scholarly journals Peer Review #2 of "The importance of local settings: within-year variability in seawater temperature at South Bay, Western Antarctic Peninsula (v0.1)"

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12679
Author(s):  
Miguel Bascur ◽  
Simon A. Morley ◽  
Michael P. Meredith ◽  
Carlos P. Muñoz-Ramírez ◽  
David K. A. Barnes ◽  
...  

The Western Antarctic Peninsula (WAP) is a hotspot for environmental change and has a strong environmental gradient from North to South. Here, for the first time we used adult individuals of the bivalve Aequiyoldia eightsii to evaluate large-scale spatial variation in the biochemical composition (measured as lipid, protein and fatty acids) and energy content, as a proxy for nutritional condition, of three populations along the WAP: O’Higgins Research Station in the north (63.3°S), Yelcho Research Station in mid-WAP (64.9°S) and Rothera Research Station further south (67.6°S). The results reveal significantly higher quantities of lipids (L), proteins (P), energy (E) and total fatty acids (FA) in the northern population (O’Higgins) (L: 8.33 ± 1.32%; P: 22.34 ± 3.16%; E: 171.53 ± 17.70 Joules; FA: 16.33 ± 0.98 mg g) than in the mid-WAP population (Yelcho) (L: 6.23 ± 0.84%; P: 18.63 ± 1.17%; E: 136.67 ± 7.08 Joules; FA: 10.93 ± 0.63 mg g) and southern population (Rothera) (L: 4.60 ± 0.51%; P: 13.11 ± 0.98%; E: 98.37 ± 5.67 Joules; FA: 7.58 ± 0.48 mg g). We hypothesize these differences in the nutritional condition could be related to a number of biological and environmental characteristics. Our results can be interpreted as a consequence of differences in phenology at each location; differences in somatic and gametogenic growth rhythms. Contrasting environmental conditions throughout the WAP such as seawater temperature, quantity and quality of food from both planktonic and sediment sources, likely have an effect on the metabolism and nutritional intake of this species.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4289 ◽  
Author(s):  
César A. Cárdenas ◽  
Marcelo González-Aravena ◽  
Pamela A. Santibañez

The Western Antarctic Peninsula (WAP) has undergone significant changes in air and seawater temperatures during the last 50 years. Although highly stenotherm Antarctic organisms are expected to be severely affected by the increase of seawater temperature, high-resolution datasets of seawater temperature within coastal areas of the WAP (where diverse marine communities have been reported) are not commonly available. Here we report on within-year (2016–2017) variation in seawater temperature at three sites on Doumer Island, Palmer Archipelago, WAP. Within a year, Antarctic organisms in South Bay were exposed to water temperatures in excess of 2 °C for more than 25 days and 2.5 °C for more than 10 days. We recorded a temperature range between −1.7° to 3.0 °C. Warming of seawater temperature was 3.75 times faster after October 2016 than it was before October. Results from this study indicate that organisms at South Bay are already exposed to temperatures that are being used in experimental studies to evaluate physiological responses to thermal stress in WAP organisms. Continuous measurements of short to long-term variability in seawater temperature provides important information for parametrizing meaningful experimental treatments that aim to assess the local effects of environmental variation on Antarctic organisms under future climate scenarios.


Author(s):  
Sebastian Zeppenfeld ◽  
Manuela van Pinxteren ◽  
Dominik van Pinxteren ◽  
Heike Wex ◽  
Elisa Berdalet ◽  
...  

Polar Biology ◽  
2021 ◽  
Author(s):  
Sebastián Fuentes ◽  
José Ignacio Arroyo ◽  
Susana Rodriguez‑Marconi ◽  
Italo Masotti ◽  
Tomás Alarcon‑Schumacher ◽  
...  

Polar Record ◽  
2018 ◽  
Vol 54 (2) ◽  
pp. 158-175 ◽  
Author(s):  
Priscila Kienteca Lange ◽  
Ryszard Ligowski ◽  
Denise Rivera Tenenbaum

ABSTRACTConsidering that phytoplankton assemblages are good bioindicators of environmental conditions, the sensitivity of the Western Antarctic Peninsula (WAP) to climate change, and the importance of some areas of its islands as Antarctic Specially Managed Areas, this work assembles published datasets on phytoplankton biodiversity and ecology in confined coastal areas (embayments) of King George Island, WAP. Over 33 years (1980–2013), 415 species from 122 genera have been identified to species level, being mostly diatoms (371 species), with 10 new species described with local material (6 diatoms, 4 cyanobacteria). The importance of diatoms was indicated by the frequent occurrence of Corethron pennatum, Pseudogomphonema kamtshaticum, and abundant benthic genera in the plankton (e.g. Navicula, Cocconeis). The increased contribution of dinoflagellates after 2010 suggests marked changes in the water column. Early-summer blooms differ between the bays' eastern and western shores, with terrestrial melting and wind-driven upwelling inducing the dominance of benthic species at eastern shores, whereas planktonic diatoms (Thalassiosira, Pseudo-nizschia, and Chaetoceros) are most abundant along western shores and central areas. The importance of an accurate identification of organisms that are becoming key ecological components of the region is discussed, as recent changes in the microflora may affect the entire marine food web.


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