The osprey is a bird of prey that eats almost nothing but fish such as trout. whirling disease is a deadly threat to many fish, especially certain kinds of trout. when whirling disease kills fish in an ecosystem, there is less energy available to and more energy available to than there was before. a. decomposers; ospreys b. trout; ospreys c. trout; decomposers d. ospreys; decomposers