CHAPTER 13 Biological Productivity and Energy Transfer Fig. 13.5.
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Transcript of CHAPTER 13 Biological Productivity and Energy Transfer Fig. 13.5.
CHAPTER 13CHAPTER 13Biological Productivity and Energy Biological Productivity and Energy
TransferTransfer
Fig. 13.5
Primary productivityPrimary productivity
Rate at which energy is stored in Rate at which energy is stored in organic matterorganic matter
PhotosynthesisPhotosynthesis using solar radiation using solar radiation ChemosynthesisChemosynthesis using chemical using chemical
reactionsreactions 99.9% of marine life relies directly or 99.9% of marine life relies directly or
indirectly on photosynthesis for foodindirectly on photosynthesis for food
Photosynthetic productivityPhotosynthetic productivity Chemical reaction that stores solar Chemical reaction that stores solar
energy in organic moleculesenergy in organic molecules
Fig. 13.1
Photosynthetic productivityPhotosynthetic productivity Gross primary productionGross primary production
Total amount of organic carbon produced Total amount of organic carbon produced by photosynthesis per unit time in certain by photosynthesis per unit time in certain areaarea
Net primary productionNet primary production Gross primary production minus cellular Gross primary production minus cellular
respiration (growth, reproduction)respiration (growth, reproduction) New productionNew production
Nutrients added to local ecosystem (e.g., Nutrients added to local ecosystem (e.g., upwelling)upwelling)
Regenerated productionRegenerated production Recycling of nutrients within ecosystemRecycling of nutrients within ecosystem
Measuring primary Measuring primary productivityproductivity
Capture planktonCapture plankton Plankton netsPlankton nets
Ocean colorOcean color ChlorophyllChlorophyll colors seawater colors seawater SeaWiFs on satelliteSeaWiFs on satellite
Factors affecting primary Factors affecting primary productivityproductivity NutrientsNutrients
Nitrate, phosphorous, iron, silicaNitrate, phosphorous, iron, silica Most from river runoffMost from river runoff Productivity high along continental Productivity high along continental
marginsmargins Solar radiationSolar radiation
Uppermost surface seawater and Uppermost surface seawater and shallow seafloorshallow seafloor
Euphotic zone surface to about 100 m Euphotic zone surface to about 100 m (330 ft)(330 ft)
Upwelling and nutrient Upwelling and nutrient supplysupply Cooler, deeper seawater nutrient-richCooler, deeper seawater nutrient-rich
Areas of coastal upwelling sites of high Areas of coastal upwelling sites of high productivityproductivity
Fig. 13.6a
Light Light transmissiontransmission
Visible light of the Visible light of the electromagnetic electromagnetic spectrumspectrum
Blue wavelengths Blue wavelengths penetrate deepestpenetrate deepest
Longer Longer wavelengths (red, wavelengths (red, orange) absorbed orange) absorbed firstfirst
Fig. 13.3
Light Light transmissiontransmission
Fig. 13.3
Light transmission in oceanLight transmission in ocean
Color of ocean ranges from deep Color of ocean ranges from deep blue to yellow-greenblue to yellow-green
FactorsFactors Turbidity from runoffTurbidity from runoff Photosynthetic pigment Photosynthetic pigment
(chlorophyll)(chlorophyll) EutrophicEutrophic OligotrophicOligotrophic
Light transmission in oceanLight transmission in ocean SeaStar satellite/SeaWiFS view of ocean SeaStar satellite/SeaWiFS view of ocean
chlorophyll and land vegetation (productivity)chlorophyll and land vegetation (productivity)
Fig. 13-5
Types of photosynthetic Types of photosynthetic marine organismsmarine organisms
AnthophytaAnthophyta Seed-bearing plantsSeed-bearing plants
Macroscopic (large) algaeMacroscopic (large) algae Microscopic (small) algaeMicroscopic (small) algae Photosynthetic bacteriaPhotosynthetic bacteria
AnthophytAnthophyta a
Only in shallow Only in shallow coastal waterscoastal waters
Primarily grasses Primarily grasses andand
Mangroves Mangroves
Fig. 13.7
Macroscopic algaeMacroscopic algae ““Seaweeds”Seaweeds” Brown algaeBrown algae Green algaeGreen algae Red algaeRed algae (most abundant and (most abundant and
most widespread)most widespread) Varied colorsVaried colors
Microscopic Microscopic algaealgae Produce food for 99% of marine animalsProduce food for 99% of marine animals Most planktonicMost planktonic Golden algaeGolden algae
