Week 12 Flashcards
1
Q
What is an intertidal zone?
A
The intertidal zone is an area that is periodically submerged and exposed due to the rise and fall of tides.
2
Q
What environmental conditions are typically high in intertidal zones?
A
High oxygen and nutrient levels.
3
Q
What types of vegetation dominate rocky vs. sandy shores?
A
Rocky shores have attached algae; protected sandy shores feature seagrasses.
4
Q
What structural adaptations are common in animals living on rocky shores?
A
Adaptations for attachment to hard substrates, such as suction or holding structures.
5
Q
What structural adaptations are common for animals on sandy shores?
A
Adaptations for burrowing into sediment.
6
Q
How are organisms distributed in the intertidal zone?
A
They are stratified based on their tolerance to physical conditions (zonation).
7
Q
What determines the upper limit of many intertidal organisms?
A
Tolerance to desiccation.
8
Q
How does species composition change across intertidal zones?
A
It changes from lower → mid → upper intertidal based on environmental stress.
9
Q
What are major threats to intertidal zones?
A
Oil spills and construction.
10
Q
What organisms are common in the upper intertidal or ‘splash zone’?
A
Lichens and periwinkles.
11
Q
What are orange lichens composed of?
A
A combination of fungi and algae.
12
Q
What are tide pools and why are they significant?
A
Tide pools are depressions on rocky intertidal shores that remain submerged at low tide, serving as microhabitats.
13
Q
What conditions must tide pool animals tolerate?
A
Fluctuations in oxygen, salinity, temperature, and pH/CO₂ levels.
14
Q
What adaptation do limpets have to prevent water loss?
A
They create a ‘home scar,’ a depression in the rock that fits their body perfectly to reduce desiccation.
15
Q
What is a dog whelk?
A
A predatory snail found in intertidal zones.
16
Q
Where is most of the life located on sandy shores?
A
Underground — referred to as infauna.
17
Q
What percentage of ice-free shoreline do sandy beaches make up?
A
Approximately two-thirds.
18
Q
What physical factors are important for sandy shore communities?
A
Wave action, particle size of the sediment, and beach slope.
19
Q
What is an estuary?
A
A transition area between a river and the sea.
20
Q
Why is the water column in estuaries often stratified?
A
Due to variations in freshwater and saltwater mixing.
21
Q
How does salinity behave in estuaries?
A
It varies both spatially and temporally.
22
Q
What is brackish water?
A
Diluted saltwater resulting from the mix of freshwater and seawater.
23
Q
Why are estuaries highly productive?
A
They contain high nutrient levels and support diverse primary producers like saltmarsh grasses, algae, and phytoplankton.
24
Q
What types of vegetation are common in estuarine zones?
A
Saltmarsh grasses, phytoplankton, and algae.
25
What kinds of animals are commonly found in estuaries?
Mollusks, worms, and arthropods.
26
Why are estuaries critical for many marine species?
They serve as breeding and nursery grounds for invertebrates and fishes.
27
What types of animals rely on estuaries as feeding grounds?
Birds and mammals.
28
What human activities threaten estuaries?
Filling, dredging, and pollution.
29
What are seagrass meadows and why are they important?
Seagrass meadows grow in sandy mud and provide habitat to a wide variety of animals. Although too tough to eat directly, they are an important source of detritus.
30
What is the main source of energy in seagrass-based food webs?
Detritus from decaying plant material supports bacteria and detritivores.
31
What are salt marshes?
Coastal ecosystems dominated by salt-tolerant grasses like cordgrass, often submerged during high tide.
32
What is the primary productivity in salt marshes used for?
It enters the marine environment as detritus, fueling food webs.
33
How is energy transferred in a salt marsh food web?
Bacteria consume detritus, which are then eaten by organisms that channel nutrients to higher consumers.
34
Which animals are commonly found in high salt marsh areas?
Crabs, periwinkles, and marsh snails.
35
What animals dominate the low marsh?
Burrowing animals such as worms and mollusks.
36
What are some examples of animals found in salt marshes?
Gull, marsh periwinkles, fiddler crabs, oysters, moon snails, slipper snails, blue crabs, quahogs, bamboo worms, etc.
37
What are mangrove communities?
Tropical coastal ecosystems with salt-tolerant trees, often growing on soft sediments.
38
What makes mangroves important habitats?
