Chapter 2: Primary Production Flashcards
Name all the different sizes of plankton
Femtoplankton - 0.02-0.2um Picoplankton - 0.2-um Nanoplankton - 2-20um Microplankton - 20-200um Mesoplankton - 0.-20mm Macroplankton - 2-20cm Megaplankton - 0.2-2m
Describe Diatoms
Class Baccilariophyceae
- silica frustule
- no visible flagella
- centric or pinnate
- pelagic/benthic forms
- solitary/colonial
Describe dinoflagellates
Class Dinophyceae
- 2 visible flagella
- cellulose plates
- typically solitary
- reproduce via mitosis, no size change
- harmful algae in blooms
- some bioluminescent
- many heterotrophs
- endosymbiotic zooxanthellae (symbiotically work with other species, illumination etc.)
Describe Haptophyceae
Naked cells, mainly solitary forms
Motile: 2 flagella, 1 haptonema
Describe Coccolithophores
Covered in coccolits (small calcium plates)
-solitary w/ complex life cycles
What is probably the most common phytoplankton in the ocean?
what does it contribute?
Prochlorophytes (a cyanobacteria)
- > 30-70% of Chl.a in open oceans
- > 30-80% of total ocean productivity
Name the big 3 algal toxins and human health issues
- PSP (paralytic shellfish poisoning)
- NSP (Neurotoxic shellfish poisoning)
- DSP (Diarrhetic shellfish poisoning)
Photosynthesis equation.
6CO(2) + 6H(2)O C(6)H(12)O(6) +6O(2)
name 3 ways to measure primary production
1) from the reaction, measure changes in O2 or in CO2
2) Light/dark-bottle method, where you use a clear (photosynthesis) + opaque (respiration) bottle, and measures of oxygen are taken by winkler titration.
3) 14C method where radioactive carbon is added to the water sample, and tested for algae growth.
Photosynthesis in the ocean is affected by:
- Radiation level
- Availability of nutrients
- Water mass properties
In the light spectrum, what is the Photosynthetic Active Radiation (PAR) range?
the visible light spectrum, from 380-710nm
name some systematic and unsystematic variations for solar radiation
systematic: with season, over the day.
unsystematic: cloud cover, vegetation, competition
Light penetration in the water column depends on:
- water clarity (absorption, reflectance)
- wavelength (red colors are absorbed more rapidly than blue)
Which law describes the attenuation of radiation?
Beer’s law
Compensation depth
The depth in the water column where photorespiration = photosynthesis
(ie: primary productivity = 0)
what are the four main nutrient salts?
Nitrate, Nitrite, ammonia and phosphate
describe the phytoplankton community succession of temperate and tropical seas.
Temp:
small diatoms->large diatoms -> dinoflagellates
Trop:
coccolithophors and dinoflagellates dominate throughout the seasons, but minor diatom blooms are common.
what factors are proposed to regulate the succession of phytoplankton?
- temperature
- changes in nutrient salt concentrations
- biological conditioning
- biological control
What is the theoretical reason for ‘high nutrient low chlorophyl’ subarctic waters, and how does iron influence this?
- waters may not receive enough light
- too much grazing pressure
- not enough iron (iron is introduced from land, and may not reach these offshore areas)
what is the typical elemental composition of an algal cell?
protein: 40%
carbohydrate: 40%
lipid: 15%
nucleic acid: 5%
how is the ocean’s capability of acting as a ‘carbon sink’ being affected by global warming?
1) as the oceans warm, they have less capability of absorbing the CO2
2) As more CO2 is absorbed there will be a reduction of pH in the water, resulting in the process of ocean acidification.
the main limiting inorganic nutrients are what?
- nitrogen
- phosphorus
- some areas iron
what large-scale processes influence the rate of primary productivity in the ocean?
frontal systems, gyres, river plumes and coastal upwelling
they transport nutrient-rich waters to the sea surface
