Marine Ecology Exam 4

What is a coral reef

Large wave resistance structure accumulated from slow growth if corals and coralline algae

What is the distribution of a coral reef

They reside in topical warm climates

What are the factors limiting coral reefs

1 High sea temperatures

2.High light

3. Basic pH

What factors can coral reefs live in

1. They live in open marine salinities

2. They require low turbidity

What is phenotypic plasticity

Physical features stick in generation but will change based on the environment (

What are the effects of depth zonation on reefs

Upper level of the sea floor causing more spread-out corals but the further you go down the flatter the coral reefs get because of waves

What are the three types of coral reefs

1. Fringing Reef

2. Barrier Reef

3. Atoll Reef

What is a Fringing Reef

1. Close to land

2. Border shoreline of continents, islands

-Little to no intervening lagoon

3.Common to Indo-Pacific, South Pacific Hawaiian Islands, parts of Caribbean

What is a barrier reef

1. Separated from land by lagoon or wide channel from erosion and coastal subsidence

2. Common in Caribbean, Indo Pacific

-Great Barrier Reef largest in the world

Atoll Reef

1. Open ocean structures away from coast

2. Most in Indo-Pacific

How do the Reefs Develop

1. Volcanic Islands

2. Fringing reef

3. Barrier reef

4. Atoll reef

Corals only grow in warm, poor-lit waters.

A) True

B) False

False

What are the two types of biologies of corals

1.Hermatypic

2.Ahermatypic

What is Hermatypic

reef farmwork building have many zooxanthellae high calcification

What is Ahermatypic

not framework builder's low calcification

What are the specifics of hermatypic

1. Belonging to the Phylum Cnidaria, Class Anthozoa Order Scleractinia

2. Secrete skeletons of calcium carbonate

3. Are colonies of many similar polyps

4. Can be divided into branching and massive forms

5. Have abundant endosymbiotic zooxanthellae

What is the growth like for a hermatypic coral

The growth can be branching or massive

What is branching

Grow in linear dimension fairly rapidly 20 cm per year

What is a massive growth

produce lots of calcium carbonate but grow more slowly in linear dimension about 1 cm per year

What is growth aided by

Symbiotic algae called a zooxanthellae

What are the benefits of the symbiotic realtionship

Coral

1. Provided nutrients

2. Facilitata calcification-increaseing pH

3. Sequester toxic compounds by algae

Benefits of Zooxanthellae

1. Protection from UV damage

2. Stable substrate and nutrients

Hermatypic corals are the biogenic structures thatform coral reefs.

A) True

B) False

True

True or False. All calcium producing corals (Hermatypic)always exhibit fast linear growth.

A) True

B) False

False

Why are there so many species in coral reefs

1. Tropics have greater total area than poles (ADH)

2. Faster demographic rates at high temp-> higher speciation rates= more species

3.Climate stability reduces extinction rates

4.Fragmented nature of island studded archipelagos

-3D habitat dispersal drives hgih regional diversity

What is niche partitioning

similar species divide resources to reduce competition

Why do herbivores dominate

There are the functional groups of herbivores called grazers and browsers

What is a Grazers

consume epilithic algal matrix from substrate

-Maintain early successional community

-Prevent growth of upright macroalgae

What is a browser

consume large established macroalgae

Coral-Algal phase shift

significant change in the reef's composition

What are the other biological interactions with coral

1. Endosymbiosis= zooxanthellae

2.Predation and grazing= some common coral predators(crown of thorns starfish) grazer (surgeon fish parrot fish, urchins)

3. Competition= shading, overgrowth, interspecific, digesting, sweeper tentacles, allelopathy

4. Disturbances storms hurricanes cyclones

5. Larval recruitment= mass spawning question of currents and recruitment of larvae

6. Disease: spread by currents can cause mass mortality of some species

Endosymbiotic interaction

Bleaching- expulsion of zooxanthellae

Causes-Stress( temperature disease)

Mechanisms- poorly understood zooxanthellae cells appear to die and are expelled

Coral biological interactions

1. Most corals have planktonic gametes

2. On Great Barriers Reef and reefs off of Texas many species of corals spawn at same time once a year at night

3. Facilitates gametes union perhaps a mechanism to flood sea with gametes to avoid all being ingested by predators

What is competition

Shading overgrowth interspecific digestion sweeper tentacles allelopathy (interspecific digestion)

Which of the following is most directly linked toinitiating a coral-algal phase shift on degraded reefsystems?

A) Increase light penetration due to sedimentation, enhancingcoral growth

B) Ocean acidification causing macroalgae to calcify moreefficiently than corals

C) Overfishing of herbivorous fish species, leading tounchecked algal growth

Overfishing of herbivorous fish species, leading tounchecked algal growth

Which football team does Taylor Swift's fiancé play for?

