2 Freshwater: flowing Freshwater = 3% of all surface water on earth Flowing systems includerivers, streams, creeksSupports a largevariety of fishes, reptilesand amphibians, as wellas their predators,such as otters, bears,eagles and raccoons.Water flow is too fastto support mostinvertebrate life.
3 Fresh water: standingLakes and ponds are the most common standing water ecosystemsWater circulates within as well as in and out of the system (little currents)This helps to distribute oxygen, nutrients and heat through the systemHabitat for “plankton,” or tiny, free-floating organisms“Phytoplankton” are single-celled algae“Zooplankton” are microscopic animals that feed mainly on the phytoplankton
4 Wetlands Water covers soil or is present at least part of year Can be fresh water, saltyor “brackish,” which is amixture of fresh and saltwater (Shollenberger)Very productiveecosystems, many plantand animal speciessupported (over 170 sppof birds alone atShollenberger Park)Over 90% of SF Baywetlands gone due todevelopment and agriculture165 acres of tidal wetlands, brackish water from Petaluma river, but also fresh water channels– different communities of plants and animals. Over 160 species of birds have been identified here.Shollenberger Park, Petaluma
5 SF Bay wetlands 150 years ago and today Bay Institute
6 Estuaries Wetlands formed where rivers meet the sea. Mixture of fresh and saltwater, affected by rise and fall ofocean tidesMany shallow, enoughlight for photosynthesis, so lotsof plant life in estuariesMost plant material is not consumedby zooplankton, but forms“detritus,” tiny particles thatprovide food for bottom of thefood web such as clams, sponges,and worms.Breeding grounds for many fishAnd shellfish that we eat
7 Continental slope and continental rise Marine EcosystemsPhotic zoneLand200 m1,000 mIntertidal zoneCoastaloceanOpenocean4,000 mAphotic zoneBenthic zone6,000 mThe ocean can be divided into zones based on light penetration and into zones based on depth and the distance from shore. Each zone contains a characteristic assemblage of organisms.OceantrenchContinental slope and continental rise10,000 mContinentalshelfAbyssalplain
8 Oceans can be divided into zones based on amount of light, depthand distance from shore.Photosynthesis is limited to“Photic” zone (200 meters deep)“Aphotic” zone below ispermanently dark and cold.Chemosynthetic organisms areThe only producers that can livein aphotic zone.They get their energy fromchemicals leaked from deepsea vents in the ocean floor.However, many differentconsumers, such asoctopuses and giant squid canlive in the deep ocean.
9 Rocky IntertidalIntertidal organisms are exposed to regular and extreme changes in their environmentOnce or twice a day, submerged in water at high tideAt low tides, exposed to sunlight, air andtemperature changes, wave shockCompetition leads to “zones” of differentorganisms living in particular habitats
10 Coastal ocean Extends from low tide mark to outer edge of continental shelfShallow enough forphotosynthesisRich in plankton and many otherorganismsKelp = giant brown algaethat can grow 50 cm/day!Kelp forests provide habitatfor snails, sea urchins, seaotters, many fish species, seals,even whales.
12 Coral reefs Found in warm, shallow tropical coastal oceans Among the most diverse andproductive systems on earthNamed for tiny coral animalsthat have hard calciumcarbonate skeletons.Live together in vast numbers andfeed on plankton with tentaclesLive symbiotically with algae in theirtissues. Algae do photosynthesisand use coral waste as nutrients.Algae also provide corals with carboncompounds for growth.
13 Open ocean Largest marine zone, over 90% of the surface area of the world’s oceans.500 meters deep to11,000 meters in thedeepest ocean trenchDeep ocean creatures aresubjected to highpressure, frigidtemperatures andtotal darknessFishes of all typesdominate, but alsomany marine mammals,jellies, octopus, etc.