Ecology- living on the edge

Question 1

Ecosystems in the coastal zone

Answer 1

1. estuary
2. lagune
3. mangroves
4. salt marshes
5. coral reefs

Question 2

coastal zone

Answer 2

area affected by the interaction between land and sea

Question 3

how do coastal ecosystems differ from oceanic ecosystems?

Answer 3

1. shallow with a lot of influence from:
   
   • weather
   • waves
   • tide
2. salinity is influenced by:
   
   • freshwater influx
   • evaporation (verdamping)

Question 4

estuary

Answer 4

An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environments and are an example of an ecotone. This habitat is very important for diadromous fish species.

Question 5

river influx vs. tidal currents in estuaries

Answer 5

1. salt-wedge
2. partially mixed
3. well-mixed

Question 6

Estuary salt-wedge

Answer 6

1. high river influx
2. little tidal currents
3. water mixes almost never- strong halocline
4. mostly river sediment

Question 7

Estuary partially mixed

Answer 7

1. more effect of tidal currents
2. turbulent
3. better mixing: weak halocline
4. sediment out of the river and sea (mixing between salt water and fresh water layers produces a vertical salinity gradient)

Question 8

Estuary well-mixed

Answer 8

1. low river influx
2. high tidal current
3. river water and seawater on the other side
4. gradual mixing of the water (lateral)
5. no halocline

Question 9

why do some animal species live in estuaries despite the challenges?

Answer 9

there is less competition due to increased space and food opportunity and there is less predation

Question 10

estuaries are very productive

Answer 10

1. influx of nutrients, organic material and oxygen through waves and currents
2. fytoplankton growth is sometimes limited through light
3. detrius chain is very important here

Question 11

diadromous

Answer 11

fish that migrate between fresh and salt water

Question 12

anadromous

Answer 12

migrates to fresh water in order to spawn

Question 13

catadromous

Answer 13

migrates to salt water in order to spawn

Question 14

examples of anadromous fish

Answer 14

1. atlantic salmon
2. rainbow trout
3. atlantic sturgeon
4. driedoornige stekelbaars

Question 15

examples of catadromous fish

Answer 15

1. bot (flounder)

2. paling (eel)

Question 16

lagune

Answer 16

A lagoon is a shallow body of water separated from a larger body of water by a narrow landform, such as reefs, barrier islands, barrier peninsulas, or isthmuses. Lagoons are commonly divided into coastal lagoons and atoll lagoons. They have also been identified as occurring on mixed-sand and gravel coastlines. Does not occur in just tropical regions. It is brackish-hypersaline.

Question 17

biggest difference between an estuary and lagune

Answer 17

no major influence of a “fresh water connection” in a lagune

Question 18

Benefits of a lagune

Answer 18

1. a lot of shelter
2. a lot of food
3. relatively low predation
4. fish reproduction (larval catch)–> useful as a nursery

Question 19

Lagunes in the subtropics

Answer 19

1. a lot evaporation
2. little rainfall
   hypersaline water sinks to the bottom and there is replenishment via the surface. This causes and inverse flow where the bottom flows out.

Question 20

Mangrove distribution is influenced by….?

Answer 20

1. temperature
2. waves and currents
3. depth and tide
4. substrate
5. salinity and other physical variables

Question 21

Mangroves can be described as…?

Answer 21

ecosystem engineers. They change the ecosystem drastically.

Question 22

what forms the foundation for the mangrove food chain?

Answer 22

detrius, mainly leaf waste

Question 23

mangroves in bonaire

Answer 23

1. variables are within a tolerant range
2. small avicennia trees
3. no development into mangrove forest

Question 24

what is the hypothesis to why the bonaire mangroves aren’t expanding into a forest?

Answer 24

goats graze on the mangroves

Question 25

how what the bonaire goat hypothesis tested?

Answer 25

2011: measured out plots and fenced of vegetations
2013: refreshed the vegetation
2015: the vegetation was overgrowing!

Question 26

salt marsh

Answer 26

A salt marsh or saltmarsh, also known as a coastal salt marsh or a tidal marsh, is a coastal ecosystem in the upper coastal intertidal zone between land and open saltwater or brackish water that is regularly flooded by the tides.

Question 27

salt marsh flooding: low salt marsh

Answer 27

daily

Question 28

salt marsh flooding: high salt marsh

Answer 28

only by extreme high tide

Question 29

youthful marsh

Answer 29

1. low marsh is larger than the high marsh
2. well developed drainage system
3. relatively rapid sedimentation rates

Question 30

mature marsh

Answer 30

1. low marsh and high marsh are relatively equal
2. good drainage (especially in low marsh)
3. relatively slow sedimentation rates

Question 31

old marsh

Answer 31

1. low marsh is smaller than the high marsh
2. poor drainage (mainly by surface runoff)
3. extremely slow sedimentation rates

Question 32

salt marsh (fully developed)

Answer 32

1. not always direct consumption of primary production
2. detritus food chain is important
3. input from estuarine ecosystem

Question 33

tidal flow inlets

Answer 33

washover fans and blowouts (dunes)