The number of joules needed to raise the temperature of 10 grams of water from 20 degrees celsius to 30 degrees celsius is

It takes 1 calorie to raise temp of 1 gram of water by 1° C so
10 calories will raise 10 grams of water by 1° . Thus 100 calories
are needed to raise 10 grams of water by 10° C from 20° to 30°

Now 1 calorie = 4.184 J so multiply the 100 calories by 4.184 to
determine that 418.4 Joules of energy are needed to complete the task

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.