2011 Pearson Education, Inc. AP Environmental Science Mr. Grant Lesson 77 Marine and Coastal Ecosystems 2014 Pearson Education, Inc. Mastery Check Where in the oceans are productive areas of biological activity likely to be found? Biologically productive areas are concentrated in areas of upwelling, in the shallower waters along continental margins, and at hydrothermal vents of the deep mid-ocean ridges. 2011 Pearson Education, Inc. Objectives: Define the term by-catch. Describe major types of marine ecosystems. 2011 Pearson Education, Inc. By-Catch: Unwanted marine creatures that are caught in the nets while fishing for another species; "thousands of dolphins and porpoises and whales are killed as part of the by-catch each year" Define the term by-catch. 2011 Pearson Education, Inc. Describe major types of marine ecosystems. Major types of marine and coastal ecosystems include intertidal zones, salt marshes, mangrove forests, estuaries, kelp forests, coral reefs, pelagic and deep- water open ocean systems. Many of these systems are highly productive and rich in biodiversity. Many also suffer heavy impacts from human influence. 2014 Pearson Education, Inc. Marine and Coastal Ecosystems Regions of ocean water differ greatly Some zones support more life than others Photic zone well-lighted top layer Absorbs 80% of solar energy Supports high primary productivity 2014 Pearson Education, Inc. Marine and Coastal Ecosystems Pelagic habitats and ecosystems between the oceans surface and floor Benthic habitats and ecosystems on the ocean floor Most ecosystems are powered by solar energy But even the darkest depths host life Marine systems are interconnected with freshwater ones 2011 Pearson Education, Inc. Marine and coastal ecosystems 2014 Pearson Education, Inc. Intertidal zones undergo constant change Intertidal (littoral) ecosystems ecosystems where the ocean meets the land Between the uppermost reach of the high tide and the lowest limit of the low tide Tides periodic rising and falling of the oceans height due to the gravitational pull of the sun and moon High and low tides occur roughly 6 hours apart Intertidal organisms spend part of their time submerged in water and part of their time exposed to sun and wind 2014 Pearson Education, Inc. Intertidal zones undergo constant change Intertidal zones are a tough place to live, but they have amazing diversity Rocky shorelines, crevices, pools of water (tide pools) Anemones, mussels, barnacles, urchins, sea slugs, starfish, and crabs Temperature, salinity, and moisture change dramatically from high to low tide Environmental variation creates horizontal bands of habitat Sandy intertidal zones have slightly less biodiversity 2011 Pearson Education, Inc. Intertidal zones undergo constant change 2011 Pearson Education, Inc. A typical intertidal zone 2011 Pearson Education, Inc. Intertidal zones are a tough place to live 2014 Pearson Education, Inc. Salt marshes line temperate shorelines Salt marshes occur along coasts at temperate latitudes Tides wash over gently sloping sandy, silty substrates Rising and falling tides flow into and out of channels called tidal creeks and overflow onto marsh flats Salt marshes have very high primary productivity Thick with salt-tolerant grasses, sedges, shrubs Critical habitat for birds, commercial fish, and shellfish They filter pollution They stabilize shorelines against storm surges Many have been lost because people want to live or do business along coasts 2011 Pearson Education, Inc. Salt marshes line temperate shorelines 2011 Pearson Education, Inc. People change and destroy salt marshes 2014 Pearson Education, Inc. Mangrove forests line coasts in the tropics and subtropics In tropical and subtropical latitudes mangrove forests replace salt marshes along sandy coasts Mangroves salt-tolerant trees that can live in changing water levels Their unique roots curve up for oxygen and down for support Provide nesting areas for birds, nurseries for fish and shellfish, food, medicine, tools, and construction materials 2011 Pearson Education, Inc. Mangrove forests line coasts Mangroves provide food, medicine, tools, and construction materials 2014 Pearson Education, Inc. Mangrove forests line coasts in the tropics and subtropics Half the worlds mangrove forests are gone