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CHAPTER 13 Biological Productivity and Energy Transfer

CHAPTER 13 Biological Productivity and Energy Transfer. Fig. 13.5. Primary productivity. Rate at which energy is stored in organic matter Photosynthesis using solar radiation 99.9% of marine life relies directly or indirectly on photosynthesis for food

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CHAPTER 13 Biological Productivity and Energy Transfer

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  1. CHAPTER 13Biological Productivity and Energy Transfer Fig. 13.5

  2. Primary productivity • Rate at which energy is stored in organic matter • Photosynthesis using solar radiation • 99.9% of marine life relies directly or indirectly on photosynthesis for food • Chemosynthesis using chemical reactions • Happens in hydrothermal vents at bottom of ocean with no light

  3. Let’s talk about energy • Biological organisms need biochemical processes to happen in an orderly fashion in order to maintain life • Needs constant input of energy to maintain that order • Our cells need energy in form of ATP • ATP formed during cellular respiration • Need input of carbon (i.e. glucose) and oxygen for cellular respiration • That carbon source and oxygen comes from photosynthesis (primary productivity)

  4. Photosynthetic productivity • Chemical reaction that stores solar energy in organic molecules • Photosynthetic organisms fix carbon and energy from atmosphere • Also incorporate other elements and molecules necessary for life (nitrogen, phosphorus, etc) • What do we need these for? For making proteins, lipids, DNA, etc. • Use some of that for their own energy source for life • Rest moves it’s way up the food chain

  5. Measuring primary productivity • Capture plankton • Plankton nets • Ocean color • Chlorophyll colors seawater • SeaWiFs on satellite

  6. Factors affecting primary productivity • Nutrients • Nitrate, phosphorous, iron, silica • Most from river runoff • Productivity high along continental margins • Solar radiation • Uppermost surface seawater and shallow seafloor • Euphotic zone surface to about 100 m (330 ft)

  7. Upwelling and nutrient supply • Cooler, deeper seawater nutrient-rich • Areas of coastal upwelling sites of high productivity Fig. 13.6a http://cordellbank.noaa.gov/images/environment/upwelling_470.jpg

  8. Light transmission • Visible light of the electromagnetic spectrum • Blue wavelengths penetrate deepest • Longer wavelengths (red, orange) absorbed first

  9. http://lh4.ggpht.com/_lQw_uDjiHTw/R7AmR74EByI/AAAAAAAAL40/VKg0nZ_Ih6c/DSC_0009.JPGhttp://lh4.ggpht.com/_lQw_uDjiHTw/R7AmR74EByI/AAAAAAAAL40/VKg0nZ_Ih6c/DSC_0009.JPG Light transmission in ocean • Color of ocean ranges from deep blue to yellow-green • Factors • Water depth • Turbidity from runoff • Photosynthetic pigment (chlorophyll) • “dirty” water in coastal areas, lagoons, etc. are areas of high productivity, lots of plankton (preventing that “blue” color) http://upload.wikimedia.org/wikipedia/commons/a/a5/LightningVolt_Deep_Blue_Sea.jpg

  10. Types of photosynthetic marine organisms • Anthophyta • Seed-bearing plants, example is mangroves • Macroscopic (large) algae • Larger seaweeds, like kelp • Microscopic (small) algae • phytoplankton • Photosynthetic bacteria

  11. Anthophyta • Only in shallow coastal waters • Primarily seagrasses & Mangroves • Very few plant species can tolerate salt water http://celebrating200years.noaa.gov/events/sanctuaries/seagrass_meadow650.jpg

  12. http://oceanexplorer.noaa.gov/explorations/02sab/logs/aug09/media/lines_600.jpghttp://oceanexplorer.noaa.gov/explorations/02sab/logs/aug09/media/lines_600.jpg Macroscopic algae – “Seaweeds” • Brown algae Sargassum http://www.starfish.ch/photos/plants-Pflanzen/Sargassum.jpg

  13. Macroscopic algae – “Seaweeds” • Green algae Caulerpa brachypus, an invasive species in the Indian River Lagoon Codium http://www.sms.si.edu/IRLspec/images/cbrachypus2.jpg http://192.107.66.195/Buoy/System_Description_Codium_Fragile.jpg

  14. Macroscopic algae – “Seaweeds” • Red algae • Most abundant and most widespread of “seaweeds” • Varied colors http://www.agen.ufl.edu/~chyn/age2062/lect/lect_15/22_14B.GIF http://www.dnrec.state.de.us/MacroAlgae/information/Indentifying.shtml

  15. http://biologi.uio.no/akv/forskning/mbot/images Microscopic algae • Produce food for 99% of marine animals • Most planktonic • Golden algae • Diatoms(tests of silica) • Most abundant single-celled algae – 5600+ spp. • Silicate skeletons – pillbox or rod-shaped ooze • Some w/ sticky threads, spines  slows sinking www.bren.ucsb.edu/ facilities/MEIAF

