Question

### Passage

Researcher 1
The primary cause of the population decline of a certain frog species (*Rana temporaria*) in a woodland pond is the increasing acidity of the pond water, caused by acid rain. As the pH of the pond decreases below $6.0$, the hatching success of frog eggs drops significantly. Additionally, increased acidity dissolves protective mucosal coatings on the eggs, making them highly susceptible to lethal fungal infections. The introduction of predatory fish to the pond has no significant impact, because these fish prefer to feed on insects rather than frog tadpoles.

Researcher 2
The primary cause of the population decline is the introduction of a non-native predatory fish species to the pond. These fish feed heavily on both the frog eggs and tadpoles, preventing them from reaching adulthood. While a low pond pH (below $6.0$) does stress the frogs, it is not the main driver of the decline, as adult frogs can tolerate a wide pH range. However, low pH levels do dissolve the protective mucosal coating of the eggs, which exposes them to fungal infections. Therefore, both acidity and predation contribute to egg mortality, but predatory fish are the primary reason the population is collapsing.

### Question
Based on the viewpoints of Researcher 1 and Researcher 2, match each statement about the frog population decline to the researcher(s) who would support that statement.