Deck 14: Estuaries

Question 1

The number of resident species in estuaries tend to be ___________ relative to nearby aquatic ecosystems.

A) an order of magnitude higher
B) greater
C) about the same
D) fewer

Answer 1

D

Question 2

An estuary where freshwater inflow is greater than evaporation is called a:

A) negative estuary.
B) positive estuary.
C) reversible estuary.
D) neutral estuary.

Answer 2

B

Question 3

In a well-mixed estuary, river flow is ____ tidal currents.

A) greater than
B) less than
C) perpendicular to
D) equal to

Answer 3

B

Question 4

Estuaries in which river flow is strong and prevents the flow of seawater upstream are called:

A) fjords.
B) salt-wedge estuaries.
C) well-mixed estuaries.
D) tectonic estuaries.
E) drowned river valleys.

Question 5

Where rivers slow and drop their sediment load they form deltas termed:

A) dendritic.
B) coastal plain.
C) tidal flats.
D) sand bar.
E) tombolos.

Question 6

San Francisco Bay was created by:

A) rising sea levels.
B) retreating fjords.
C) erosion of the coastline.
D) tectonic activity.
E) glaciers.

Question 7

The concentration of nutrients in estuaries causes____ productivity.

A) extremely low
B) low
C) average
D) medium
E) high

Question 8

Which factor currently tends to regulate abundance of commercially valuable estuary species such as oysters and crabs?

A) Competition
B) Predation
C) Human activities
D) Normal seasonal die off
E) Disease

Question 9

Estuaries tend to be well supplied in the following limiting nutrient(s) of the open ocean:

A) phosphorus.
B) nitrogen and silica.
C) phosphorus and silica.
D) nitrogen and phosphorus.
E) carbon and oxygen.

Question 10

In a partially mixed estuary the salinity

A) is extremely variable from place to place.
B) is stratified with lower salinity near the bottom.
C) is lower than the ocean but relatively homogenous.
D) increases with depth.

Question 11

Pseudofeces are:

A) semisolid deposits containing un-digested material.
B) semisolid deposits of digested material.
C) solid deposits containing un-digested material.
D) solid deposits containing digested material.

Question 12

When dense seawater sinks below lighter fresh water we observe a condition called:

A) downwelling.
B) salt wedge.
C) tidal overmixing.
D) upwelling.
E) convection current.

Question 13

An example of a negative estuary is:

A) Delaware Bay.
B) Puget Sound.
C) Laguna Madre.
D) San Francisco Bay.
E) Chesapeake Bay.

Question 14

When sediment removal is less than input we often find:

A) fjords.
B) tectonic estuaries.
C) tidal flats.
D) bar-built estuaries.
E) drowned river valleys.

Question 15

In a salt-wedge estuary the relationship between salinity and depth is that salinity:

A) is even from top to bottom.
B) increases with depth.
C) changes abruptly with depth.
D) varies horizontally.
E) decreases with depth.

Question 16

When retreating glaciers carved deep coastal valleys they created:

A) fjords.
B) salt-wedge estuaries.
C) well-mixed estuaries.
D) tectonic estuaries.
E) drowned river valleys.

Question 17

An example of a salt-wedge estuary is:

A) the Mississippi Delta.
B) Delaware Bay.
C) Chesapeake Bay.
D) Puget Sound.

Question 18

It is common for negative estuaries to be:

A) lower in salinity than the ocean.
B) nutrient poor.
C) nutrient rich.
D) lower in temperature than the ocean.
E) brackish.

Question 19

In estuaries at high latitudes, which of the following factors strongly influences mixing?

A) Oxygen concentrations
B) Nutrient concentrations
C) Carbon dioxide concentrations
D) Temperature
E) Turbidity

Question 20

What causes tidal overmixing in estuaries?

A) strong tidal currents.
B) strong river flow.
C) an unstable water column.
D) downwelling.
E) animal migrations.

Question 21

An example of an osmoregulator at low salinities and an osmoconformer at higher salinities is a(n):

A) blue crab.
B) salmon.
C) oyster.
D) sea squirt.
E) tuna.

Question 22

A euryhaline species can tolerate:

A) a wide range of temperatures.
B) a narrow range of temperatures.
C) a wide range of salinities.
D) a narrow range of salinities.

Question 23

Ghost shrimp live:

A) in burrows.
B) under rocks on the mud flat.
C) on the surface of the mud.
D) in the water above the mud flat.
E) symbiotically with bivalves.

