Lecture 9 Flashcards
1
Q
Esturaries
A
- Transient zones between rivers and the sea
- doesn’t include brackish waters
- Intermediate levels for salinity
- Complex and dynamic habitats - daily fluctuations
- High nutrients, low species diversity, high biomass
1
Q
Tidal range
A
- Drives fluctuations
- Height difference between maximum and mimimum tide
2
Q
Adaptions to esturay fluctuations
A
- Osmoregulation for salinity changes
- Clsoe shells
- Bury in sediment
- Migrate
3
Q
Density
A
- Freshwaeter is less dense than seawater creating stratification levels
4
Q
Mixing
A
Occurs as depth decreases towards the rivers, (e.h., salinity gradient)
5
Q
Sediment
A
- Sediment gradient of clay to sand affects water turbidity
- Sand is bigger and heavier, settles more quickly than clay
6
Q
Estuary production
A
- Dominated by periphyton
- Turbid water - light limitation for phytoplankton
- Sediments exposed by low tide get plenty of sunlight
7
Q
Periphyton
A
- Attached microbial communities
- Algae and heterotrophic microbes live in a jeely-like matric
- Major algae are pennate diatoms
- Matrix prevents dehydration
8
Q
Benthic invertebrate community
A
Dominated by collectors (moluscs)