A) Philadelphia Eagles

B) Kansas City Chiefs

C) Denver Broncos

Kansas City Chiefs

What is speciation

When a group within a species separates from other members of its species and develops its own unique characteristic

What are the types of speciation

1.Allopatric

2.Peripatric

3.Parapatric

4.Sympatric

What is Allopatric

The origin of species as a result of separation by extrinsic barriers

What is Peripatric

a small group of individuals breaks off to form a new species (similar to allopatric, one small group and one large group

What is parapatric

Species is spread out over a large geographical area resulting in mating with individuals in their immediate vicinity

What is sympatric

no geographic barrier but gene flow is restriction in another ways

What are the factors influencing extrinsic speciation rates

1. Habitat age

2. Habitat area/geographic range

3. Temperature

What Habitat age

older habitat allow for colonization

What is Habitat area/geographic range

Provide greater geographical separation, niche diversity

What is temperature

tropical regions have higher speciation rates

What is the special energy hypothesis

Species richness is higher in habitats that receive more of the energy needed to power metabolism

What are the factors influencing Intrinsic speciation rates

1. Body size

2. Life history and dispersal ability

3. Resource specialization

True or False. Small organisms (low mass) have a lower mutation rate compared to larger organisms (larger mass).

A) True

B) False

False

How is productivity affected by light

1. Seasonally light limited

2. Generally not nutrient limited

3.Less light more nutrients

4. More light less nutrients

How is productivity influenced by thermocline

1. No (or weak) thermal stratification (Very well mixed all throughout the year until you get sunlight which can cause algal blooms

2. Nutrients plentiful in surface waters

What are the traits of the Arctic ocean

1. Semi enclosed sea

2. Wide continental shelves

3. Central deep water is isolated

4. Significant river input

5. Permanent pack ice

What is the shape of the arctic ocean

Shaped like a flat bowl on the top that sinks into the middle

What currents are guiding sea ice in the arctic oceans and flushes in into the North Atlantic

1. Transpolar Current (flushes in into the North Atlantic)

2. Beaufort Gyre (recycles current ice)

3. North Atlantic Drift

What are the traits of Antarctic

1. Ocean ring around continental land mass

2. Deep water adjacent to narrow shelf

3.No river input

4.Mostly temporary pack ice

What is the Antarctic shaped like

Its shaped like a Bundt shaped tin that sing from the side

What drives the food webs in the Arctic

Fish based driven by fish connections

What drives the food webs in the Antarctic

Krill based a lot of the organisms feed on krill

What is pack ice

Brine channels that are a mixture of ice crystals and Briney solution channels

What are krill vs Salps in Antartica

1. Planktonic grazers

High interannual variation

3. High sea-ice yearns favor krill

4. Low sea-ice yearns favor Salps

Are the benthic and the Palaic Processes connected

Yes, they are couples between the surface and the seafloor

More important for Antarctic example copepod dormancy

True or False. Antarctic food webs are dependent on krill (Euphausiids).

A. True

B. False

True

What is the community like in the Arctic

1. Soft sediment

2. Disturbance dominated

-Physical

-Biological

3. N. Atlantic derived

What is the community in the Antarctic

1. Hard bottom

2. Minor soft bottom

3. Physical disturbances

4. High endemism

What type of disturbances can occur

1. Waves

2. Ice

-Anchor Ice

-Ice scour

3 Salinity variation

-Freshening

-Hypersalinity

4.Macrofauna (primarily Arctic infauna)

-Digging

-Bioturbation

Low sea-ice in the Antarctic Ocean favors:

A. Euphausiids

B. Salps

B

What are the 4 hypotheses

1. Oxygen availability

2.Silica chemistry

3.Carbonate chemistry

4.Biogeographic and Ecological

What is the oxygen availability hypothesis

High oxygen coupled with lower metabolic rates

What is the Silica chemistry hypothesis

High silica abundance in polar seas

What is the carbonate chemistry hypothesis

CO2 more soluble in colder waters -> more acidified waters -> affect calcifying organisms (CaCO2)

What is the biogeographic and Ecological hypothesis

Monsters from the deep -> invasion of polar seas by giants from the deep sea (Abyssal gigantism)

What are the types of ecological change

1. Fluctuations

-Regular cyclic change

- Tides, Day/Night, Seasons, Phenology

What is a disturbance

A discrete event in time that disrupts ecosystem, community or population structure and changes resources substratum or the physical environment

