Holographic scare tape attached to cormorants' favorite perches has worked so far for us, but it's only been 3 weeks or so. Scare eye balloons now up, too.
7 acre pond in east Texas, full pool reached March 2016. CNBG, RES, FHM stocked Nov 15; TP May 16; LSL bass 30 June 16. Added 100 12 inch N LMB and 1,000 shiners Oct 17.