Developed for residential, commercial, and recreational uses Removed for shrimp farming Once destroyed, coastal areas no longer: Slow runoff Filter pollutants Retain soil Protect communities against storm surges 2011 Pearson Education, Inc. Mangrove forests have been destroyed 2014 Pearson Education, Inc. Fresh meets salt water in estuaries Estuaries water bodies where rivers flow into the ocean, mixing fresh and salt water They are biologically productive Have fluctuations in salinity Critical habitat for shorebirds and shellfish Transitional zone for fish that spawn in streams and mature in salt water They have been affected by development, pollution, habitat alteration, and overfishing 2011 Pearson Education, Inc. Fresh and salt water meet in estuaries 2014 Pearson Education, Inc. Kelp forests harbor many organisms Kelp large, dense, brown algae growing from the floor of continental shelves Can reach 60 m (200 ft) long and grow 45 cm (18 in) per day Dense strands form kelp forests along temperate coasts They provide shelter and food for organisms They absorb wave energy and protect shorelines from erosion People use kelp in food, cosmetics, paints, paper, soap, etc. 2011 Pearson Education, Inc. Kelp forests harbor many organisms 2014 Pearson Education, Inc. Coral reefs are treasure troves of biodiversity Coral reef a mass of calcium carbonate composed of the skeletons of tiny marine animals (corals) May be an extension of a shoreline Or exist along a barrier island, parallel to the shore Or as an atoll (a ring around a submerged island) Corals are tiny colonial invertebrate animals related to sea anemones and jellyfish Attach to a rock or reef and capture passing food with stinging tentacles Get nourishment from symbiotic algae (zooxanthallae) 2011 Pearson Education, Inc. Coral reefs are treasure troves of biodiversity 2014 Pearson Education, Inc. Coral reefs are treasure troves of biodiversity Reefs consist of millions of densely packed animals Colors come from zooxanthellae Reefs are located in shallow subtropical and tropical waters Protect shorelines by absorbing waves Reefs provide complex physical structure High primary productivity Innumerable invertebrates and fish species find food and shelter in reef nooks and crannies 2011 Pearson Education, Inc. Most corals are colonial 2014 Pearson Education, Inc. Coral reefs are treasure troves of biodiversity Coral bleaching occurs when zooxanthellae leave the coral or die Corals lose their color and die, leaving white patches Results from climate change, pollution, or unknown natural causes Nutrient pollution causes algal growth, which smothers coral Divers damage reefs by using cyanide to capture fish Acidification of oceans deprives corals of carbonate ions for their structural parts 2011 Pearson Education, Inc. Coral reefs are in worldwide decline 2014 Pearson Education, Inc. Coral reefs are treasure troves of biodiversity A few coral species thrive in waters outside the tropics On the ocean floor at depths of 200500 meters (6501650 ft) Occur in cold-water areas off the coasts of Spain, the British Isles, and elsewhere Little is known about these reefs Already, many have been badly damaged by trawling Some reefs are now being protected 2011 Pearson Education, Inc. Deepwater coral reefs exist Squat lobsters on a cold-water coral reef off the coast of Ireland 2014 Pearson Education, Inc. Open-ocean ecosystems vary in their biodiversity Microscopic phytoplankton are the base of the marine food chain Productivity is concentrated in areas of nutrient-rich upwelling Algae, protists, cyanobacteria feed zooplankton, which then feed fish, jellyfish, whales, etc. Predators at higher trophic levels Larger fish, sea turtles, sharks, and fish-eating birds 2011 Pearson Education, Inc. Open ocean systems vary in biodiversity 2014 Pearson Education, Inc. Open-ocean ecosystems vary in their biodiversity Animals of the deep ocean have adapted to extreme water pressure and the dark Some scavenge carcasses or organic detritus Others are predators Others have mutualistic relationships with bacteria Hydrothermal vents support tubeworms, shrimp, and chemosynthetic bacterial species Derive energy from chemicals in the heated water rather than photosynthesis 2011 Pearson Education, Inc. Animals of the deep ocean