Lecture 5 -- Puget Sound Nearshore Environments

Question 1

1. Which nearshore habitat type is most common in Puget Sound, high bluff/beach, delta, rocky shore, or lagoons?

Answer 1

High Bluff/Beach

Question 2

2. Define feeder bluff.

Answer 2

A bluff that constantly feeds the beach with sediments.

Question 3

3. What is a drift cell? Describe how the beach substrate differs from the source to the sink end of a drift cell. How does this affect that biota that lives on/in intertidal beach sediments?

Answer 3

Drift Cell is independent sections of the beach with identifiable sinks and sources. predominant waves erode and moves sediment along beach.

Organisms can live in the sand not just on it.

Question 4

4. Would you tend to find a spit at the sink or source end of a drift cell?

Answer 4

Sink End. Its the finest sediments

Question 5

5. How and what do mussels eat?

Answer 5

Filter feed, mostly plankton

Question 6

6. Mussels and barnacles both live on rocks and hard surfaces. Compare/contrast their feeding habits?

Answer 6

Barnacles “reach out” and filter.

Mussels siphon thru themselves and filter

Question 7

7. What trophic level does a whelk occupy? What does is its food source?

Answer 7

The top, they are predators of shellfish (mussels and barnacles)

Question 8

8. Starfish wasting disease is reducing the starfish population in this area. How do you think the reduction in starfish might affect the composition of species that live on rocky shorelines?

Answer 8

With no starfish the entire rock would be covered in mussels

Question 9

9. Is a geoduck a benthic infauna or epifauna? How about mussels? Oysters? Clams? Crabs? Mudshrimp?

Answer 9

Benthic INfaune (lives in ground)

Mussels- on the rock
Clams - infauna
Crabs- Epifauna
Mudshrimp - infauna

Question 10

10. How do mudshrimp affect N fixation in muddy/sandy beaches?

Answer 10

Faciliate with bacteria living in burrows.

Question 11

11. Why do sandy substrates and muddy substrates have different kinds and numbers of infauna organisms?

Answer 11

Because they provide different habitats. Sandy is for filter feeders, muddy is for deposit feeders

Question 12

12. Name a predator of benthic infauna that weighs more than you do.

Answer 12

Grey Whale!

Question 13

13. Where do sand lance and surf smelt lay their eggs? How might the removal of riparian vegetation from a spawning beach affect the hatching of smelt eggs? Name two predators that depend on healthy forage fish populations.

Answer 13

Upper intertidal zones of sandy and gravel beaches.

Birds and salmon both depend on them!