Question 24

The animals that remain isosmotic to the surrounding seawater are called:

A) osmoconformers.
B) osmoregulators.
C) hyperosmotic.
D) hyposmotic.
E) euryhaline.

Question 25

The energy base on mud flats is:

A) phytoplankton.
B) detritus.
C) marsh plants.
D) algae.
E) chemosynthesis.

Question 26

An animal that maintains a constant salt concentration in their body is called:

A) an osmoconformer.
B) an osmoregulator.
C) hyperosmotic.
D) hypo-osomotic.

Question 27

All of the following tend to hold nutrients in estuaries for use by other organisms except:

A) adsorption onto silt particles.
B) reduced numbers of filter feeders.
C) the formation of pseudofeces.
D) overturn.

Question 28

Ghost shrimp and mud shrimp play an active role in:

A) compacting the sediment.
B) reducing species through competition.
C) decomposition of seagrass roots.
D) oxygenating the sediments.
E) consuming marsh plants.

Question 29

Ecologically mud flat areas are a focal area of:

A) nutrient recycling.
B) primary production.
C) tertiary consumers.
D) nutrient sink.
E) sessile epifauna.

Question 30

Most of the animals of mud flats are:

A) planktonic.
B) epifaunal.
C) oysters.
D) infaunal.
E) nektonic.

Question 31

Many of the burrowing animals of the mud flat must actively

A) keep digging to exchange gasses.
B) circulate water through their burrows.
C) live near natural breaks in the sediment for gas exchange.
D) maintain an anaerobic environment.

Question 32

All of the following are adaptations to remain stationary in the ever-shifting soft bottom of estuaries except:

A) extensive roots and rhizomes.
B) holdfasts.
C) sessile lifestyle.
D) operculum.
E) byssal threads.

Question 33

Seagrasses can reach high productivity levels with the aid of:

A) oxygen brought to their roots via mud shrimp burrows.
B) symbiotic, nitrogen-fixing bacteria.
C) their leaves, cleared of epiphytes by grazers.
D) fertilization by manatees.
E) eutrophic water conditions.

Question 34

All are true of oyster reefs except

A) they are oriented perpendicular to currents.
B) they are concentrated in lower salinity areas.
C) they are important habitats for other organisms.
D) they are adversely affected by rapid changes in salinity.
E) they are increasing in the Chesapeake Bay.

Question 35

All of the following are adaptations against excessive water and salt exchange between animals and their surrounding environment except:

A) having very permeable tissues.
B) covering body with mucus.
C) living inside a tube that can be isolated from the external environment.
D) covering the body with a hard exoskeleton.
E) actively absorbing salt ions with gills.

Question 36

Oysters generally settle at right angles to tidal currents. These currents:

A) carry food away from the oysters.
B) clear sediments from the oysters.
C) help them avoid oyster drills.
D) deposit sediments among the oysters.

Question 37

An example of a species that uses the estuary as a nursery ground is the:

A) Atlantic eel.
B) seal.
C) shad.
D) lobster.
E) tuna.

Question 38

Larval oysters attach themselves to:

A) They do not have specific requirements.
B) any available solid substrate.
C) other oyster shells.
D) both b and c
E) sand.

Question 39

An example of an osmoconformer is:

A) a crab.
B) a polychaete worm.
C) a fish.
D) a sea squirt (tunicate).

Question 40

Estuaries for many transient species are considered:

A) a place to spawn.
B) nurseries.
C) too full of predators for juveniles.
D) very stable environments.

Question 41

Most burrowing animals of estuaries exchange gases with their environment through their skin.

Question 42

The species diversity in estuaries is high, but the number of individuals is low.

Question 43

Mud flats are typically low in organic matter.

Question 44

MATCHING
Match the mangrove ecosystem species with its most closely associated trophic level.
a.heterotrophic bacteria
b.mangrove
c.amphipod
Detritivore

Question 45

Pneumatophores of black mangroves are:

A) prop roots.
B) aerial roots.
C) germinated seeds.
D) pores on leaves.
E) salt-excreting structures.

Question 46

The major source of nitrogenous nutrients in estuaries is incoming seawater.

Question 47

Estuaries are important nurseries because of the relatively low numbers of predators in these areas.

Question 48

The dominant plant species closest to the water line of salt marsh communities is:

A) cordgrass.
B) pickleweed.
C) spike grass.
D) salt wort.
E) mangroves.

Question 49

Seawater and fresh water do not mix very well in fjords.

Question 50

Estuaries are immune from larger temperature variations.

Question 51

Seagrasses are usually consumed directly by grazers in estuaries.

