Question

what are two major negative impacts humans have had on salt marshes?
using them for transportation routes and introducing non - native species
restricting tidal flow and over - harvesting cordgrass
overfishing of shrimp and excessive removal of deep mud
polluting the atmosphere and causing high relative humidity
question 29
1 pts
what are the primary physical features that characterize a rocky shore and provide homes for various species
rock pools, damp cracks, bare rocks, and sand.
sandy beaches, salt marshes, and tidal creeks.
coral reefs, kelp forests, and open ocean.
open sand dunes, mangrove swamps, and deep - sea trenches.

Explanation:

First Question (about salt marshes):

To determine the correct answer, we analyze each option:

• Option 1: Using salt marshes for transportation routes is not a major negative impact, and introducing non - native species is more of a general ecosystem impact not specific to salt marshes' main issues.
• Option 2: Restricting tidal flow (e.g., through dikes, dams) disrupts the natural functioning of salt marshes, and over - harvesting cordgrass (a key plant in salt marshes) can damage the marsh ecosystem. These are major negative impacts on salt marshes.
• Option 3: Overfishing of shrimp is not a direct impact on the salt marsh habitat itself, and excessive removal of deep mud is not a typical major impact on salt marshes.
• Option 4: Polluting the atmosphere and causing high relative humidity are not direct negative impacts on salt marshes.

We analyze each option:

• Option 1: Rock pools (formed at low tide), damp cracks (in rocks), bare rocks, and sand (in some rocky shore areas) are physical features of rocky shores that provide habitats for various species.
• Option 2: Sandy beaches, salt marshes, and tidal creeks are not characteristic physical features of rocky shores. Sandy beaches are a different coastal habitat, salt marshes are another type of coastal wetland, and tidal creeks are more associated with salt marshes or muddy shores.
• Option 3: Coral reefs are a separate marine ecosystem, kelp forests are in deeper or different coastal areas, and the open ocean is not a rocky shore feature.
• Option 4: Open sand dunes are a terrestrial or beach - dune habitat, mangrove swamps are tropical coastal wetlands, and deep - sea trenches are in the open ocean, not rocky shores.

Answer:

B. Restricting tidal flow and over - harvesting cordgrass

Second Question (about rocky shores):