2. Marine Biodiversity and species of conservation concern
... plant phyla, one group of Chromista, and three groups of Protoctista (Miloslavich et al 2010)7. The most characteristic ecosystems in the Caribbean are coral reefs covering about 26,000 km2 (Burke and Maidens 2004)8, seagrass beds with an area of about 66,000 sq. km (Jackson 1997)9, and mangroves at ...
... plant phyla, one group of Chromista, and three groups of Protoctista (Miloslavich et al 2010)7. The most characteristic ecosystems in the Caribbean are coral reefs covering about 26,000 km2 (Burke and Maidens 2004)8, seagrass beds with an area of about 66,000 sq. km (Jackson 1997)9, and mangroves at ...
Predation in Sea Urchins
... Tripneustes around, as if seeking an area of uneaten spines. By the next morning, Diadema had gnawed a roughly circular hole, 6 square em. in area, in the test of Tripneustes. To see whether or not this was an isolated case, another aquarium was set up, containing a single Diadema, several individua ...
... Tripneustes around, as if seeking an area of uneaten spines. By the next morning, Diadema had gnawed a roughly circular hole, 6 square em. in area, in the test of Tripneustes. To see whether or not this was an isolated case, another aquarium was set up, containing a single Diadema, several individua ...
Global Biodiversity Outlook 3
... human well-being. The provision of food, fibre, medicines and fresh water, pollination of crops, filtration of pollutants, and protection from natural disasters are among those ecosystem services potentially threatened by declines and changes in biodiversity. Cultural services such as spiritual and ...
... human well-being. The provision of food, fibre, medicines and fresh water, pollination of crops, filtration of pollutants, and protection from natural disasters are among those ecosystem services potentially threatened by declines and changes in biodiversity. Cultural services such as spiritual and ...
Gradients in density variations of small rodents: the importance of
... Summary. Microtine rodents are known to show extreme population variations (cycles) but non-cyclic populations have also been recognized during recent years. The cyclic populations have been widely thought to be regulated by intrinsic mechanisms. However, such predictions for cyclic populations are ...
... Summary. Microtine rodents are known to show extreme population variations (cycles) but non-cyclic populations have also been recognized during recent years. The cyclic populations have been widely thought to be regulated by intrinsic mechanisms. However, such predictions for cyclic populations are ...
Challenging The "Distinct Population Segment" Definition Of Atlantic
... approaches to administering the Act. This result would be unfortunate because the Services' proposed rule fails to extend ESA protection to populations which may be crucial to the survival of Atlantic salmon, and ...
... approaches to administering the Act. This result would be unfortunate because the Services' proposed rule fails to extend ESA protection to populations which may be crucial to the survival of Atlantic salmon, and ...
223 kb
... A variety of freshwater and marine predators such as northern pikeminnows, Caspian terns, and pinnipeds, can significantly reduce overall survival rates of program fish. Predation by northern pikeminnow poses a high risk of significant negative impacts on the productivity of hatchery chinook (SWIG 1 ...
... A variety of freshwater and marine predators such as northern pikeminnows, Caspian terns, and pinnipeds, can significantly reduce overall survival rates of program fish. Predation by northern pikeminnow poses a high risk of significant negative impacts on the productivity of hatchery chinook (SWIG 1 ...
Spatial and seasonal patterns of habitat partitioning
... and rocks were removed if necessary. O n 1 occasion, when it was discovered that a crevice was too deep to be adequately searched, the pool was discarded from the study. All fish were identified to species a n d their total lengths measured to the nearest mm. The rocks were then replaced, the pool r ...
... and rocks were removed if necessary. O n 1 occasion, when it was discovered that a crevice was too deep to be adequately searched, the pool was discarded from the study. All fish were identified to species a n d their total lengths measured to the nearest mm. The rocks were then replaced, the pool r ...
2014 Lake Winnebago Bottom Trawling Assessment_Final
... since 1995. Weak year classes of freshwater drum and gizzard shad were also observed during 2014 averaging 14.20 and 11.41 YOY/trawl, respectively. In fact, the cumulative YOY catch of trout perch, freshwater drum, and gizzard shad averaged 119.84/trawl in 2014 that is the lowest cumulative average ...
