafoeidae, Haleciidae, Hebellidae, Kirchenpaueriidae, Schizotrichidae, Staurothecidae, Symplectoscyphidae and Zygophylacidae. Symplectoscyphidae is the richest family with 19 species (31%), followed by Staurothecidae with eight (13%) and Haleciidae with seven species (11%). At the generic level, Symplectoscyphus with 14 species (two of them identified only at the genus level), Staurotheca with eight species (one identified to genus level) and Halecium with seven species are the most speciose genera. Twenty-two species (including the four new species) constitute new records for the Ross Sea, thus raising the number of valid, known species of the area to 77.

Download Full-text