Question 52

Salt marsh communities predominate in temperate and subarctic areas.

Question 53

Caribbean seagrasses are extensively fed on by all except

A) manatees.
B) green sea turtles.
C) some sea urchins.
D) sea cucumbers.

Question 54

All estuaries are diluted by freshwater runoff.

Question 55

MATCHING
Match the mangrove ecosystem species with its most closely associated trophic level.
a.heterotrophic bacteria
b.mangrove
c.amphipod
Primary producer

Question 56

Mangrove forests predominantly occur in temperate regions.

Question 57

Salt marsh plants play an important role in expanding the terrestrial environment.

Question 58

Seagrasses are important in all the following except:

A) nutrient recycling.
B) providing a habitat for animals.
C) stabilizing sediments.
D) being consumed by most estuarine herbivores.

Question 59

A common direct consumer of eelgrass (Zostera) is:

A) snails.
B) waterfowl.
C) sea cucumbers.
D) manatees.
E) sea stars.

Question 60

Marsh plants are important in all of the following except:

A) trapping sediments.
B) serving as a refuge for animals.
C) being directly consumed food.
D) stabilizing sediments.

Question 61

Match the plant with its most closely associated substrate attachment method.
a.algae
b.red mangrove
c.seagrasses
d.black mangrove
Rhizomes

Question 62

Match the process with its most closely associated result.
a.sediment based barrier islands
b.water-filled, steep-sided valleys
c.sediment deposition at the upper river mouth
Fjord

Question 63

Match the process with its most closely associated result.
a.sediment based barrier islands
b.water-filled, steep-sided valleys
c.sediment deposition at the upper river mouth
Tidal flats

Question 64

Match the process/epoch with its most closely associated estuary type.a.glacial formed
b.land movement
c.inter-glacial periods
Fjord

Question 65

Match the process with its most closely associated result.
a.sediment based barrier islands
b.water-filled, steep-sided valleys
c.sediment deposition at the upper river mouth
Bar-built

Question 66

Match the process with its most closely associated estuarine mixing type.a.Evaporation can exceed freshwater input.
b.Fresh water flows over seawater.
c.Dense surface seawater mixes into freshwater below.
Negative estuary

Question 67

Match the process/epoch with its most closely associated estuary type.a.glacial formed
b.land movement
c.inter-glacial periods
Coastal plain

Question 68

Match the plant with its most closely associated substrate attachment method.
a.algae
b.red mangrove
c.seagrasses
d.black mangrove
Prop roots

Question 69

Match the process/epoch with its most closely associated estuary type.a.glacial formed
b.land movement
c.inter-glacial periods
Tectonic

Question 70

Match the process with its most closely associated estuarine mixing type.a.Evaporation can exceed freshwater input.
b.Fresh water flows over seawater.
c.Dense surface seawater mixes into freshwater below.
Positive estuary

Question 71

Match the process with its most closely associated estuarine mixing type.a.Evaporation can exceed freshwater input.
b.Fresh water flows over seawater.
c.Dense surface seawater mixes into freshwater below.
Tidal overmixing

Question 72

Match the words with those they are most closely associated with.
a.Scandinavia estuaries
b.Long Island Sound
c.Cape Hatteras region
Fjord

Question 73

Match the area with the type of estuary.
a.Puget Sound
b.Delaware Bay
c.Sacramento River mouth in San Francisco Bay
Well-mixed estuary

Question 74

Match the words with those they are most closely associated with.
a.Scandinavia estuaries
b.Long Island Sound
c.Cape Hatteras region
Drowned river valley

Question 75

Match the area with the type of estuary.
a.Puget Sound
b.Delaware Bay
c.Sacramento River mouth in San Francisco Bay
Partially-mixed estuary

Question 76

Match the plant with its most closely associated substrate attachment method.
a.algae
b.red mangrove
c.seagrasses
d.black mangrove
Pneumatophores

Question 77

Match the words with those they are most closely associated with.
a.Scandinavia estuaries
b.Long Island Sound
c.Cape Hatteras region
Bar-Built estuaries

Question 78

Match the area with the type of estuary.
a.Puget Sound
b.Delaware Bay
c.Sacramento River mouth in San Francisco Bay
Salt-wedge estuary

Question 79

Match the plant with its most closely associated substrate attachment method.
a.algae
b.red mangrove
c.seagrasses
d.black mangrove
Holdfast

Question 80

MATCHING
Match the mangrove ecosystem species with its most closely associated trophic level.
a.heterotrophic bacteria
b.mangrove
c.amphipod
Secondary consumer