  16. Microscopic algae • Coccolithophores(plates of ate) • Flagellated • calcium carbon plates  possibly sunshades • Coccolithid ooze  fossilized in white cliffs of Dover http://www.esa.int/images http://epod.usra.edu/archive/images/coccolith.jpg

  17. Microscopic algae • Dinoflagellates • Mostly autotrophic; some heterotrophic or both • Flagella in grooves for locomotion • Many bioluminescent • Often toxic • Red tides (algal blooms)  fish kills (increase nutrients, runoff) Karenia spp., the alga that causes red tide http://oceanworld.tamu.edu/students/fisheries/images/red_tide_bloom_1.jpg http://www.hku.hk/ecology/porcupine/por24gif/Karenia-digitata.jpg

  18. Manatees died in Brevard and Volusia counties in 2007, and on west coast, possibly due to red tide • concentrates on seagrass manatees eat • Breath in toxic fumes http://www.nepa.gov.jm/yourenv/biodiversity/Species/gifs/manatee.jpg

  19. http://www.odu.edu/sci/biology/pfiesteria Microscopic algae • Dinoflagellates • Pfiesteria in temperate coastal waters • Ciguatera (from) Gambierdiscustoxicus in tropical fishes • Paralytic, diarhetic, amnesic shellfish poisoning Pfiesteria Gambierdiscus Alexandrium – paralytic shellfish Alexandrium – paralytic shellfish http://www.hrw.com/science/si-science/ biology/plants/algae/ images/Gambitox.jpg http://www.slv2000.qc.ca/bibliotheque/lefleuve/vol11no5/images_f/alexandrium1.jpg

  20. Photosynthetic bacteria • Extremely small • May be responsible for half of total photosynthetic biomass in oceans Anabaena Gleocapsa http://www.micrographia.com/specbiol/bacteri/bacter/bact0200/anabae03.jpg http://silicasecchidisk.conncoll.edu/Pics/Other%20Algae/Blue_Green%20jpegs/Gloeocapsa_Key45.jpg

  21. Regional primary productivity • Varies from very low to very high depending on • Distribution of nutrients • Seasonal changes in solar radiation • About 90% of surface biomass decomposed in surface ocean • About 10% sinks to deeper ocean • Only 1% organic matter not decomposed in deep ocean  reaches bottom • Biological pump (CO2 and nutrients to sea floor sediments)

  22. Table 13.1 = 4785 Smaller than land but this is by meter2 (think about how large ocean is compared to land) = 6450

  23. Temperate ocean productivity • Seasonal variation with temperature/light/nutrients • Winter: • High winter winds  mixing of sediments/plankton • Low light & few phytoplankton  nutrients increase • Spring: • Phytoplankton blooms with more light, nutrients • Bloom continues until… • Nutrients run out • Herbivores eat enough phytoplankton • Summer: often low production due to lack of nutrients • Fall: Often second bloom, as winds bring up nutrients

  24. Polar ocean productivity • Winter darkness • Summer sunlight (sometimes 24 hours/day) • Phytoplankton (diatoms) bloom • Zooplankton (mainly small crustaceans) productivity follows • HIGH PRODUCTIVITY!! • Example Arctic Ocean Fig. 13.13

  25. Polar ocean productivity • Availability of sunlight during summer and • High nutrients due to upwelling of North Atlantic Deep Water • No thermocline • No barrier to vertical mixing • Blue whales migrate to feed on maximum zooplankton productivity

  26. Tropical ocean productivity • Permanent thermocline is barrier to vertical mixing • Low rate primary productivity (lack of nutrients) above thermocline • That’s why tropical waters tend to be clear and blue

  27. Tropical ocean productivity • Productivity in tropical ocean is lower than that of polar oceans • That’s why tropical oceans look clear • Tropical oceans are deserts with some high areas of sporadic productivity (oasis) • Equatorial upwelling • Coastal upwelling (river runoff, etc.) • Coral reefs

  28. Energy flow in marine ecosystems • Consumers eat other organisms • Herbivores (primary consumers) • Carnivores • Omnivores • Bacteriovores • Decomposers breaking down dead organisms or waste products

  29. Nutrient flow in marine ecosystems • Nutrients cycled from one chemical form to another • Biogeochemical cycling • Example, nutrients fixed by producers • Passed onto consumers • Some nutrients released to seawater through decomposers • Nutrients can be recycled through upwelling

  30. Feeding strategies • Suspension feeding or filter feeding • Take in seawater and filter out usable organic matter • Deposit feeding • Take in detritus and sediment and extract usable organic matter • Carnivorous feeding • Organisms capture and eat other animals

  31. Trophic levels • Feeding stage is trophic level • Chemical energy is transferred from producers to consumers • On average, about 10% of energy is transferred to next trophic level • Much of the energy is lost as heat Fig. 13-18

  32. Food chain Food web • Branching network of many consumers • Consumers more likely to survive with alternative food sources • Primary producer • Herbivore • One or more carnivores

  33. Foodwebs are more complex & more realistic • Consumers often operate at two or more levels http://users.aber.ac.uk/pmm1

