Phytoplankton: diversity and ecology
● Phytoplankton and earth’s chemistry
○ Marine cyanobacteria evolved 3.8 billion years ago and altered earth’s chemistry through photosynthesis
○ Photosynthesis reduces carbon dioxide concentrations and increased oxygen content
○ Two major oxygenation events: early proterozoic and late proterozoic
● Roles of phytoplankton in ecosystems
○ Marine phytoplankton play crucial roles in marine ecosystems
○ They form the base of the marine food web
○ Contribute to 50% of global primary production
○ Primary production is highest in coastal areas, equator (upwelling) and poles
● Basics of marine productivity
○ Productivity fuels life in the ocean and lowers atmospheric carbon dioxide
○ Ocean primary productivity refers to the production of organic matter by phytoplankton
○ Phytoplankton are photoautotrophs that convert inorganic to organic carbon
○ Phytoplankton utilize nutrients from the ocean and dissolved carbon dioxide
● Phytoplankton growth and succession
○ Phytoplankton growth requires light, nutrients, and optimal environmental conditions
○ Phytoplankton reproduce through asexual and sexual reproduction
○ Diatoms, green algae, and cyanobacteria take turns with their blooms
○ Different species have different growth preferences
● Photosynthesis in phytoplankton
○ Photosynthesis occurs in eukaryotic chloroplasts and internal membranes of some prokaryotes
○ Photosynthesis can be separated into light and dark reactions
○ Photosynthetic pigments capture sunlight and convert it into energy
○ Photosynthesis can be measured using various methods
● Photosynthetic activity in the ocean
○ Photosynthetic activity in the ocean is influenced by incident solar radiation
○ Light availability affects photosynthetic activity varies with depth and wavelength
○ Satellite remote sensing provides information about phytoplankton distribution
Metazoan zooplankton diversity
● Zooplankton classification
○ Definition: drifting animals
○ Animal (that eat other plankton)
○ Drifting (weak swimming) animals
○ Classified by size
○ Classified by developmental stage
● Protist zooplankton
, ○ Single-celled
○ Includes invertebrates and vertebrates from many different phyla
○ Complex reproduction
● Metazoan zooplankton
○ Multi-cellular
○ Includes invertebrates and vertebrates from many different phyla
○ Complex reproduction
● Zooplankton diversity
○ Crustaceans
○ Pelagic tunicates
○ Appendicularians
○ Salps
○ Doliolids
○ Pyrosomes
○ Chaetognaths
○ Pelagic molluscs
○ Ctenophores
○ Cnidarians
○ Pegliac polychaetes
● Zooplankton diversity - crustaceans
○ Crustaceans - copepods
■ Small crustaceans found in the sea and nearly every freshwater habitat
■ Some species are planktonic, some are benthic, and some live in terrestrial habitats
■ Copepods are sometimes used as biodiversity indicators
■ Copepods have a complex life history
○ Crustaceans - cladocerans
■ Commonly found in lakes and ponds
■ Characterized by branched antennae and a carapace
■ Parthenogenesis is common
■ Some undergo cyclomorphosis
○ Crustaceans - ostracods
■ Characterized by a bivalved carapace and a small number of appendages
■ Usually found in the euphotic zone
○ Crustaceans - euphausiids
■ Incredibly common in the plankton
■ Large taxa that are common filter feeders
■ Strong swimmers that often exhibit swarming behavior
● Phytoplankton and earth’s chemistry
○ Marine cyanobacteria evolved 3.8 billion years ago and altered earth’s chemistry through photosynthesis
○ Photosynthesis reduces carbon dioxide concentrations and increased oxygen content
○ Two major oxygenation events: early proterozoic and late proterozoic
● Roles of phytoplankton in ecosystems
○ Marine phytoplankton play crucial roles in marine ecosystems
○ They form the base of the marine food web
○ Contribute to 50% of global primary production
○ Primary production is highest in coastal areas, equator (upwelling) and poles
● Basics of marine productivity
○ Productivity fuels life in the ocean and lowers atmospheric carbon dioxide
○ Ocean primary productivity refers to the production of organic matter by phytoplankton
○ Phytoplankton are photoautotrophs that convert inorganic to organic carbon
○ Phytoplankton utilize nutrients from the ocean and dissolved carbon dioxide
● Phytoplankton growth and succession
○ Phytoplankton growth requires light, nutrients, and optimal environmental conditions
○ Phytoplankton reproduce through asexual and sexual reproduction
○ Diatoms, green algae, and cyanobacteria take turns with their blooms
○ Different species have different growth preferences
● Photosynthesis in phytoplankton
○ Photosynthesis occurs in eukaryotic chloroplasts and internal membranes of some prokaryotes
○ Photosynthesis can be separated into light and dark reactions
○ Photosynthetic pigments capture sunlight and convert it into energy
○ Photosynthesis can be measured using various methods
● Photosynthetic activity in the ocean
○ Photosynthetic activity in the ocean is influenced by incident solar radiation
○ Light availability affects photosynthetic activity varies with depth and wavelength
○ Satellite remote sensing provides information about phytoplankton distribution
Metazoan zooplankton diversity
● Zooplankton classification
○ Definition: drifting animals
○ Animal (that eat other plankton)
○ Drifting (weak swimming) animals
○ Classified by size
○ Classified by developmental stage
● Protist zooplankton
, ○ Single-celled
○ Includes invertebrates and vertebrates from many different phyla
○ Complex reproduction
● Metazoan zooplankton
○ Multi-cellular
○ Includes invertebrates and vertebrates from many different phyla
○ Complex reproduction
● Zooplankton diversity
○ Crustaceans
○ Pelagic tunicates
○ Appendicularians
○ Salps
○ Doliolids
○ Pyrosomes
○ Chaetognaths
○ Pelagic molluscs
○ Ctenophores
○ Cnidarians
○ Pegliac polychaetes
● Zooplankton diversity - crustaceans
○ Crustaceans - copepods
■ Small crustaceans found in the sea and nearly every freshwater habitat
■ Some species are planktonic, some are benthic, and some live in terrestrial habitats
■ Copepods are sometimes used as biodiversity indicators
■ Copepods have a complex life history
○ Crustaceans - cladocerans
■ Commonly found in lakes and ponds
■ Characterized by branched antennae and a carapace
■ Parthenogenesis is common
■ Some undergo cyclomorphosis
○ Crustaceans - ostracods
■ Characterized by a bivalved carapace and a small number of appendages
■ Usually found in the euphotic zone
○ Crustaceans - euphausiids
■ Incredibly common in the plankton
■ Large taxa that are common filter feeders
■ Strong swimmers that often exhibit swarming behavior
