Question

part 2: threats to biodiversity
instructions: read each scenario carefully. you will first determine whether each situation is more beneficial or harmful to biodiversity and the environment, then list the pros and cons of each scenario.

1. melting polar ice exposes new land, allowing human development but displacing native species.
2. scientists develop heat - resistant coral to help reefs survive climate change.
3. a shipping vessel accidentally introduces a non - native mussel species to a freshwater lake.
4. a city expands green rooftops and urban gardens to support pollinators.
5. an island community builds seawalls to prevent erosion, but this disrupts local turtle nesting sites.

Explanation:

1. Melting polar ice exposes new land, allowing human development but displacing native species:

• Harmful: Disrupts native ecosystems.
• Pros: Potential for human development (e.g., resource extraction, new settlements).
• Cons: Loss of habitat for native species, disruption of food chains, increased risk of invasive species introduction as native species are displaced.

1. Scientists develop heat - resistant coral to help reefs survive climate change:

• Beneficial: Aids in reef conservation.
• Pros: Helps coral reefs (biodiversity hotspots) survive rising temperatures, supports marine life that depends on reefs (fish, invertebrates), maintains ecosystem services like coastal protection.
• Cons: Potential unintended ecological consequences (e.g., if the heat - resistant coral outcompetes native coral varieties in non - stressed environments, or if it has unknown interactions with other reef organisms).

1. A shipping vessel accidentally introduces a non - native mussel species to a freshwater lake:

• Harmful: Can cause ecological imbalance.
• Pros: (Unlikely in this context, but if the mussel had some minor, unforeseen benefit like filtering water in a very limited way - but this is highly speculative).
• Cons: Competes with native species for resources (food, space), can disrupt the food web (e.g., by altering nutrient cycling or preying on native species' food sources), may lead to a decrease in native biodiversity.

1. A city expands green rooftops and urban gardens to support pollinators:

• Beneficial: Enhances urban biodiversity.
• Pros: Provides food (nectar, pollen) and habitat for pollinators (bees, butterflies), can improve air quality (through plant photosynthesis), may have a positive psychological impact on city residents.
• Cons: (Minor) Initial cost of installation and maintenance, potential for attracting some pests (but this is usually manageable).

1. An island community builds seawalls to prevent erosion, but this disrupts local turtle nesting sites:

• Harmful: Affects turtle populations.
• Pros: Protects human infrastructure (buildings, roads) from erosion, reduces the risk of property damage and loss.
• Cons: Disrupts turtle nesting (can lead to a decline in turtle populations, which are important for the ecosystem - e.g., as seed dispersers in some cases), may have knock - on effects on other species that interact with turtles (predators, scavengers that rely on turtle eggs or hatchlings).

Answer:

1. Harmful. Pros: Potential for human development. Cons: Displaces native species, disrupts ecosystems.
2. Beneficial. Pros: Helps reefs survive, supports marine life. Cons: Potential unintended ecological consequences.
3. Harmful. Pros: (Almost none). Cons: Competes with natives, disrupts food web.
4. Beneficial. Pros: Supports pollinators, improves air quality. Cons: Minor installation/maintenance costs.
5. Harmful. Pros: Protects human infrastructure. Cons: Disrupts turtle nesting, affects turtle populations.