Term
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Definition
| gradual changes in the biological community of a river as energy sources and physical conditions change from headwaters to lowlands. |
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Term
| How do large man channel reservoirs alter biophysical processes in freshwater running water habitats. (list 3 alterations) |
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Definition
1. Water levesl/breeding habitats
2. sediments/nutrients/turbidity
3. disrupts RCC |
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Term
| Describe how the variable effects of competition operate differentially in rhithronic and potamonic freshwater habitats to limit diversification of body form and limit resources partitioning among freshwater fish species. |
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Definition
| Competition varies with constraints of habitat size, habitat variety and hydraulic forces that limit diversification of body form and limit resource partitioning. |
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Term
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Definition
| MEI (total dissolved solids in mg/L divided by mean depth in meters) developed by Richard Ryder in the mid=1960's as an estimator of potential fish yield in lakes. Can be used to predict fish harvest and standing crop in the US reservoirs. |
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Term
| Why is morphoedaphic index relevant to the management of freshwater reservoir fisheries resources. |
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Definition
| Used to predict fish harvest and standing crop. Useful to reservoir managers who must make decisions based on minimal field data. |
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Term
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Definition
| limnological term associated with lakes that are nutrient poor and relatively unproductive |
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Term
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Definition
| limnological term associated with lakes that are nutrient rich and highly productive |
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Term
| Impoundment Basin Morphology - Oligotrophic Lake |
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Definition
deep, steep banked.
blue to green transparent water.
sediments low in organic matter.
low nutrients % Ca ++. |
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Term
| Impoundment Basin Morphology - Eutrophic Lakes |
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Definition
shallow, broad littoral.
green-yellow-brown, low transparency.
organic profundal sediments.
high nutrients and Ca++ |
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Term
| Littoral plant community - Oligotrophic Lakes |
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Definition
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Term
| Littoral plant community - Eutrophic Lakes |
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Definition
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Term
| Dissolved Oxygen concentrations - Oligotrophic Lakes |
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Definition
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Term
| Dissolved Oxygen concentrations - Eutrophic Lakes |
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Definition
| O2 depletion in hypolimnion. |
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Term
| Attributes of dominant fish community - Oligotrophic Lakes |
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Definition
| Deep water salmonid and coregonid fishes |
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Term
| Attributes of dominant fish community - Eutrophic Lakes |
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Definition
| No stenothermal fish in hypolimnion |
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Term
| Phytoplankton abundance - Oligotrophic Lakes |
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Definition
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Term
| Phytoplankton abundance - Eutrophic Lakes |
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Definition
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Term
| Blooms of blue-green algae - Oligotrophic Lakes |
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Definition
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Term
| Blooms of blue-green algae - Oligotrophic Lakes |
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Definition
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Term
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Definition
| deep zone of a body of water, such as an ocean or lake, located below the range of effective light penetration. This is typically below the thermocline, the vertical zone in the water through which temperature drops rapidly. |
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Term
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Definition
| net available storage of a body of water divided by mean annual flow. Ratios between .6 and 1.5 most conducive to fish production |
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Term
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Definition
| thin but distinct layer in a large body of flid in which temperature changes more rapidly with depth than it does in the layers above or below. |
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Term
| At what temperature is water most dense? |
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Definition
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Term
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Definition
| lakes that are nutrient poor and relatively unproductive. Insufficient organic matter is produced in the epilimnion to reduce hypolimnetic oxygen concentrations; thus, the hypolimnion remains relatively oxygenated throughout the year. |
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Term
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Definition
| lakes that have intermediate nutrient availability and biological productivity. |
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Term
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Definition
| lakes that are nutrient rich and highly productive. Decomposition of the abundant organic matter may often exhaust that dissolved oxygen in unlighted zones, leading to anoxia in the hypolimnion. |
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Term
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Definition
| lakes that are extremely productive and rich, often experience pea-soup conditions because high concentrations of algae and/or excessive densities of rooted aquatic plants |
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Term
| What would need to occur for a lake to cross the ecologic threshold from mesotrophic to eutrophic? |
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Definition
| Increased nutrients and productivity. |
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Term
| What is the Redfield ratio? |
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Definition
| ratio of nitrogen to phosphorous (N:P) Values of 16 have traditionally been regarded as the point of transition from N to P limitation in the sea |
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Term
| Major trophic levels of freshwater lakes |
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Definition
| Piscivores, planktivores, herbivores, herbivores, primary producers, bacteria/detritus/detritivores |
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Term
| What would an expected consequence of introducing a zooplanktivorous feeding fish species to an eutrophic lake. |
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Definition
| Zooplankton population declines, allowing their prey (algae) to increase without being limited by nutrients. This resulting algae bloom will lead to low O2 levels after they die off and are subjected to bacteria decomposition. |
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Term
| Three environmental determinants that limit membership of a species community |
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Definition
dispersal constraints
physiological constraints
biotic interaction constraints |
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Term
| Component of the trophic pyramid that is quantitatively the most important fuel for running water food webs. |
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Definition
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Term
| Describe two ways that extractive industries such as grazing of domestic livestock, logging, and irrigated agriculture can alter energy in puts and impact the biota of freshwaters. |
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Definition
1. Decrease course particulates matter
2. increase fine particulate matter (increase # of fish that can take advantage of carbon source) |
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Term
| Natural flow regime paradigm |
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Definition
| NFRP is fundamental to the biological study of running water ecosystems. It pertains to evolutionary linkages of the natural flow regime and species fitness to live in a given stream Adaptation is presumed to occur as a response to the intersection between aspects of the natural flow regime, specifically as regards the frequency, duration, magnitude, and predictability of mortality-causing events. |
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Term
| Give one example of water management policy with long term consequesnces of cross-generational equity |
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Definition
| altered flow regiem and depleted aquifers |
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Term
| Under what conditions is biological overfishing predicted |
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Definition
| unregulated (open access) fisheries whenever price/cost rations are sufficiently high |
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Term
| Under what conditions is biological overfishing predicted |
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Definition
| unregulated (open access) fisheries whenever price/cost rations are sufficiently high |
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Term
| What is the ecological basis of sustainable harvesting? |
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Definition
Compensatory change in survival rates and/or fecundity is the fundamental ecological basis of sustainable harvesting.
