BIO 1150 1st Edition Lecture 29Topic Discussed: Aquatic BiomesAquatic biomes -diverse and dynamic systems that cover most of Earth- Marine biomes have salt concentrations of about 3%- Oceans cover about 75% of Earth’s surface and have an enormous impact on the biosphere- Freshwater biomes have salt concentrations of less than 0.1%- Freshwater biomes are closely linked to soils and the biotic components of the surrounding terrestrial biomeZonation in Aquatic Biomes- Aquatic biomes are stratified into zones:- upper photic zone- sufficient light for photosynthesis- lower aphotic zone receives little light- The abyssal zone is at a depth of 2,000 to 6,000 m- The benthic zone - ocean or lake bottom, and the sediments and organisms it representsThermocline- In oceans and most lakes, a temperature boundary that separates the warm upper layer from the cold deeper waterLakes- Temperate lakes may have a seasonal thermocline; tropical lowland lakes have a year-round thermocline- Oligotrophic lakes - nutrient-poor and generally oxygen-rich; often deep- Eutrophic lakes - nutrient-rich and often depleted of oxygen; often shallowThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.- Zooplankton are drifting heterotrophs that graze on the phytoplankton- Invertebrates live in the benthic zone; fishes live in all zones with sufficient oxygenWetlands- a habitat that is inundated by water at least some of the time and that supports plants adapted to water-saturated soil- have high organic production and decomposition and have low dissolved oxygen- Plants include: lilies, cattails, sedges, tamarack, and black spruce; diverse invertebrates and birds, as well as otters, frogs, and alligatorsStreams and Rivers- Headwaters -generally cold, clear, turbulent, swift, and oxygen-rich; they are often narrow and rocky- Downstream waters form rivers and are generally warmer, more turbid, and less oxygenated; they are often wide and meandering and have silty bottoms- Brown trout tolerate warmer, less oxygenated waters- Brook trout require cooler, highly oxygenated water- They may contain phytoplankton or rooted aquatic plantsEstuaries- transition area between river and sea - nutrient-rich and highly productive- Salinity varies with the rise and fall of the tidesIntertidal Zones- A periodically submerged, exposed by the tides- Intertidal organisms are challenged by variations in temperature and salinity and by the mechanical forces of wave action- Oxygen and nutrient levels are high- Substrate varies from rocky to sandy- Sites of some classic studies of species competition and ecological successionOceanic Pelagic Zone- The oceanic pelagic zone is constantly mixed by wind-driven oceanic currents- Oxygen levels are high- Turnover in temperate oceans renews nutrients in the photic zones; year-round stratification in tropical oceans leads to lower nutrient concentrations- This biome covers approximately 70% of Earth’s surfaceCoral Reefs- formed from the calcium carbonate skeletons of corals (cnidarians)- Shallow reef-building corals live in the photic zone in warm (about 20–30C), clear water; deepsea corals live at depths of 200–1,500 m- require high oxygen concentrations and a solid substrate for attachment- progresses from a fringing reef to a barrier reef to a coral atollMarine Benthic Zone- consists of the seafloor below the surface waters of the coastal, or neritic, zone and the offshore pelagic zone- Organisms in the very deep benthic (abyssal) zone are adapted to continuous cold and extremely high water pressure- Substrate is mainly soft sediments; some areas are rockyHydrothermal vent- volcanic gases released in ocean, a black cloud- Bacteria eats the hydrogen sulfide released by vent for energy- There is a whole community around the ventIn the community, are worms that are symbiotic with the
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