SFSU Geography 316-Fall 2006 Dr. Barbara A. Holzman. Photosynthesis. Darkness. Fig. 7.5, p. 156

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1 Aquatic Biomes Marine Biome oceans cover 70% of earth's surface Freshwater Biome lakes, ponds, rivers, streams cover only a small fraction Marine Communities Ocean: essentially continuous and fairly stable Most important features: *light and substrate ALSO: salinity, tides, pressure (Salinity :Oceans: 35 parts per thousand Freshwater: < 0.5 parts per thousand) Vertical Zonation based on light: Photic Zone (Euphotic zone): sunlight, penetration increases from coastal waters (~30 meters) b/c of organisms and suspended particles to open ocean (~100+ meters) ** Zone where photosynthesis occurs ** Vertical Zonation based on light: Aphotic Zone: below photic zone, organisms obtain energy by consuming organic material produced in the photic zone Ocean Zones High tide Low tide Coastal zone Estuarine Zone Continental shelf Continental Open Sea Sea level Euphotic Zone Bathyal Zone Slope Abyssal Zone Depth in Sun meters 0 Photic zone ,000 Photosynthesis Aphotic 1,500 zone 2,000 3,000 4,000 5,000 10,000 Darkness Classification based on bathymetry Intertidal (Littoral) Zone: where sea meets land, really an ecotone between land and ocean Neritic (Sublittoral) Zone: beyond intertidal zone, few meters to ~200m deep Bathyal Zone: edges of continental shelf Abyssal Zone: most of the ocean, deep waters ( m in depth) Fig. 7.5, p

2 Intertidal (Littoral) where sea meets land, really an ecotone between land and ocean. Intertidal: Littoral Zone Neritic (Sublittoral) Zone Neritic (Sublittoral) Zone : beyond intertidal zone, few meters to ~200m deep Neritic Zone beyond intertidal zone, few meters to ~200m deep Bathyal Zone: edges of continental shelf 2

3 Abyssal Zone: most of the ocean, deep waters ( m in depth) Organisms are also classified: Benthic or Pelagic (oceanic): Association with substrate or water column Benthic: hard substrates: kelp forests, coral reefs vs. soft muddy substrate: burrowing organisms beneath surface Pelagic (Oceanic): Zooplankton Plankton: microscopic organisms that float in water column simple plants: phytoplankton tiny animals: zooplankton Nekton: comprises the actively swimming animals, i.e. fish, whales, large invertebrates (higher trophic levels) Phytoplankton PLANKTON 3

4 Hogfish Cobia Pacific sailfish Yellow jack Moray Red snapper Batfish Striped drum Angelfish Orange roughy Chinook salmon Great barracuda Porcupine fish Devilfish Sockeye salmon Grouper Chilean sea bass Nekton Nekton or Plankton? Coral Reefs Gray reef shark Green sea turtle Sea nettle Producer to primary consumer Parrot fish Hard corals Symbiotic algae Fairy basslet Blue tangs Sergeant major Algae Brittle star Banded coral shrimp Phytoplankton Coney Primary to secondary consumer Secondary to higher-level consumer Sponges Zooplankton Black basslet Moray eel All consumer and producers to decomposers Bacteria Fig. 7.13, p. 163 Estuaries, salt marshes, swamps 4

5 Freshwater Biomes Sunlight Green frog Painted turtle Blue-winged teal Pond snail Muskrat Littoral zone Flowing water (Lotic) Diving beetle Limnetic zone Profundal zone Benthic zone Plankton Standing water (Lentic) Yellow perch Bloodworms Northern pike Lotic: Running water Rapids zone Pool zones Lentic: Littoral zone: shallow water where light penetrates to the bottom (vegetation) Lakes Types of Lakes: Eutrophic Eutrophic: lakes are shallow-highly productive b/c light penetrates almost to the bottom, good vertical circulation Oligotrophic: lakes usually so deep that little to no vertical circulation occurs, limited nutrients and limited sunlight restricts primary productivity Salt, sand, clay bottom Eutrophic Lake Much shore vegetation Limnetic zone High concentration of nutrition and plankton Dense fish population Sunlight Wide littoral zone Gently sloping shorelines 5

6 Types of Lakes: Oligotrophic Sunlight Little shore vegetation Low concentration of nutrition and plankton Narrow littoral zone Limnetic zone Profundal zone Sparce fish population Steeply sloping shorelines Lake Tahoe Sand, gravel, rock bottom Oligotrophic Lake Other aquatic communities Hypersaline lakes Caves Geysers/Hot springs Human Impacts Coral Reef Destruction Loss of Biodiversity Pollution Dumping 6

7 Competition? 7