The Niche
... 2. When an environmental conditions, such as temperature, extends in either direction beyond an organism’s optimum range, the organism experiences stress. The organism 3. this means the organism must expend more ...
... 2. When an environmental conditions, such as temperature, extends in either direction beyond an organism’s optimum range, the organism experiences stress. The organism 3. this means the organism must expend more ...
Bathymetric trends in demersal fish size: is there a
... steeper increase in fish size with depth (Fig. 5). Similarly, large species (i.e. those displaying relatively large sizes in all samples) are, as expected, larger at the upper end of their depth range than are smaller species. The size-dependence of the depth-size relationships is best described by ...
... steeper increase in fish size with depth (Fig. 5). Similarly, large species (i.e. those displaying relatively large sizes in all samples) are, as expected, larger at the upper end of their depth range than are smaller species. The size-dependence of the depth-size relationships is best described by ...
fox
... relatively resilient to harvesting pressure, and are able to sustain harvest rates of 50 to 75 percent of the fall population. However, since managers will almost never have detailed population inventory information, planning and managing for a sustainable harvest and healthy population involves mor ...
... relatively resilient to harvesting pressure, and are able to sustain harvest rates of 50 to 75 percent of the fall population. However, since managers will almost never have detailed population inventory information, planning and managing for a sustainable harvest and healthy population involves mor ...
and the degree of omnivory of five Celtic Sea fish predato
... the first analysis (Pinnegar et al., 2003) was that the diet of predator species changed as ...
... the first analysis (Pinnegar et al., 2003) was that the diet of predator species changed as ...
12 September 2016 PIRSA Fisheries and
... interaction rates with syngnathids, suggesting an average rate of around 0.33 per trawl-hour in medium and high intensity trawl areas, and at least double that in low intensity areas. With a total effort of around 3,000 hours it could be expected that about 1,000 syngnathids would be caught by the f ...
... interaction rates with syngnathids, suggesting an average rate of around 0.33 per trawl-hour in medium and high intensity trawl areas, and at least double that in low intensity areas. With a total effort of around 3,000 hours it could be expected that about 1,000 syngnathids would be caught by the f ...
Summary
... resource limitation in marine populations. In the second, we review available data on density-dependent changes in lifehistory traits. The third section summarizes the available evidence on spillover from MPAs, and in the final section, the findings and implications for MPA managers are discussed. A ...
... resource limitation in marine populations. In the second, we review available data on density-dependent changes in lifehistory traits. The third section summarizes the available evidence on spillover from MPAs, and in the final section, the findings and implications for MPA managers are discussed. A ...
Fish Population Dynamics
... SHADYS is a virtual laboratory which couples three entities: the environment, fish populations and the fishing fleet. Numerical models representing these entities are interfaced with a GIS to aid in visualizing the results. In this example, a marine reserve was modeled and the effects of fishing ou ...
... SHADYS is a virtual laboratory which couples three entities: the environment, fish populations and the fishing fleet. Numerical models representing these entities are interfaced with a GIS to aid in visualizing the results. In this example, a marine reserve was modeled and the effects of fishing ou ...
Amphibians of Jamaica
... Two species with SVL up to 40 mm • Genus Osteopilus: one species, SVL up to 80 mm • Genus Calyptahyla: one species, SVL up to 80 mm Some authors consider all four Jamaican hylid frogs to be Osteopilus. ...
... Two species with SVL up to 40 mm • Genus Osteopilus: one species, SVL up to 80 mm • Genus Calyptahyla: one species, SVL up to 80 mm Some authors consider all four Jamaican hylid frogs to be Osteopilus. ...
Galapagos vertebrates: endangered status and conservation actions
... distributed along the coasts of Fernandina and Isabela and the northern coast of Floreana. The flightless cormorant, Phalacrocorax harrisi, is found on the coasts of Fernandina and Isabela. Both species are catalogued on the IUCN’s Red List as Endangered1. The threats include introduced species, suc ...
... distributed along the coasts of Fernandina and Isabela and the northern coast of Floreana. The flightless cormorant, Phalacrocorax harrisi, is found on the coasts of Fernandina and Isabela. Both species are catalogued on the IUCN’s Red List as Endangered1. The threats include introduced species, suc ...
`wasp-waist` food webs
... dynamics and fisheries-relevant issues as well as the food web [11,12], whereas krill research tends to be more foodweb based [6,13]. Despite these differences, the species all achieve enormously high biomass densities at mid-trophic levels, with unusually large variability in population size on tim ...
... dynamics and fisheries-relevant issues as well as the food web [11,12], whereas krill research tends to be more foodweb based [6,13]. Despite these differences, the species all achieve enormously high biomass densities at mid-trophic levels, with unusually large variability in population size on tim ...
From Population to the Biosphere
... Other limiting factors include light, water, nutrients or minerals, oxygen, the ability of an ecosystem to recycle nutrients and/or waste, disease and/or parasites, temperature, space, and predation. Can you think of some other factors that limit populations? Weather is also a limiting factor. For e ...
... Other limiting factors include light, water, nutrients or minerals, oxygen, the ability of an ecosystem to recycle nutrients and/or waste, disease and/or parasites, temperature, space, and predation. Can you think of some other factors that limit populations? Weather is also a limiting factor. For e ...
