Chapter 12 OCE All marine algae must live near the surface because they need the sunlight most marine animals live near the surface because this is where food can be obtained Living things are classified based on their physical characteristics Defining Life Atoms basic building blocks move continuously in and out of living and nonliving things Simple definition of life Consumes energy from its environment Capture store transmit energy Contain highly organized matter Low enthropy Reproduce nearly identical forms 3 domains of life Bacteria Archaea Eukarya Bacteria includes simple life forms with cells that usually lack a nucleus Archaea group of simple microscopic bacteria like creatures many of which prefer environments with extreme temperatures or pressures Eukarya complex organisms multicellular plants multicellular animals fungi protocists Microscopic organisms that don t fit into any other groups Universal common ancestry all organisms on Earth share a common genetic heritage Symbiosis groups of organisms helping each other out for mutual benefit Monera some of the simplest organisms single celled but lack discrete nuclei found in the depth of the oceans Plantae multicelled plants all which photosynthesize Animalia multicelled animals includes simple sponges complex vertebrates to humans Fungi includes 100 000 species of mold and lichen less than one half of 1 are sea dwellers Protoctista diverse collection of single celled and multicelled organisms that 5 Kingdoms of organisms have a nucleus o Protozoa single celled organisms Linnaeus and Taxonomic Classification Carolus Linnaeus created a system that is the basis of the modern scientific system of classification called taxonomic hierarchy All life forms are described at some level or another increasing detail greater discrimination Scientific description highly formal must reproducibly distinguish the form while identifying traits that make it part of an interrelated group Kingdom Phylum Class Order Family Genus Species Species The fundamental unit of taxonomic classification consist of populations of genetically similar interbreeding individuals that share a collection of inherited characteristics whose combination is unique How are Marine Organisms Classified o All animals capable of moving independently of the ocean currents by Pelagic free swimming Nekton fish whales turtles etc swimming or propulsion o When we go swimming we become nekton Neutson skimming the surface Plankton vertical motion not horizontal o Drifters move where the ocean takes them o Types Autotrophic photosynthesizes called phytoplankton Heterotrophic cannon produce its own food called zooplankton Virioplankton a virus limit other plankton through infection Demersal preferring the seafloor o Epifauna live on the surface of the sea floor attached to rocks or moving on the bottom o Infauna live buried in the sand shells or mud o Nektobenthos live on the bottom but have the ability to swim or crawl through the water Water s Viscosity Viscosity substance s internal resistance to flow The viscosity of ocean water increases as salinity increases and temperature decreases Water s Gravity and Buoyancy Osmosis Because of the density of water and the animal s density much of acceleration due to gravity is offset by buoyancy All organisms living in the ocean have to compensate for sea water density problems are different for animals living in upper water columns and those living on the bottom To combat buoyancy animals have gas bladders oil rich livers drift appendages spines some fish swim all the time while some are happy to sit on the bottom Swim Bladder many fish have this used to adjust their buoyancy thus allowing them to regulate their depth in the water column Animals living in a fluid media have to either maintain the same osmotic concentration as their surrounding or do work to keep in balance Osmosis water molecules always move from the less concentrated solution into the more concentrated solution Osmotic pressure the pressure that much be applied to the more concentrated solution to prevent water molecules from passing into it Osmosis allows water to move through an organism s skin and affects both marine and freshwater organisms Isotonic if the organism s body fluid equals that of the ocean no net transfer of water will occur Hypertonic the organisms is saltier than the surrounding seawater seawater will pass through the cell walls into the cells toward the more concentrated solution Hypotonic if the salinity within an organism s cells is less than that of the surrounding seawater Saltwater fish hypotonic saltwater fish drink ocean water and excrete the salts through special chloride releasing cells located in their gills help maintain their body water by discharging very small amount of very highly concentrated urine Freshwater fish hypertonic osmotic pressure is 20 to 30 times the water that surrounds them do not drink water and excrete large volumes of very dilute urine to reduce the amount of water in their cells Dissolved gases and temperature Amount of gases that dissolve in seawater increases as the temperature of seawater decreases Fish need dissolved oxygen they breathe through their gills Heat capacity of water is much higher than that of land land heats up by a greater amount and much more rapidly than the ocean Pelagic Environment into than 200 meters deep into 4 biozones Biozones the distinctive life zones the pelagic environment can be divided Neritic province extends from the shore seaward and includes all water less Oceanic province depth increases beyond 200 meters further subdivided o Epipelagic zone from the surface to a depth of 200 meters upper half is the only place in the ocean where there is sufficient light to support photosynthesis o Mesopelagic zone from 200 o 1000 meters o Bathypelagic 1000 to 4000 meters o Abyssopelagic includes all the deepest parts of the ocean below 4000 meters Ocean provinces based on availability of sunlight o Euphotic zone surface to a depth where enough light still exists to support photosynthesis o Disphotic zone small but measurable quantities of light o Aphotic no light iClicker questions and answers Of Earth s total number of species why are the fewest in the marine pelagic realm o Uniform conditions in the pelagic realm make fewer specialized environments for organism adaptation as different species Why do most fish and marine mammals have the same torpedo like streamlined shape the water o
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