1. Biological Productivity and Energy Transfer

2. Primary Productivity
“The rate at which energy is stored by organisms through the formation of organic matter using energy derived from solar radiation or chemical reactions”
Photosynthesis
Chemosynthesis

3. Primary Productivity
Photosynthetic Productivity

4. Primary Productivity Gross Primary Production
Total amount of organic carbon produced by photosynthesis per unit time
Includes
New production
Regenerated production

5. Primary Productivity Net Primary Production
Gross primary production – cellular respiration
Results in growth & reproduction

6. Primary Productivity Measurement of Primary Productivity Plankton nets
Amount of chlorophyll

7. Seasonal Global Primary Production Maps - Winter
Source:

8. Seasonal Global Primary Production Maps - Summer
Source:

9. Primary Productivity Factors Affecting Primary Productivity
Available Nutrients
Available Solar Radiation

10. Primary Productivity Ocean Margins Upwelling and Nutrient Supply
The Benguela Upwelling Zone - Annual Area Average Plots (
The Benguela Upwelling Zone -- Annual Area Average Plots
     In the SST image, the location of the coldest upwelled water is observed to be very close to the coast.       In the chlorophyll image, the dramatic effect of the nutrients provided by the upwelling process can be seen.   Also note the much warmer water of the Agulhas Current south of the African continent, and the distribution of chlorophyll corresponding to the Agulhas Current.

11. Primary Productivity Light Transmission in Ocean Water
Solar radiation creates:
Atmospheric circulation, ocean circulation and waves
A layer of warm water at the surface
photosynthesis

12. Electromagnetic Spectrum

13. Photosynthetic Marine Organisms
Seed-Bearing Plants (Anthophyta)
Shallow coastal waters (< 6 m)
Include
Seagrass
Grasses (salt marshes)
mangroves
Surfgrass (Phyllospadix torreyi) Source:

14. Photosynthetic Marine Organisms
Macroscopic (Large) Algae aka “seaweeds”
Shallow waters of the coastal margins
Include:
Brown algae
Size varies
Upper & middle intertidal zone
Kelp forests
Food in intertidal zone
Pacific Rockweed (Fucus distichus) in Olympic National Park Source:

15. Photosynthetic Marine Organisms
Macroscopic (Large) Algae aka “seaweeds”
Shallow waters of the coastal margins
Include:
Green algae
Intertidal or shallow bays
Sea lettuce & sponge weed
A growth of the green seaweed, Enteromorpha on rock substratum at the ocean shore.
Source:

16. Photosynthetic Marine Organisms
Macroscopic (Large) Algae aka “seaweeds”
Shallow waters of the coastal margins
Include:
Red algae
Most abundant
Highest intertidal zone to outer edge of the sublittoral zone
Attached to the bottom
Several species of red algae grow on rhodoliths at about 75 m depth (225 ft) on McGrail Bank.
Source: oceanexplorer.noaa.gov

17. Photosynthetic Marine Organisms
Microscopic (Small) Algae
Base of food chain
Include:
Golden Algae
Diatoms
Coccolithophores
Dinoflagellates
Acinetospora crinita Source:

18. Photosynthetic Marine Organisms
Synechococcus
Source:
Photosynthetic Bacteria
May be responsible for nearly half of the primary production of food in the ocean
Able to reduce nitrogen and carbon in aerobic conditions
Prochlorococcus Source:

19. Regional Productivity
Productivity in Polar Oceans
Productivity in Tropical Oceans
Productivity in Temperate Oceans

20. Regional Productivity
Polar Oceans
Continuous darkness for three months
Continuous sunlight for three months
Productivity higher in the Antarctic due to upwelling
Tropical Oceans
Temperate Oceans

21. Polar Productivity
Highly seasonal phytoplankton blooms characterize these polar waters, where photosynthesis is strongly influenced by the availability of light. Note differences in Artic (left) and Antarctic (right) summers where the ocean is surrounded by land and the land surrounded by ocean, respectively. Source:

