| 11. |
- Juhna, Talis, et al.
(author)
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Water-Quality Changes in Latvia and Riga 1980–2000: Possibilities and Problems
- 2001
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In: Ambio. - : Royal Swedish Academy of Sciences. - 0044-7447 .- 1654-7209. ; 30:4-5, s. 306-14
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Journal article (peer-reviewed)abstract
- Long-term changes in the environmental quality of water in Latvia (chemical composition of inland waters, wastewater treatment, and drinking-water treatment practices and quality) as a response to socioeconomic changes have been studied. Water composition, the major factors influencing water chemistry, and human impacts (wastewater loading) were studied to determine changes that occurred after recent reductions in pollution emissions, particularly nutrient loading, to surface waters. After 1991, (Latvia regained independence in 1991) inland water quality has begun to improve mainly as a result of decreases in nutrient loads from point and nonpoint sources and substantial efforts in the area of environmental protection. The situation differs, however, for drinking-water treatment, where practices have also changed during the whole period from 1980 till 2000. More stringent drinking-water-quality standards and novel insights regarding changes in water quality in the distribution network, necessitate further improvements in public water supply, and place this particular water issue among Latvia's main priorities.
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| 12. |
- Köhlin, Gunnar, et al.
(author)
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Impact of Plantations on Forest Use and Forest Status in Orissa, India
- 2001
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In: Ambio. - : Royal Swedish Academy of Sciences. - 0044-7447 .- 1654-7209. ; 30:1, s. 37-42
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Journal article (peer-reviewed)abstract
- In Orissa 100 thousand ha of village plantations were established from 1985 to 1992 as an aid project to support the subsistence needs of rural poor and to relieve heavy pressure on the natural forests. The aim of this paper is to examine the welfare and environmental effects of these village plantations. To do this, extensive data collection was needed which included both household utilization of different sources of biomass as well as remote-sensing information, to establish the status of the vegetation and it's spatial location vis-a-vis the users. The study shows that plantations have the potential for substantial welfare improvements for the target population, especially women, through increased consumption of biomass, decreased time for collection and decreased pressure on natural forests. However, interventions need to be very selective in order to be successful, with special consideration given to plantation location compared to natural forest.
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| 13. |
- Lind, Monica, et al.
(author)
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Bone mineral density in male Baltic grey seal (Halichoerus grypus)
- 2003
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In: Ambio. - 0044-7447 .- 1654-7209. ; 32:6, s. 385-388
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Journal article (peer-reviewed)abstract
- Bone mineral density (mg cm(-3)) was studied in male Baltic grey seals (4-23 years of age) by noninvasive computed tomography (pQCT). The material was grouped according to year of collection. Group A: 1850-1955, a period before the main introduction of organochlorines (OCs); Group B: 1965-1985, a period with very high OC contamination; and Group C: 1986-1997, a period with decreasing concentrations of OCs. The reproducibility of the measurements was good with a Coefficient of Variation (CV) ranging from 0.1% to 2.1%. Trabecular bone mineral density of the radius was significantly higher in specimens collected 1986-1997 than in those collected 1965-1985 (p < 0.05). Cortical bone mineral density of the mandible was significantly lower in specimens collected 1986-1997 compared with those collected 1850-1955 (p < 0.05). These results indicate different responses over time in trabecular and cortical bone. During the period of very high OC contamination (1965-1985), trabecular bone density was lowest, whereas cortical bone density was lowest in specimens collected 1985-1997, representing a period of fairly low OC contamination. The mechanisms behind these effects are not known. However, it can be assumed that OCs are involved. Information about residue levels of OCs in the studied individuals is lacking and, therefore, it was not possible to evaluate the impact of OCs in this respect.
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| 14. |
- Marques, Marcia, et al.
(author)
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Water environments : Anthropogenic pressures and ecosystem changes in the Atlantic drainage basins of Brazil
- 2004
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In: Ambio. - : Royal Swedish Academy of Sciences. - 0044-7447 .- 1654-7209. ; 33:1-2, s. 68-77
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Journal article (peer-reviewed)abstract
- Densely occupied drainage basins and coastal zones in developing countries that are facing economic growth are likely to suffer from moderate to severe environmental impacts regarding different issues. The catchment basins draining towards the Atlantic coast from northeastern to southern Brazil include a wide range of climatic zones and diverse ecosystems. Within its borders lies the Atlantic rain forest, significant extensions of semiarid thorn forests (caatinga), vast tree and scrub woodlands (cerrado) and most of the 6670 km of the Brazilian coast and its marine ecosystems. In recent decades, human activities have increasingly advanced over these natural resources. Littoralization has imposed a burden on coastal habitats and communities. Most of the native vegetation of the cerrado and caatinga was removed and only 7% of the original Atlantic rainforest still exists. Estuaries, bays and coastal lagoons have been irreversibly damaged. Land uses, damming and water diversion have become the major driving forces for habitat loss and aquatic ecosystem modification. Regardless of the contrast between the drought-affected northeastern Brazil and the much more prosperous and industrialized southeastern/southern Brazil, the impacts on habitat and communities were found equally severe in both cases. Attempts to halt environmental degradation have not been effective. Instead of focusing on natural resources separately, it is suggested that more integrated environmental policies that focus on aquatic ecosystems integrity are introduced.
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| 15. |
- McCarthy, Jenny, et al.
