Macrozoobenthos of two Antarctic glacial coves: a comparison with non-disturbed bottom areas

Abstract

There are only few studies on shallow Antarctic benthic communities associated with habitats affected by intense mineral sedimentation inflow. The analysis of macrofaunal communities associated with two shallow, isolated glacial coves was performed in Admiralty Bay (King George Island) and compared with non-disturbed sites. Multivariate analyses (hierarchical classification, nMDS) clearly separated glacial cove communities (two assemblages) from the sites situated outside both basins (two assemblages). The community influenced by the streamflow of glacial discharge of meltwater situated in the area with sandy-clay-silt sediments had a very low species richness, diversity and abundance. It was dominated by eurytopic, motile deposit feeding polychaetes such as Mesospio moorei, Tharyx cincinnatus and Leitoscoloplos kerguelensis as well as the bivalve Yoldia eightsi. The second glacial community of the area located at a grater distance from the outlet of the stream was characterized by sandy-clay-silt and clay-silt deposits and showed also a low diversity and species richness. The most abundant here were peracarid crustaceans, with the dominant opportunistic feeder Cheirimedon femoratus. Community from the non-disturbed area with silty-clay-sand, and silty-sand sediments had higher species richness and diversity. The assemblage of fauna from the sandy bottom has values of those two indexes similar to those found in the disturbed areas.

Low abundance and high species richness: the structure of the soft-bottom isopod fauna of a West Antarctic glacial fjord

“…So far, a total of 99 species of isopod crustaceans have been recorded in the basin (Arnaud et al 1986;Presler 1986;Teodorczyk and Wagele 1994;Zemko and Kaiser 2012;Siciński et al 2012;Zemko et al 2015;Zemko unpublished results). Isopods are the third most speciose macrofaunal group in the Admiralty Bay, following the Amphipoda (172 species) and Polychaeta (162 species) ).…”

“…They are an important component of the Antarctic trophic web and represent a high diversity of feeding modes (Poore and Bruce 2012;Kaiser 2014). Isopods are benthic brooders characterized by a limited dispersal potential, which makes them potentially good indicators of changes associated with various types of natural and anthropogenic disturbance (Veloso et al 2011;Siciński et al 2012;Longo et al 2013). Some species have been shown to be vulnerable to largescale environmental changes observed in the region of the West Antarctic Peninsula (Ingels et al 2012).…”

“…Kussakin 1967;Kussakin 1973;Brandt 1990Brandt , 1992De Broyer et al 2011;Kaiser 2014), although ecological studies have been scarce, most concerning only the shallowest soft-bottom areas (e.g. Lowry 1975;Richardson and Hedgpeth 1977;Siciński et al 2012;Bick and Arlt 2013). Moreover, no studies have addressed exclusively distribution patterns of the isopod fauna.…”

Age-dependent expression of stress and antimicrobial genes in the hemocytes and siphon tissue of the Antarctic bivalve, Laternula elliptica, exposed to injury and starvation

“…This may lead to an alteration in the age structure of the general population towards a higher abundance of young (reproductively immature) animals. In the longer run, this will not only influence the composition and structure of L. elliptica populations but also the composition and function of Antarctic shallow benthic communities (Husmann et al 2011;Philipp et al 2011;Siciński et al 2012).…”

Distribution patterns of polychaete fauna in an Arctic fjord (Hornsund, Spitsbergen)

“…Benthic diversity and biomass can change significantly from the outer to the inner parts of Arctic and Subarctic fjords (Kendall and Aschan 1993;Holte and Oug 1996;Włodarska-Kowalczuk et al 2005;Blanchard et al 2010). The chronic disturbance associated with glacial activity is especially visible in the shallow areas located close to the glacial terminus (Włodarska-Kowalczuk et al 1998;Włodarska-Kowalczuk and Pearson 2004;Siciński et al 2012); however, this influence can be very strong to as deep as 100 m (Siciński 2004). Thus, it is important to show the effects of glacial disturbance on benthic fauna in the deeper parts of fjords.…”