22. Regional Productivity
Tropical Oceans
Deep light penetration produces layering of water masses
Prevents mixing of waters & nutrients from upwelling
Production about 1/2 of temperate oceans
Exceptions:
Equatorial & Coastal Upwelling
Coral Reefs

23. Productivity in Tropical Oceans

24. Regional Productivity
Temperate Oceans
Productivity limited by available sunlight & nutrient supply
Winter
Spring
Summer
Fall
Productivity
Low
High
(spring bloom)
High (fall bloom)
Nutrient levels
Highest
Decreasing
Lowest
Increasing
Sunlight

25. Productivity in Temperate Oceans

27. Energy Flow and Nutrient Cycling
Energy Flow in Marine Ecosystems
Biotic Community – assemblage of organisms that live together within a definable area
Ecosystem – includes the biotic community + the environment with which it exchanges energy & chemical substances
Three categories of organisms: Producers, consumers and decomposers

28. Energy Flow and Nutrient Cycling
Biogeochemical Cycling
Includes:
nitrogen cycle
oxygen cycle
carbon cycle
phosphorus cycle
sulfur cycle
water cycle
hydrogen cycle

29. Oceanic Feeding Relationships
Feeding Strategies
Suspension feeding (filter feeding)
Deposit feeding
Carnivorous feeding

30. Oceanic Feeding Relationships
Trophic Levels
Chemical energy stored by plants is transferred to the animal community via feeding
Each stage is called a tropic level

31. Oceanic Feeding Relationships
Transfer Efficiency
Transfer of energy between trophic levels is inefficient

32. Oceanic Feeding Relationships
Food Chains, Food Webs, and the Biomass Pyramid
Food chains – a sequence of organisms through which energy is transferred from primary producer up to the top carnivores

33. Oceanic Feeding Relationships
Food Chains, Food Webs, and the Biomass Pyramid
Food webs – top carnivores feed off of numerous animals that have their own food chain or web

34. Oceanic Feeding Relationships
Food Chains, Food Webs, and the Biomass Pyramid
Biomass Pyramid – the number of individuals & total biomass decrease through successive trophic levels as the amount of available energy decreases

35. Oceanic Feeding Relationships
Symbiosis
Occurs when two or more organisms associate in a way that benefits at least one of them
Commensalim – smaller group benefits, host not affected
Mutualism – both groups benefit
Parasitism – one group benefits at another’s expense

36. Issues Affecting Marine Fisheries
Overfishing
When harvesting of fish stocks takes place so rapidly that the majority of the population is sexually immature and is therefore unable to reproduce
Affects the size of the fishes (smaller)

37. Issues Affecting Marine Fisheries
Overfishing
Whaling
The whaling industry has pushed most of the dozen species of great whales to the brink of extinction.

38. Issues Affecting Marine Fisheries
Overfishing
Fur-Bearing Mammals
Sea Otter
Harbor Seals
Sea Lion

39. Issues Affecting Marine Fisheries
Incidental Catch
Organisms which are caught by accident with the rest of the catch
Tuna and Dolphins

40. Issues Affecting Marine Fisheries
Fishery Management
Fishing employs fifteen million people worldwide.
Fish, Crustaceans, And Mollusks
the most valuable living marine resources.
© 2002 Brooks/Cole, a division of Thomson Learning, Inc.

41. Biological Resources
Some of the major types of commercially harvested fish, mollusks and crustaceans.
© 2002 Brooks/Cole, a division of Thomson Learning, Inc.

42. Issues Affecting Marine Fisheries
Fishery Mismanagement
Maximum sustainable yield - the maximum amount of any species that can be harvested without affecting future yields
Overfished - a status assigned to fish stocks that have been harvested so there is not enough breeding stock left for replenishment
© 2002 Brooks/Cole, a division of Thomson Learning, Inc.

43. Issues Affecting Marine Fisheries
Fishery Mismanagement
Commercial extinction - the depletion of a species to the point where it is no longer profitable to harvest
Bykill - animals unintentionally killed when other species are being harvested
© 2002 Brooks/Cole, a division of Thomson Learning, Inc.