... since 1995. Weak year classes of freshwater drum and gizzard shad were also observed during 2014 averaging 14.20 and 11.41 YOY/trawl, respectively. In fact, the cumulative YOY catch of trout perch, freshwater drum, and gizzard shad averaged 119.84/trawl in 2014 that is the lowest cumulative average ...
ST. MARYS RIVER FISHERIES ASSESSMENT PLAN ST. MARYS RIVER FISHERIES TASK GROUP
... interagency cooperation, and the recommendation of prioritized assessment and research projects to deal with current fishery concerns in the St. Marys River. Public stakeholders, including representatives from local sport fishing clubs, environmental organizations, municipalities, Native American Tr ...
... interagency cooperation, and the recommendation of prioritized assessment and research projects to deal with current fishery concerns in the St. Marys River. Public stakeholders, including representatives from local sport fishing clubs, environmental organizations, municipalities, Native American Tr ...
Migratory Fishes as Material and Process Subsidies in Riverine Ecosystems
... Pacific salmon Oncorhynchus spp. with en masse programmed senescence in oligotrophic Pacific Northwest streams can be large material subsidies. In contrast, process subsidies arise from feeding or other activities of migratory species that directly affect process rates within recipient ecosystems. F ...
... Pacific salmon Oncorhynchus spp. with en masse programmed senescence in oligotrophic Pacific Northwest streams can be large material subsidies. In contrast, process subsidies arise from feeding or other activities of migratory species that directly affect process rates within recipient ecosystems. F ...
View or download OIP Achatinella species Management
... populations in the Koolau Mountains can be a destructive undertaking. In the past, intensive monitoring has resulted in extensive trampling of habitat. In order to avoid negative impacts like this, OANRP propose to monitor these fragile sites only every three years. At sites where the habitat is not ...
... populations in the Koolau Mountains can be a destructive undertaking. In the past, intensive monitoring has resulted in extensive trampling of habitat. In order to avoid negative impacts like this, OANRP propose to monitor these fragile sites only every three years. At sites where the habitat is not ...
The University of Chicago
... via density-mediated and trait-mediated effects. Predictions are made for simple interaction webs containing only one or the other herbivore species relative to the more complex system containing both herbivores. Hypothesized Species Interactions According to the linkages described in figure 1, a wo ...
... via density-mediated and trait-mediated effects. Predictions are made for simple interaction webs containing only one or the other herbivore species relative to the more complex system containing both herbivores. Hypothesized Species Interactions According to the linkages described in figure 1, a wo ...
KILHAM, PETER, AND ROBERT E. HECKY. Comparative ecology of
... during the course of succession. Even though the identity and basic ecology of organisms that are present early and late in successional sequences are generally known, little is known about their physiology. Marked differences in uptake ability, storage capacity, and growth and loss rates will be fo ...
... during the course of succession. Even though the identity and basic ecology of organisms that are present early and late in successional sequences are generally known, little is known about their physiology. Marked differences in uptake ability, storage capacity, and growth and loss rates will be fo ...
Causes of Mass Extinctions - With Special Reference to Vanishing
... http://curious.astro.cornell.edu/comets.php. There, you can simply know the difference between asteroids, comets, meteors and meteorites. In spite of this, what is related to my article is the question that was asked to Prof. Britt Scharringhousen (Professor of physics and astronomy, Beloit College ...
... http://curious.astro.cornell.edu/comets.php. There, you can simply know the difference between asteroids, comets, meteors and meteorites. In spite of this, what is related to my article is the question that was asked to Prof. Britt Scharringhousen (Professor of physics and astronomy, Beloit College ...
Endophytic fungi alter relationships between diversity and
... relationship between diversity and ecosystem properties may help to clarify some of the conflicting results found in other studies. Here, we use a field experiment with a dominant, introduced grass species to examine the question: Do endophytic fungi alter the relationship between diversity and ecos ...
... relationship between diversity and ecosystem properties may help to clarify some of the conflicting results found in other studies. Here, we use a field experiment with a dominant, introduced grass species to examine the question: Do endophytic fungi alter the relationship between diversity and ecos ...
On chaos, transient chaos and ghosts in single population models
... Here, Nn is the population density at generation n, and f (Nn ) corresponds to the per-capita growth rate of the population. For the sake of clarity, we will briefly explain the dynamics of such models, studied in detail by Schreiber [26]. In these models, very large population densities at time n c ...
