Zones are classified by depth and by how much light penetrates OCEAN ZONES Zones are classified by depth and by how much light penetrates

Objective: 8.E.1.2 Summarize evidence that Earth‘s oceans are a reservoir of nutrients, minerals, dissolved gases, and life forms: • Estuaries • Marine ecosystems • Upwelling • Behavior of gases in the marine environment • Deep ocean technology and understandings gained _______________________________________________ I can summarize the impact of upwelling and down welling on aquatic ecosystems I can explain the behavior and impact of dissolved gases in a marine environment. I can explain how advances in deep ocean exploration have increased our understanding of ocean environments.

Intertidal Zone: Think of some intertidal creatures: coquinas, mole crabs, barnacles on piers, seaweeds on rocky shores, etc.

Earth is typically divided into “-spheres”: hydrosphere refers to water, lithosphere to the landforms (“litho” means rock), biosphere to the living world (“bios” means living), and the atmosphere (“atmos” means air). Four zones of interest in the hydrosphere are intertidal, pelagic, abyssal, and benthic.

Intertidal: the area between high tide and low tide. Sometimes covered, sometimes exposed, a very tough habitat to live in. Subjected to drying and submersion, temperature extremes, the pull of the waves, and sea and land predators. Burrowing animals or animals with hard shells that can be sealed to prevent water loss live here. Plants that cling to hard bottoms are present. Think of some intertidal creatures: coquinas, mole crabs, barnacles on piers, seaweeds on rocky shores, etc.

Intertidal (continued): During the day, the sun relentlessly heats tide pools left behind when the water moves from high tide to low tide. Water evaporates leaving dissolved salts behind (increasing salinity levels). Warm water holds less dissolved gases (like oxygen) than cold water. A tide pool’s oxygen content can fall to almost nil. Think of some intertidal creatures: coquinas, mole crabs, barnacles on piers, seaweeds on rocky shores, etc.

Intertidal (continued): That means the intertidal zone water can have high salinity levels and low dissolved oxygen levels. Conditions in the intertidal zone include rough waves during high tide and the hot sun during low tide. No special equipment is needed to explore this zone. Think of some intertidal creatures: coquinas, mole crabs, barnacles on piers, seaweeds on rocky shores, etc.

Intertidal zone creatures High Tide Some organisms need a hard bottom to attach to. Our beaches are generally sandy, without hard substrate, but piers, docks, boat ramps, bulkheads, etc. do provide hard bottom. Many of these organisms are motile (can move around) rather than attached– crawlers, grazers, burrowers, swimmers. Low Tide

Do you recognize these organisms. The first two are sponges Do you recognize these organisms? The first two are sponges. The crab is a mangrove crab, related to our fiddler crabs with one big claw. Mangroves are intertidal, with a whole group of animals that inhabit the mud flats when the tide is out. We see a lot of hermit crabs on our shores– crabs that live in discarded gastropod shells. The orange disk on the gastropod is its “trap door”, which it pulls shut to keep from drying out during low tide. Gastropods are snails that secrete spiral shells. The plants that look like palm trees are seaweeds with holdfasts to cling to the rocks. The corner picture is anemones– where’s Nemo?

Neritic Zone:

Neritic Zone: This zone begins at the low tide mark and extends to the edge of the continental shelf. Sunlight can vary but is present throughout the zone. Lot’s of sunshine. The majority of sea life lives here - photosynthetic bacteria and algae & thousands of species of fish - Kelp Forest and Coral Reefs are found here. This zone has stable and abundant amounts of dissolved oxygen and salt.

Neritic Zone (continued): A large amount of nutrients are present here due to rivers and runoff and due to upwelling. The combination of all these factors along with lots of sunlight and lots of nutrients allow the majority of sea life to thrive here. Scuba diving, sonar, and small submarines are used to explore this zone.

Coral Reef Video

Pelagic Zone

Pelagic zone: Located in the open ocean. Usually sub-divided by depth or amount of sunlight.

Pelagic zone (continued): The upper pelagic receives sunlight, so there are many phytoplankton for photosynthesis. The lower reaches receive less or no sunlight, so there are no plants and animals are often bioluminescent (make their own light). Due to the vast differences between the levels of the Pelagic Zone, gases, salinity, organisms, and habitats differ greatly.

