CHAPTER 13 Biological Productivity and Energy Transfer Fig

CHAPTER 13 Biological Productivity and Energy Transfer Fig. 13. 5

http: //www. oxygentimerelease. com/A/imagesa/phytoplankton. jpg Primary productivity n Rate at which energy is stored in organic matter n Photosynthesis using solar radiation n n 99. 9% of marine life relies directly or indirectly on photosynthesis for food Chemosynthesis using chemical reactions http: //www. ocean. udel. edu/deepsea/level-2/chemistry/magnified. jpg

Photosynthetic productivity n Chemical reaction that stores solar energy in organic molecules Fig. 13. 1

Photosynthetic productivity n Gross primary production n n Net primary production n Gross primary production minus cellular respiration (growth, reproduction) NPP = GPP – Respiration New production n n Total amount of organic carbon produced by photosynthesis per unit time in certain area Nutrients added to local ecosystem (e. g. , upwelling) Regenerated production n Recycling of nutrients within ecosystem http: //www. ecologyandsociety. org/vol 1/iss 2/art 2/fig 6. gif

Measuring primary productivity n n Capture plankton n Plankton nets Ocean color n Chlorophyll colors seawater n Sea. Wi. Fs on satellite

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

Upwelling and nutrient supply n n Cooler, deeper seawater nutrient-rich Areas of coastal upwelling sites of high productivity Fig. 13. 6 a http: //cordellbank. noaa. gov/images/environment/upwelling_470. jpg

Light transmission n Visible light of the electromagnetic spectrum Blue wavelengths penetrate deepest Longer wavelengths (red, orange) absorbed first Fig. 13. 3

http: //lh 4. ggpht. com/_l. Qw_u. Dji. HTw/R 7 Am. R 74 EBy. I/AAAAL 40/VKg 0 n. Z_Ih 6 c/DSC_0009. JPG Light transmission in ocean n n Color of ocean ranges from deep blue to yellow-green Factors Water depth n Turbidity from runoff n Photosynthetic pigment (chlorophyll) n Eutrophic n Oligotrophic n http: //upload. wikimedia. org/wikipedia/commons/a/a 5/Lightning. Volt_Deep_Blue_Sea. jpg

Light transmission in ocean n Sea. Star satellite/Sea. Wi. FS view of ocean chlorophyll and land vegetation (productivity) Fig. 13 -5

Types of photosynthetic marine organisms Anthophyta n Seed-bearing plants n Macroscopic (large) algae n Microscopic (small) algae n Photosynthetic bacteria n

n Anthophyta n n Only in shallow coastal waters Primarily seagrasses & Mangroves http: //celebrating 200 years. noaa. gov/events/sanctuaries/seagrass_meadow 650. jpg

http: //oceanexplorer. noaa. gov/explorations/02 sab/logs/aug 09/media/lines_600. jpg Macroscopic algae – “Seaweeds” n Brown algae Sargassum http: //www. starfish. ch/photos/plants-Pflanzen/Sargassum. jpg

Macroscopic algae – “Seaweeds” n Green algae Caulerpa brachypus, an invasive species in the Indian River Lagoon Codium http: //www. sms. si. edu/IRLspec/images/cbrachypus 2. jpg http: //192. 107. 66. 195/Buoy/System_Description_Codium_Fragile. jpg

Macroscopic algae – “Seaweeds” n Red algae Most abundant and most widespread of “seaweeds” n Varied colors n http: //www. dnrec. state. de. us/Macro. Algae/information/Indentifying. shtml http: //www. agen. ufl. edu/~chyn/age 2062/lect_15/22_14 B. GIF

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

Microscopic algae n Coccolithophores (plates of ate) n n n 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

Microscopic algae n Dinoflagellates n n Mostly autotrophic; some heterotrophic or both Flagella in grooves for locomotion Many bioluminescent Often toxic n 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/por 24 gif/Karenia-digitata. jpg

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

Microscopic algae n http: //www. odu. edu/sci/biology/pfiesteria Dinoflagellates n n n Pfiesteria in temperate coastal waters Ciguatera (from) Gambierdiscus toxicus in tropical fishes Paralytic, diarhetic, amnesic shellfish poisoning Pfiesteria Gambierdiscus Alexandrium – paralytic shellfish http: //www. slv 2000. qc. ca/bibliotheque/lefleuve/vol 11 no 5/images_f/alexandrium 1. jpg http: //www. hrw. com/science/si-science/ biology/plants/algae/ images/Gambitox. jpg

Figure 13. D

Photosynthetic bacteria n n Extremely small May be responsible for half of total photosynthetic biomass in oceans Anabaena http: //www. micrographia. com/specbiol/bacteri/ bacter/bact 0200/anabae 03. jpg Gleocapsa http: //silicasecchidisk. conncoll. edu/Pics/Other%20 Algae/ Blue_Green%20 jpegs/Gloeocapsa_Key 45. jpg

Regional primary productivity n n n Varies from very low to very high depending on n Distribution of nutrients n Seasonal changes in solar radiation About 90% of surface biomass decomposed in surface ocean About 10% sinks to deeper ocean n n Only 1% organic matter not decomposed in deep ocean reaches bottom Biological pump (CO 2 and nutrients to sea floor sediments)

Table 13. 1

Temperate ocean productivity n Seasonal variation with temperature/light/nutrients n Winter: n High winter winds mixing of sediments/plankton n Low light & few phytoplankton nutrients increase n Spring: n Phytoplankton blooms with more light, nutrients n Bloom continues until… n n Nutrients run out Herbivores eat enough phytoplankton Summer: often low production due to lack of nutrients Fall: Often 2 O bloom, as winds bring up nutrients

