AICE marine chapter 5 ESQs

1. State and describe the relationship shared by the following pairs of organisms:
   i. coral polyps and zooxanthellae
   ii. crown-of-thorns starfish and coral polyps

i. symbiotic/mutualism; zooxanthellae give the coral carbohydrates from photosynthesis; coral provides nitrogen, phosphorus, and carbon dioxide to the zooxanthellae, creating a benefit to each.
ii. predation/predator-prey; crown-of-thorns eat the coral polyps

2. Describe each of the following reef types:
   i. fringing reef
   ii. barrier reef
   iii. patch reefs

i. A shallow reef that forms along a coastline; narrow or no lagoon
ii. reef far from coastline; wide lagoon present
iii. small, isolated reef; survives within lagoon of a barrier reef or atoll

3. Sketch a diagram of an atoll.

A circle/oval within a circle/oval is drawn; inner circle/oval is labelled lagoon; outer circle is labelled atoll; sea/ocean is labelled

4. State one adaptation mangrove crabs have for living in the intertidal zone.

Mangrove crabs burrow

6. Mangrove forests are being deforested globally. Give three reasons why they are being cut down.

Any three of the following:

• timber

• shrimp aquaculture

• coastal resorts

• fuel source

7. Explain what is meant by the term intertidal zone.

Area of a shoreline that is submerged during high tide and exposed during low tide

8. Compare the physical factors affecting organisms living on a rocky shore to those living on a sandy shore.

On a rocky shore, organisms have to deal with increased wave action/weathering from exposed shoreline.

• They must attach themselves to rocks.

• On a sandy shore, the organisms must contend with: large amounts of erosion/unstable/shifting sediment.

• Organisms on this shore tend to be infauna/burrowers.

9. Define the term zonation.

When organisms within an ecosystem organize themselves into definite bands according to biological and physical factors

10. i. Explain how the physical and biological factors of a rocky shore ecosystem contribute to vertical zonation of the organisms that live there.
    ii. Then, name an example organism and describe its adaptation for survival in the upper shore of the rocky intertidal habitat.

i. Physical factors determine an organism's upper limit in the ecosystem, including exposure to air, desiccation/temperature tolerance
ii. Biological factors determine the organism's lower limit in the ecosystem; for example, predation/competition/finding a mate

• channelled wrack; can survive up to 8 hours without water

11. Suggest reasons for why the biodiversity on a sandy shore is different than that of a coral reef.

• Any five from:
  lower biodiversity than a coral reef
  fewer niches available
  lack of places for attachment
  few producers
  fewer habitats
  fewer food sources
  less shelter available
  must be able to burrow

  12. State and explain two processes that impact the shape of a sandy shore.

Erosion: sand is moved by waves/wind/water changing shape of shoreline
Sedimentation: sand is deposited from other areas changing shape of shoreline

13. State three adaptations you would expect most organisms living on a sandy shore to share.

• burrowers/live within the sand grains;
  detritivores/eat leftover organic matter/decomposers;
  able to withstand desiccation at low tide

14. Outline three reasons why artificial reefs are beneficial to shorelines.

Any three from:
reduce wave height and strength
reduce erosion
protect coastal development
protect coastal development
protect anchorages for boats
provide economic benefits

15. In order to determine the best placement for artificial reefs, developers must take certain physical factors into consideration. Explain which factors are most important when determining placement of a coral reef for healthy growth.

clear water of appropriate depth/20m or less
sunlight can reach zooxanthellae in coral polyps for photosynthesis
water temperature between 23 and 25 degrees C
allows for optimal growth and reduced stress
hard stable substrate for attachment

16. Most artificial reefs are now constructed from a pH-neutral cement material. Explain why scientist prefer this material to old truck tires, abandoned planes and ships.