Their prop roots and pneumatophores provide attachment sites and shelter for various animals.
39
What is the function of pneumatophores?
They are specialized roots used for gas exchange.
40
What is a lagoon?
A partially isolated body of coastal water, often more stable than estuaries.
41
What types of vegetation fringe lagoons?
Mangroves in tropical regions and reed beds in temperate areas.
42
How do lagoon salinities compare with estuaries?
Lagoons also have a wide range of salinities but are generally more stable.
43
What are the two main types of corals?
Hermatypic (reef-building) and ahermatypic (non-reef-building).
44
What skeletal material is used by reef-building corals?
Calcium carbonate (CaCO₃).
45
What are examples of ahermatypic corals?
Gorgonians (sea fans), black corals, and branching soft corals.
46
What is the relationship between coral and zooxanthellae?
A symbiotic one where the algae provide nutrients, and the coral provides a habitat.
47
What are the products zooxanthellae give to coral?
Glucose, glycerol, and amino acids.
48
What does the coral provide to zooxanthellae in return?
A suitable habitat and nutrients like CO₂ and waste products.
49
Why are coral reefs important ecosystems?
They support high biodiversity, protect coasts, cycle carbon, and provide economic and pharmaceutical benefits.
50
What are major threats to coral reefs?
Over-collecting, overfishing, climate change, pollution, and coastal development.
51
How do physical changes like hurricanes affect reefs?
They can damage coral structures and alter community composition.
52
What is ENSO and its effect on reefs?
El Niño Southern Oscillation — a climate pattern that can elevate sea temperatures, causing coral stress or bleaching.
53
How do coral colonies form (steps)?
Planula larva → attaches to hard surface → develops into polyp → buds to form colony → some polyps become reproductive.
54
How do coral polyps reproduce asexually?
By budding and fragmentation.
55
How do corals feed in addition to photosynthesis?
They use cnidocytes to paralyze zooplankton and consume them.
56
What is coral bleaching?
The loss of zooxanthellae due to elevated temperature or other stress, causing coral to turn white and become vulnerable.
57
How do most corals reproduce sexually?
Through synchronous broadcast spawning, releasing sperm and eggs into the water.
58
What are brooders in coral reproduction?
Corals that retain eggs internally, fertilize with externally released sperm, and release larvae at the planula stage.
59
How long can corals live?
Some can live for thousands of years.
60
What is coral coring used for?
To determine coral age and past environmental conditions.
61
What is a fringing reef?
A reef that develops along the coastline of tropical or subtropical shores, directly connected to land.
62
Why are fringing reefs more vulnerable to human activities?
Because of their close proximity to land, they are more affected by runoff, pollution, and coastal development.
63
What is a barrier reef?
A reef separated from land by a lagoon.
64
What is the world’s largest barrier reef?
The Great Barrier Reef off northeastern Australia.
65
How large is the Great Barrier Reef?
Approximately 2,300 km long, nearly 3,000 individual reefs, covering ~350,000 square km.
66
What is an atoll?
A ring-shaped coral reef that encloses a lagoon, usually forming over sunken volcanic islands.
67
How does Darwin’s theory explain atoll formation?
Fringing reefs form around volcanic islands → islands erode and sink → reef becomes barrier reef → eventually forms an atoll as island disappears.
68
Where are massive dome-shaped and columnar corals found?
On the reef front and intermediate slopes.
69
Where are plate-like coral formations typically found?
Below the reef slope where light is limited.
70
Which corals are common in wave-exposed areas?
Branching corals like elkhorn coral (Caribbean).
71
What corals are common in shallow, protected reef flats?
Smaller species like rose, flower, and star corals.
72
What limits coral reef distribution?
Temperature, light, sediment accumulation, salinity, wave action, and air exposure.
73
At what depth are coral reefs typically found?
Usually less than 60 meters, where sufficient light is available.
74
What temperature range do most coral reefs prefer?
Warm water — generally within the 20°C isotherm.
75
What are common nutrient sources for reefs near land?
Runoff from land provides nutrients.
76
How do fish contribute nutrients to reefs?
They feed offshore and return to reefs, releasing nutrient-rich waste.
77
Why are nutrients efficiently recycled on reefs?
They are stored in biomass and reused by reef organisms.
78
How can decomposing cyanobacteria contribute to nutrients?
Decomposing cyanobacteria can release nutrients into the environment.
79
Why is grazing important for coral reefs?
