Answer:
The algae would decrease.
Step-by-step explanation:
As the number of steelhead fish increases, they will consume more predatory insects, which in turn would consume more midge larvae. As a result, there would be fewer midge larvae to feed on the algae, leading to a decrease in the amount of algae in the stream. This is an example of a trophic cascade, where changes in the population of one species can have cascading effects on other species in the ecosystem through the food web.