Perhaps after evaluating these waters, he will choose a lake or something similar
Having a sewage system in your neighborhood means you don’t need the ocean, rivers, lakes, or even ponds. Maybe there’s a brand-new species of fish lurking under those things. We’re crossing our fingers that he doesn’t capture a rat, but that looks more plausible.
Could be disheartening. Perhaps he’ll go for a lake or something after trying these waters.