scholarly journals Antarctic Fish as a Global Pollution Sensor: Metals Biomonitoring in a Twelve-Year Period

2021 ◽  
Vol 8 ◽  
Author(s):  
Alessandro Marrone ◽  
Daniele La Russa ◽  
Elvira Brunelli ◽  
Gianfranco Santovito ◽  
Mauro Francesco La Russa ◽  
...  
Keyword(s):  
Ross Sea ◽  
Antarctic Fish ◽  
Conservation Strategies ◽  
Early Step ◽  
Low Latitudes ◽  
Contamination Levels ◽  
Global Threat ◽  
Land Water ◽  
Natural Laboratory ◽  
Over Time

Antarctica represents a unique natural laboratory for ecotoxicological studies as it is characterized by low internal pollutants emissions but high external contamination levels. Indeed, warm temperatures promote pollutant evaporation (low latitudes), while cool temperatures (high latitudes) promote its deposition from the atmosphere on land/water. Metals are the most important pollutants in ecosystems and represent a serious and global threat to aquatic and terrestrial organisms. Since 2000, the risks posed by metals have led many States to ratify protocols aimed at reducing their emissions. Endemic Antarctic organisms represent excellent bioindicators in order to evaluate the efficacy of global measures adopted to mitigate pollutants release into the environment. In this study (supported by PNRA18-00133), we estimated the metals contamination levels and the metallothionein-1 expression in liver samples of two Antarctic fish species, the icefish Chionodraco hamatus and the red-blooded Trematomus bernacchii, collected in the same area during 2002 and 2014. The chosen area is located in the Ross Sea, a unique area as it is also isolated from the rest of the Southern Ocean. The analysis of contamination trends throughout this period showed, in both species, a significant increase over time of metals bioaccumulation and metallothionein-1 expression. In addition, our result clearly indicated that the detoxifying ability of the two organisms analyzed greatly differs, probably due to haemoglobin presence/absence. Our work represents an important early step to obtain valuable information in conservation strategies for both Antarctic and non-Antarctic ecosystems.

Cooperation in Microcredit Borrowing Groups: Identity, Sanctions, and Reciprocity in the Production of Collective Goods

2005 ◽  
Vol 70 (3) ◽  
pp. 496-515 ◽  
Author(s):  
Denise Anthony
Keyword(s):  
High Risk ◽  
Group Identity ◽  
Social Dilemma ◽  
Theoretical Concept ◽  
Access To Credit ◽  
Group Cooperation ◽  
Collective Goods ◽  
Distinct Process ◽  
Natural Laboratory ◽  
Over Time

Cooperation to produce collective goods is widespread in society, and yet so is its failure. Theorists have identified competing mechanisms for facilitating group cooperation, including group identity, sanctions and reciprocity. Here I use empirical data to explore how these mechanisms influence cooperation in the natural laboratory of microcredit borrowing groups. Microcredit makes loans to high-risk borrowers through borrowing groups in which individuals' access to credit is dependent on the behavior of other members of the group, thereby creating a social dilemma for members and an opportunity to observe cooperation in real world groups. By analyzing both collective goods production (loans) and compliance (repayment), I find that the competing mechanisms have differential effects. Group identity, sanctions and reciprocity are all associated with more borrowing in the group. Only reciprocity, however, limits loan delinquency and is associated with group longevity, suggesting both that collective goods production is a distinct process from group compliance over time, and that reciprocity may be an important mechanism in both processes. I discuss how these findings contribute to our understanding of group cooperation, as well as the implications for the related theoretical concept of embeddedness.

Vitellogenin gene expression in males of the Antarctic fish Trematomus bernacchii from Terra Nova Bay (Ross Sea): A role for environmental cadmium?

