Question

healthy freshwater ecosystems are needed for the protection of native fish and invertebrate species. streams and rivers are vulnerable to extreme weather events, including prolonged droughts. which statement describes a possible consequence of a prolonged drought on native fish and invertebrate species in streams and rivers? a decreased waterflow in streams and rivers could result in lower numbers of young fish migrating, which could decrease population sizes. b decreased connections between streams and rivers could result in fewer interactions between individuals, which could increase genetic diversity within populations. c increased competition between species in streams cut - off from rivers could result in an increase in the fitness of individuals and an increase in population sizes. d increased interactions between species due to increased waterflow from streams into rivers could result in increased reproduction rates and increased numbers of offspring.

Explanation:

During a prolonged drought, water levels drop in streams and rivers. Lower water - flow can impede the migration of young fish, which are crucial for population replenishment. This can lead to decreased population sizes. Decreased connections between water bodies would reduce gene - flow and lower genetic diversity, not increase it. Increased competition would likely decrease fitness and population sizes, not increase them. Drought causes decreased, not increased, water - flow.

Answer:

A. Decreased waterflow in streams and rivers could result in lower numbers of young fish migrating, which could decrease population sizes.