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Doris Soto

Bio: Doris Soto is an academic researcher from University of Concepción. The author has contributed to research in topics: Aquaculture & Rainbow trout. The author has an hindex of 30, co-authored 62 publications receiving 7827 citations. Previous affiliations of Doris Soto include Food and Agriculture Organization & Austral University of Chile.


Papers
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Journal ArticleDOI
TL;DR: This article explores the special features of freshwater habitats and the biodiversity they support that makes them especially vulnerable to human activities and advocates continuing attempts to check species loss but urges adoption of a compromise position of management for biodiversity conservation, ecosystem functioning and resilience, and human livelihoods.
Abstract: Freshwater biodiversity is the over-riding conservation priority during the International Decade for Action - 'Water for Life' - 2005 to 2015. Fresh water makes up only 0.01% of the World's water and approximately 0.8% of the Earth's surface, yet this tiny fraction of global water supports at least 100000 species out of approximately 1.8 million - almost 6% of all described species. Inland waters and freshwater biodiversity constitute a valuable natural resource, in economic, cultural, aesthetic, scientific and educational terms. Their conservation and management are critical to the interests of all humans, nations and governments. Yet this precious heritage is in crisis. Fresh waters are experiencing declines in biodiversity far greater than those in the most affected terrestrial ecosystems, and if trends in human demands for water remain unaltered and species losses continue at current rates, the opportunity to conserve much of the remaining biodiversity in fresh water will vanish before the 'Water for Life' decade ends in 2015. Why is this so, and what is being done about it? This article explores the special features of freshwater habitats and the biodiversity they support that makes them especially vulnerable to human activities. We document threats to global freshwater biodiversity under five headings: overexploitation; water pollution; flow modification; destruction or degradation of habitat; and invasion by exotic species. Their combined and interacting influences have resulted in population declines and range reduction of freshwater biodiversity worldwide. Conservation of biodiversity is complicated by the landscape position of rivers and wetlands as 'receivers' of land-use effluents, and the problems posed by endemism and thus non-substitutability. In addition, in many parts of the world, fresh water is subject to severe competition among multiple human stakeholders. Protection of freshwater biodiversity is perhaps the ultimate conservation challenge because it is influenced by the upstream drainage network, the surrounding land, the riparian zone, and - in the case of migrating aquatic fauna - downstream reaches. Such prerequisites are hardly ever met. Immediate action is needed where opportunities exist to set aside intact lake and river ecosystems within large protected areas. For most of the global land surface, trade-offs between conservation of freshwater biodiversity and human use of ecosystem goods and services are necessary. We advocate continuing attempts to check species loss but, in many situations, urge adoption of a compromise position of management for biodiversity conservation, ecosystem functioning and resilience, and human livelihoods in order to provide a viable long-term basis for freshwater conservation. Recognition of this need will require adoption of a new paradigm for biodiversity protection and freshwater ecosystem management - one that has been appropriately termed 'reconciliation ecology'.

5,857 citations

Journal ArticleDOI
TL;DR: The role of aquaculture, as at large a small-scale farmer driven production sector, in the quest for sustainable development, reducing poverty and improving food security on a global scale is discussed in this article.
Abstract: Aquaculture is the fastest growing food-producing sector in the world. It is developing, expanding and intensifying in almost all regions of the world. The global population is increasing, thus, the demand for aquatic food products is also increasing. Production from capture fisheries has levelled off and most of the main fishing areas have reached their maximum potential. Sustaining fish supplies from capture fisheries will, therefore, not be able to meet the growing global demand for aquatic food and aquaculture is considered to be an opportunity to bridge the supply and demand gap of aquatic food in most regions of the world. However, in our efforts to achieve this potential, the sector will face significant challenges. Key development trends indicate that the sector continues to intensify and diversify and is continuing to use new species and modify its systems and practices. Markets, trade and consumption preferences strongly influence the growth of the sector, with clear demands for the production of safe and quality products. As a consequence, increasing emphasis is placed on enhanced enforcement of regulation and better governance of the sector. It is increasingly realized that sustainable development and responsible production of aquaculture, in the long run, cannot be achieved without the full participation of the producers in the decision-making and regulation process, which has led to efforts to empower farmers and their associations and move toward increasing self-regulation. These factors are all contributing to an improvement in the management of the sector, typically through the promotion of ‘better management’ practices of producers. This review discusses the role of aquaculture, as at large a small-scale farmer driven production sector, in the quest for sustainable development, reducing poverty and improving food security on a global scale.

