Biology 473 (Limnology) Final Study Guide Complete Study Solutions Rated A+

Pelagic Habitat - CORRECT ANSWER-Open water habitat; studied most by limnologists Benthic habitat - CORRECT ANSWER-Habitat associated with the bottom substrate Littoral habitat - CORRECT ANSWER-Portion of the benthic habitat located above the compensation depth; Any habitat where rooted macrophytes grow Compensation depth - CORRECT ANSWER-Where there is enough light for net photosynthesis Heterophylly - CORRECT ANSWER-The variation among leaf morphology within one plant Periphyton - CORRECT ANSWER-Microscopic attached algae Summary of major macrophyte functions in aquatic ecosystems - CORRECT ANSWER-1. Major contributor to primary production/ 2. Provide habitat (structure) for aquatic organisms (esp fish and invertebrates) 3. Serve as pumps of nutrients from lake sediments to the water column, and of oxygen from the water column (or atmosphere) to the sediments 4. Provide substratum for the growth of other plants Marshes - CORRECT ANSWER-Dominated by emergent aquatic macrophytes and can have some floating or submergant macrophytes. No woody plants, lots of peat, external water supply. Peat - CORRECT ANSWER-Organic material/matter Seasonal wetlands - CORRECT ANSWER-Usually wet for a small portion of an annual cycle. Productivity can be very high but constrained to a fairly short period of time. Peak productivity usually occurs in late spring following inundation/flooding Permanent wetlands - CORRECT ANSWER-Consistently inundated and form an ecotone (transition zone) between aquatic and terrestrial systems. Much less productive than season wetlands Swamps - CORRECT ANSWER-Contain woody plants, macrophytes can grow in the open, does not accumulate a lot of peat; has an external water supply Bogs - CORRECT ANSWER-Accumulate peat and primary vegetation in acidophilic mosses and sedges; Trees and macrophytes are rare; no external water supply-- reliant on rain water; ombrotrophic Ombrotrophic - CORRECT ANSWER-Minerals enter through rainwater. Fens - CORRECT ANSWER-Share characteristics of bogs and marshes; distinguished by mineral-rich groundwater inputs that cause a higher pH than bogs; minerotrophic Minerotrophic - CORRECT ANSWER-Minerals are loaded via groundwater Lacunae system - CORRECT ANSWER-Allow some higher plants to invade areas with anoxic soils Paleolimnology - CORRECT ANSWER-The use of a stratifigraphic record in lake sediments to assess the historic conditions within a lake and in surrounding areas Acid rain - CORRECT ANSWER-The sum total of wet and dry atmospheric deposition that lead to excess loading of hydrogen ions within a geographic region. Deposited H+ ions usually associated with sulfur and nitrate ions which are produced from a variety of atmospheric reactions involving water, oxygen, light and two general classes of compounds referred to as Nox and SOx What controls whether a lake has been or will be acidified? - CORRECT ANSWER-1. Hydrogen ions loading within a region 2. Acid neutralizing capacity of the lakes 3. Extent of biological alkalinity generation Persistent toxic chemicals - CORRECT ANSWER-Substances having a bioconcentration factor greater than 100-250 and a half life greater than eight weeks Bioaccumulation - CORRECT ANSWER-Process by which organisms take up contaminants more rapidly than their bodies can eliminate them, thus the amount of contaminants in their body accumulate over time. Bioconcentration - CORRECT ANSWER-The accumulation of a chemical in tissues of an organism (such as fish) to levels that are greater than the level in the medium (such as water) in which the organism resides Biomagnification - CORRECT ANSWER-Incremental increase in concentration of a contaminant at each level of the food chain. The conversion of inorganic mercury to methylmercury is important for 2 reasons - CORRECT ANSWER-1. Methyl mercury is more toxic than inorganic mercury 2. Organisms require considerably longer to eliminate methyl mercury Octanol-water partition coefficient (Kow) - CORRECT ANSWER-This number reflects the relative degree of solubility of a contaminant in a standard organic solvent (octanol) vs. water. Most problematic solvents have a number between 10^5-10^7 Differences in the spawning behavior of fish can be due to - CORRECT ANSWER-1. Degree of parental care 2. Courtship behavior 3. Timing of spawning 4. Location of spawning Anadromous - CORRECT ANSWER-Spawns in freshwaters and spend most of their lives in the marine environment (e.g salmon) Catadromous - CORRECT ANSWER-Spawns in marine systems and spend most of their lives in freshwater habitats (e.g freshwater eel) What type of prey is a fish most likely to consume - CORRECT ANSWER-One that minimizes the cost/benefit ratio, or simply minimizes its overall costs. Gape-limited - CORRECT ANSWER-Fish that consume their prey whole can only swallow prey smaller than their mouth gape Planktivores - CORRECT ANSWER-Fish that prey mostly on plankton (especially zooplankton), Ex. smelt, juvenile sockeye salmon Piscivores - CORRECT ANSWER-Fish that prey mostly on other fish, Ex. largemouth bass, walleye, northern pike, lake trout, etc Benthivores - CORRECT ANSWER-Fish that feed mostly on benthic organisms, Ex. suckers, carp, etc Environmental Factors that Mediate the Ecology of Fish - CORRECT ANSWER-Temperature, oxygen concentration, pH, light regimes, habitat heterogeneity Multivoltine - CORRECT ANSWER-Produce several broods a year Parthenogenesis - CORRECT ANSWER-Cloning; asexual re