44. Issues Affecting Marine Fisheries
Effects on California Economy
Market Value of Industries $17.3 Billion, Supporting 370,000 Jobs (1992 data)
Commercial Fishing, Mariculture and Kelp Harvesting
Includes tuna, sea urchin, rockfish, crab, and salmon
$554 million to the state's economy
17,000 jobs
Source: California's Ocean Resources: An Agenda for the Future (1995)

45. Issues Affecting Marine Fisheries
How Fish are Caught - Unfriendly
Dredging
Dredgers rake the seafloor for shellfish. Dredging damages the seafloor and results in unintentional catch
Gillnetting
The size of a gillnet's mesh determines the type of fish it will catch. Gillnets may accidentally entangle and kill sea turtles
Longlining
Longlines at different depths attract different species. Pelagic longlining can accidentally kill sea turtles and seabirds
Source:

46. Issues Affecting Marine Fisheries
How Fish are Caught - Unfriendly
Purse Seining
Purse seines are primarly used for schooling fish. Purse seining for tuna results in large amounts of unintended catch
Trawling/Dragging
Trawling at different depths catches different animals. Trawl nets catch everything in their path and can damage the seafloor
Traps and Pots
Traps and pots catch bottom-dwellers. Most traps and pots are environmentally responsible, but have issues too
Source:

47. Issues Affecting Marine Fisheries
How Fish are Caught - Friendly
Hook and Lining
Hook and liners fish near the surface and down below
Hook and lining is an environmentally responsible fishing method
Traps and Pots
Traps and pots catch bottom-dwellers. Most traps and pots are environmentally responsible, but have issues too
Harpooning
Harpooners catch large, pelagic predators such as bluefin tuna & swordfish.
An environmentally responsible fishing method
Source:

48. Issues Affecting Marine Fisheries
How Fish are Farmed – Unfriendly
Open Net Pens or Cages
Waste passes freely into the surrounding environment.
Escaped fish compete with wild fish for natural resources.
Escaped fish can interbreed with wild fish of the same species, compromising the hardiness of the wild population.
Diseases and parasites can spread to wild fish living near or swimming past net pens.
Source:

49. Issues Affecting Marine Fisheries
How Fish are Farmed – Unfriendly
Ponds
Ponds enclose fish in a coastal or inland body of fresh or salt water.
Wastewater can be contained and treated.
The construction of shrimp ponds in mangrove forests has destroyed more than 3.7 million acres of coastal habitat.
Untreated wastewater can pollute the surrounding environment and contaminate groundwater.
Source:

50. Issues Affecting Marine Fisheries
How Fish are Farmed – Unfriendly
Raceways
Water is usually treated before returning it.
Strict regulation and monitoring required
Untreated wastewater can contaminate waterways and spread diseases.
Escaped fish can
Compete with wild fish for natural resources
Interbreed with wild fish of the same species
Source:

51. Issues Affecting Marine Fisheries
How Fish are Farmed – Friendly
Recirculating Systems
Recirculating systems address many environmental concerns associated with fish farming: fish cannot escape, and wastewater is treated.
Costly to operate and rely on electricity or other power sources.
Source:

52. Issues Affecting Marine Fisheries
How Fish are Farmed – Friendly
Shellfish Culture
Shellfish are grown on beaches or suspend them in water by ropes, plastic trays or mesh bags.
Since oysters, mussels and clams are filter feeders, they can actually cleanse nutrient-rich water.
Farming in high densities in areas with little current or tidal flow can lead to the accumulation of waste.
Responsible for the introduction of exotic species
Source:

53. Issues Affecting Marine Fisheries
Seafood Choices
"Best Choices" are abundant, well managed and fished or farmed in environmentally friendly ways.
Seafood to "Avoid" are overfished and/or fished or farmed in ways that harm other marine life or the environment.
Your consumer choices make a difference.
Buy seafood from the green or yellow columns to support those fisheries and fish farms that are healthier for ocean wildlife and the environment.
Source:

54. Source: www.seafoodwatch.org

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