Reduced survival of Antarctic benthos linked to climate-induced iceberg scouring

Barnes, David K. A.; Souster, Terri

doi:10.1038/nclimate1232

Cited by 100 publications

(103 citation statements)

References 14 publications

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“…Since gametogenesis of A. eightsii shows synchrony in seasonality between males and females, the loss of a relatively large proportion of gametes between April and May and the absence of brooded embryos suggest this bivalve is a broadcast spawner with lecithotrophic larvae. Winter spawning of lecithotrophic larvae may facilitate the avoidance of predators feeding on larvae associated with the summer bloom (Sahade et al 2004), ice-mediated disturbance (Barnes and Souster 2011), and a greater availability of free substratum for larval settlement (Bowden 2005). As adult A. eightsii can inhibit larval settlement via density-dependent control (Peck and Bullough 1993), larvae spawned during periods with more available habitat could increase the chance of settlement.…”

Section: Discussionmentioning

confidence: 99%

“…In the Southern Ocean, the waters around the West Antarctic Peninsula have experienced pronounced warming relative to the global average (see review by Mayewski et al 2009), with sea surface summer temperatures in the Bellingshausen Sea on the west of the Peninsula increasing by ~ 1 °C since the 1950s (Meredith and King 2005). Antarctic shallow-water invertebrates are particularly susceptible to the effects of climate change, as warming causes perturbations in sea ice dynamics, which could subsequently lead to ecological regime shifts in benthic systems (Barnes and Conlan 2007;Barnes and Souster 2011;Barnes 2016). Presently, there is a lack of knowledge specific to the recovery potential of the benthos after these disturbance events (Clark et al 2015).…”

Section: Introductionmentioning

confidence: 99%

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The reproductive ecology of the Antarctic bivalve Aequiyoldia eightsii (Protobranchia: Sareptidae) follows neither Antarctic nor taxonomic patterns

et al. 2018

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The accepted paradigm for reproduction in Antarctic marine species is one where oogenesis takes 18 months to 2 years, and a bimodal egg-size distribution where two cohorts of eggs are present in female gonads throughout the year. These slow gametogenic traits are driven by low temperature and/or the restriction of resource availability because of extreme seasonality in the marine environment. Here we present data on the reproductive ecology of the common Antarctic bivalve Aequiyoldia eightsii (Jay, 1839) (Protobranchia: Sarepidae) from monthly samples collected between January 2013 and May 2014 at Hangar Cove, Rothera Point on the West Antarctic Peninsula. These data show that A. eightsii is unusual because it does not follow the typical pattern expected for reproduction in Antarctic marine invertebrates, and differs also from closely related nuculanid protobranch bivalves with respect to gametogenic duration and reproductive periodicity. Continuous oogenesis, evidenced by the year-round occurrence of previtellogenic, vitellogenic, and ripe oocytes in female gonads, is supplemented by a seasonal increase in reproductive intensity and spawning in Austral winter (April-May), evidenced by the loss of mature spermatozoa and ripe oocytes from males and females, respectively. The simultaneous occurrence of these contrasting traits in individuals is attributed to a flexible feeding strategy (suspension and deposit feeding) in response to seasonal changes in food supply characteristic of the Antarctic marine environment. Asynchrony between individual females is also notable. We hypothesise that the variability may represent a trade-off between somatic and reproductive growth, and previously reported internal interannual cycles in shell growth.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The reproductive ecology of the Antarctic bivalve Aequiyoldia eightsii (Protobranchia: Sareptidae) follows neither Antarctic nor taxonomic patterns

et al. 2018

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“…Future collapse of ice shelves together with increased retreat and calving of glaciers means the influence of ice scour is likely to increase over the next century, but will ultimately rapidly decrease as glaciers pass their grounding lines (see Smale and Barnes 2008). For example, in the area local to Rothera Research Station (Adelaide Island), remote sensing data suggest that the decrease in the duration of winter-fast ice over the last 25 years has been 10 times greater than that of the overall vicinity, leading to a rise in iceberg scouring in the shallows and to significant increases in mortality (Smale et al 2008b, Barnes andSouster 2011).…”