  34. http://www-sci.pac.dfo-mpo.gc.ca/mehsd/images/ross_photos

  35. Biomass pyramid • Both number of individuals and total biomass (weight) decrease at successive trophic levels • Organisms increase in size Fig. 13.21

  36. Symbiosis • Organisms associate in beneficial relationship • Commensalism • One benefits without harm to other • Mutualism • Mutually beneficial • Parasitism • One benefits and may harm the other

  37. Marine fisheries • Commercial fishing • Most tonnage from continental shelves and coastal fisheries, compared to open ocean fisheries • Over 20% of catch from areas of upwelling that make up 0.1% of ocean surface area Fig. 13.23

  38. http://www.fao.org/docrep/009/y5852e/Y5852E12.jpg Overfishing Figure A2.4 - Stage of development of the 200 major marine fishery resources: 1950–2000 • Taking more fish than is sustainable over long periods • Remaining fish younger, smaller • About 30% of fish stocks depleted or overfished • About 47% fished at biological limit State of exploitation of selected stock or species groups for which assesment information is available, by major marine fishing areas, 2004 http://www.fao.org/docrep/009/y5852e/Y5852E08.jpg

  39. Aquaculture becoming a more significant component of world fisheries Marine fisheries leveling off over last 10-15 years http://www.fao.org/docrep/009/y5852e/Y5852E02.jpg

  40. Figure 13.26

  41. http://gristmill.grist.org/images/admin/By_Catch_On_Boat.jpg Incidental catch or bycatch • Bycatch - Non-commercial species (or juveniles of commercial species) taken incidentally by commercial fishers • Bycatch may be 25% or 800% of commercial fish • Birds, turtles, dolphins, sharks http://www.motherjones.com/news/featurex/2006/03/bycatch_265x181.jpg http://www.int-res.com/uploads/pics/esrspecial-bycatch_01.jpg

  42. http://ourworld.compuserve.com/homepages/CVisco/tuna.gif Incidental catch or bycatch • Technology to help reduce bycatch • Dolphin-safe tuna • TEDs – turtle exclusion devices • Driftnets or gill nets banned in 1989 • Gill nets banned in Florida by constitutional amendment in 1994 http://www.teara.govt.nz/NR/rdonlyres/A5B74D1E-5BD8-4D7B-B75D-F1480DC74C5D/207170/p6281atl.jpg http://www.st.nmfs.noaa.gov/st4/images/TurtTEDBlu_small.jpg

  43. http://www.cefas.co.uk/media/70062/fig10b.gif Fisheries management Plaice • Regulate fishing • Closings – Cod fisheries of New England • Seasons • Size limits • Minimum size limits –protects juveniles, less effective • Min/max size (slot) limits – preserves juvs and larger adults (contribute most reproductive effort) http://www.cefas.co.uk/media/70037/fig7b.gif

  44. Fisheries management • Conflicting interests • Conservation vs. economic – “tragedy of the commons” • Self-sustaining marine ecosystems • Human employment • International waters • Enforcement difficult “Tragedy of the commons” – All participants must agree to conserve the commons, but any one can force the destruction of the commons http://dieoff.org/page109.htm http://farm1.static.flickr.com/178/380993834_09864a282c.jpg

  45. http://newsroom.nt.gov.au/adminmedia/mailouts/3879/attachments/Indonesian%20fishing%20boat%202.JPGhttp://newsroom.nt.gov.au/adminmedia/mailouts/3879/attachments/Indonesian%20fishing%20boat%202.JPG Fisheries management • Governments subsidize fishing • Many large fishing vessels – often purchased with economic stimulus loans • 1995 world fishing fleet spent $124 billion to catch $70 billion worth of fish 34m Fishing Vessel Apprehended In Australian Waters, April 2008 Activists deploying a banner reading, 'No Fish No Future' next to tuna fishing vessel Albatun Tre, which they claim is the world's largest tuna fishing vessel http://www.telegraph.co.uk/earth/main.jhtml?xml=/earth/2008/05/30/eatuna130.xml

  46. http://yukna.free.fr/science/zebramussels/300px-Grand_Banks.pnghttp://yukna.free.fr/science/zebramussels/300px-Grand_Banks.png Fisheries management • Northwest Atlantic Fisheries such as Grand Banks and Georges Bank • Canada and U.S. restrict fishing and enforce bans • Some fish stocks in North Atlantic rebounding • Other fish stocks still in decline (e.g., cod) http://content.answers.com/main/content/wp/en/thumb/7/7d/300px-GulfofMaine.jpg

  47. Fisheries management • Consumer choices in seafood • Consume and purchase seafood from healthy, thriving fisheries • Examples, farmed seafood, Alaska salmon • Avoid overfished or depleted seafood • Examples, bluefin tuna, shark, shrimp, swordfish • Visit: ORCA's Blue Diet page http://marineresearch.ca/hawaii/wp-content/uploads/tuna-auction-largeview.jpg

  48. Figure 13.28

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