Chemosphere ◽  
2007 ◽  
Vol 66 (7) ◽  
pp. 1270-1277 ◽  
Author(s):  
Adriana Canapa ◽  
Marco Barucca ◽  
Stefania Gorbi ◽  
Maura Benedetti ◽  
Sara Zucchi ◽  
...  
Keyword(s):  
Gene Expression ◽  
Ross Sea ◽  
Antarctic Fish ◽  
Terra Nova Bay ◽  
Trematomus Bernacchii ◽  
Terra Nova ◽  
Vitellogenin Gene ◽  
The Antarctic

Metals in Waters and Sediments of the Morrocoy National Park, Venezuela: Increased Contamination Levels of Cadmium over Time

2010 ◽  
Vol 214 (1-4) ◽  
pp. 609-621 ◽  
Author(s):  
E. M. García ◽  
C. Bastidas ◽  
J. J. Cruz-Motta ◽  
O. Farina
Keyword(s):  
National Park ◽  
Contamination Levels ◽  
Over Time

scholarly journals Anthropogenic Changes in a Mediterranean Coastal Wetland during the Last Century—The Case of Gialova Lagoon, Messinia, Greece

Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 350 ◽  
Author(s):  
Giorgos Maneas ◽  
Eirini Makopoulou ◽  
Dimitris Bousbouras ◽  
Håkan Berg ◽  
Stefano Manzoni
Keyword(s):  
Coastal Wetland ◽  
Methodological Approach ◽  
Open Water ◽  
Natura 2000 ◽  
Aerial Photographs ◽  
Conservation Strategies ◽  
Holistic Understanding ◽  
Human Interventions ◽  
Surrounding Areas ◽  
Over Time

Human interventions during the last 70 years have altered the characteristics of the Gialova Lagoon, a coastal wetland that is part of a wider Natura 2000 site. In this study, we explore how human interventions and climate altered the wetland’s hydrological conditions and habitats, leading to changing wetland functions over time. Our interpretations are based on a mixed methodological approach combining conceptual hydrologic models, analysis of aerial photographs, local knowledge, field observations, and GIS (Geographic Information System) analyses. The results show that the combined effects of human interventions and climate have led to increased salinity in the wetland over time. As a result, the fresh and brackish water marshes have gradually been turned into open water or replaced by halophytic vegetation with profound ecological implications. Furthermore, current human activities inside the Natura 2000 area and in the surrounding areas could further impact on the water quantity and quality in the wetland, and on its sensitive ecosystems. We suggest that a more holistic understanding of the broader socio-ecological system is needed to understand the dynamics of the wetland and to achieve sustainable long-term management and conservation strategies.

Evidence for egg brooding and parental care in icefish and other notothenioids in the Southern Ocean

2006 ◽  
Vol 18 (2) ◽  
pp. 223-227 ◽  
Author(s):  
K.-H. Kock ◽  
L.K. Pshenichnov ◽  
A.L. Devries
Keyword(s):  
Southern Ocean ◽  
Parental Care ◽  
Incubation Period ◽  
Fish Species ◽  
Ross Sea ◽  
Antarctic Fish ◽  
Size And Shape ◽  
Relative Fecundity ◽  
Egg Carrying ◽  
Egg Brooding

One of the least known Antarctic fish species is the icefish Chionobathyscus dewitti described first in 1978. Some of its reproductive characteristics appear to be similar to other channichthyids of similar size and shape. Females close to spawning have gonado–somatic indices (GSIs) of more than 20, and absolute fecundity was 2967 to 15612 oocytes in females 33–62 cm long. Relative fecundity was 7.6 in one female. Spawning has been observed in the Ross Sea at 1300 to 1500 m depth from January to March. Chionobathyscus dewitti may exhibit a remarkable egg carrying behaviour: eggs stick together in batches around the pelvic fins of females. The comparatively large number of mature males observed with no indication of an egg batch attached to their ventral fins makes it unlikely that males are involved in egg carrying. The few larvae of C. dewitti caught so far occurred from October onwards. Their size indicates that they have hatched as early as September. This suggests an incubation period of at least six months. We compare this with parental care reported in other notothenioids.