Section: Ice Scour Disturbancementioning

confidence: 99%

The spatial structure of Antarctic biodiversity

Convey

Chown

Clarke

et al. 2014

Ecological Monographs

Self Cite

316

296

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Patterns of environmental spatial structure lie at the heart of the most fundamental and familiar patterns of diversity on Earth. Antarctica contains some of the strongest environmental gradients on the planet and therefore provides an ideal study ground to test hypotheses on the relevance of environmental variability for biodiversity. To answer the pivotal question, “How does spatial variation in physical and biological environmental properties across the Antarctic drive biodiversity?” we have synthesized current knowledge on environmental variability across terrestrial, freshwater, and marine Antarctic biomes and related this to the observed biotic patterns. The most important physical driver of Antarctic terrestrial communities is the availability of liquid water, itself driven by solar irradiance intensity. Patterns of biota distribution are further strongly influenced by the historical development of any given location or region, and by geographical barriers. In freshwater ecosystems, free water is also crucial, with further important influences from salinity, nutrient availability, oxygenation, and characteristics of ice cover and extent. In the marine biome there does not appear to be one major driving force, with the exception of the oceanographic boundary of the Polar Front. At smaller spatial scales, ice cover, ice scour, and salinity gradients are clearly important determinants of diversity at habitat and community level. Stochastic and extreme events remain an important driving force in all environments, particularly in the context of local extinction and colonization or recolonization, as well as that of temporal environmental variability. Our synthesis demonstrates that the Antarctic continent and surrounding oceans provide an ideal study ground to develop new biogeographical models, including life history and physiological traits, and to address questions regarding biological responses to environmental variability and change.

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“…Glacier melt water streams carry high amounts of terrestrial mineral suspensions into the marine coastal environment, and therefore, higher levels of glacier melt result in increased nearshore marine sedimentation loads (Dominguez and Eraso 2007;Schloss et al 2012). The calving of glacial fronts and ice shelves produces increased amounts of floating brash ice and icebergs and hence more ice scouring in shallow coastal areas (Turner et al 2009;Barnes and Souster 2011;Brown et al 2004). Such changes will have marked consequences for benthic animals colonizing coastal areas around the WAP (Barnes and Conlan 2007;Barnes and Kaiser 2007).…”

Section: Introductionmentioning

confidence: 99%

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

Husmann

Abele

Rosenstiel

et al. 2014

Cell Stress and Chaperones

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Increasing temperatures and glacier melting at the Western Antarctic Peninsula (WAP) are causing rapid changes in shallow coastal and shelf systems. Climate change-related rising water temperatures, enhanced ice scouring, as well as coastal sediment runoff, in combination with changing feeding conditions and microbial community composition, will affect all elements of the nearshore benthic ecosystem, a major component of which is the Antarctic soft-shelled clam Laternula elliptica. A 454-based RNA sequencing was carried out on tissues and hemocytes of L. elliptica, resulting in 42,525 contigs, of which 48 % was assigned putative functions. Changes in the expression of putative stress response genes were then investigated in hemocytes and siphon tissue of young and old animals subjected to starvation and injury experiments in order to investigate their response to sedimentation (food dilution and starvation) and iceberg scouring (injury). Analysis of antioxidant defense (Le-SOD and Lecatalase), wound repair (Le-TIMP and Le-chitinase), and stress and immune response (Le-HSP70, Le-actin, and Letheromacin) genes revealed that most transcripts were more clearly affected by injury rather than starvation. The upregulation of these genes was particularly high in the hemocytes of young, fed individuals after acute injury. Only minor changes in expression were detected in young animals under the selected starvation conditions and in older individuals. The stress response of L. elliptica thus depends on the nature of the environmental cue and on age. This has consequences for future population predictions as the environmental changes at the WAP will differentially impact L. elliptica age classes and is bound to alter population structure.

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Reduced survival of Antarctic benthos linked to climate-induced iceberg scouring

Cited by 100 publications

References 14 publications

The reproductive ecology of the Antarctic bivalve Aequiyoldia eightsii (Protobranchia: Sareptidae) follows neither Antarctic nor taxonomic patterns

The reproductive ecology of the Antarctic bivalve Aequiyoldia eightsii (Protobranchia: Sareptidae) follows neither Antarctic nor taxonomic patterns

The spatial structure of Antarctic biodiversity

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

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