BIO SCI 94 Lecture Notes - Lecture 25: Thermocline, Upwelling, Turbidity
5 Mar 2019
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Document Summary
Freshwater/saltwater, three key factors- affect distribution/abundance of organisms. Salinity- proportion of solutes dissolved in water. Solutes have positive charge(sodium,potassium), combines with negative charge(chlorine, bromine) salt. Salinity- dramatic effect of osmosis, water balance in organism. Water depth- determine amount of light reaches organism in area. Water absorbs/scatters light; amount/type of wavelength available change as water water depth/light intensity increases. Turbidity- cloudiness of water- important in light penetration. Light important to productivity- total amount of of carbon fixed by photosynthesis per unit area per year. Rate of water movement/water depth- important factors shaping environment in aquatic ecosystem. Water movement critical- presents physical challenge, sweeps organisms off feet. Nutrients washed away in moving water fall to bottom of still water short supply in aquatic ecosystem. Nutrient level important- limit growth rates in photosynthetic organisms which provide food for other species. Ocean upwelling/lake turnover bring nutrients from bottom to water surface affect nutrient availability.