... Here, Nn is the population density at generation n, and f (Nn ) corresponds to the per-capita growth rate of the population. For the sake of clarity, we will briefly explain the dynamics of such models, studied in detail by Schreiber [26]. In these models, very large population densities at time n c ...
BAY-DELTA HEARINGS
... dynamic nature of the changing Bay-Delta environment, which has recently been further altered by the rapid population expansion of several introduced fish and macroinvertebrate species, also makes it difficult to utilize quantitative data developed from historic surveys in projecting future populati ...
... dynamic nature of the changing Bay-Delta environment, which has recently been further altered by the rapid population expansion of several introduced fish and macroinvertebrate species, also makes it difficult to utilize quantitative data developed from historic surveys in projecting future populati ...
Structure changes in a planktonic food web: biotic and abiotic controls
... High mountain oligotrophic lakes present simple planktonic communities which make them suitable to study complex interactions (Neill 1988). Oligotrophy promotes the existence of small sized phytoplankton species with high turnover rates (Reynolds 1984; Psenner & Zapf 1990) and large-bodied zooplankt ...
... High mountain oligotrophic lakes present simple planktonic communities which make them suitable to study complex interactions (Neill 1988). Oligotrophy promotes the existence of small sized phytoplankton species with high turnover rates (Reynolds 1984; Psenner & Zapf 1990) and large-bodied zooplankt ...
Sea otter (Enhydra lutris) - Registre public des espèces en péril
... to 2004) based on a simple log-linear regression. A piece-wise regression which allows for an inflection in the log-linear trend showed that the initial rapid growth of 19.1% per year from 1977 to 1995 slowed to 8.0% per year from 1995 to 2004. This decline in the growth rate likely reflects parts o ...
... to 2004) based on a simple log-linear regression. A piece-wise regression which allows for an inflection in the log-linear trend showed that the initial rapid growth of 19.1% per year from 1977 to 1995 slowed to 8.0% per year from 1995 to 2004. This decline in the growth rate likely reflects parts o ...
Aquaculture: global status and trends
... of Africa and Latin America. However, a strengthening environmental lobby as well as competition for land resources in some areas is likely to limit developments of the kind seen in some Asian countries. Coastal aquaculture using onshore tanks has developed in some areas (e.g. South Korea, Spain, Ic ...
... of Africa and Latin America. However, a strengthening environmental lobby as well as competition for land resources in some areas is likely to limit developments of the kind seen in some Asian countries. Coastal aquaculture using onshore tanks has developed in some areas (e.g. South Korea, Spain, Ic ...
Ecosystem context and historical contingency in apex predator
... [reviewed by Duffy (18)], but other direct and indirect human influences can also play a role. Strong exploitation and poaching often continue during recovery efforts because the predators are themselves valuable (17, 19). For example, tigers are at risk of extinction due to intentional human impact ...
... [reviewed by Duffy (18)], but other direct and indirect human influences can also play a role. Strong exploitation and poaching often continue during recovery efforts because the predators are themselves valuable (17, 19). For example, tigers are at risk of extinction due to intentional human impact ...
Behavioral responses of American toad and bullfrog - Gt-ibma
... determine more definitively the role of each of these variables in affecting observed behavioral responses to mosquitofish. If tadpoles are unable to respond to the presence of mosquitofish cues appropriately, then their ability to avoid predation by mosquitofish may be compromised and this may cont ...
... determine more definitively the role of each of these variables in affecting observed behavioral responses to mosquitofish. If tadpoles are unable to respond to the presence of mosquitofish cues appropriately, then their ability to avoid predation by mosquitofish may be compromised and this may cont ...
A Conceptual Framework For Conservation Hatchery
... populations in the ecosystem. Secondly, for aquatic species with any commercial value, an added threat was annual over-harvesting. With more well-intentioned attempts to control over-harvesting, and in compliance with regional fishing agreements promulgated by international organizations and fisheri ...
... populations in the ecosystem. Secondly, for aquatic species with any commercial value, an added threat was annual over-harvesting. With more well-intentioned attempts to control over-harvesting, and in compliance with regional fishing agreements promulgated by international organizations and fisheri ...
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.