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Marine biodiversity

Marine biodiversity

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Marine biodiversity

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  1. Marine biodiversity Threats & Conservation

  2. What is biodiversity? • Variety of life • Species • Genes • Habitats

  3. Three domains of life • Bacteria • Archaea • Eukarya • All present in the ocean • Bacteria, archaea are poorly known—few thousand or tens of thousand of species known • 230,000 or so marine plants and animals

  4. Diversity in different ocean zones • Pelagic – open ocean, upper 200 meters • Very low biodiversity • Dominated by floating animals in 4 groups, mainly copepods. • Only some 2000 species • 1-2 mm long • May be largest biomass

  5. Ocean biodiversity • Benthic habitats much more diverse • Includes coral reefs • Remember: benthic means bottom, not necessarily deep

  6. Food Oxygen Drugs Carbon storage Weather moderation Coastal protection (mangroves) The goods and services to the left have monetary value What about: Beauty Stewardship of nonhuman life Other? Value of biodiversityGoods and servicesThis is an IMPORTANT general idea: what goods or services does nature (in this case, the marine environment) provide?

  7. Marine food webs • Primary producers • Bottom of food web • Photosynthesizers • In ocean: tiny cyanobacteria that are responsible for 2/3 of the production (of biomass) • More generally: PHYTOPLANKTON, which means ``floating plants’’

  8. Marine food webs • Phytoplankton • Limited by nutrient availability • Nutrients such as iron • Iron fertilization as a technique to slow global warming

  9. Marine food webs • Next level: ZOOPLANKTON • Floating animals • Grazers • Then, various levels of larger grazing animals, culminating in large predators • Tuna, sharks, groupers, cod, etc

  10. Threats • Fisheries • Target top predators • Compare to terrestrial food webs • Climate change • Increasing temperature of sea water • More carbon dioxideincreased acidity • CO2 + H2O  carbonic acid

  11. threats • Pollution • Most pollutants ultimately enter the oceans • Oil • Nutrients – carried by rivers to the sea • Atmospheric deposition – mercury

  12. Most oil in the sea is from land-based operations • Including dumping oil when changing motor oil

  13. Nutrients: dead zones

  14. Atmospheric deposition: mercury • Burning fossil fuels • Especially coal-burning power plants • Incinerating municipal wastes • Found in common household products, including fluorescent bulbs, thermometers, batteries

  15. Atmospheric deposition: mercury • Mercury enters marine and freshwater systems • Concentration grows up the food chain • BIOACCUMULATION