Water Flashcards
The biological activity of an aquatic ecosystem ultimately depends on
The activities of the primary producers (phytoplankton)
What are primary producers in the ocean
Algae
Cyanobacteria
Phytoplankton serve as ___ for chemeheterotrophs
A food source
The activities and net number of phytoplankton and net numbers of phytoplankton depend on
- Temperature
- Light received
- Availability of specific limiting nutrients such as nitrogen and phosphorus
What is photic zone
In clear water, light will penetrate to a maximum of 300 m
How deep the light penetrates in coastal waters
50 m
Why in open ocean there is more light penetration than in the coastal region
Near the coat there is more particles dissolved
What organisms live in the ocean and why ( salt)
High salinity (3%)-> halotolerant or hylophylic
What is pelagic zone
the water column of the open ocean, and can be further divided into regions by depth. . It goes from the surface almost to the bottom
75 % of the ocean is deeper than
1000 m
What is the pressure at the deepest place in the ocean
1100 atm
What is the correlation between the depth and the pressure
every 10 m increasing by 1 atm
Below 100 m the temperature of the ocean is constant
2-3C
The open ocean is ___ (low nutrients)
oligotrophic
What is the outcome of the fact that the open ocean is oligotrophic
primary productivity is very low due to the lack of inorganic nutrients ( nitrogen, phosphorus, iron) that are required byp hytoplankton
Temperature of the water is ___ closer tot he shore
Warmer
What happens in some regions due to wind and ocean currents
Upwelling of water from the ocean floor bringing nutrients to the surface and promoting productivity
What is an indicator of the primary productivity
Chlorophyll
Chlorophyll concentration depends on
The season
bulk of primary productivity comes from
prochlorophytes
What are procholorophytes and there latin name
Tiny phototrophs phylogenetically related to the cyanobacteria.
Prochlorococcus
General adaptations seen in pelagic (open ocean) microorganisms
- Reduced size (high surface//volume ration)
- High affinity transport system
Who are trichodesmium and there characteristics
- Filamentous cyanobacteria
- Contains phycobilins ( help to capture light)
- Nitrogen fixation
As the primary productivity is higher in coastal water, how it can be called
Eutrophic