    • idea of coral susceptible to reduced pH

    • idea of coral grow best in slightly basic environment

    • truck tires, planes, ships contain chemicals that may alter pH

    • may contain chemicals that will contaminate the water (for example, oil or rust)

    • pH neutral material allows the coral to grow on a substrate similar to basaltic rocks

    • lower chance of chemical damage

17. Describe the habitat where you would expect to find mangrove trees.

• equatorial/tropical/subtropical coastal regions

• brackish/mix of salt and fresh water

• low oxygen concentration within the sediment

• estuary/sandy shore/muddy shore/find grained sediment

• intertidal regions

18. Identify two environmental challenges within the mangrove forest and explain an adaptation the red mangrove has for each.

• soil is anoxic/low oxygen concentration [1]; absorbs oxygen through the bark or roots
  ecosystem submerged/underwater twice a day [1]; prop roots hold the plants above high water mark
  high salinity levels [1]; highly efficient filtration system in roots to prevent salt from entering tissues
  shifting sediment [1]; prop roots stabilize the plant in the unstable sediment

19. Explain how red mangroves benefit coastal ecosystems.

• provide habitat for juvenile fish/invertebrates among their roots
  trap sediments/building land
  create wave break/reduce wave energy
  prevent erosion
  reduce sediment accumulation on corals and seagrass beds

20. Figurine 5.24 is a diagram of the open ocean.
    Using. Figure 5.25, state the two primary abiotic factors used to differentiate between the zones of the open ocean.

• light and depth

• Using named examples, give two adaptations organisms may have for living in the abyssopelagic zone.

• squid/ctenophores and bioluminescence; translucence

  21. i. State the name of the zone labelled A in Figure 5.24.
      
      ii. Give two abiotic factors, other than lack of light, that organisms have to adapt to in order to live here.

i. benthic zone

ii. high pressure; low oxygen; low nutrient levels; near-freezing temperatures

22. Define the term carbon sink.

a reservoir which accepts more carbon than it releases

23. Explain how El Nino events interfere with the World's Ocean's ability to function as a carbon sink.

El Nino: prevents upwelling; keeps nutrients locked under the epipelagic zone; phytoplankton cannot access nutrients; phytoplankton are unable to photosynthesize; less carbon dioxide is pulled from atmosphere; may also bring more rain during that time

24. The Gulf Stream (Figure 5.25) is a warm water current that flows from the Gulf of Mexico around the southern tip of Florida in the south-eastern United States up the eastern seaboard. Explain what impacts this warm water current may have on the northern coastal states.

Those states nearest the ocean would expect to have a milder winter; warm ocean water will bring warmer air in cold months; reduce impacts of cooling atmosphere; may also bring more rain during that time

25. Outline the connection between increased carbon dioxide in the atmosphere and ocean acidification.

As carbon dioxide in the atmosphere increases; [CO2] dissolves more quickly into oceans through dissolution; carbon dioxide combines with water to form a weak form of carbonic acid; reduces ocean pH/makes ocean more acidic

26. Explain how limiting nutrients, such as nitrogen and phosphorus, can have both positive and negative impacts on coral growth.

When the levels of nutrients are in balance, zooxanthellae are able to grow well and provide corals with more nutrients; coral build their skeletons.
When the concentration of nutrients is too high, it leads to a plankton bloom; can cause turbidity in the water; prevents sunlight from reaching zooxanthellae; reduces photosynthesis and availability of energy to coral; increased nutrients increases the number of crown-of-thorns starfish larvae; able to survive due to an increase in food source/phytoplankton; may cause an outbreak

27. Suggest one reason why coral reefs are not usually found in upwelling areas.

Cold water limits coral growth/excess nutrients limits coral growth

28. Create a flowchart to represent the intended results of geoengineering through ocean fertilization.

add iron and/or other nutrients
v
increase phytoplankton productivity
v
decrease atmospheric CO2 and reduce impacts of climate change

29. Explain how increased levels of nutrients would decrease the rate of climate change.

As nutrient levels increase, producers would be able to create more proteins and other vital compounds. This would lead to higher populations of producers all photosynthesizing. The extra photosynthesis would require phytoplankton to pull more carbon dioxide from the atmosphere. Those plankton would then die and sink, removing the carbon dioxide from the atmosphere permanently, thereby reducing its ability to affect climate change.

30. Compare the potential benefits of ocean fertilization with. the potential risks. In your opinion, is this an idea worth pursuing? Justify your response.

