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Marine Ecology 010

Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

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Page 1: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Marine Ecology

010

Page 2: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Ecology = the study of the interaction of organisms with their environments.

Page 3: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

It involves understanding biotic and abiotic factors influencing the distribution and abundance of living things.

Page 4: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Biotic Factors• Competitors

• Disease

• Predators

• Food availability

• Habitat availability

• Symbiotic relationships

Abiotic Factors• pH

• Temperature

• Weather conditions

• Water availability

• Chemical composition of environment

• nitrates, phosphates, ammonia, O2, pollution

Page 5: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

The word "ecology" coined from Greek word "oikos", which means "house" or "place to live”.

Page 6: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

• population growth

• competition between species

• symbiotic relationships

• trophic (=feeding) relationships

• origin of biological diversity

• interaction with the physical environment

Page 7: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Energy Flow & Nutrient CycleEnergy Flow & Nutrient Cycle

Page 8: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Food ChainsFood Chains

• Artificial devices to illustrate energy flow from one trophic level to another

• Trophic Levels: groups of organisms that obtain their energy in a similar manner

Page 9: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

• Total number of levels in a food chain depends upon locality and number of species

• Highest trophic levels occupied by adult animals with no predators of their own

• Secondary Production: total amount of biomass produced in all higher trophic levels

Food ChainsFood Chains

Page 10: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

NutrientsNutrients• Inorganic nutrients incorporated

into cells during photosynthesis- e.g. N, P, C, S

• Cyclic flow in food chains

• Decomposers release inorganic forms that become available to autotrophs again

Page 11: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

EnergyEnergy• Non-cyclic, unidirectional flow• Losses at each transfer from one

trophic level to another- Losses as heat from respiration- Inefficiencies in processing

• Total energy declines from one transfer to another- Limits number of trophic levels

Page 12: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Energy Flow

Page 13: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Primary Producer

Primary Consumer

Secondary Consumer

Tertiary Consumer

Food Chain

Decomposer

zooplankton larval fish

fish

fungi

Energy Flow through an EcosystemEnergy Flow through an Ecosystem

heat heatheat

phytoplankton

sun

water

Nutrients

Page 14: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Transfer EfficienciesTransfer Efficiencies• Efficiency of energy transfer called

transfer efficiency

• Units are energy or biomass

Et = Pt

Pt-1

Pt = annual production at level t

Pt-1 = annual production at t-1

Page 15: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Transfer Efficiency ExampleTransfer Efficiency Example• Net primary production = 150 g C/m2/yr• Herbivorous copepod production = 25 g C/m2/yr

• Typical transfer efficiency ranges*Level 1-2 ~20%*Levels 2-3, …: ~10%

Et = Pt

Pt-1

= Pcopepods

Pphytoplankton

= 25 = 0.17150

Page 16: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Primary producers

Tertiary consumers

Secondary consumers

Primary consumers

1,000 J

10% efficiency

Deposit feeders, filter feeders, grazers

1,000,000 J sunlight

10,000 J

algae, seagrass, cyanobacteria, phytoplankton

100 J

1st order carnivores

10 J

2nd order carnivores

Page 17: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Feces

Growth

CellularRespiration

Page 18: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Food WebsFood Webs

• Food chains don’t exist in real ecosystems

• Almost all organisms are eaten by more than one predator

• Food webs reflect these multiple and shifting interactions

Page 19: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Antarctic Food Web

Page 20: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Some Feeding TypesSome Feeding Types

Many species don’t fit into convenient categories• Algal Grazers and Browsers• Suspension Feeding• Filter Feeding• Deposit Feeding• Benthic Animal Predators• Plankton Pickers• Corallivores• Piscivores• Omnivores• Detritivores• Scavengers• Parasites• Cannibals• Ontogenetic dietary shifts

Page 21: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Recycling: The Microbial LoopRecycling: The Microbial Loop

• All organisms leak and excrete dissolved organic carbon (DOC)

• Bacteria can utilize DOC• Bacteria abundant in the euphotic

zone (~5 million/ml)• Numbers controlled by grazing due to

nanoplankton• Increases food web efficiency

Page 22: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Solar Energy

Microbial Loop

CO2

nutrients

Phytoplankton

Herbivores

Planktivores

Piscivores

DOC

Bacteria Nanoplankton(protozoans)

Page 23: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Keystone Species

A species whose presence in the community exerts a significant influence on the structure of that community.

Page 24: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Keystone predator hypothesis - predation by certain keystone predators is important in maintaining community diversity.