Lichen and moss communities of Botany Bay, Granite Harbour, Ross Sea, Antarctica

2010 ◽  
Vol 22 (6) ◽  
pp. 691-702 ◽  
Author(s):  
Rodney D. Seppelt ◽  
Roman Türk ◽  
T.G. Allan Green ◽  
Gerald Moser ◽  
Stefan Pannewitz ◽  
...  
Keyword(s):  
Ross Sea ◽  
Plant Distribution ◽  
Vegetation Changes ◽  
Substrate Type ◽  
Vegetation Map ◽  
Bird Population ◽  
Continental Antarctica ◽  
Ordination Analysis ◽  
Changes Over Time ◽  
Over Time

AbstractBotany Bay is one of the richest sites for lichen and bryophyte biodiversity in continental Antarctica. A total of 29 lichen, nine moss and one liverwort species have been identified. The most extensive vegetation occurs on a sheltered raised beach terrace. Vegetation associations are described and compared to other continental Antarctic localities that also possess a rich vegetation cover. Ordination analysis clearly indicates the importance of the type of water supply, its regularity, the substrate type, and particularly in Botany Bay, the influence of nutrients derived from the local bird population in governing plant distribution and associations. A vegetation map has been produced and can be used as a baseline to assess vegetation changes over time.

scholarly journals A 200 year sulfate record from 16 Antarctic ice cores and associations with Southern Ocean sea-ice extent

2005 ◽  
Vol 41 ◽  
pp. 155-166 ◽  
Author(s):  
Daniel Dixon ◽  
Paul A. Mayewski ◽  
Susan Kaspari ◽  
Karl Kreutz ◽  
Gordon Hamilton ◽  
...  
Keyword(s):  
Sea Ice ◽  
Ross Sea ◽  
Ice Core ◽  
Ice Cores ◽  
South Pole ◽  
West Antarctica ◽  
The South ◽  
Sea Ice Extent ◽  
West Antarctic ◽  
Low Latitudes

AbstractChemistry data from 16, 50–115m deep, sub-annually dated ice cores are used to investigate spatial and temporal concentration variability of sea-salt (ss) SO42– and excess (xs) SO42– over West Antarctica and the South Pole for the last 200 years. Low-elevation ice-core sites in western West Antarctica contain higher concentrations of SO42– as a result of cyclogenesis over the Ross Ice Shelf and proximity to the Ross Sea Polynya. Linear correlation analysis of 15 West Antarctic ice-core SO42– time series demonstrates that at several sites concentrations of ssSO42– are higher when sea-ice extent (SIE) is greater, and the inverse for xsSO42–. Concentrations of xsSO42– from the South Pole site (East Antarctica) are associated with SIE from the Weddell region, and West Antarctic xsSO42– concentrations are associated with SIE from the Bellingshausen–Amundsen–Ross region. The only notable rise of the last 200 years in xsSO42–, around 1940, is not related to SIE fluctuations and is most likely a result of increased xsSO42– production in the mid–low latitudes and/or an increase in transport efficiency from the mid–low latitudes to central West Antarctica. These high-resolution records show that the source types and source areas of ssSO42– and xsSO42– delivered to eastern and western West Antarctica and the South Pole differ from site to site but can best be resolved using records from spatial ice-core arrays such as the International Trans-Antarctic Scientific Expedition (ITASE).

scholarly journals Past, present, future: tracking and simulating genetic differentiation over time in a closed metapopulation system

2021 ◽  
Author(s):  
Florian Kunz ◽  
Annette Kohnen ◽  
Ursula Nopp-Mayr ◽  
Joy Coppes
Keyword(s):  
Genetic Differentiation ◽  
Extinction Risk ◽  
Recent Time ◽  
Conservation Strategies ◽  
Tetrao Urogallus ◽  
Migration Rates ◽  
Time Period ◽  
Conservation Concern ◽  
Set Up ◽  
Over Time

AbstractGenetic differentiation plays an essential role in the assessment of metapopulation systems of conservation concern. Migration rates affect the degree of genetic differentiation between subpopulations, with increasing genetic differentiation leading to increasing extinction risk. Analyses of genetic differentiation repeated over time together with projections into the future are therefore important to inform conservation. We investigated genetic differentiation in a closed metapopulation system of an obligate forest grouse, the Western capercaillieTetrao urogallus, by comparing microsatellite population structure between a historic and a recent time period. We found an increase in genetic differentiation over a period of approximately 15 years. Making use of forward simulations accounting for population dynamics and genetics from both time periods, we explored future genetic differentiation by implementing scenarios of differing migration rates. Using migration rates derived from the recent dataset, simulations predicted further increase of genetic differentiation by 2050. We then examined effects of two realistic yet hypothetical migration scenarios on genetic differentiation. While isolation of a subpopulation led to overall increased genetic differentiation, the re-establishment of connectivity between two subpopulations maintained genetic differentiation at recent levels. Our results emphasize the importance of maintaining connectivity between subpopulations in order to prevent further genetic differentiation and loss of genetic variation. The simulation set-up we developed is highly adaptable and will aid researchers and conservationists alike in anticipating consequences of conservation strategies for metapopulation systems.

