Macrophytes shape trophic niche variation among generalist fishes
... role in ecosystems. Generalists can, for instance, regulate the abundance, composition and niche use of organisms at lower and higher trophic levels and also integrate spatially distinct habitats and food-web compartments [2], thereby affecting the structure and stability of food webs [3,4]. General ...
... role in ecosystems. Generalists can, for instance, regulate the abundance, composition and niche use of organisms at lower and higher trophic levels and also integrate spatially distinct habitats and food-web compartments [2], thereby affecting the structure and stability of food webs [3,4]. General ...
Benthic and Pelagic Secondary Production in Lake Erie
... temperature. Production estimates calculated from P/B ratios depend on seasonally-weighted mean body size, seasonally-weighted mean population biomass, and median temperature. Therefore, production was calculated for each species within individual thermal layers over the temporal duration of that la ...
... temperature. Production estimates calculated from P/B ratios depend on seasonally-weighted mean body size, seasonally-weighted mean population biomass, and median temperature. Therefore, production was calculated for each species within individual thermal layers over the temporal duration of that la ...
Ecology
... ecosystem through primary production. 3. The frequency of disturbances or other agents of change can determine whether populations of top predators can be sustained. ...
... ecosystem through primary production. 3. The frequency of disturbances or other agents of change can determine whether populations of top predators can be sustained. ...
independent gradients of producer, consumer
... composition were similar among trophic levels. METHODS Study region We sampled 31 lakes throughout an area of ;30 000 km2 in the southern interior and the mainland coast of southwestern British Columbia (Fig. 1). The lakes ranged in surface area from 20 to 395 ha. Lakes were selected to represent th ...
... composition were similar among trophic levels. METHODS Study region We sampled 31 lakes throughout an area of ;30 000 km2 in the southern interior and the mainland coast of southwestern British Columbia (Fig. 1). The lakes ranged in surface area from 20 to 395 ha. Lakes were selected to represent th ...
Habitat Requirements for Coastal Coho Salmon Populations
... Columbia, the group of stocks designated as northern chum, spawn in coastal systems ranging from the Nass River in the north to the mainland streams opposite the northern end of Vancouver Island in the south. Chum salmon spawn in more than 600 streams and rivers in this area. While there are a few l ...
... Columbia, the group of stocks designated as northern chum, spawn in coastal systems ranging from the Nass River in the north to the mainland streams opposite the northern end of Vancouver Island in the south. Chum salmon spawn in more than 600 streams and rivers in this area. While there are a few l ...
Habitat Requirements for Coastal Coho Salmon Populations
... marine mammals and, since feeding has stopped in preparation for spawning, vital energy reserves are used up. As a result, it is important to critically assess any activities that impact river flows or water temperatures when chinook salmon are returning to spawn and to ensure that fish have unimped ...
... marine mammals and, since feeding has stopped in preparation for spawning, vital energy reserves are used up. As a result, it is important to critically assess any activities that impact river flows or water temperatures when chinook salmon are returning to spawn and to ensure that fish have unimped ...
Ruffe Diet and Diel Movements
... individual of that taxon, ruffe size-class, and col- factors was used to identify possible differences lection week. Calculation of total weight of stom- in the total number and weight of prey organisms ach contents in this manner corrects for different (i.e., denominators). When month was significa ...
... individual of that taxon, ruffe size-class, and col- factors was used to identify possible differences lection week. Calculation of total weight of stom- in the total number and weight of prey organisms ach contents in this manner corrects for different (i.e., denominators). When month was significa ...
Litchman CV - Litchman-Klausmeier Lab
... of Marine Phytoplankton to Rising Temperatures ($102,468), lead PI, with C. Klausmeier and E.V. Armbrust (U Washington) Biogeochemistry Environmental Research Initiative (BERI), MSU grant Development of an autonomous robotic fish-based sensor to detect Harmful Algal Blooms (HABs) ($10,000 direct cos ...
... of Marine Phytoplankton to Rising Temperatures ($102,468), lead PI, with C. Klausmeier and E.V. Armbrust (U Washington) Biogeochemistry Environmental Research Initiative (BERI), MSU grant Development of an autonomous robotic fish-based sensor to detect Harmful Algal Blooms (HABs) ($10,000 direct cos ...
Applications, Considerations, and Sources of Uncertainty When
... FIGURE 1. Theoretical biomagnification of contaminants in contrasting food webs with similar baselines and different slopes (A), and similar slopes and different baselines (B). Animals deriving greater than 70% of their biomass from carbon source 1 or carbon source 2 were separated using δ13C. Anima ...
... FIGURE 1. Theoretical biomagnification of contaminants in contrasting food webs with similar baselines and different slopes (A), and similar slopes and different baselines (B). Animals deriving greater than 70% of their biomass from carbon source 1 or carbon source 2 were separated using δ13C. Anima ...
Document
... latter are not resource-limited (bottom-up) and hence must be controlled by mortality factors (top-down) which are largely attributed to selective predation by metazooplankton (Irigoien et al., 2005; Sherr and Sherr, 2009), in particular copepods (Calbet and Saiz, 2005; Sherr and Sherr, 2007). An al ...