Figure 13. 13 a

Temperate ocean productivity Fig. 13

Polar ocean productivity n n n Winter darkness Summer sunlight Phytoplankton (diatoms) bloom Zooplankton (mainly small crustaceans) productivity follows Example Arctic Ocean Fig. 13

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

Fig. 13 -11 b

Tropical ocean productivity n n Permanent thermocline is barrier to vertical mixing Low rate primary productivity (lack of nutrients) above thermocline

http: //www-das. uwyo. edu/~geerts/cwx/notes/chap 11/equat_upwel. html Tropical ocean productivity n High primary productivity in areas of… n Equatorial upwelling n Coastal upwelling n Coral reefs n Symbiotic algae n Recycle nutrients within the ecosystem http: //www. igfa. org/images/zooxanthellae. jpg http: //static. howstuffworks. com/gif/coral-reef-life. jpg

Fig. 13. 12

Regional productivity summarized Fig. 13. 14

Energy flow in marine ecosystems n n Ecosystem includes living organisms (biotic community) and environment (abiotic factors) Solar energy converted to chemical energy by producers (mainly photosynthesis)

Energy flow in marine ecosystems n n Consumers eat other organisms n Herbivores n Carnivores n Omnivores n Bacteriovores Decomposers breaking down dead organisms or waste products

Algae-supported biotic community Fig. 13. 15

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

Biogeochemical cycling Fig. 13. 16

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

Feeding strategies Fig. 13. 17 d

Trophic levels n n n 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 Fig. 13 -18

Passage of energy between trophic levels Fig. 13. 19

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

q Food webs are more complex & more realistic q Consumers often operate at two or more levels http: //users. aber. ac. uk/pmm 1

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

Biomass pyramid n n Fig. 13. 21 Both number of individuals and total biomass (weight) decrease at successive trophic levels Organisms increase in size

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

Marine fisheries n n Commercial fishing Most tonnage from continental shelves and coastal fisheries, compared to open ocean fisheries n Fig. 13. 23 Over 20% of catch from areas of upwelling that make up 0. 1% of ocean surface area

Overfishing n n 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/y 5852 e/Y 5852 E 08. jpg http: //www. fao. org/docrep/009/y 5852 e/Y 5852 E 12. jpg Figure A 2. 4 - Stage of development of the 200 major marine fishery resources: 1950– 2000

n Aquaculture becoming a more significant component of world fisheries Marine fisheries leveling off over last 10 -15 years http: //www. fao. org/docrep/009/y 5852 e/Y 5852 E 02. jpg

Figure 13. 26

Figure 13. G

http: //gristmill. grist. org/images/admin/By_Catch_On_Boat. jpg Incidental catch or bycatch n n Bycatch - Non-commercial species (or juveniles of commercial species) taken incidentally by commercial fishers Bycatch may be 25% or 800% of commercial fish n Birds, turtles, dolphins, sharks http: //www. motherjones. com/news/featurex/2006/03/bycatch_265 x 181. jpg http: //www. int-res. com/uploads/pics/esrspecial-bycatch_01. jpg

http: //ourworld. compuserve. com/homepages/CVisco/tuna. gif Incidental catch or bycatch n n Technology to help reduce bycatch n Dolphin-safe tuna n TEDs – turtle exclusion devices Driftnets or gill nets banned in 1989 n Gill nets banned in Florida by constitutional amendment in 1994 http: //www. teara. govt. nz/NR/rdonlyres/A 5 B 74 D 1 E 5 BD 8 -4 D 7 B-B 75 D-F 1480 DC 74 C 5 D/207170/p 6281 atl. jpg http: //www. st. nmfs. noaa. gov/st 4/images/Turt. TEDBlu_small. jpg

http: //www. cefas. co. uk/media/70062/fig 10 b. gif Fisheries management n Plaice Regulate fishing Closings – Cod fisheries of New England n Seasons n Size limits n Minimum size limits –protects juveniles, less effective n Min/max size (slot) limits – preserves juvs and larger adults (contribute most reproductive effort) n http: //www. cefas. co. uk/media/70037/fig 7 b. gif

Fisheries management n Conflicting interests Conservation vs. economic – “tragedy of the commons” n Self-sustaining marine ecosystems n Human employment n International waters n Enforcement difficult n “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/page 109. htm http: //farm 1. static. flickr. com/178/380993834_09864 a 282 c. jpg

http: //newsroom. nt. gov. au/adminmedia/mailouts/3879/ attachments/Indonesian%20 fishing%20 boat%202. JPG Fisheries management n Governments subsidize fishing n n Many large fishing vessels – often purchased with economic stimulus loans 1995 world fishing fleet spent $124 billion to catch $70 billion worth of fish 34 m 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/eatuna 130. xml

Figure 13. 27

http: //yukna. free. fr/science/zebramussels/300 px-Grand_Banks. png Fisheries management n n 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/7/7 d/300 px-Gulfof. Maine. jpg

http: //paulbuckley 14059. files. wordpress. com/2007/08/sushi 1. jpg Fisheries management n n Consumer choices in seafood Consume and purchase seafood from healthy, thriving fisheries n n Examples, farmed seafood, Alaska salmon Avoid overfished or depleted seafood n Examples, bluefin tuna, shark, shrimp, swordfish http: //marineresearch. ca/hawaii/wp-content/uploads/tuna-auction-largeview. jpg

Figure 13. 28

End of CHAPTER 13 Biological Productivity and Energy Transfer Fig. 13. 25