scholarly journals Regenerative Agriculture: farmer motivation, environment and climate improvement

2021 ◽  
Vol 17 (3) ◽  
Author(s):  
Edgar A. Burns
Keyword(s):  
Climate Change ◽  
Paradigm Shift ◽  
Soil Health ◽  
No Till ◽  
The Social ◽  
Regenerative Agriculture ◽  
Signal Significance ◽  
New Form ◽  
Land Water ◽  
Over Time

Regenerative agriculture has become a social movement in farming. It embraces the environmental basis of farming. Land, water and nutrients are viewed as an ecological whole. This includes bacteria and mycorrhiza as essential to soil health and plant diversity, and mob stocking and no-till farming above ground. Regen ag, as regenerative agriculture is often called, is a paradigm shift for farmers, who are often perceived as resistant. There is a mismatch between academic and policy interest focusing on the scientific need for and value of regenerative agriculture, and the social and human motivating benefits of regenerative agriculture. This crucial willingness, not simply the turn away from denialism, is the signal significance of this new form of farming. In New Zealand and globally, climate change and environmental degradation can be addressed much more quickly, more thoroughly and less contentiously if regenerative agriculture is supported and extended, even as science documentation is achieved over time.

scholarly journals Productivity and Change in Fish and Squid in the Southern Ocean

2021 ◽  
Vol 9 ◽  
Author(s):  
Jilda Alicia Caccavo ◽  
Henrik Christiansen ◽  
Andrew J. Constable ◽  
Laura Ghigliotti ◽  
Rowan Trebilco ◽  
...  
Keyword(s):  
Climate Change ◽  
Southern Ocean ◽  
Life Histories ◽  
Ross Sea ◽  
Global Climate ◽  
Management Strategies ◽  
Antarctic Fish ◽  
Ecosystem Approach ◽  
Ecosystem Structure ◽  
Global Drivers

Southern Ocean ecosystems are globally important and vulnerable to global drivers of change, yet they remain challenging to study. Fish and squid make up a significant portion of the biomass within the Southern Ocean, filling key roles in food webs from forage to mid-trophic species and top predators. They comprise a diverse array of species uniquely adapted to the extreme habitats of the region. Adaptations such as antifreeze glycoproteins, lipid-retention, extended larval phases, delayed senescence, and energy-conserving life strategies equip Antarctic fish and squid to withstand the dark winters and yearlong subzero temperatures experienced in much of the Southern Ocean. In addition to krill exploitation, the comparatively high commercial value of Antarctic fish, particularly the lucrative toothfish, drives fisheries interests, which has included illegal fishing. Uncertainty about the population dynamics of target species and ecosystem structure and function more broadly has necessitated a precautionary, ecosystem approach to managing these stocks and enabling the recovery of depleted species. Fisheries currently remain the major local driver of change in Southern Ocean fish productivity, but global climate change presents an even greater challenge to assessing future changes. Parts of the Southern Ocean are experiencing ocean-warming, such as the West Antarctic Peninsula, while other areas, such as the Ross Sea shelf, have undergone cooling in recent years. These trends are expected to result in a redistribution of species based on their tolerances to different temperature regimes. Climate variability may impair the migratory response of these species to environmental change, while imposing increased pressures on recruitment. Fisheries and climate change, coupled with related local and global drivers such as pollution and sea ice change, have the potential to produce synergistic impacts that compound the risks to Antarctic fish and squid species. The uncertainty surrounding how different species will respond to these challenges, given their varying life histories, environmental dependencies, and resiliencies, necessitates regular assessment to inform conservation and management decisions. Urgent attention is needed to determine whether the current management strategies are suitably precautionary to achieve conservation objectives in light of the impending changes to the ecosystem.

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