Lake Nojiri in Nagano Prefecture provides insights into attempting to balance management of native species while also maintaining a recreational fishery for invasive sport fish. One species, Bluegill (Lepomis macrochirus), which utilize colony spawning, has largely been ignored from a management standpoint. The removal of nest guarding males is a common management technique in Japan to reduce Bluegill. However, the colony spawning strategy may influence the effectiveness of selective male removal. In Lake Nojiri, Bluegill males utilized a variety of guarding behaviors such as rim circling and predator chases, and male removal revealed that brood predators were primarily conspecific Bluegill, as well as other fishes such as invasive Smallmouth Bass, Largemouth Bass and native Japanese Dace. In concurrence with the colony spawning theory, nest proximity decreased brood predation and increased predator arrival time after male removal. In addition, aggressive male guarding prior to removal reduced subsequent brood predation. These results indicate that the common guarding male removal management strategy may have reduced effectiveness due to colony spawning. In conclusion, future invasive fish management strategies are discussed such as the benefits of the recent resurgence of aquatic vegetation after a decades long removal effort of invasive grass carp.