Answers will vary.
Example: ocean fertilization is not worth the risks it places on ocean ecosystems. Experiments have shown this to be an ineffective method of carbon sequestration while the side effects can be disastrous.

Relationships Between Organisms

i. Coral Polyps and Zooxanthellae

• Type of Relationship: Symbiotic/Mutualism

• Details: Zooxanthellae are microscopic algae that live within the tissues of coral polyps. They perform photosynthesis, converting sunlight into energy, which produces carbohydrates. In return, coral polyps provide zooxanthellae with essential nutrients such as nitrogen, phosphorus, and carbon dioxide, creating a mutually beneficial relationship that enhances the growth and health of both organisms. The presence of zooxanthellae is crucial for the vibrant colors of coral reefs and helps in the building of the coral calcium carbonate structure, which forms the habitat for numerous marine species.

ii. Crown-of-Thorns Starfish and Coral Polyps

• Type of Relationship: Predation/Predator-Prey

• Details: The crown-of-thorns starfish is a notorious predator of coral polyps. It feeds on coral by everting its stomach and secreting digestive enzymes to break down the coral tissue. This relationship often leads to increased coral mortality, especially in areas where crown-of-thorns populations surge, resulting in significant ecological impacts on reef structures and health.

Types of Reef

i. Fringing Reef

• Description: A shallow reef that develops along the edge of a coastline, extending directly from the shore and often exhibiting a narrow or no lagoon. Fringing reefs are typically the first type of reef a diver encounters and serve as a buffer for coastal erosion while providing habitat for various marine life.

ii. Barrier Reef

• Description: A reef that is situated further from the coastline, separated by a wide lagoon. Barrier reefs are often larger and more complex, featuring rich biodiversity. The Great Barrier Reef in Australia is the most famous example and serves vital ecological functions, including serving as a breeding ground for various marine species.

iii. Patch Reefs

• Description: Small, isolated reefs that survive within the lagoon of a barrier reef or atolls. These reefs can vary in size and structure and are important for providing habitat to marine species seeking refuge from predation and harsh environmental conditions.

Diagram of an Atoll

• Description: An atoll is characterized by a circular or oval shape surrounding a lagoon; the inner ring is labeled ‘lagoon’, while the outer circle is identified as ‘atoll’. This formation is typically the result of a volcanic island subsiding over time, with corals building up around it.

Adaptations of Mangrove Crabs

Adaptation: Mangrove crabs are known for their burrowing behavior, which helps them avoid harsh environmental conditions in the intertidal zone, such as desiccation and temperature fluctuations. They dig into the sediment, creating a stable microhabitat.

Mangrove Crab Population Estimate Using Mark-Release-Recapture

• Data Provided:

  • Initial sampling: 53 marked crabs

  • Second sampling: 75 crabs, of which 25 were marked.

• Calculation:

  • Estimated size of population = (n1 * n2) / n3

  • Using the data: (53 * 75) / 25 = 159

• Mean Crab Density Calculation:

  • Total area: 10m x 10m = 100m²

  • Mean number of mangrove crabs per square metre = 159 crabs / 100m² = 1.59 ≈ 2 crabs/m²

• Challenges with the Mark-Release-Recapture Method:

  • Burrowing: Mangrove crabs often burrow, making recapture difficult and leading to potential underestimation of the population.

  • Mobility: They can relocate to trees or waters, complicating the re-sampling process.

Reasons for Mangrove Deforestation

Three Reasons:

1. Timber Harvesting: Valuable wood leads to deforestation for construction and other uses.

2. Shrimp Aquaculture: Coastal areas are cleared for shrimp farming, leading to significant ecosystem changes.

3. Coastal Development: Expansion of resorts and urban areas results in habitat loss.

Intertidal Zone Definition

• Definition: The intertidal zone is a coastal area that alternates between being submerged during high tide and exposed during low tide. This dynamic environment challenges organisms to adapt to varying conditions, including salinity and moisture levels.

Comparisons of Physical Factors

• Rocky Shore Organisms: Face high wave action and must adapt by attaching to solid surfaces to avoid being swept away.