(author)
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Flooding patterns of the Okavango wetland in Botswana between 1972 and 2000
- 2003
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In: Ambio. - 0044-7447 .- 1654-7209. ; 32:7, s. 453-457
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Journal article (peer-reviewed)abstract
- The inundated area of the Okavango Delta changes annually and interannually. The variability relates to regional precipitation over the catchment area in the Angolan highlands, and to local rainfall. The patterns of the wetland were captured using more than 3000 satellite images for the period 1972 to 2000, near daily NOAA AVHRR data for 1985-2000, and less frequent images of the Landsat sensors from 1972 onwards. One AVHRR image for every 10-day period was classified into land and water using an unsupervised classification method. Evaluation against Landsat TM and ERS2-ATSR data indicate an agreement of 89% for the size of estimated inundation area. Results show that the wetland area has varied between approximately 2450 km(2) and 11 400 km(2) during the last 30 years.
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| 16. |
- Moraes, Rosana, 1968, et al.
(author)
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Pesticide residues in rivers of a Brazilian Rain Forest Reserve: Assessing the potential concern for effects on aquatic life and human health.
- 2003
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In: Ambio. - : Royal Swedish Academy of Sciences. - 0044-7447 .- 1654-7209. ; 32:4, s. 258-263
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Journal article (peer-reviewed)abstract
- Pesticide residues in water, sediment, and fish samples from rivers of a Brazilian Rain Forest Reserve were measured in November 1998, March 1999, and January 2000. Concentrations of the individual pesticides were compared to ecotoxicological benchmarks based on acute toxicity tests, and to regulatory guidelines to determine the potential concern for effects on aquatic life and human health. Pesticides and metabolites were detected at all 7 sites surveyed. Residues of a total of 27 pesticides or metabolites were found in water and/or sediment samples and fish have accumulated some of the most persistent of these residues. Measured concentrations in water and sediment indicated concern for preservation of aquatic fauna. Several pesticides in water were above levels for drinking water recommended by Brazilian and/or European Union authorities, indicating also a concern for human health.
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| 17. |
- Person, Johan N, et al.
(author)
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Validating Possible Effects of Eutrophication Using PCB Concentrations in Bivalves and Sediment of the US Musselwatch and Benthic Surveillance Programs.
- 2000
-
In: Ambio. - 0044-7447 .- 1654-7209. ; 29:4-5, s. 246-251
-
Journal article (peer-reviewed)abstract
- In order to examine the possible interactions of eutrophication and hydrophobic organic contaminants, data for polychlorinated biphenyl (PCB) concentrations (C-PCB) in three species of bivalves and in sediments were examined. These were correlated to total organic carbon content of sediments (TOCsed), which was assumed to represent the trophic status of the sampling sites. Almost all C-PCB on dry weight basis in the bivalves and in the sediments were positively linearly correlated to TOCsed. Regarding the sediments, this simply reflects the high affinity of these compounds for TOC, but for the bivalves the correlation was not explained. In the bivalves, the difference in PCB homologue concentration was positively linearly correlated to TOCsed. To understand these field data, a box model was used to simulate the fate of PCB in oligotrophic, mesotrophic, eutrophic, and hypertrophic marine environments. The calculated results qualitatively predicted the change in C-PCB for the sediment correctly. For increased trophic status of the water compartment, on a scale from oligo- to hypertrophic, the model predicted decreasing fugacities for the PCBs, and thus could not support the observations of increased bivalve C-PCB seen in the field data study. It was suggested that the PCB pattern change in the bivalves could be influenced by algae-growth dynamics in the watercolumn. This would selectively intensify the washout of the lighter chlorinated homologues from the water and, thereby, decrease their concentrations in the bivalves.
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| 18. |
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| 19. |
- Rönnbäck, Britt-Inger, et al.
(author)
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Evaluation of environmental monitoring strategies
- 2003
-
In: Ambio. - 0044-7447 .- 1654-7209. ; 32:8, s. 495-501
-
Journal article (peer-reviewed)abstract
- In environmental monitoring, it is important that the monitoring system should emit early warnings when undesired events occur. These events may be sudden or of a more subtle nature. In the design of such monitoring systems, a proper balance between cost and risk must be achieved. There are 2 classic types of risk connected with early warning systems, namely the risk of not detecting significant changes and the risk of false alarms. The purpose of this paper is to describe a method for comparing the performance of different monitoring systems, considering the classic types of risk and cost. The method is applied to the monitoring of the lichen cover as a test case. The expected utility has been used as a measure of performance. When estimating the probabilities of the events, spatial microsimulation and Monte-Carlo simulation techniques have been used. The monitoring programs studied are based on satellite images, aerial photos, field samples, and land-cover maps. The major conclusions of this study are that standardized quality measures are extremely useful for evaluating the usability of environmental monitoring methods. In addition, when estimating gains and costs, spatial microsimulation techniques are useful. To improve the method, however, macroconstraints should also be used for aligning the simulation model.
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| 20. |
- Rönnbäck, Patrik, et al.
(author)
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Coastal Aquaculture Development in Eastern Africa and the Western Indian Ocean : Prospects and Problems for Food Security and Local Economies
- 2002
-
In: Ambio. - Stockholm : Royal Swedish Academy of Sciences. - 0044-7447 .- 1654-7209. ; 31:7/8, s. 537-542
-
Journal article (peer-reviewed)abstract
- This paper reviews the experience and status of coastal aquaculture of seaweeds, mollusks, fish and crustaceans in eastern Africa and the islands of the western Indian Ocean. In many respects, coastal aquaculture is still in its infancy in the region, and there is a pressing need to formulate development strategies aimed at improving the income and assuring the availability of affordable protein to coastal communities. This paper also draws from positive and negative experiences in other parts of the world. The requirements of feed and fry, and the conversion of mangroves are used to illustrate how some aquaculture activities constitute a net loss to global seafood production. The paper presents both general and specific sustainability guidelines based on the acknowledgement of aquaculture as an ecological process. It is concluded that without clear recognition of its dependence on natural ecosystems, the aquaculture industry is unlikely to develop to its full potential in the region.
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