Death of majar fish
In the assumption that an undisclosed group may be behind such events and may continue to carry out such acts in future, I like to oppose the actions on two grounds. One, the large carnivorous fish and turtles are threatened species in these days of commercial production of fish, because fish farmers will not allow their growth. The only places where they can survive are ponds and lakes where they find natural habitats.
Two, the faith and practices of people are hurt by such acts.
However, may I also submit humbly to Muslim faith upholders that, majar activities and the faith related acts of touching the grave of any person and feeding their pet fish population with the expectation of getting their wishes fulfilled is against the belief of Islam.