Sustainable yield theory is based on the assumption that populations are regulated by compensatory processes. According to the theory, as populations biomass declines, production per unit biomass increases in response to reduced intraspecific competition. |
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Term
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Definition
| based on the assumption that populations are regulated by compensatory processes. According to the theory, as population biomass declines, production per unit biomass increases in response to reduced intraspecific competition. |
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Term
| Describe how animal populations are regulated by compensatory density effects. |
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Definition
| birthrates are regulated by the size of a population |
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Term
| Why is the growth function of the classical Schaefer population model convex? |
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Definition
| The convex function carries the implication that per capita net growth rate is a decreasing function of population size. This phenomenon, often referred to as density "compensation," may be due to population crowding or depletion of food supply. |
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Term
| Name two basic tactical options for regulating levels of exploitation by commercial fisheries. |
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Definition
1. Taking surplus stock above a fixed base stock
2. Taking the same fixed population of the stock every year. |
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Term
| What is one unintentional consequence of captive breeding and release programs to stocks of Chinook salmon stock? |
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Definition
| Captive breeding and release programs, widely used to supplement populations of declining species, minimize juvenile mortality to achieve rapid population growth. However, raising animals in benign environments may promote traits that are adaptive in captivity but maladaptive in nature. In chinook salmon, hatchery rearing relaxes natural selection favoring large eggs, allowing fecundity selection to drive exceptionally rapid evolution of heavily supplimented by hatcheries, but not in minimally supplemented populations. Unintentional selection in captivity can lead to rapid changes in critical life-history traits that may reduce the success of supplementation or reintroduction programs. |
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Term
| What are the three models for simulating single species demographic processes for the management of commercial fishery. |
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Definition
| Spawner-recruit. Dynamic Pool. Production. |
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Term
| Spawner-recruit (S-R) model |
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Definition
| Deals only with the recruitment component and describes the relationship between generations. These models are based on compensatory mortality during the early life history stages. |
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Term
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Definition
| yield per recruit. describes changes in biomass following recruitment of a cohort. these models are based on age-specific growth and mortality rates and are used to examine the efforts of varying the fishing mortality rate or age at first capture |
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Term
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Definition
| describes the aggregate effects of recruitment, growth, and natural mortality in a single compensatory function such as the Shaefer logistic model. |
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Term
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Definition
| type of population simulation model that utilizes an age or stage-based record of survival and fecundity for predicting the future growth or decline of populations. |
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Term
| Assumptions of a geometric model of population growth. |
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Definition
1. population has no age structure
2. population has no sex structure
3. all individuals are reproductively active when the census is taken.
4. resources are virtually unlimited and that growth is unaffected by the size of the population |
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Term
| Name one factor that governs how the cumulative number of species sampled in a study area varies with sampling effort |
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Definition
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Term
| Name 2 ways in which sampling variation can be reduced |
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Definition
| increase sampling effort. split the population into a number of more homogeneous groups |
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Term
| What is the relationship between the reduction in the likely error range in a parameter estimator and sample size |
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Definition
| function of the square root of the sample size, thus to half the error range, the sampling effort has to be increased four-fold. |
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Term
| Name two conditions under which coastal communities make a positive contribution to the conservation of marine fisheries resources. |
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Definition
| 1. Communities have strong access rights to local marine resources. 2. Communities have strong rights to participate in management decisions. |
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Term
| What causes coral bleaching? |
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Definition
| Response to stress due to temperature, solar radiation, sedimentation, etc. Results from loss of symbiotic zooxantheallae. |
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Term
| Lower order rights (name specific right) |
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Definition
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Term
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Definition
| plan timing and location of fishery |
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Term
| broader rights affecting other actors and users of marine space |
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Definition
| rule making for fish habitat protection |
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Term
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Definition
| fishery policy developement |
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Term
| Explain why beneficial effects of simple reductions of mortality in MPAs may not work as well as hoped |
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Definition
1. Trophic cascade effects often result in higher foraging fish populations following prey species.
2. Initial success causes an increase in the fish dispersing out of it (attracting fisherpeople)
3. High mortality rates just outside the MPA suggests that there will be a dispersal imbalance with a net movement to less densly occupied areas. |
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Term
| 2 options for limiting nutrient loading in attempts to limit the effects of eutrophication in freshwater habitats |
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Definition
1. diversion/stream controls
2. improved wastewater treatment |
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Term
| 2 options for treating the symptoms of eutrophication in freshwater habitats? |
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Definition
1. harvesting macrophytes
2. biological manipulation |
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Term
| biotic/ecologic integrity |
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Definition
| organizing, self-correcting capability of the biota of an ecosystem that enables populations and communities of organisms to recover from disturbances and gain an end-state that is 'normal and good' |
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Term
| List three broad ecosystem stewardship strategies to achieve objectives of sustainability |
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Definition
| reduce vunerability, foster adaptive capacity and resiliance, and naviage transformations to avoid or allow escape from undesirable social-ecological states |
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Term
| Three problems of public opinion |
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Definition
1. Lack of competence
2. lack of resources
3. potential susceptibility to the tyranny of the majority |
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