Primary Producers

Document Sample
Primary Producers Powered By Docstoc
					             Marine Biology
• Study of living organisms in the ocean
• LIFE = ?
  – Ability to capture, store, and transmit energy
  – Ability to reproduce
  – NASA: A self-sustained chemical system
    capable of Darwinian evolution
                 Evolution
• Explains the unity and diversity of life
• Charles Darwin and Alfred Wallace
• Definition?
  – Change
• Mechanism = natural selection
  – reproduction, mutation/variation, selection
          Primary Producers
• aka autotrophs
• Organisms that can capture solar energy and
  convert it to chemical energy by building
  organic compounds
• Photosynthesis
Fig. 12-2, p. 238
          Primary Producers
• Others use chemosynthesis
  – Much less common
  – Use the oxidation of inorganic compounds as
    energy source,
  – ex: bacteria use hydrogen sulfide at
    hydrothermal vents
        Cellular Respiration
• Opposite of photosynthesis
• Breakdown of food
• All organisms
Figure 13.1
              Consumers
• aka heterotrophs
• Must consume (eat) other organisms
               Consumers
• Primary consumers
  – Eat producers
• Secondary Consumers
  – Eat primary consumers
• These all are Trophic Levels
              Food webs
• Complex representation of who eats who
        Primary Productivity
• Refers to how active the producers are
• grams of Carbon bound into organic
  material per square meter per year
  (gC/m2/y)
Figure 13.18
Only 10% of “food” gets transferred to the next trophic level
Figure 13.19
    Ocean’s Primary Producers
• Algae – in Kingdom Protista
  – Have chlorophyll but no vessels to conduct
    fluids
  – Unicellular = phytoplankton – pelagic
  – Multicellular = seaweed – benthic
• Plants
  – Angiosperms = flowering plants
            The Pelagic Zone
• Pelagic organisms are suspended in the
  water
  – Plankton = drifters
     • Phytoplankton= unicellular photosynthetic algae
     • Zooplankton = “animal” plankton
  – Nekton = swimmers
            Phytoplankton
• 95% of ocean’s primary productivity
• Mostly Single-celled organisms
• Diatoms & Dinoflagellates
                 Diatoms
• Dominant (>5600 species)
• Silica shell – two valves
• Produce large portion of O2 in ocean and
  atmosphere
              Dinoflagellates
•   Mostly autotrophs
•   Most are free living (except zooxanthellae)
•   Two whip-like flagella
•   “Red tides” or HABs (Harmful Algal
    Blooms)
    Phytoplankton Distribution
• Depends on:
  – light availability
  – nutrient concentration
• Varies with:
  – Depth, Proximity to land, Location on the earth
   Phytoplankton Distribution
• Compensation Depth
  – Where rate of photosynthesis = rate of
    respiration
  – Below this phytoplankton will die
    Phytoplankton Distribution
• Higher near coast
  – Runoff
  – upwelling
Figure 13.6
   Phytoplankton Distribution

Varies across the globe – How?
    Phytoplankton Distribution
• Tropics
  – Low
  – Nutrients trapped below thermocline
    Phytoplankton Distribution
• Poles
  – Mostly Low (except for summer peak)
  – Insufficient light
    Phytoplankton Distribution
• Temperate Regions
  – Highest overall
  – sufficient light & nutrients
  – Spring Peak
     • Increasing sunlight
  – Fall Peak
     • Increasing mixing of nutrients
            Zooplankton
• Animal plankton – many different types
• Heterotrophic – primary consumers
• Based on the phytoplankon abundance
  graph…how would you expect zooplankton
  abundance to vary?
Figure 13.11a: Arctic Ecosystem
Figure 13.13a: Temperate Ecosystem
                Zooplankton
• Major types –
  –   Radiolarians
  –   Foraminifers
  –   Copepods
  –   Krill
                 Zooplankton
• Holoplankton
  – Spend their entire life in plankton
• Major types –
  –   Radiolarians
  –   Foraminifers
  –   Copepods
  –   Krill
  –   Jellyfish (cnidarians) and comb jellies
      (ctenophores)
Figure 14.3: Radiolarians

  Single-
  celled;
  Hard shell
  made of
  silica
Figure 14.4: Foraminifers

  Single-celled;
  shell made
  from calcium
  carbonate
Copepods
Small crustaceans
(<1 mm)
Very abundant
Figure 14.5: Copepod diversity
Krill – Important in Antarctic Ecosystem




                                           Fig. 13-9, p. 265
Fig. 13-10c, p. 266
               Zooplankton
• Meroplankton
  – Only found in plankton for part of their life
    cycle
  – Larvae of benthic adults & fish
Meroplankton

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:1
posted:11/4/2012
language:English
pages:50