351 citations

Journal ArticleDOI
TL;DR: In this article, the tropical N-cycle is traced from pre-disturbance conditions through the phases of disturbance, highlighting major differences between tropical and temperate systems that might influence development strategies in the tropics.
Abstract: Published data and analyses from temperate and tropical aquatic systems are used to summarize knowledge about the potential impact of land-use alteration on the nitrogen biogeochemistry of tropical aquatic ecosystems, identify important patterns and recommend key needs for research. The tropical N-cycle is traced from pre-disturbance conditions through the phases of disturbance, highlighting major differences between tropical and temperate systems that might influence development strategies in the tropics. Analyses suggest that tropical freshwaters are more frequently N-limited than temperate zones, while tropical marine systems may show more frequent P limitation. These analyses indicate that disturbances to pristine tropical lands will lead to greatly increased primary production in freshwaters and large changes in tropical freshwater communities. Increased freshwater nutrient flux will also lead to an expansion of the high production, N- and light-limited zones around river deltas, a switch from P- to N-limitation in calcareous marine systems, with large changes in the community composition of fragile mangrove and reef systems. Key information gaps are highlighted, including data on mechanisms of nutrient transport and atmospheric deposition in the tropics, nutrient and material retention capacities of tropical impoundments, and N/P coupling and stoichiometric impacts of nutrient supplies on tropical aquatic communities. The current base of biogeochemical data suggests that alterations in the N-cycle will have greater impacts on tropical aquatic ecosystems than those already observed in the temperate zone.

233 citations

Journal ArticleDOI
TL;DR: In this article, the authors conducted experimental fishing, in six locations in the salmon farming regions (41°46° S) in the inner seas of Chiloe (X Region) and Aysen (XI Region), between November 1995 and December 1996.
Abstract: During heavy storms in 1994–1995, salmon farms in southern Chile lost several million fish from the most commonly farmed species, rainbow trout (Oncorhynchus mykiss), coho salmon (Oncorhynchus kisutch), and Atlantic salmon (Salmo salar). To determine the abundance and distribution of such exotic salmon populations in the wild and their effect on native organisms, we conducted experimental fishing, in six locations in the salmon farming regions (41°–46° S) in the inner seas of Chiloe (X Region) and Aysen (XI Region), between November 1995 and December 1996. At the same time, we collected information from salmon farms and insurance companies about escaped individuals. During the experimental fishing we captured 2602 coho salmon, 984 trout, and 271 Atlantic salmon. Captures of the three species declined through the duration of the study; thus in November 1996 we captured <10% of initial catches. Population projections based on three possible mortality rates (0.4, 0.8, and 1.2) predicted the disappearance of salmon by year 2000, and the highest mortality rate was the best predictor of the observed available biomass in 1996. Thus, artisanal fishing may control escaped salmon. Of the three species, coho salmon had the best chances of becoming established in the remote XI Region where the artisanal fishing pressure was less intense. The three salmon species showed feeding similarities, since each kept feeding on pellets beneath the farms, particularly Atlantic salmon, while coho salmon showed greater preference for schooling fish, and rainbow trout fed more often on crustaceans. Thus, the three species, particularly coho salmon, could compete with native southern hake and mackerel. As a management approach to avoid salmon colonization and naturalization in southern Chile, local artisanal fishing should be encouraged because it is probably the most efficient way to remove escaped individuals and reduce the chance of populations becoming self-sustaining.

184 citations

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TL;DR: In this paper, the effect of forest management on streamflow in two watersheds in the Valdivian Andes (600-650 m of elevation; 39837 0S), and fish abundance as a function of forest cover in 17 watersheds located in the Coastal Range and the Central Depression (39850 0 -42830 0 S).

174 citations


Cited by
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Journal ArticleDOI
30 Sep 2010-Nature
TL;DR: The first worldwide synthesis to jointly consider human and biodiversity perspectives on water security using a spatial framework that quantifies multiple stressors and accounts for downstream impacts is presented.
Abstract: Protecting the world’s freshwater resources requires diagnosing threats over a broad range of scales, from global to local. Here we present the first worldwide synthesis to jointly consider human and biodiversity perspectives on water security using a spatial framework that quantifies multiple stressors and accounts for downstream impacts. We find that nearly 80% of the world’s population is exposed to high levels of threat to water security. Massive investment in water technology enables rich nations to offset high stressor levels without remedying their underlying causes, whereas less wealthy nations remain vulnerable. A similar lack of precautionary investment jeopardizes biodiversity, with habitats associated with 65% of continental discharge classified as moderately to highly threatened. The cumulative threat framework offers a tool for prioritizing policy and management responses to this crisis, and underscores the necessity of limiting threats at their source instead of through costly remediation of symptoms in order to assure global water security for both humans and freshwater biodiversity.

