Eduardo Infantes - Marine ecology 2

Question 1

Competition for space

Answer 1

High compeition, everyone wants to live on the rock.
Resouces: light, nutrients, attachment surfaces, hydrodynamics.
Strategies: predation, growing rates, morphology

Question 2

What do the communities depend on?

Answer 2

Location, tidal range, wave exposition, temperature. Lower part dominated by competitve species, top parts dominated by tough species.

Question 3

Upper intertidal

Answer 3

Dominated by physical factors: temperature, salinity, exposure to air, hydrodynamics.

Question 4

Lower intertidal

Answer 4

Dominated by biological factors: predation and competition.

Question 5

Intertidal habitat species

Answer 5

Macroalgae, gastropoda, limpets, chitons, mussels, hermit crabs, sea stars, barnacles, crabs, sea weed.

Question 6

Adaptation to hydrodynamic exposure

Answer 6

Change shape, flexibility, size, to have low drag and be streamlined.

Question 7

Turbulence and morphology

Answer 7

Laminar, less resistance to the fluid movement - transition - turbulent, more friction to the fluid

Question 8

Algae: green, brown, red

Answer 8

Grows on different water depth, depends on what wavelength of light they use. Green close to surface, then brown, and red deepest. Kelp is a type of brown algae.

Question 9

Kelp forests

Answer 9

Provides habitats. Can grow 25-30 m in one season. Can be 45 m long. They are among the most productive plants. The like cold water, 6-14 degrees. Provides coastal protection. They need nutrient rich water, and grow fast. Used for food, soap, alginate and sodium carbonate.

Question 10

Kelp structure

Answer 10

Blade, air bladder, stripe, anchoring part.

Question 11

Sea otters tipping point

Answer 11

Without sea otters, bare sea floor with a lot of urchins. Sea otters eat sea urchins, without them, the sea urchins will grow and eat the kelp.

Question 12

Tropical coral reefs

Answer 12

In warm water in tropical areas. The coral skeletons are made by calcium carbonate. Many different types of fishes, huge biodiversity.

Question 13

Types of corals

Answer 13

Soft or hard corals. Massive or branching. Platelike, encrusting, foliaceous, free living, columnar.

Question 14

Hard vs soft corals

Answer 14

Hard: tentacles in multiples of six, create limestone skeleton, the main reef builders, both colonial and solitary, bleach when stressed, skeleton remains after death.
Soft: tentacles in multiples of eight, no limestone skeleton, very few reefbuilders, resilient, both colonial and solitary, bleach when stressed, no trace after death.

Question 15

Importance of coral reefs

Answer 15

Medication, biodiversity, food and fishing, coastal protection, tourism and recreation.

Question 16

Threats to coral reefs

Answer 16

Sewage pollution, sediment load, physical damage, overfishing, oil spills, boats, temperature rise.

Question 17

Regime shift, coral vs algae

Answer 17

Healthy, coral dominated. Temperature rise tipping point. Unhealthy, algae dominated

Question 18

Deep, cold water corals

Answer 18

Depth 200-400 meters. Cold water. Grows slowly, 1 mm per year. In the atlantic and the pacific.

Question 19

Deep cold corals vs tropical corals

Answer 19

Deep cold: global distribution, depth range 40 - 1200 meters, largest reef 100 km2, temperature 4-13 degrees, 6 species.
Tropical: between 30 degrees north and 30 degrees south, 0-100 meters deep, largest reef 30000 km2, 20-29 degrees, 800 species.

Question 20

Hydrothermal vents communities

Answer 20

A fissure in the surface crust from which geothermally heated water arises. Water temperature 60-450 degrees, ambient water around 2 degrees. Fish, octupus, crabs, filter feeders.