Lec 12 Flashcards
Holoplankton =
organisms that spend their entire life cycle as part of the plankton
(e.g. most algae, copepods, salps, and jellyfish)
Meroplankton:
organisms that are only planktonic for part of their lives (usually the larval stage), and then graduate to either the nekton or a benthic existence
Phytoplankton =
autotrophic prokaryotic or eukaryotic algae that live near the water surface where there is sufficient light to support photosynthesis - diatoms, cyanobacteria, and dinoflagellates
Zooplankton =
animals that feed on other plankton. Eggs and larvae of larger animals, such as fish, crustaceans, and annelids, are included here
Bacterioplankton =
bacteria and archaea, which play an important role in remineralizing organic material down the water column
Nutrients =
Nitrogen is the most important limiting nutrient, but phosphate and iron are also important
Light =
phytoplankton is limited to the photic zone, also seasonality is going to play an important role, especially near the poles.
The phytoplankton also affects…
the size of the photic zone = (self-shading)
3 Phytoplankton
Diatoms
Dinoflagellates
Cyanobacteria
Diatoms:
Very important primary producers, common in temperate and cold waters
Dinoflagellates:
More common in warm waters, better adapted to low nutrient conditions
Cyanobacteria:
Account for more than half of the ocean’s primary producers
spring bloom
Spring: light no longer limiting, nutrients available as a consequence of winter mixing and upwelling
fall bloom
Fall: storms produce mixing, some light still available, small burst of production
red tides
With stable conditions dinoflagellates can grow explosively into huge numbers, some times causing red tides
