Estuarine and intertidal ecosystems Flashcards
how did Elliott and Whitfield, 2011, define an estuarine ecosystem
A semi enclosed costal body of eater which is connected to the sea either permanently or periodically, varying in salinity due to freshwater inputs and includes characteristic biota
What is the definition of an intertidal ecosystem
the area above water level at low tide and underwater at high tide
outline some characteristics of the Granges-Brahmaputra-Meghna delta estuary
- it has fertile alluvial soil
- supports 400 million people
flows into the bay of begal
what are the 4 types of estuary
1) Fjord- carved and modified by glaciers
2) costal plain- water fills already existing valley
3) bar built- formed by deposited sediments from waves
4) Tectonic- formed from tectonic plate activity
what is the differences between the terms halocline and isohaline
Halo= a salinity gradient
Iso = a line of uniform salinity
what is a positive and negative estuary
positive = where freshwater input exceeds evaporation and dominated over sea water
negative/inverse= low precipitation and high evaporation increasing salinity
what affect does the coriolis effect have on estuary’s
inward and outward currents are displaced rightwards of the direction o flow meaning deeper water to the right is saltier in the northern hemisphere
what does primary production to with solutes in esturarys
removes dissolved inorganic carbon, nurtients and some traces of metals and also forms particles
what is flocculation
when the ions on the surface of particles allow other particles to stick together
outline some extremes which come with living in an estuary
1) temperature
2) salinity
3) desication
4) oxygen depletion
what are the salt tolerances of stenohaline, euryhaline and brackish species
S- marine species live up to 30 can grow under this
E- marine species survive below 30
B- optimum for growth is 3-10
what is the difference between osmoconformers and osmoregulators
formers = allow their body fluid to change with salinity
regulators= keep salt conc constant by regulating conc of solutes in their body
outline some estuarine plant adaptations
1) absorb salt and concentrate sugars to prevent water from leaving tissues = GRASSES
2) excrete salt from salt glands in their leaves
3) absorb more water to dilute salts
what are some common features between estuarine and inter-tidal communities
- open water communities
- mudflat and sedimentary communities
- rocky shore communities
- salt-marshes and mangroves
outline some characteristics of open water communities
have high abundance and variety
leads to rich supply of fish and shellfish which many settlements take advantage of