Pelagic zone (continued): To explore this zone, scientist use: Platform Vessels Submersibles/Submarines Satellites Sonar

Dolphins, school of fish, submersible, sea turtles, shark, sperm whale, shark, seahorse, giant squid, sea turtle, plankton, eye of giant squid. Sperm whales dive very deep to eat the giant squid.

BENTHIC PELAGIC The organisms in blue are pelagic; the organisms on the orange are all benthic. Pelagic– open water– swimming around. Benthic– in or on the bottom.

Benthic Zone Fish are generally small with huge mouths and small compact bodies.

Benthic Zone: This zone starts at the intertidal zone and goes all the way into deep ocean trenches. This zone is the ocean floor. The amount of sunlight varies and depends of depth. Many kinds of organisms live in the benthic zone– plants, anemones, sponges, fish, skates and rays, octopus, mollusks, crabs, sea stars, corals and worms. Most are scavengers that eat decomposing organic matter. Collectively these organisms are called “Benthos”. Life in the deepest parts of the ocean is fairly sparse except around hydrothermal vents, where it is quite concentrated.

Benthic Zone (continued): In the deep ocean, there are special benthic communities around hydrothermal vents whose energy comes from chemical reactions rather than from the sun. Chemosynthetic organisms are bacteria found around hydrothermal vents that produce energy by oxidizing (burning) chemicals that seep up from the Earth’s crust Life in the deepest parts of the ocean is fairly sparse except around hydrothermal vents, where it is quite concentrated.

Benthic Zone (continued): In the deep ocean, there are special benthic communities around hydrothermal vents whose energy comes from chemical reactions rather than from the sun. To explore this zone, scientist use: Scuba Platform Vessels Submersibles/Submarines Satellites Sonar Life in the deepest parts of the ocean is fairly sparse except around hydrothermal vents, where it is quite concentrated.

Ratfish and ray, octopus, anemone, sea star, sea urchin, group of shells and mole crab, crab, soft coral and flatworm (black with ruffly edges), group of shells and spider crab, spiny oyster.

Abyssal Zone

Abyssal Zone: This zone is located 2,000 to 6,000 meters (6,560 to 19,680 feet) below the surface of the ocean. It is known as the midnight zone of the ocean because no light penetrates. Animals are adapted to withstand the dark, the cold (near freezing), and the tremendous pressure. Most animals are dark or nearly transparent in color, and are bioluminescent. They don’t move much, and usually eat what falls from above. Fish are generally small with huge mouths and small compact bodies.

Abyssal Zone (continued): Most animals jaws are big to swallow large objects whole. This zone has high oxygen content and low nutrient levels. Unmanned submersibles, Satellites, and Sonar have been used to explore the Abyss. Only three humans have journeyed to the deepest part of the ocean. Fish are generally small with huge mouths and small compact bodies. March 26, 2012 Run to 16:13

Fantastic Denizens of the Deep Notice the large gaping mouths to take advantage of any food that falls from above. Most organisms are small and do not have muscular bodies– with the extreme cold, lack of food, and low oxygen, they don’t chase around preying on other organisms. The first two pictures on the bottom row are vampire squids. Denizens is just another word for inhabitants. Fantastic Denizens of the Deep

References: http://students.cis.uab.edu/archived/troberge/neritic.html http://www.sciencerush.net/files/MarineDownloads1st/Oceanography/Wksht-The_Neritic_Zone___Open_Ocean.pdf http://www.untamedscience.com/biology/biomes/ http://books.google.com/books?id=9fEKAAAAQBAJ&pg=PA434&lpg=PA434&dq=nutrients+in+the+neritic+zone&source=bl&ots=MamXgh9ucr&sig=-jthVS_Vxmd45BXtUPqRls0ZDIM&hl=en&sa=X&ei=CuL6UsSJD-br0gHlvYGADg&ved=0CEwQ6AEwBg#v=onepage&q=nutrients%20in%20the%20neritic%20zone&f=false http://www.brighthub.com/environment/science-environmental/articles/60014.aspx http://www.ucmp.berkeley.edu/exhibits/biomes/marine.php