A cyanobacteria bloom

1
Phytoplankton
MARE 444 Lecture 2
2
Phytoplankton

• the majority of the plants in the ocean are
  planktonic unicellular algae called
  phytoplankton.
• some can be caught be nets, others can only be
  collected by filtering or centrifugation (e.g.,
  nano- and picoplankton).

3
Phytoplankton

• Group Phycological Terminology
• Diatoms Bacilliariophyceae
• Dinoflagellates Dinophyceae
• Microflagellates Haptophyta, Prymnesiophyta,
• Chrysomonadales,
• Cryptomonadales
• Picoplankton Photoautotrophs lt 2µm
• Cyanobacteria Cyanophyta, photosynth bact.
• Prochlorococcus Photosynth bacteria
• Eukaryotic Pico Very small, struct. advanced

4
Phytoplankton

• Vital role in marine food chain
• 4000 species of phytoplankton have been
  described, new species are continually being
  described
• At least 13 classes of marine phytoplankton are
  distinguished, representing a wide variety of
  organisms

5
Phytoplankton
Phytoplankton account for about half of global
primary production
6
Types of Phytoplankton

• Bacteria and cyanobacteria
• Diatoms
• Dinoflagellates
• Others

7
Photosynthetic Bacteria and Cyanobacteria
8
Photosynthetic Bacteria

• Prokaryotic (Kingdom Monera)
• Contain bacterial chlorophyll (different from the
  other chlorophyll molecules)

9
Cyanobacteria

• Prokaryotic (Kingdom Monera)
• Contain chlorophyll-a (like eukaryotic autotrophs)

10
Cyanobacteria

• Important primary producers
• Small size (1-2µm)- large SAV ratio
• Sink or rise very slowly
• Maximize nutrient absorption
• Reduces grazing loss

11
Cyanobacteria

• Distribution

12
A cyanobacteria bloom
13
The Diatoms

• Microalgae

14
Diatom Cellular Structure
(chrysolaminarin)
(chlorophyll a and c, fucoxanthin, etc)
15
The Diatoms
16
Planktonic diatoms

• Silica shell and lack of flagella sinking
• diatoms evolved various strategies to counter
  sinking
• chains
• spines
• oil droplets
• ionic regulation - internal ion concentration is
  lower than external seawater reduction in
  density

17
(No Transcript)
18
Diatoms with elaborate spines and
processes Functions
19
The Dinoflagellates
20
Dinoflagellate Characteristics

• Typically 2 flagella
• Large nucleus (looks like a fingerprint)
• Chlorophylls a and c
• Accessory pigments (ß-carotene, peridinin,
  xanthophylls)
• Food reserve is starch

21
Dinoflagellate Characteristics

• Some have

22
Dinoflagellate Characteristics

• Some are autotrophic, others are auxotrophic,
  others are mixotrophic, others are heterotrophic

23
Dinoflagellate Taxonomy

• Armored
• plates (numbers, shapes)
• Naked
• size and shape
• cingular position, displacement, and overhang
• sulcal placement and intrusion
• presence/shape of apical groove

24
Dinoflagellate Ecology

• Dinos tend to occur in the summer and early fall
  when nutrients are more depleted and seas are
  calmer

25
Microflagellates

• Some (e.g., coccolithophorids) are very common

26
Coccolithophores
Unicell containing a haptonema between two smooth
flagella Haptonema - a coiled appendage that is
used for feeding and sensory purposes Chlorophylls
a, c1, and c2, carotenoids Chrysolaminarin
27
Coccolithophores
Single regular calcareous plates
28
Prokaryotic Picoplankton
Prochlrophyta Often most abundant phtoplankton in
oligotrophic, tropical waters Have traits in
common with several taxonomic groups bacteria,
cyanobacteria, green algae
29
Eukaryotic Picoplankton
Typically green algae (Chlorophyta) Contain
chlorophylls a and b, carotenoids,
xanthophylls Starch is the food reserve 1, 2, 4,
or 8 flagella
30
(No Transcript)