Life in Water

Question 1

life began in water

Answer 1

stable temp, buoyancy (less structure), viscosity, density (large animals can fly), solvent

Question 2

what is the limiting resource

Answer 2

oxygen

Question 3

freshwater comes in two kinds:

Answer 3

lentic (still) and lotic (moving)

Question 4

physical factors

Answer 4

light, temperature, water movement, salinity, oxygen, pressure

Question 5

light compensation point

Answer 5

depth where rate of oxygen production and use are the same (less light, less photosynthesis in deep)

Question 6

thermocline

Answer 6

a layer of water through which temperature changes dramatically
layers: thermal stratification

Question 7

water cycling facts

Answer 7

driven by solar energy - wind, evaporation, clouds etc.
97% - oceans
2% polar icecaps
1% freshwater

Question 8

the hydrological cycle

Answer 8

reservoirs - lakes, ocean, atmosphere etc.
enterning water: precipitation or sub/surface flow
exits: evaporation, flow
cycle turn over is 9 days in atmosphere and 3100 in oceans

Question 9

how are currents formed? what do currents do?

Answer 9

wind blows

moderate climate, move nutrients, gene flow

Question 10

gyres

Answer 10

circulation systems that under Coriolis move right in NH and left in SH
- cold water from poles to equator
- warm water from equator to poles
this moderates climate

Question 11

upwelling

Answer 11

deep water moved to surface

Question 12

oceans as an environment

Answer 12

largest continuous environment

Question 13

littoral/intertidal zone

Answer 13

shallow shoreline, influenced by tides rising and falling

Question 14

neurotic zone

Answer 14

from coast to shelf (200m)

Question 15

oceanic zone

Answer 15

beyond continental zone

Question 16

epipelagic (photic) zone

Answer 16

surface to 200m

Question 17

mesopelagic zone

Answer 17

200-1000

Question 18

bathypelagic zone

Answer 18

1000-4000

Question 19

abyssal zone

Answer 19

4000-6000

Question 20

hadal zone

Answer 20

deepest

Question 21

benthic

Answer 21

habitants at bottom of aquatic environment

Question 22

pelagic

Answer 22

habitants above the bottom

Question 23

thermocline trends

Answer 23

permanent and drastic at tropics but weak at poles

Question 24

thermohaline circulation

Answer 24

at poles water freezes, leaving salt behind. water gets saltier and denser and sinks, pulling up less salty water = upwelling

• threatened by freshwater melting (less salty)
• cycles nutrients

Question 25

salinity

Answer 25

varies with evaporation and precipitation

Question 26

oxygen

Answer 26

highest at surface and bottom

Question 27

comparison of oceans

Answer 27

tropical seas are physically and chemically stable
temperature and high lat are more productive
highest productivity at coastlines
open ocean supports species and is important to O and CO2 budgets

Question 28

fringing reef

Answer 28

shore of island or continent (shallow, photosynthesis, tropics and subtropics)

Question 29

barrier reef

Answer 29

stands between open sea and lagoon (photosynthesis, shallow, tropics and subtropics)

Question 30

atolls

Answer 30

dotting islands

Question 31

kelp forests

Answer 31

photosynthesis, temperature regions

Question 32

levels of intertidal zone

- oxygen

Answer 32

supra tidal (splash zone), high intertidal, middle intertidal, low intertidal, subtotal (always covered)
- larger amount of oxygen

Question 33

spring tides and neap tides

Answer 33

sun and moon pull together (big); sun and moon work opposite (small)

Question 34

salt marshes, mangrove forests and estuaries

Answer 34

transition between freshwater and marine and marine and terrestrial
salt marshes have salt plans (evaporated water)
mangroves are tropical and subtropical
estuaries are dynamic
high productivity and many species in wetlands

Question 35

rivers and streams

• riparian zone
• vertical divisions

Answer 35

O not limiting
riparian zone: transition between water and terrestrial
vertical divisions: water surface, water column, benthic zone, hypoheic zone (transition to ground water), phreatic zone

Question 36

trees and turbidity on rivers and streams

Answer 36

limit light

Question 37

flood pulse concept

Answer 37

periodic flooding brings nutrients to flood plains and wetlands

Question 38

biochemical oxygen demand

Answer 38

some pollutants require a lot of oxygen to breakdown

Question 39

zones of lakes

Answer 39

littoral (shore) and limnetic (open)

Question 40

oligotrophic lake

Answer 40

well-mined, well oxygenated, low production

Question 41

eutrophic lakes

Answer 41

high production, low oxygen