Diatoms Diatoms (tests of silica) (tests of silica) Coccolithophores Coccolithophores (plates of calcium carbonate)(plates of calcium carbonate)
DinoflagellatesDinoflagellates
Red tide (harmful algal bloom)Red tide (harmful algal bloom)
ToxinsToxins
Fish killsFish kills
Human illnessHuman illness
Photosynthetic bacteriaPhotosynthetic bacteria
Extremely smallExtremely small May be responsible for half of May be responsible for half of
total photosynthetic biomass total photosynthetic biomass in oceansin oceans
Regional primary Regional primary productivityproductivity Varies from very low to very high Varies from very low to very high
depending ondepending on Distribution of nutrientsDistribution of nutrients Seasonal changes in solar radiationSeasonal changes in solar radiation
About 90% of surface biomass About 90% of surface biomass decomposed in surface oceandecomposed in surface ocean
About 10% sinks to deeper oceanAbout 10% sinks to deeper ocean Only 1% organic matter not decomposed Only 1% organic matter not decomposed
in deep oceanin deep ocean Biological pump (COBiological pump (CO22 and nutrients to sea and nutrients to sea
floor sediments)floor sediments)
Polar ocean productivityPolar ocean productivity Winter darknessWinter darkness Summer sunlightSummer sunlight Phytoplankton (diatoms) bloomPhytoplankton (diatoms) bloom Zooplankton (mainly small Zooplankton (mainly small
crustaceans) productivity followscrustaceans) productivity follows ExampleExample
Arctic OceanArctic Ocean
Fig. 13.13
Polar ocean productivityPolar ocean productivity Availability of sunlight andAvailability of sunlight and High nutrients due to upwelling of High nutrients due to upwelling of
North Atlantic Deep WaterNorth Atlantic Deep Water No thermocline No thermocline No barrier to vertical mixingNo barrier to vertical mixing
Blue whales migrate to feed on Blue whales migrate to feed on maximum zooplankton productivitymaximum zooplankton productivity
Fig. 13-11b
Tropical ocean productivityTropical ocean productivity Permanent thermocline is barrier to Permanent thermocline is barrier to
vertical mixingvertical mixing Low rate primary productivity (lack Low rate primary productivity (lack
of nutrients)of nutrients) High primary productivity in areas ofHigh primary productivity in areas of Equatorial upwellingEquatorial upwelling Coastal upwellingCoastal upwelling Coral reefsCoral reefs
Symbiotic algaeSymbiotic algae Recycle nutrients within the ecosystemRecycle nutrients within the ecosystem
Fig. 13.12
Temperate ocean Temperate ocean productivityproductivity Limited by both available sunlight andLimited by both available sunlight and Available nutrientsAvailable nutrients Highly seasonal patternHighly seasonal pattern
Winter low (lots of nutrients, little Winter low (lots of nutrients, little sunlight)sunlight)
Spring high (spring bloom)Spring high (spring bloom) Summer low (little nutrients, lots of Summer low (little nutrients, lots of
sunlight)sunlight) Fall high (fall bloom)Fall high (fall bloom)
Regional productivity Regional productivity summarizedsummarized
Fig. 13.14
Energy flow in marine Energy flow in marine ecosystemsecosystems Ecosystem includes living organisms Ecosystem includes living organisms
(biotic community) and environment(biotic community) and environment Solar energy converted to chemical Solar energy converted to chemical
energy by energy by producersproducers (mainly (mainly photosynthesis)photosynthesis)
ConsumersConsumers eat other organisms eat other organisms HerbivoresHerbivores CarnivoresCarnivores OmnivoresOmnivores BacteriovoresBacteriovores
DecomposersDecomposers breaking down dead breaking down dead organisms or waste productsorganisms or waste products
Algae-supported biotic Algae-supported biotic communitycommunity
Fig. 13.15
Nutrient flow in marine Nutrient flow in marine ecosystemsecosystems Nutrients cycled from one chemical Nutrients cycled from one chemical
form to anotherform to another BiogeochemicalBiogeochemical cycling cycling Example, nutrients fixed by producersExample, nutrients fixed by producers Passed onto consumersPassed onto consumers Some nutrients released to seawater Some nutrients released to seawater
through decomposersthrough decomposers Nutrients can be recycled through Nutrients can be recycled through
upwellingupwelling
Fig. 13.16
Biogeo-Biogeo-chemical chemical cyclingcycling
Feeding strategiesFeeding strategies Suspension feeding or filter feedingSuspension feeding or filter feeding
