Lecture 14

Question 1

Coastal subtidal habitats are dominated by what species?

Answer 1

Foundation species
-seagrass
-algae
-epibenthic invertebrates
-corals

Question 2

How do seagrasses reproduce?

Answer 2

Sexually (pollen transported in water) and asexually

Question 3

Where do seagrasses occur?

Answer 3

in soft sediments

Question 4

What are seagrasses limiting factors?

Answer 4

-light (high)
-flow (intermediate)
-turbidity

Question 5

Where is seagrass more likely to survive?

Answer 5

in more diverse plots

Question 6

The more diverse plots contain which species?

Answer 6

Halodule, a species that performs better

Question 7

What do seaweeds do?

Answer 7

-stabilize sediments
-trap and supply nutrients
-enhance organic matter

Question 8

What is the role of seagrass as a foundation species?

Answer 8

-provide structure on a flat enviroment
-settlement substrate
-shelter
-nursery habitat

Question 9

What does seagrass do to mitigate disease risk?

Answer 9

Seagrass helps reduce the amount of bacteria where it is present.

Question 10

Where do rocky reefs and kelp forests thrive?

Answer 10

on hard bottoms and in cold water

Question 11

What do dominant species in the rocky reef depend on?

Answer 11

Depth; produces live in shallower areas
Aspect: producers on horizontal

Question 12

What happens when light availability decreases?

Answer 12

There is a shift from producer dominant system to an invertebrate dominated system because they don’t need light

Question 13

What are the requirements of an alternate stable state?

Answer 13

-same location
-same environmental conditions
-stable
-stable over one complete population turnover

Question 14

What are Kelp?

Answer 14

large brown algae

Question 15

What are canopy kelps?

Answer 15

-grow from bottom to surface
-provide structure in the water column
- have Pneumatocysts (air bladders that float)

Question 16

What are the pneumatocysts filled with?

Answer 16

Carbon monoxide

Question 17

What species are present in kelp forest zonation?

Answer 17

-canopy kelps
-understory kelps
-benthic invertebrates

Question 18

What are the grazers present in kelp forests?

Answer 18

urchins and abalone

Question 19

Kelp detritus is an important food source for which group ?

Answer 19

Benthic suspension feeders and detritivores

Question 20

What is the effect of bottom-up in kelp forests?

Answer 20

-storms (El NIno) cause disturbance
-Nutrients drive productivity
-upwelling is directly related to kelp growth

Question 21

What is the effect of top-down impacts of kelp forests?

Answer 21

-storms (El NIno) cause disturbance
-Nutrients drive productivity
-trophic cascade (kelp,urchin, sea otter, Orca)

Question 22

Where do coral reefs occur?

Answer 22

-tropics and subtropics
-open ocean conditions

Question 23

Name some taxa present in the coral reef?

Answer 23

-coralline algae
-sponges
-worms
-corals

Question 24

Zooxanthellae provide coral with what?

Answer 24

Carbohydrates and increased calcification

Question 25

What stresses zooxanthellae ?

Answer 25

-disease
-salinity
-temperature

Question 26

What are coral reefs top-down and bottom-up impacts?

Answer 26

-storms
-zooxanthellae production is largely light-dependent
-consumed by predatory fish and seastars
-mortality from disease

Question 27

What threatens seagrass?

Answer 27

coastal development, growing human populations, climate change, tourism

Question 28

What threatens kelp?

Answer 28

commercial kelp harvesting, pollution, climate change, invasive species and diseases

Question 29

What threatens corals?

Answer 29

diseases, predators, storms, earthquakes, hurricanes, overfishing, pollution, tourism, climate change, coastal development

Question 30

What happens is seagrass decline?

Answer 30

decrease in primary production, carbon sequestration, and nutrient cycling in the coastal zone

Question 31

What happens to kelp if they decline?

Answer 31

abalone and fish vanished, sea urchins declined, primary production, biodiversity

Question 32

What happens if coral decline?

Answer 32

biodiversity, extinction of some fish, no shelter or spawning ground for fish