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- Maasri, Alain, et al.
(author)
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A global agenda for advancing freshwater biodiversity research
- 2022
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In: Ecology Letters. - : Wiley. - 1461-023X .- 1461-0248. ; 25:2, s. 255-263
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Journal article (peer-reviewed)abstract
- Global freshwater biodiversity is declining dramatically, and meeting the challenges of this crisis requires bold goals and the mobilisation of substantial resources. While the reasons are varied, investments in both research and conservation of freshwater biodiversity lag far behind those in the terrestrial and marine realms. Inspired by a global consultation, we identify 15 pressing priority needs, grouped into five research areas, in an effort to support informed stewardship of freshwater biodiversity. The proposed agenda aims to advance freshwater biodiversity research globally as a critical step in improving coordinated actions towards its sustainable management and conservation.
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| 2. |
- Castillo, Luisa Eugenia, 1949-
(author)
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Pesticide impact of intensive banana production on aquatic ecosystems in Costa Rica
- 2000
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Doctoral thesis (other academic/artistic)abstract
- A combination of chemical and biological studies demonstrated extensive surface water contamination, the occurrence of pesticides in sediments, especially near the banana plantation areas, and biological impacts. Pesticides were even found in the downstream waters of the Tortuguero conservation area, a highly diverse wetland that protects several endangered species.The frequency of observation and the found concentrations were higher closer to the banana plantation areas. Peak concentrations were observed following application of ground and aerially applied pesticides. The fungicides used in packing plants (imazalil and thiabendazole), as well as several insecticide-nematicides (chlorpyrifos, diazinon, cadusafos, carbofuran, ethoprofos and terbufos) were detected in concentrations that have the potential to damage aquatic life. Acute and chronic toxicity tests with effluent water from the packing plant indicated increased mortality as well as sublethal effects on the cladoceran Daphnia magna and the cnidarian Hydra attenuata. Changes in protein patterns and respiration rates of the indigenous cichlid fish Cichlasoma dovii and the mussel Anodontites luteola were observed in the laboratory at ecologically relevant environmental levels of pesticides, before any mortality could be observed.Community richness and composition measures such as the percentage of EPT, ratio EPT/Chironomidae abundance, community loss and the Jaccard similarity index allowed detection of differences between the benthic community in the forested area streams of the reference sites from that of the disturbed banana plantation area. Multivariate analysis (non-metric multi-dimensional scaling, MDS) revealed that terbufos, cadusafos and carbofuran applications resulted in significant community changes at all the studied banana plantation sites and that these changes were similar (i.e. the same genera were affected, among them Microcylloepus sp., Leptohyphes sp., Leptonema sp. and Cf. Pseudochironomus sp.) at all sites and for all pesticides. The study of the macrobenthic community was more sensitive in distinguishing pesticide effects than the used toxicity tests, the multivariate analysis used (MDS) was also more sensitive than the richness and composition measures. Community studies, however, would benefit from a better understanding of natural variability in wet tropical areas.The use of biomarkers and field and laboratory toxicity tests with relevant native organisms could help clarify the relationship between chemical stress and effects on invertebrate populations. An integrated approach combining chemical exposure evaluations, bioassays and including the biological assessment methods used in this thesis, seem to be more appropriate for ecological risk assessment of banana production, than the use of chemical analysis and laboratory bioassays only.
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| 3. |
- Karlsson, Edvin, 1985-
(author)
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Using airborne eDNA to study ecosystem dynamics
- 2021
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Doctoral thesis (other academic/artistic)abstract
- In this era of global biodiversity crisis, the need to monitor ecological communities over space and time is more pressing than ever to effectively direct biodiversity conservation and management efforts. To understand the natural dynamics of an ecosystem, and the impact of anthropogenic activities related to environmental and climate change, long time series are needed to accurately link such processes to ecosystem change. This thesis uses a unique resource of archived air filters collected in Sweden originally intended for radioactive particle measurements to reconstruct historical eDNA abundance in the most extensive time-series of airborne eDNA abundance to date - spanning across four decades. By using metabarcoding and metagenomic analysis, it is evident that airborne eDNA from a very large diversity of species is present in air, representing all major branches of the tree of life, including bacteria, fungi, plants, metazoans, and viruses, from a wide range of terrestrial and aquatic sources. These have seasonal as well as long term trends that in part can be explained by temporal variation in climate and regional differences. The data generated in this thesis comprise an extensive resource for analysis of trends related to climate and environmental change and will also allow deeper studies on phenology, phenological change, functional genomics, and potentially antibiotic resistance. The results presented here show the potential of using airborne eDNA to monitor species in the local ecosystem over time and the methods provides an efficient tool for assessment of broad scale biodiversity, in a non-invasive and cost-effective way.
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| 4. |
- Peters, Daniel L., et al.
(author)
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A multi-scale hydroclimatic analysis of runoff generation in the Athabasca River, western Canada
- 2013
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In: Hydrological Processes. - : Wiley. - 1099-1085 .- 0885-6087. ; 27:13, s. 1915-1934
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Journal article (peer-reviewed)abstract
- A multi-scale hydroclimatic study of runoff generation in the Athabasca River watershed located in western Canada is presented. Mann-Kendall trend detection tests performed on hydrometric data for the lower Athabasca River (LAR) revealed predominantly significant (p<0.05) declines in annual and open-water season median/mean runoff indices over 1958-2009, with the ice-influenced season experiencing significant declines in the median and not the mean. The presence or absence of significant declines in the 25th and 75th runoff percentiles helped explain these results. The only noteworthy result from the mid-point of the watershed was a probable (p<0.10) decline in median open-water runoff, which was not seen over the 1913-2009 period. Divergent seasonal runoff trends from the headwater zone were seen since 1958 and back to 1913, increasing ice-influenced and declining open-water season runoff trends. Although precipitation was observed to decline over 1958-2009, only the LAR watershed scale annual index emerged as a probable decline. Multiple non-linear regression analysis indicated that variation in precipitation explained >67% of the annual median/mean LAR runoff variability since 1958. A first-order precipitation driven hindcasting model suggested that LAR watershed scale runoff may have increased since 1913, warranting further study. A correlation analysis of climatic teleconnections with median/mean runoff indices revealed that the winter North Pacific American index showed a strong, positive association with open-water runoff. The results from our study demonstrated that potentially inconsistent and/or divergent trend results can be obtained when using different time periods and/or regions of the watershed, emphasizing that extreme caution should be exercised when extrapolating sub-watershed results to the watershed scale, or to adjacent watersheds. Our multi-scale study approach also identified the drainage area between Athabasca and Fort McMurray as a zone that influenced runoff declines observed at the LAR watershed scale since 1958, which warrants further investigation with competent hydrological models. Copyright (c) 2013 John Wiley & Sons Ltd and Her Majesty the Queen in Right of Canada Reproduced with the permission of the Ministry of the Environment.
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