• Sandy Shore Organisms: Deal with unstable sediments which can shift easily; many develop burrowing abilities to remain stable.

Definition of Zonation

• Definition: Zonation refers to the organization of organisms into distinct bands or zones within an ecosystem, dictated by both biological (e.g., competition) and physical (e.g., exposure to the elements) factors.

Vertical Zonation in Rocky Shores

i. Explanation of Zonation:

• Physical Factors: Define the upper limits where organisms survive based on desiccation tolerance and temperature extremes.

• Biological Factors: Set the lower limits through predation pressures and resource competition.

ii. Example Organism:

• Organism Name: Channelled wrack (a type of seaweed)

• Adaptation: Able to withstand prolonged exposure to air and water loss, surviving up to 8 hours without submersion.

Biodiversity Comparisons

Reasons for lower biodiversity on sandy shores:

1. Less structural complexity compared to coral reefs.

2. Fewer ecological niches available for species.

3. Limited attachment surfaces due to shifting sand.

4. Lower primary production with fewer photosynthetic organisms.

5. Reduced food sources and shelter for various marine organisms.

Processes Affecting Sandy Shore Shape

• Erosion: Movement of sand caused by waves and winds, shaping the shoreline over time.

• Sedimentation: Deposition of sand can alter shoreline profiles, creating new formations.

Shared Adaptations of Organisms on Sandy Shores

1. Burrowing to avoid predators and desiccation.

2. Functioning as detritivores to recycle nutrients.

3. Ability to withstand dry conditions at low tide.

Benefits of Artificial Reefs

1. Helping to reduce wave energy, protecting fragile shorelines.

2. Minimizing coastal erosion by providing structural integrity.

3. Fostering marine biodiversity and habitat creation.

Factors for Coral Reef Placement

• Assessment Criteria: Clear water that allows sunlight penetration; depth of less than 20m is ideal for growth due to light availability.

• Temperature Range: Optimal water temperature is between 23-25 degrees Celsius to support coral health.

• Stable Substrate: Hard, stable seabed materials for coral attachment are essential for the establishment and growth of reefs.

Preferred Materials for Artificial Reefs

• Reason for Preference: pH-neutral materials do not alter the marine environment's chemistry, unlike ships or tires that may leach harmful chemicals. This helps create a stable environment conducive to coral growth, reducing the risk of contaminating the surrounding ecosystem.

Habitat Characteristics of Mangrove Trees

• Expected Habitat: Thrive in tropical to subtropical coastal areas where saltwater and freshwater mix (brackish).

• **Geographic Distribution: Found in intertidal zones characterized by soft sediment and anaerobic conditions.

Environmental Challenges for Red Mangroves

• Anoxic Soil Adaptation: They have specialized roots that can absorb oxygen directly from air in order to survive in oxygen-poor environments.

• Adaptation to Submersion: Prop roots elevate the tree structure above water levels, maintaining stability and avoiding drowning.

• Salt Filtration: Adapted roots filter out high salinity levels to prevent salt entry into the plant tissues.

Benefits of Red Mangroves

• Provide critical habitats for juvenile marine organisms, fostering biodiversity.

• Help stabilize sediment, preventing erosion and protecting coastal lines.

• Act as natural barriers against strong wave actions, reducing coastal damage.

Muddy Shore and Rocky Shore Formation Processes

Muddy Shore Formation

• Sedimentation: Soft sediments from rivers and ocean currents accumulate in coastal areas, creating muddy environments. These sediments often consist of fine particles that settle slowly in calm waters, allowing the land to build up over time.

• Erosion: While muddy shores are typically protected from strong wave action, they can still experience erosion from rising water levels or human activities that destabilize the sediment. Over time, this can lead to the loss of land in some areas.

Rocky Shore Formation

• Erosion: Rocky shores are formed primarily through the erosion of underlying bedrock by wave action. This process wears down the rock, creating cliffs and other rocky structures over geological timescales.

• Sedimentation: In some rocky shore environments, sedimentation can occur where small fragments of rock and organic material accumulate in tide pools or depressions, enhancing habitat complexity and providing niches for various marine organisms.