Take in seawater and filter out Take in seawater and filter out usable organic matterusable organic matter
Deposit feedingDeposit feeding Take in detritus and sediment and Take in detritus and sediment and
extract usable organic matterextract usable organic matter Carnivorous feedingCarnivorous feeding
Organisms capture and eat other Organisms capture and eat other animalsanimals
Feeding strategiesFeeding strategies
Fig. 13.17d
Trophic Trophic levelslevels
Chemical Chemical energy is energy is transferred transferred from from producers producers to to consumersconsumers
Feeding Feeding stage is stage is trophic trophic levellevel
About 10% About 10% of energy of energy transferred transferred to next to next trophic trophic levellevel
Fig. 13-18
Passage of energy between Passage of energy between trophic levelstrophic levels
Fig. 13.19
Food chainFood chain Food web Food web
Primary Primary producerproducer
HerbivoreHerbivore One or more One or more
carnivorescarnivores
Branching Branching network of many network of many consumersconsumers
Consumers more Consumers more likely to survive likely to survive with alternative with alternative food sourcesfood sources
Fig. 13.20
Biomass Biomass pyramidpyramid
Number of Number of individuals individuals and total and total biomass biomass decrease at decrease at successive successive trophic levelstrophic levels
Organisms Organisms increase in increase in sizesize
Fig. 13.21
SymbiosiSymbiosis s Organisms associate in beneficial Organisms associate in beneficial
relationshiprelationship CommensalismCommensalism
One benefits without harm to otherOne benefits without harm to other MutualismMutualism
Mutually beneficialMutually beneficial ParasitismParasitism
One benefits and may harm the One benefits and may harm the other other
Commercial Commercial fishingfishing
Most from Most from continental continental shelvesshelves
Over 20% from Over 20% from areas of areas of upwelling that upwelling that make up 0.1% of make up 0.1% of ocean surface ocean surface areaarea
Fig. 13.23
Marine Marine fisheriesfisheries
OverfishinOverfishing g Taking more fish than sustainableTaking more fish than sustainable Remaining fish young, smallRemaining fish young, small About 30% of fish stocks depleted or overfishedAbout 30% of fish stocks depleted or overfished About 47% fished at biological limitAbout 47% fished at biological limit
Fig. 13.24
Incidental catch or bycatchIncidental catch or bycatch Non-commercial species taken Non-commercial species taken
incidentally by commercial fishersincidentally by commercial fishers Bycatch may be 25% or 800% of Bycatch may be 25% or 800% of
commercial fishcommercial fish Birds, turtles, dolphins, sharksBirds, turtles, dolphins, sharks Dolphin-safe tunaDolphin-safe tuna
Driftnets or gill nets banned in 1989Driftnets or gill nets banned in 1989
Fisheries managementFisheries management
Regulate fishing Regulate fishing Conflicting interestsConflicting interests Human employmentHuman employment Self-sustaining marine ecosystemsSelf-sustaining marine ecosystems International watersInternational waters Enforcement difficultEnforcement difficult
Fisheries managementFisheries management
Many large fishing vesselsMany large fishing vessels 1995 world fishing fleet spent 1995 world fishing fleet spent
$124 billion to catch $70 $124 billion to catch $70 billion worth of fishbillion worth of fish
Governments subsidize fishingGovernments subsidize fishing
Fisheries managementFisheries management
Northwest Atlantic Fisheries such as Northwest Atlantic Fisheries such as Grand Banks and Georges BankGrand Banks and Georges Bank
Canada and U.S. restrict fishing and Canada and U.S. restrict fishing and enforce bansenforce bans
Some fish stocks in North Atlantic Some fish stocks in North Atlantic reboundingrebounding
Other fish stocks still in decline (e.g., Other fish stocks still in decline (e.g., cod)cod)
Fisheries managementFisheries management
Consumer choices in seafoodConsumer choices in seafood Consume and purchase seafood from Consume and purchase seafood from
healthy, thriving fisherieshealthy, thriving fisheries Examples, farmed seafood, Alaska Examples, farmed seafood, Alaska
salmonsalmon Avoid overfished or depleted seafoodAvoid overfished or depleted seafood
Examples, tuna, shark, shrimpExamples, tuna, shark, shrimp
End of CHAPTER 13 End of CHAPTER 13 Biological Productivity and Energy Biological Productivity and Energy
TransferTransferFig. 13.25