Biotic and Abiotic Controls in River and Stream Communities
... sublayers and how frequently these are penetrated by turbulent eddies. By observing diatoms flowing under a microscope set over an artificial stream, Stevenson (1983) showed that small roughness elements (in this case, threads 0.1 mm in diameter) increased the rate at which cells within turbulent ed ...
... sublayers and how frequently these are penetrated by turbulent eddies. By observing diatoms flowing under a microscope set over an artificial stream, Stevenson (1983) showed that small roughness elements (in this case, threads 0.1 mm in diameter) increased the rate at which cells within turbulent ed ...
Trophic promiscuity, intraguild predation and the problem of omnivores
... in the average pest burden on plants as predator density increases. The latter effect of resource partitioning raises an important point: the predicted effects of predator–predator interactions on pest suppression depend upon the number of pest species within the production system. For example, if t ...
... in the average pest burden on plants as predator density increases. The latter effect of resource partitioning raises an important point: the predicted effects of predator–predator interactions on pest suppression depend upon the number of pest species within the production system. For example, if t ...
Why are there so many jellyfish in our rivers? A Case
... Why are there so many jellyfish in our rivers? A Case Study for Middle School Abstract In this two-day exercise, students will become farmers, tourists, fishers and scientists who must all work together using the information they’ve learned to find out why jellyfish populations have been blooming in ...
... Why are there so many jellyfish in our rivers? A Case Study for Middle School Abstract In this two-day exercise, students will become farmers, tourists, fishers and scientists who must all work together using the information they’ve learned to find out why jellyfish populations have been blooming in ...
Invertebrates: zoobenthos
... same lake, but there generally is higher biodiversity in common than that to be found in deeper waters. The sub-littoral zone (2.5-6 m) is a more homogeneous environment, less diversified than the littoral one, with benthic communities which include species of both deep and littoral benthos. The sub ...
... same lake, but there generally is higher biodiversity in common than that to be found in deeper waters. The sub-littoral zone (2.5-6 m) is a more homogeneous environment, less diversified than the littoral one, with benthic communities which include species of both deep and littoral benthos. The sub ...
- Hambrey Consulting
... Therapeutic chemicals such as antibiotics are used to treat a range of diseases and parasites – chiefly sea lice – in farmed salmon. Applied as a bath treatment or incorporated in feed, quantities of these therapeutics eventually find their way into the wider marine environment. The type of chemical ...
... Therapeutic chemicals such as antibiotics are used to treat a range of diseases and parasites – chiefly sea lice – in farmed salmon. Applied as a bath treatment or incorporated in feed, quantities of these therapeutics eventually find their way into the wider marine environment. The type of chemical ...
World Conservation Strategy
... The World Conservation Strategy (WCS) was commissioned by the United Nations Environment Programme (UNEP) which together with the World Wildlife Fund (WWF) provided the financial support for its preparation and contributed to the evolution of its basic themes and structure. IUCN is grateful to both ...
... The World Conservation Strategy (WCS) was commissioned by the United Nations Environment Programme (UNEP) which together with the World Wildlife Fund (WWF) provided the financial support for its preparation and contributed to the evolution of its basic themes and structure. IUCN is grateful to both ...
Beavers and biodiversity: the ethics of ecological restoration
... partially submerged lodges, and was once abundant in forest zones and wooded river valleys in Europe and Asia. In the course of the last millennium, beavers have died out in many ...
... partially submerged lodges, and was once abundant in forest zones and wooded river valleys in Europe and Asia. In the course of the last millennium, beavers have died out in many ...
Impacts of environmental variability in open populations and
... Ecological communities are typically open to the immigration and emigration of individuals, and also variable through time. In this paper we argue that interesting and potentially important effects arise when one splices together spatial fluxes and temporal variability. The particular system we exami ...
... Ecological communities are typically open to the immigration and emigration of individuals, and also variable through time. In this paper we argue that interesting and potentially important effects arise when one splices together spatial fluxes and temporal variability. The particular system we exami ...
Wildlife Populations in the Pacaya
... Research and conservation activities should use an interdisciplinary approach to find a balance between the needs of the indigenous people and the conservation of the animals and plants (Bodmer and Puertas 2000, Peres 2000). For example, some animals like the primates, jaguars, manatees and tapir ...
... Research and conservation activities should use an interdisciplinary approach to find a balance between the needs of the indigenous people and the conservation of the animals and plants (Bodmer and Puertas 2000, Peres 2000). For example, some animals like the primates, jaguars, manatees and tapir ...
- Blue Ventures
... consequence of their overfished status in parts of the Pacific where they are used for food and traditional medicine purposes for centuries. In the Caribbean they are not consumed except by very small oriental communities, for example in Jamaica. This study revealed that sea cucumbers have been quie ...