... latter are not resource-limited (bottom-up) and hence must be controlled by mortality factors (top-down) which are largely attributed to selective predation by metazooplankton (Irigoien et al., 2005; Sherr and Sherr, 2009), in particular copepods (Calbet and Saiz, 2005; Sherr and Sherr, 2007). An al ...
Trophic roles of heterotrophic nanoflagellates and ciliates among
... Carrick et al. 1991, Sanders et al. 1994) are also considered to be important links in the transfer of bacterial biomass to metazoan zooplankton. Since HNF (Nakano 1994) and ciliates (Stoecker & Capuzzo 1990) are rich in nitrogen and phosphorus, as are bacteria (Nagata 1986, Vadstein et al. 1988),th ...
... Carrick et al. 1991, Sanders et al. 1994) are also considered to be important links in the transfer of bacterial biomass to metazoan zooplankton. Since HNF (Nakano 1994) and ciliates (Stoecker & Capuzzo 1990) are rich in nitrogen and phosphorus, as are bacteria (Nagata 1986, Vadstein et al. 1988),th ...
Ecological gradients and relative abundance of native (Mytilus
... Based on their diverse evolutionary histories with respect to environmental temperatures and salinities, several authors have suggested that these two environmental variables may play a key role in determining blue mussel distribution patterns in hybrid zones, including those in the Canadian Maritim ...
... Based on their diverse evolutionary histories with respect to environmental temperatures and salinities, several authors have suggested that these two environmental variables may play a key role in determining blue mussel distribution patterns in hybrid zones, including those in the Canadian Maritim ...
Food Web Theory and Ecological Restoration
... (Dobson et al. 2009; Hobbs et al. 2011). Ecological restoration is undertaken to hasten the recovery of damaged ecosystems, restore ecosystem function, and slow the declines of biodiversity. Ecological restoration in North America is historically rooted in plant community ecology: a perusal of the l ...
... (Dobson et al. 2009; Hobbs et al. 2011). Ecological restoration is undertaken to hasten the recovery of damaged ecosystems, restore ecosystem function, and slow the declines of biodiversity. Ecological restoration in North America is historically rooted in plant community ecology: a perusal of the l ...
Invasion of a stream food web by a new top predator
... 2. The pre-invasion web was species-poor but complex, with prevalent intraguild predation, cannibalism and omnivory. Such characteristics differ from expectations based upon the early food web literature, but are consistent with more recent empirical webs and theoretical developments. 3. Exhaustive ...
... 2. The pre-invasion web was species-poor but complex, with prevalent intraguild predation, cannibalism and omnivory. Such characteristics differ from expectations based upon the early food web literature, but are consistent with more recent empirical webs and theoretical developments. 3. Exhaustive ...
The influence of midwater hypoxia on nekton vertical migration
... 11.3 mg l21), and lowest salinity (24.6–28.6 psu) values (Figure 3a–c). In June and August, the lowest DO (,2.2 mg l21) was near the bottom (.115 m, Figure 3a and b). In September, an OML had developed and the lowest DO level (1.7 mg l21) was at 22 m (Figure 3c). A small zone of low DO water (3.7 mg ...
... 11.3 mg l21), and lowest salinity (24.6–28.6 psu) values (Figure 3a–c). In June and August, the lowest DO (,2.2 mg l21) was near the bottom (.115 m, Figure 3a and b). In September, an OML had developed and the lowest DO level (1.7 mg l21) was at 22 m (Figure 3c). A small zone of low DO water (3.7 mg ...
Chapter 4. What We Know About Large Trees in Estuaries, in the
... higher vegetated areas. Currently, the greatest concentration of woody debris is found along the shoreline of an estuary out of reach of tidal water. The most stationary wood is in the marshes, or at least partly buried in the channel. Driftwood deposited in marshy areas between the main channel and ...
... higher vegetated areas. Currently, the greatest concentration of woody debris is found along the shoreline of an estuary out of reach of tidal water. The most stationary wood is in the marshes, or at least partly buried in the channel. Driftwood deposited in marshy areas between the main channel and ...
Lesson Overview
... Warmer water also enables zooplankton to graze heavily on marine algae. This eliminates the late-winter algal bloom whose primary production used to provide organic carbon to the entire food web. ...
... Warmer water also enables zooplankton to graze heavily on marine algae. This eliminates the late-winter algal bloom whose primary production used to provide organic carbon to the entire food web. ...
The consequences of scale: assessing the distribution of benthic
... 1988). The research effort described here focuses on one sediment type and uses a sampling design tailored to avoid these artifacts as fully as possible. Attempts to separate the effects of salinity from those of other estuarine forcing functions such as sediment type or wave action have usually invol ...
... 1988). The research effort described here focuses on one sediment type and uses a sampling design tailored to avoid these artifacts as fully as possible. Attempts to separate the effects of salinity from those of other estuarine forcing functions such as sediment type or wave action have usually invol ...