Page 25: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Paine’s study on Pisaster and blue mussels

Page 26: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Kelp Forests

Keystone Species

Keystone Species

Page 27: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments
Page 28: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Keystone SpeciesKeystone Species

Algal turf farming by the Pacific Gregory (Stegastes fasciolatus)

Page 29: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

An Ecological Mystery

Page 30: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

An Ecological MysteryAn Ecological Mystery• Long-term study of sea otter populations

along the Aleutians and Western Alaska• 1970s: sea otter populations healthy and

expanding• 1990s: some populations of sea otters

were declining• Possibly due to migration rather than

mortality• 1993: 800km area in Aleutians surveyed

- Sea otter population reduced by 50%

Page 31: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Vanishing Sea OttersVanishing Sea Otters

• 1997: surveys repeated• Sea otter populations had declines by 90%

- 1970: ~53,000 sea otters in survey area- 1997: ~6,000 sea otters

• Why?- Reproductive failure?- Starvation, pollution disease?

Page 32: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Cause of the DeclineCause of the Decline• 1991: one researcher observed an orca

eating a sea otter• Sea lions and seals are normal prey for

orcas• Clam Lagoon inaccessible to orcas- no

decline• Decline in usual prey led to a switch to sea

otters• As few as 4 orcas feeding on otters could

account on the impact- Single orca could consume 1,825 otters/year

Page 33: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments
Page 34: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments
Page 35: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Ecological Succession

The progressive change in the species composition of an ecosystem.

Page 36: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Ecological Succession

Climax StageClimax Stage

New Bare SubstrateNew Bare Substrate

Colonizing StageColonizing Stage

Successionist StageSuccessionist Stage

Page 37: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

PRIMARY SECONDARY

Growth occurs on newly exposed surfaces where no soil exists

Ex. Surfaces of volcanic eruptions

Growth occurring after a disturbance changes a community without removing the soil

2 types of succession

Page 38: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

• For example, new land created by a volcanic eruption is colonized by various living organisms

Page 39: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

• Disturbances responsible can include cleared and plowed land, burned woodlands

Page 40: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Mount St. Helens

prior 1980

Page 41: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Mount St. Helens

May 18, 1980

Sep. 24, 1980

Page 42: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Mount St. Helens

Fireweed 1980 after eruption

2004

2012

Page 43: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Hanauma Bay Tuff Ring(shield volcano)

Succession after Volcanic Eruption

What organisms would appear first?

How do organisms arrive, i.e., methods for dispersal?

Volcanic eruption creates sterile environment

Page 44: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Mechanisms of Succession

Facilitation

Inhibition

Tolerance

Early species improve habitat.

Ex. Early marine colonists provide a substrate conducive for settling of later arriving species.

As resources become scarce due to depletion and competition, species capable of tolerating the lowest resource levels will survive.

Competition for space, nutrients and light; allopathic chemicals.

First arrivals take precedence.

Page 45: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

r & K Selected Species

Pioneer species- 1st species to colonize a newly disturbed area

r selected

Late successional species

K selected

low competitive abilityshort life spanhigh growth rate

higher maternal investment per offspringlow reproductive output

high reproductive output

slow growth ratelong life spanhigh competitive ability

r & K refer to parameters in logistic growth

equation

Page 46: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Ecological Succession on a Coral Reef

Page 47: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Successional Models and their Impacts

Case 1: No Disturbance (Competitive Exclusion Model)

Case 2: Occasional Strong Disturbance (Intermediate Disturbance Model)

Case 3: Constant Strong Disturbance (Colonial Model)

Page 48: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Case 1: No Disturbance(Competitive Exclusion Model)

• As the reef becomes complex, organisms compete for space.• Dominant organism outcompetes other species.• Occurs in stable environments. • Results in low species diversity.• Highly protected patch reefs within lagoons or protected bays• Deeper water

Page 49: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Case 2: Occasional Strong Disturbance(Intermediate Disturbance Model)

• Storms and hurricanes allow for other species to move in

• Dominant species would not be allowed to reach competitive exclusion

• After each disturbance have a recovery period

• Area of high diversity

Page 50: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Case 3: Constant Strong Disturbance(Colonial Model)

• Constant exposure to disturbance• Shallow environment• High turnover of species• r-selected species

Page 51: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Reef

Case 3

Case 2

Case 1Deep reef slope

Reef slope beneath reef crest

Near reef crest

Page 52: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Ecological Succession on a Coral ReefThe Big Island

Page 53: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Ecological Succession on a Coral Reef

Page 54: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Ecological Succession on a Coral Reef

Page 55: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Ecological Succession on a Coral Reef

Page 56: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Ecological Succession on a Coral Reef

Page 57: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Ecological Succession on a Coral Reef

Page 58: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Ecological Succession on a Coral Reef

Page 59: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Ecological Succession on a Coral Reef

Page 60: Marine Ecology 010. Ecology = the study of the interaction of organisms with their environments

Successional Models and their Impacts

Successional Models and their Impacts