What are the natural disturbances in the marine environment

1. Weather

2. Sediments processes: burial, erosion

3.Harmful algal bloom: red tide

4. Anoxic/hypoxic events

5.Disease outbreaks, species die-offs

6. Variable recruitment leading to extreme high/loe abundance of key organisms in the food web

What are the Anthropogenic Disturbances in the marine environment

1. Direct physical disturbance to habitats

-Trawling, dredge/ fill operations coastal construction

2. Overfishing

-And its indirect effects ex. trophic cascades

3. Climate Change & Acidification

-Exacerbating natural disturbances

4. Pollution/Eutrophication

-toxic effects, harmful algal blooms, hypoxia/anoxia

5. Non- native species introductions

What marine ecosystems are frequently disturbed

1. Shallow water/intertidal environments

2.Estruaries

3. Storm-exposed coast

4. Heavily trawled/trafficked/polluted coastal waters

What marine ecosystems are rarely disturbed

1. Deep sea environments

2. Open ocean pelagic environments

3. Some Arctic/Antarctic environments

How does ecological responded to disturbances

1. Alter populations communities and physical /chemical features of the environments

2. Typically decreases biodiversity and habitat structure at least initially

What is Resistance

How well the ecosystem resists disturbances how little it changed from its original state

What is resilience

How quickly the ecosystem returns to its original state after the disturbance

How are ecosystems becoming resistant to disturbance

1. Strong biogenetic structures-massive stony corals, well established mangroves and seagrasses

2. large healthy populations of hardy organisms

3. High biodiversity including species immune to the disturbances

How are ecosystems becoming resilient to disturbances

1. Quick growing quick reproducing species

2. recruitment from nearby undisturbed areas

3. High biodiversity including species able to recover quickly

What is a succession

The process of gradual change in the species composition of an ecological community over time

What is the order of a succession to recovery in a terrestrial type of ecosystem

1. Disturbances by something like a forest fire

2. Early colonization by opportunistic species

3. Early colonizers replaced by competitively superior species

4. Climax community

What happen during an Early Successional Adaptations

1. Effect r-selected species

-Able to survive in recently disturbed habitats not dependent on preexisting biogenic structure

-Live fast die young produce many offspring with long range dispersal

-Small body size weak defense weak competitors

What happen during an Late Successional Adaptations

1. Effected k-selected species

-Dependent on stabilized habitat less likely to colonize recently disturbed habitat

-Grow slow live long dominate and outcompete others in the area

-Large body size strong defense competitively superior in the long term

The figure on the right depicts the intermediate disturbance hypothesis. We would expect the following at letter c:

A. Low levels of diversity because species can't tolerate much disturbance

B. Intermediate levels of disturbance prevent competitive exclusion

C. Low levels of diversity because of competitive exclusion

A

How can fish indicate the health of ecosystems?

Fish can reveal information about production, community structure, and evolution within ecosystems.

What does 'production' refer to in the context of fish and ecosystems?

It refers to the number of consumers and how much energy is transferred from the base of the food web.

What is meant by 'community structure' in fish populations?

It refers to the relative abundance of different sizes of fish, indicating which species are more or less common.

What evolutionary features do fish use to survive in their environments?

Fish utilize specific adaptations that enable them to thrive in their particular habitats.

What is the significance of scientific ocean drilling?

It allows scientists to extract sediment layers from the ocean floor, which serve as a historical record of Earth's climate and biological changes.

What types of organisms are primarily preserved in ocean sediments?

Phytoplankton, including coccolithophores and diatoms, are commonly preserved due to their hard parts.

How do fossil accumulation rates help us understand past ecosystems?

They indicate the presence of organisms during specific time periods based on how well their remains survive through predation and sedimentation.

What was the impact of the Cretaceous-Paleogene Mass Extinction on marine life?

It led to the extinction of terrestrial and marine reptiles, 90% of calcareous plankton, and a significant decline in fish populations.

What findings did Dr. Sibert discover regarding fish teeth in sediment samples after the K/Pg extinction?

There were more teeth found in samples after the extinction, and the teeth were larger compared to those before the extinction.

What does the presence of denticles in sediment cores indicate?

A higher presence of denticles suggests a greater number of sharks in the ecosystem.

What was the temperature trend during the transition from the Cretaceous to the Paleogene period?

It was the warmest period the planet had experienced in the last 100 million years.

How did fish abundance correlate with temperature changes during the Paleogene period?

Fish abundance increased in sync with rising temperatures, indicating their adaptability to warmer conditions.

What are denticles?

Denticles are small, tooth-like structures found on sharks that are resistant to dissolution and can accumulate as fossils.

What role do calcareous organisms play in sediment formation?

Calcareous organisms sink to the ocean floor and contribute to the formation of sediment layers over time.