Linking nutrient loading, local abiotic variables, richness and
... that increasing availability of inorganic nutrients stimulates the abundance of ephemeral macroalgae and causes the dominance shift from perennial to annual macroalgae in shallow coastal waters (Sand-Jensen and Borum, 1991; Duarte, 1995; Valiela et al., 1997). It is therefore expected that ephemeral ...
... that increasing availability of inorganic nutrients stimulates the abundance of ephemeral macroalgae and causes the dominance shift from perennial to annual macroalgae in shallow coastal waters (Sand-Jensen and Borum, 1991; Duarte, 1995; Valiela et al., 1997). It is therefore expected that ephemeral ...
Effects of Enrichment on Simple Aquatic Food Webs.
... Submitted March 24, 2000; Accepted January 19, 2001 ...
... Submitted March 24, 2000; Accepted January 19, 2001 ...
`wasp-waist` food webs
... Top-down, bottom-up, and wasp-waist controls on the food web The relative importance of predation from upper trophic levels (‘top-down control’) and resource availability at the food web base (‘bottom-up control’) in structuring ecosystems is a topic of lively debate [1]. Many ecologists suggest tha ...
... Top-down, bottom-up, and wasp-waist controls on the food web The relative importance of predation from upper trophic levels (‘top-down control’) and resource availability at the food web base (‘bottom-up control’) in structuring ecosystems is a topic of lively debate [1]. Many ecologists suggest tha ...
Salmonid and Green Sturgeon Supporting Information for Endangered Species Act... Temporary Urgency Change Petition Regarding Delta Water Quality January 27,...
... Winter-run Chinook salmon A small number of winter-run Chinook salmon (Oncorhynchus tshawytscha) (n=3,015; 90% CI= 2,741-3,290) returned to spawn in the upper Sacramento River in 2014. Of these 3,105 winterrun Chinook, 388 were collected for broodstock at the Keswick trap. Assuming that 3-year old f ...
... Winter-run Chinook salmon A small number of winter-run Chinook salmon (Oncorhynchus tshawytscha) (n=3,015; 90% CI= 2,741-3,290) returned to spawn in the upper Sacramento River in 2014. Of these 3,105 winterrun Chinook, 388 were collected for broodstock at the Keswick trap. Assuming that 3-year old f ...
What is hidden behind the concept of ecosystem efficiency in energy
... and the effective connectance, m, with regard to a sample of 113 community webs reported in Briand and Cohen (1987). (ii) The above correlation is strengthened for a sub-sample of 36 aquatic community webs while, on the other hand, it is almost vanishing for a sub-sample of 21 terrestrial community ...
... and the effective connectance, m, with regard to a sample of 113 community webs reported in Briand and Cohen (1987). (ii) The above correlation is strengthened for a sub-sample of 36 aquatic community webs while, on the other hand, it is almost vanishing for a sub-sample of 21 terrestrial community ...
BULLARD, STEPHAN G., AND MARK E. HAY Palatability of marine
... provided juvenile stages of benthic organisms with an escape from high nearshore predation. In contrast, investigators studying holoplankton have suggested that offshore predation pressure might be intense. Hamner (1996) and McClintock et al. (1996) argued that spatial refuges in the open ocean are ...
... provided juvenile stages of benthic organisms with an escape from high nearshore predation. In contrast, investigators studying holoplankton have suggested that offshore predation pressure might be intense. Hamner (1996) and McClintock et al. (1996) argued that spatial refuges in the open ocean are ...
an evaluation of intertidal feeding habitats from a shorebird
... is a function of the harvestable biomass (top graph). The lat- these papers had sufficient detail and gave biomass ter consists of the prey with the appropriate size and within data in proper currencies and taxonomic groupings to reach of the bill, the harvestable fraction (bottom graph). appear in ...
... is a function of the harvestable biomass (top graph). The lat- these papers had sufficient detail and gave biomass ter consists of the prey with the appropriate size and within data in proper currencies and taxonomic groupings to reach of the bill, the harvestable fraction (bottom graph). appear in ...
Ecology of the San Francisco Estuary
The San Francisco Estuary together with the Sacramento-San Joaquin River Delta represents a highly altered ecosystem. The region has been heavily re-engineered to accommodate the needs of water delivery, shipping, agriculture, and most recently, suburban development. These needs have wrought direct changes in the movement of water and the nature of the landscape, and indirect changes from the introduction of non-native species. New species have altered the architecture of the food web as surely as levees have altered the landscape of islands and channels that form the complex system known as the Delta.This article deals particularly with the ecology of the low salinity zone (LSZ) of the estuary. Reconstructing a historic food web for the LSZ is difficult for a number of reasons. First, there is no clear record of the species that historically have occupied the estuary. Second, the San Francisco Estuary and Delta have been in geologic and hydrologic transition for most of their 10,000 year history, and so describing the ""natural"" condition of the estuary is much like ""hitting a moving target"". Climate change, hydrologic engineering, shifting water needs, and newly introduced species will continue to alter the food web configuration of the estuary. This model provides a snapshot of the current state, with notes about recent changes or species introductions that have altered the configuration of the food web. Understanding the dynamics of the current food web may prove useful for restoration efforts to improve the functioning and species diversity of the estuary.