5,401 citations

Journal ArticleDOI
TL;DR: Food in the Anthropocene : the EAT-Lancet Commission on healthy diets from sustainable food systems focuses on meat, fish, vegetables and fruit as sources of protein.

4,710 citations

Journal ArticleDOI
TL;DR: A large-scale meta-analysis of experimental enrichments shows that P limitation is equally strong across these major habitats and that N and P limitation are equivalent within both terrestrial and freshwater systems.
Abstract: The cycles of the key nutrient elements nitrogen (N) and phosphorus (P) have been massively altered by anthropogenic activities. Thus, it is essential to understand how photosynthetic production across diverse ecosystems is, or is not, limited by N and P. Via a large-scale meta-analysis of experimental enrichments, we show that P limitation is equally strong across these major habitats and that N and P limitation are equivalent within both terrestrial and freshwater systems. Furthermore, simultaneous N and P enrichment produces strongly positive synergistic responses in all three environments. Thus, contrary to some prevailing paradigms, freshwater, marine and terrestrial ecosystems are surprisingly similar in terms of N and P limitation.

3,543 citations

Journal ArticleDOI
29 Jun 2000-Nature
TL;DR: If the growing aquaculture industry is to sustain its contribution to world fish supplies, it must reduce wild fish inputs in feed and adopt more ecologically sound management practices.
Abstract: Global production of farmed fish and shellfish has more than doubled in the past 15 years. Many people believe that such growth relieves pressure on ocean fisheries, but the opposite is true for some types of aquaculture. Farming carnivorous species requires large inputs of wild fish for feed. Some aquaculture systems also reduce wild fish supplies through habitat modification, wild seedstock collection and other ecological impacts. On balance, global aquaculture production still adds to world fish supplies; however, if the growing aquaculture industry is to sustain its contribution to world fish supplies, it must reduce wild fish inputs in feed and adopt more ecologically sound management practices.

2,931 citations

Journal ArticleDOI
TL;DR: For example, a recent review of the early phase of the coastal eutrophication problem can be found in this article, where the authors suggest that the early (phase I) con- ceptual model was strongly influenced by limnologists, who began intense study of lake eutrophicication by the 1960s.
Abstract: A primary focus of coastal science during the past 3 decades has been the question: How does anthropogenic nutrient enrichment cause change in the structure or function of nearshore coastal ecosystems? This theme of environmental science is recent, so our conceptual model of the coastal eutrophication problem continues to change rapidly In this review, I suggest that the early (Phase I) con- ceptual model was strongly influenced by limnologists, who began intense study of lake eutrophication by the 1960s The Phase I model emphasized changing nutrient input as a signal, and responses to that signal as increased phytoplankton biomass and primary production, decomposition of phytoplankton- derived organic matter, and enhanced depletion of oxygen from bottom waters Coastal research in recent decades has identified key differences in the responses of lakes and coastal-estuarine ecosystems to nutrient enrichment The contemporary (Phase II) conceptual model reflects those differences and includes explicit recognition of (1) system-specific attributes that act as a filter to modulate the responses to enrichment (leading to large differences among estuarine-coastal systems in their sensitivity to nu- trient enrichment); and (2) a complex suite of direct and indirect responses including linked changes in: water transparency, distribution of vascular plants and biomass of macroalgae, sediment biogeochem- istry and nutrient cycling, nutrient ratios and their regulation of phytoplankton community composition, frequency of toxic/harmful algal blooms, habitat quality for metazoans, reproduction/growth/survival of pelagic and benthic invertebrates, and subtle changes such as shifts in the seasonality of ecosystem functions Each aspect of the Phase II model is illustrated here with examples from coastal ecosystems around the world In the last section of this review I present one vision of the next (Phase III) stage in the evolution of our conceptual model, organized around 5 questions that will guide coastal science in the early 21st century: (1) How do system-specific attributes constrain or amplify the responses of coastal ecosystems to nutrient enrichment? (2) How does nutrient enrichment interact with other stressors (toxic contaminants, fishing harvest, aquaculture, nonindigenous species, habitat loss, climate change, hydro- logic manipulations) to change coastal ecosystems? (3) How are responses to multiple stressors linked? (4) How does human-induced change in the coastal zone impact the Earth system as habitat for humanity and other species? (5) How can a deeper scientific understanding of the coastal eutrophication problem be applied to develop tools for building strategies at ecosystem restoration or rehabilitation?

2,658 citations