Well, if we go by geological survey terms 1 magma would be 1 acre of magma with relative heat.
1 Electric eel would be about 3lbs, so 3 quintillion pounds of wet sea eels falling on 1 acre. Enough eels to put out at least 2 forest fires by volume. I think they could handle the thermal transfer of 1 acre of molten rock and have a few hundred thousand eels ready to die in the sun the next day.
Is the implication here that if the magma cools down it loses? I figured it'd turn to rock after a billion eels and then it'd either be a stalemate or molten lava would win after the eels starve to death.