lecture 9 cards Flashcards
Pmax varies with
Physiological condition, temperature, nutrient status
Temperature dependence**
Photochemical reactions are NOT temperature dependent, metabolic reactions ARE temperature dependent because they use enzymes
PAR
Photosynthetically active radiation
Factors affecting total productivity
Changes in surface irradiance, daylength, atmospheric conditions, water transparency, concentration of phytoplankton, nutrient availability
Surface irradiance
Io, varies with latitude and season
Biomass
Numbers of individuals x mass per individual
Cohort analysis
Used when organisms reproduce with distinctive stages and generations do not overlap. Used to help estimate populations/secondary production.
Trophic Dynamic Concept
Lindeman. Less energ is available to each higher trophic level because of work performed and inefficiency of biological transformations
What limits number of trophic levels?
Magnitude of primary production, ecological efficiency, areal extent
Ecological efficiency
Efficiency of transfer of energy–proportion of food “burned away” and therefore not available to the next trophic level. Highest in phytoplankton-herbivore transfers and lowest for carnivore transfers (upwellings have greatest potential for fish production)
Areal extent
Size of system. Typically top carnivores forage over large areas, requires large enough population size
Dr. Robert Hecky
Structure of pelagic food webs
Open ocean chains
5+, open ocean is 90% of area, EE is 10%
Coastal chains
3 links, 9.9% of the area, EE is 15%
Coastal upwelling chains
1-2 links, 0.1% of area, EE is 20%
Cetaceans
Whales (odontoceti and mysticeti)
Pinnipeds
Seals, walruses
Sirenians
Sea cows: dugongs and manatees
Baleen whales behavior
Migration, early weaning, 11 month gestation, sexual maturity in 4-5 years, brief social interactions, common songs that change slowly with 10 yr half lives
Toothed whales behavior
Not much migration, 1-13 years weaning, 10-16 month gestation, maturity at 4-25 years, stable social interactions, have individual songs
Cetacean modifications for marine life
Fusiform shape (streamlining), blubber, skin smooth and elastic, horizontal tail flukes, migration of nostrils to top of head, rapid air exchange, negatively buoyant