It prevents algae from outcompeting corals.
80
What organism is a key grazer on coral reefs?
The long-spined black sea urchin, Diadema.
81
What happened to Diadema populations in 1982?
A pathogen reduced their populations by 99%.
82
What ecological impact did the Diadema die-off have?
Without grazing pressure, macroalgae overgrew Caribbean reefs.
83
What is meant by 'mosaic of microhabitats' on reefs?
Grazing and spatial variation create diverse small-scale habitats.
84
How do damselfish affect grazing patterns?
They defend territories and exclude grazers, allowing algae to grow.
85
How does predation support coral diversity?
Predators open space by removing dominant species, allowing others to grow.
86
What is the crown-of-thorns sea star?
A coral-eating sea star that can devastate reef ecosystems during population booms.
87
How much coral loss in the Indo-Pacific is attributed to crown-of-thorns since 1957?
Approximately one-third.
88
What caused crown-of-thorns outbreaks like the one in 1960?
The exact cause is unknown, but natural phenomena may be involved.
89
What predator helps control crown-of-thorns sea stars?
Triton’s trumpet (a large predatory gastropod).
90
What do parrotfish eat and why is it important?
They graze on algae and coral; their feeding helps maintain balance and contributes to sand formation.
91
What is a cleaning symbiosis?
A mutualistic relationship where one species (e.g., wrasse) removes parasites from another (e.g., pufferfish).
92
How do invertebrates avoid predation?
By hiding during the day or camouflaging themselves.
93
What role does mucus play in reef defense?
Some animals secrete poisonous mucus as a deterrent.
94
What are radioles?
Highly ciliated, feather-like tentacles on worms used for feeding.
95
What are mantis shrimp known for?
Powerful appendages capable of breaking aquarium glass.
96
How do snapping shrimp defend themselves?
By creating loud snapping sounds with specialized claws that can stun prey.
97
What is the function of color in reef animals?
Used for concealment, mate attraction, and warning predators.
98
Why are coral reefs important to human society?
They provide coastal protection, habitat, economic and recreational value, and potential medical resources.
99
What are examples of reef-related pharmaceuticals under study?
Potential compounds for treating cancer and viruses.
100
What are the major human threats to coral reefs?
Climate change, overfishing, pollution, and coastal development.
101
What is the pelagic ecosystem?
An oceanic ecosystem composed of organisms living in the open water column.
102
What is plankton?
Organisms that cannot swim against ocean currents.
103
What is nekton?
Actively swimming organisms, such as fish, squid, and whales.
104
What limits primary production in the open ocean?
Scarcity of nutrients.
105
What organisms are the primary producers in the open ocean?
Phytoplankton.
106
What is the secondary base of open ocean food webs?
Heterotrophic bacteria.
107
Why are there fewer large animals in the open ocean?
Limited primary production and energy loss through long food chains.
108
What are meso- and microzooplankton?
Small drifting animals that are a critical link in the food web.
109
What is the role of zooplankton in the pelagic ecosystem?
They consume phytoplankton and serve as food for larger animals.
110
What are some gelatinous zooplankton?
Salps, ctenophores, and jellyfish.
111
What are megaplankton?
Megaplankton are large planktonic animals, such as jellyfish and some mollusks.
112
What are cnidarian zooplankton?
They include jellyfish, which are among the largest members of the plankton community.
113
What are molluscan zooplankton?
These include pteropods, purple sea snails, and some species of nudibranchs.
114
What is pteropod ooze?
A layer of accumulated pteropod shells on the ocean floor in areas of high abundance.
115
How do purple sea snails stay afloat?
By creating bubble rafts that prevent sinking.
116
What are salps, pyrosomes, and larvaceans?
Types of urochordate megaplankton known for their efficient filter feeding.
117
What types of nekton are found in the open ocean?
Invertebrates (squid), fish (tuna, billfish), reptiles (sea turtles), and mammals (whales, dolphins).
118
What adaptations help plankton avoid sinking or predation?
Transparency, oil droplets, flattened bodies, and sometimes bioluminescence.
119
Why are gelatinous plankton ecologically significant?
They are efficient feeders, reduce prey nutritional quality, and serve as food for specialized carnivores.
120
What are key characteristics of open ocean ecosystems?
They include low nutrient levels, highly efficient recycling by bacteria, and long food chains dominated by plankton and nekton.