... consequence of their overfished status in parts of the Pacific where they are used for food and traditional medicine purposes for centuries. In the Caribbean they are not consumed except by very small oriental communities, for example in Jamaica. This study revealed that sea cucumbers have been quie ...
Spatial complementarity in tree crowns explains overyielding in
... Tables 1 and 2), and led to differences among mixtures in crown complementarity. Within species, considerable variation was observed both within and among neighbourhoods (Supplementary Table 2). As a result of these differences in crowns, crown complementarity observed in species mixtures (CCIobs) r ...
... Tables 1 and 2), and led to differences among mixtures in crown complementarity. Within species, considerable variation was observed both within and among neighbourhoods (Supplementary Table 2). As a result of these differences in crowns, crown complementarity observed in species mixtures (CCIobs) r ...
(1999) Consequences of the Allee effect for behaviour, ecology and
... because of compensation – the increase in population growth as a population is reduced. However, when populations are subject to an Allee effect, the population growth rate is depressed at reduced sizes and harvesting could have unforeseen consequences (Box 3). The most important impact of harvestin ...
... because of compensation – the increase in population growth as a population is reduced. However, when populations are subject to an Allee effect, the population growth rate is depressed at reduced sizes and harvesting could have unforeseen consequences (Box 3). The most important impact of harvestin ...
Prescription for Great Lakes Ecosystem Protection and Restoration
... stress and promote the lakes’ recovery.1 From this perspective, protecting the Great Lakes is not particularly urgent and action can wait until we conduct more studies, while taking small corrective measures when the opportunity or need arises. However, if not addressed with great urgency, the Great ...
... stress and promote the lakes’ recovery.1 From this perspective, protecting the Great Lakes is not particularly urgent and action can wait until we conduct more studies, while taking small corrective measures when the opportunity or need arises. However, if not addressed with great urgency, the Great ...
Complete proposal, October 2006, 186KB PDF
... assess the importance of shark bycatch and to address the feasibility of using commercial ships of opportunity to collect meaningful data regarding bycatch rates, life history, and feeding ecology of sharks in the Bering Sea. Our underlying hypothesis is that bycatch is an ecosystem level phenomenon ...
... assess the importance of shark bycatch and to address the feasibility of using commercial ships of opportunity to collect meaningful data regarding bycatch rates, life history, and feeding ecology of sharks in the Bering Sea. Our underlying hypothesis is that bycatch is an ecosystem level phenomenon ...
The functional role of biodiversity in ecosystems
... research had shown that loss of predator species can have impacts that cascade down a food chain to plants, altering basic ecosystem processes. One classic example is the kelp – sea urchin – sea otter food chain in the northeast Pacific. Hunting of sea otters by fur traders in the late 19th century ...
... research had shown that loss of predator species can have impacts that cascade down a food chain to plants, altering basic ecosystem processes. One classic example is the kelp – sea urchin – sea otter food chain in the northeast Pacific. Hunting of sea otters by fur traders in the late 19th century ...
Invasive American razor clam Ensis directus in Belgian waters
... Dutch Ensis fishery started in 1990s Since 2006: 8 fishing licenses (5 active) 2012: MSC label for Ensis fishery (Hervas et al. 2012) Harvest strategy complies with conservation requirements of Voordelta & Dutch coastal zone Precautionary approach to maintain the productivity of the stock at sustain ...
... Dutch Ensis fishery started in 1990s Since 2006: 8 fishing licenses (5 active) 2012: MSC label for Ensis fishery (Hervas et al. 2012) Harvest strategy complies with conservation requirements of Voordelta & Dutch coastal zone Precautionary approach to maintain the productivity of the stock at sustain ...
Food Webs and Graphs - SciTech Connect
... Trophic levels in food webs provide a way of organizing species in a community food web into feeding groups. Scientists have used various methods in classifying species in a food web into these various feeding groups. The most elementary method is to divide them into the following categories: primar ...
... Trophic levels in food webs provide a way of organizing species in a community food web into feeding groups. Scientists have used various methods in classifying species in a food web into these various feeding groups. The most elementary method is to divide them into the following categories: primar ...
Community stability and selective extinction during Earth`s
... sustain those functions will be associated with the expected loss of species and their particular functional traits. The extent to which ecosystem functions and key processes are maintained as species are lost and added to systems is linked directly to human well-being because of societal reliance o ...
... sustain those functions will be associated with the expected loss of species and their particular functional traits. The extent to which ecosystem functions and key processes are maintained as species are lost and added to systems is linked directly to human well-being because of societal reliance o ...
roundtable session 2a: national legislation, eu directives and
... In order to limit the decline of native crayfishes, various European nations have adopted some regulations to protect them independent of actions of other countries. Some participants at the roundtable agreed to summarise the types of regulations in force in their country in order to examine the lev ...
