34: Estuaries

benefits of the sea

supporting, regulating, cultural, provisioning

sea covers ___% of earth

70

sea provides __% of space for life on earth

98

majority of sea is

deep sea (>200m)

marine biodiversity has the ______ 'phylogenetic' level

greatest

there are ____ animal phyla in marine systems

>30

how many freshwater/terrestrial phyla are there?

11-14

how many phyla are found only in marine ecosystems?

15

there are an estimated 600,000 to ___ million species associated with tropical coral reefs

9 million

ecosystem functioning

how nature provides clean water, air, food etc.

biodiversity relates to ecosystem functioning and thus provides

clean water, air, food etc

loss of predator species, not intermediate consumers, triggers rapid and dramatic

extinction cascades

what enables marine communities to resist warming?

herbivory

marine habitats by depth

estuary

where rivers meet the sea

how to define an estuary

difficult - usually based on salinity

topographical classification of estuaries

- coastal plains with eustatic sea level rise or fjords

- offshore deposits can cause barriers across bays or inlets

- isostatic variation driven by tectonic activity

large estuaries tend to have _____ tidal ranges

large

1 multiple choice option

estuaries can be defined by

salinity, topography, tidal range

tidal range classifications

microtidal (<2m)

mesotidal (2-4m)

macrotidal (4-6m)

hypertidal (>6m)

tidal prism

difference between volume of water when tide is in and ot

tidal range moderates the variability of

extreme environments

tidal range can be altered by

urbanisation

tidal range is a source of

renewable energy

what key environmental factors influence organisms in estuaries?

- salinity

- sediment

- dissolved oxygen

- temperature

which is not a key environmental factor influencing organisms in estuaries?

light

3 multiple choice options

salinity is measured using

dimensionless measure: practical salinity unit

salinity ______ along an estuary, dramatically in ___-estuary

varies, mid

________ salinity profiles are used to classify estuaries

vertical

intertidal mudflats

river sediment

- soft fine silt, difficult to walk in

- rich in organic material

- high secondary production

- deposit feeders can thrive

temperature _______ vary with tidal cycles

doesn't

1 multiple choice option

zones within estuaries

1: head

2: upper reaches

3: middle reaches

4: lower reaches

5: mouth

estuarine organisms

fish, chironomids, nematodes, crustaceans, bivalves, amphipods, diatoms, green algae

plants ____ common in estuaries

aren't (only seagrass)

are estuaries important habitats for birds

yes

bioturbators

organisms that move/mix sediment while burrowing or feeding