Consumers of sea urchins, Paracentrotus lividus and Arbacia lixula
... thus probably overestimated predation rates of M. glacialis upon sea urchins. Although Fanelli et al. (1999) reported negative correlations between M. glacialis and sea urchin density in shallow rocky reefs in SE Italy, there is no clear evidence so far to show that this starfish is an efficient sea ...
... thus probably overestimated predation rates of M. glacialis upon sea urchins. Although Fanelli et al. (1999) reported negative correlations between M. glacialis and sea urchin density in shallow rocky reefs in SE Italy, there is no clear evidence so far to show that this starfish is an efficient sea ...
western blue groper - Department of Fisheries
... Sex change in western blue groper occurs at a length of about 820 mm and at an age of between 30 and 35 years. This change in sex is closely associated with a change in the groper’s colour from green to blue. Western blue groper prefer to live in small groups or ‘harems’, consisting of one male, one ...
... Sex change in western blue groper occurs at a length of about 820 mm and at an age of between 30 and 35 years. This change in sex is closely associated with a change in the groper’s colour from green to blue. Western blue groper prefer to live in small groups or ‘harems’, consisting of one male, one ...
Inland Aquaculture in Western Australia
... This paper identifies some of the important factors that need to be considered before undertaking and/or investing in an inland aquaculture enterprise. It assumes suitable land is available to develop an aquaculture project. ...
... This paper identifies some of the important factors that need to be considered before undertaking and/or investing in an inland aquaculture enterprise. It assumes suitable land is available to develop an aquaculture project. ...
Where The Wild Extinctions Are
... By surveys both on and off islands, this relationship has been generally verified. It also passes the reasonability test -- for example, we would expect to find more species in a state than we find in any one county in that state. Does this species-area relationship work in reverse? That is to say, ...
... By surveys both on and off islands, this relationship has been generally verified. It also passes the reasonability test -- for example, we would expect to find more species in a state than we find in any one county in that state. Does this species-area relationship work in reverse? That is to say, ...
Volume 192 - 1991 - Part 14 of 41
... biomass yield from a manipulated stock may be too high. Furtherm ore, in coho salmon (O . kisutch), sur vival rate and total adult biomass result from a complex interaction between time and size at which juveniles are released into the wild (Bilton et a i , 1982). If the time and size are properly ...
... biomass yield from a manipulated stock may be too high. Furtherm ore, in coho salmon (O . kisutch), sur vival rate and total adult biomass result from a complex interaction between time and size at which juveniles are released into the wild (Bilton et a i , 1982). If the time and size are properly ...
Worksheet - Rudds Classroom
... the ________________ state of an ecosystem is crucial to its _______________ development ...
... the ________________ state of an ecosystem is crucial to its _______________ development ...
1995 Why is the Double-crested Cormorant a Problem
... then di~ing)relative to actual feeding which may take less than a second for small fish. In terms of foraging theory (MacZrthur and Pianka 1966),such a predator should take tirtually any edible prey it encounters and can eat, rather then being selective, because handling and consuming the prey costs ...
... then di~ing)relative to actual feeding which may take less than a second for small fish. In terms of foraging theory (MacZrthur and Pianka 1966),such a predator should take tirtually any edible prey it encounters and can eat, rather then being selective, because handling and consuming the prey costs ...
LAPB 2008 Program wi.. - Louisiana Association of Professional
... observations planned for this summer. Using Peak Motus motion analysis software, swimming speeds were measured over 1-2 sec periods sampled every 30 min during two nights in the summer of 2007 as well as from videos recorded in two previous years. Ground speeds of the swimming shrimp varied from 0.6 ...
... observations planned for this summer. Using Peak Motus motion analysis software, swimming speeds were measured over 1-2 sec periods sampled every 30 min during two nights in the summer of 2007 as well as from videos recorded in two previous years. Ground speeds of the swimming shrimp varied from 0.6 ...
Lecture Notes for ecological_structure
... by ventilating more rapidly in order to decrease the diffusion distance and offset the gradient decline. ...
... by ventilating more rapidly in order to decrease the diffusion distance and offset the gradient decline. ...
1 Stresses and Threats to Natural Resources of Michigan Lakes
... biological communities resulting from human lakeshore development in north temperate lakes. Deadwood (coarse woody debris) is a habitat component of north temperate lakes that is produced immediately adjacent to lake shorelines or streams flowing into lakes. The ecological function of deadwood is no ...
... biological communities resulting from human lakeshore development in north temperate lakes. Deadwood (coarse woody debris) is a habitat component of north temperate lakes that is produced immediately adjacent to lake shorelines or streams flowing into lakes. The ecological function of deadwood is no ...
Competition, predation and environmental factors as structuring
... in the lakes studied. However, abiotic factors such as conductivity and pH were also found to affect fish community structure. In a larger data set of Finnish lakes (including the data used here), Tonn et al. (1990) found that the relative abundance of roach depended on lake isolation, pH, lake area ...
... in the lakes studied. However, abiotic factors such as conductivity and pH were also found to affect fish community structure. In a larger data set of Finnish lakes (including the data used here), Tonn et al. (1990) found that the relative abundance of roach depended on lake isolation, pH, lake area ...
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.