... In order to limit the decline of native crayfishes, various European nations have adopted some regulations to protect them independent of actions of other countries. Some participants at the roundtable agreed to summarise the types of regulations in force in their country in order to examine the lev ...
Chapter 4. Complex Life Cycles and Marine Food Webs: Migrating
... an entire life history. Mapping an entire life history onto a size spectrum requires data on stagespecific mortality and growth rates (Hartvig et al. 2011), which are available for the intensively studied Chesapeake Bay striped bass (Setzler et al. 1980; Houde 1996). For cohorts originating in two h ...
... an entire life history. Mapping an entire life history onto a size spectrum requires data on stagespecific mortality and growth rates (Hartvig et al. 2011), which are available for the intensively studied Chesapeake Bay striped bass (Setzler et al. 1980; Houde 1996). For cohorts originating in two h ...
Chapter 12 Aquaculture
... Estimates of total usage of terrestrial animal by-product meals and oils in compound aquafeeds ranges between 0.15 and 0.30 million tons, or less than 1 percent of total global production. Patterns in the use of fishmeal and fish oil have changed in time due to the growth and evolution of the world ...
... Estimates of total usage of terrestrial animal by-product meals and oils in compound aquafeeds ranges between 0.15 and 0.30 million tons, or less than 1 percent of total global production. Patterns in the use of fishmeal and fish oil have changed in time due to the growth and evolution of the world ...
The Ecological Role of the Mammalian Mesocarnivore
... Michigan, the ecological effects of wolves were caused by just two or three packs (McLaren and Peterson 1994). Thus, it is clear that a relatively small number of large carnivores can directly or indirectly influence multiple trophic levels and precipitate community-level cascades that increase the ...
... Michigan, the ecological effects of wolves were caused by just two or three packs (McLaren and Peterson 1994). Thus, it is clear that a relatively small number of large carnivores can directly or indirectly influence multiple trophic levels and precipitate community-level cascades that increase the ...
The Ecological Role of the Mammalian Mesocarnivore
... Michigan, the ecological effects of wolves were caused by just two or three packs (McLaren and Peterson 1994). Thus, it is clear that a relatively small number of large carnivores can directly or indirectly influence multiple trophic levels and precipitate community-level cascades that increase the ...
... Michigan, the ecological effects of wolves were caused by just two or three packs (McLaren and Peterson 1994). Thus, it is clear that a relatively small number of large carnivores can directly or indirectly influence multiple trophic levels and precipitate community-level cascades that increase the ...
The dependence of root system properties on root system biomass... North American grassland species
... biomass was log-transformed and the resultant transformed data then centered at its mean. The model tests for separate relationships between fine root biomass and soil NO3 − between the two nitrogen treatments and among the three harvests for which data on soil moisture were collected. A few of the ...
... biomass was log-transformed and the resultant transformed data then centered at its mean. The model tests for separate relationships between fine root biomass and soil NO3 − between the two nitrogen treatments and among the three harvests for which data on soil moisture were collected. A few of the ...
Coevolutionary dynamics of adaptive radiation for food
... evolutionary history seems to have been influenced by both external and internal factors. Ecological interaction among organisms (e.g., predator–prey interaction and resource competition), which is one of the internal factors, induces their coevolution. Their evolutionary changes can also change the ...
... evolutionary history seems to have been influenced by both external and internal factors. Ecological interaction among organisms (e.g., predator–prey interaction and resource competition), which is one of the internal factors, induces their coevolution. Their evolutionary changes can also change the ...
Overexploitation
Overexploitation, also called overharvesting, refers to harvesting a renewable resource to the point of diminishing returns. Sustained overexploitation can lead to the destruction of the resource. The term applies to natural resources such as: wild medicinal plants, grazing pastures, game animals, fish stocks, forests, and water aquifers.In ecology, overexploitation describes one of the five main activities threatening global biodiversity. Ecologists use the term to describe populations that are harvested at a rate that is unsustainable, given their natural rates of mortality and capacities for reproduction. This can result in extinction at the population level and even extinction of whole species. In conservation biology the term is usually used in the context of human economic activity that involves the taking of biological resources, or organisms, in larger numbers than their populations can withstand. The term is also used and defined somewhat differently in fisheries, hydrology and natural resource management.Overexploitation can lead to resource destruction, including extinctions. However it is also possible for overexploitation to be sustainable, as discussed below in the section on fisheries. In the context of fishing, the term overfishing can be used instead of overexploitation, as can overgrazing in stock management, overlogging in forest management, overdrafting in aquifer management, and endangered species in species monitoring. Overexploitation is not an activity limited to humans. Introduced predators and herbivores, for example, can overexploit native flora and fauna.