Calcium, magnesium, and phosphorus are all examples of

Calcium, magnesium, and phosphorus are all examples of minerals, or more concrete macrominerals (minerals that the human body needs in large amounts).
These three mineral compose the most of the the body’s mineral content (98%) and play important roles in various biochemical reaction at cellular level and metabolic functions.

I’d have to say no because without oxygen in the water the fish would all be dead. so if you want to fish for dead fish, pick the ponds with the lowest oxygen concentrations.