drift with currents.

• weak swimmers at best
• phytoplankton = photosynthetic plankton
• zooplankton = animal plankton

spend whole life in plankton

eg copepods, krill

spend part of life in plankton

eg larvae or many invertebrates

• need to maintain position in epipelagic zone
• no place to hide from visual predators

• Increased drag - flat, spines
• Increased buoyancy - gas floats, fat droplets
• Swim - cilia, appendages

1. adaptive response to slow down metabolism (colder at depth)
2. predator avoidance (migrate to the surface at night to avoid visual predators)
3. predator avoidance (migrate to depth during night to avoid predators migrating the opposite way)
4. laying eggs

• Phototrophic (photosynthetic) prokaryotes
• probably first organisms to release O2 in atmosphere
• Photosynthetic pigments: "blue-green algae"
• fix nitrogen - convert nitrogen gas (N2) to nitrate (NO3) or nitrite (NO2)

Cyanobacteria discovered in 1979

Very small (ca. 1 um)

Good competitors for nutrients

cyanobacteria discovered in 1988

very small (<1.0 um)

Most abundant autotroph on earth

forms aggregates

fixes nitrogen

• All have nucleus
• Usually single celled
• Include both autotrophs and heterotrophs
• Genome analysis also shows that many of the groups placed in the Protista are not at all closely related to one another
• Eukaryotes that are neither Animals, Fungi, nor Plants

• Unicellular micoalgae
• protozoans
• macroalgae (formerly considered plants)

• Important in coastal areas and spring blooms
• they are responsible for as much as 40 percent of the photosynthesis that occurs in fresh water and in the oceans

Usually marine form

Radial symmetry

Usually shallow and freshwater form

Bilateral symmetry

• Motile; can migrate vertically
• there are autotrophic and heterotrophic species
• about 1000 species
• cellulose plates

• Phytosynthetic Nanoplankton
• CaCO3 skeletal plates (coccoliths)
• Flagellated and photosynthetic
• Found mostly in low nutrient regions
• Leading calcite producers in the ocean
• Reflects light and primary production is supressed

• single celled
• animal like, but some can photosynthesize
• major groups: formaniniferans, radiolarans, ciliates (all zooplankton)

• Considered by many as protists though almost all are multicellular
• Photosynthetic autotrophs
• Lack true features of plants - roots and shoots
• Entire body of alga called thallus which can include blades, pneumatocycts, stipe, and holdfast

1. Macroalgae are primary producers, i.e. belong to first trophic level and "feeds" herbivorous grazers. Production is high locally (1% of the ocean's total primary productivity)
2. Macroalgae provides shelter for larvae of marine animals inclusive of fishes

1. Green algae: Chlorophyta
2. Brown algae: Phaeophyta
3. Red algae: Rhodophyta

Differences in color due to different photosynthetic pigments

• small percentage marine
• grass green or yellow green in color
• have chlorophyll - similar to terrestrial plants, may have given rise to terrestrial plants

• mostly marine
• brown/yellow-brown in color
• Chlorophyll
• Fucoxanthin (accessory pigment)
• the largest of the macroalgae

largest of the kelps

Kelp forests are among the richest, most productive marine environments

• floating seaweed forms a unique community
• Sargasso Sea with large rafts
• many animals are endemic
• special camouflage to match Sargassum seaweed

• Almost exlusively marine
• sometimes red but color variable
• chlorophyll
• phycobillins (accessory pigments) - phycocyanin (blue) and phycoerythrin (red)

Coralline red algae important reef builders

• Pharmaceutical and food products
• algin is a stabilizer and emulsifier in the manufacture of dairy products
• carrageenan from rd algae is an emulsifier found in dairy products and instant puddings
• agar forms gels and is employed to protect ham, fish and meats during canning; laxatives, and other pharmaceuticals and cosmetics; growth medium for bacteria

• Eukaryotes
• Multicellular
• Photosynthetic autotrophs
• terrestrial adaptations - roots and shoots

• only truly marine plant
• not really grasses
• root like, horizontal stems
• small inconspicuous flowers
• provides food and shelter
• stabilizes sediments and prevents erosion
• take up dissolved nutrients and trap sediments in the water resulting in high water clarity

• really land plants that are tolerant to salt
• do not tolerate submergence
• adaptations to get rid of excess salt - salt glands in leaves
• include - cordgrass, pickle weed

• around 80 unrelated species or trees and shrubs
• tropical / subtropical
• special adaptations - long roots, thick leaves

• almost every animal phylum has representatives
• holoplankton: spends whole life in plankton
• meroplankton: spends only part of life in plankton - includes many larvae of benthic animals

• shell of calcium carbonate: test
• pseudopodia: used for feeding
• most live on bottom, few in plankton
• important microfossils

• shells of glass
• pseudopodia, used for feeding
• found throughout the ocean

• covered with many hair like cilia
• can be attached or free
• some have vase like cases called loricas
• micropredators

• currents carry the offspring to new areas, especially important for sessile (immobile) benthic animals
• meroplankton live in surface waters where food is abundant

• if the spring bloom is not "on time", meroplankton may starve
• meroplankton are food for the many predators on plankton
• the currents may not carry the meroplankton to an area that provides suitable conditions for adults