Experimental Rainbow Trout Stocking Program:  Rainbow Trout, Brown Trout and Brook Trout Hatchery Comparisons


By Jamie J. Bray

Maine Department of Inland Fisheries and Wildlife
Division of Fisheries and Hatcheries
Augusta, Maine

February 2007


Maine Department of Inland Fisheries and Wildlife (MDIFW) hatchery system evaluated the growth, mortality, and feed conversion rates;  relative stress tolerance and disease resistance of rainbow trout (Oncorhynchus mykiss), against both brook trout (Salvelinus fontinalis), and brown trout (Salmo trutta) over a four-year period.  Equal if not better performance of Eagle Lake strain rainbow trout is needed to successfully compete with the hatcheries' fast growing homogenous populations of brook trout and brown trout.  At the conclusion of the hatchery study, monthly production reports were collected and compared for each specie from January 2000 to October 2003.  The average size of rainbow trout at all age groups was larger than brown trout or brook trout.  Prior to stocking, mean length and weight of spring yearling  rainbow trout (288 mm; 276 g) were significantly larger than spring yearling brook trout and brown trout.  Fall yearling rainbow trout (343 mm; 547 g) length and weight were significantly greater than fall yearling brook trout and brown trout throughout the study.  However, rainbow trout mortality and feed conversion efficiency did not differ significantly.  Diagnostic tests for pathogens throughout study were negative for all three species.  Questioned fish culturists from participating hatcheries determined rainbow trout and brown trout more stress tolerant than brook trout.  Generally, Eagle Lake strain rainbow trout out-performed the Maine hatchery strain brook trout and New Gloucester strain brown trout.  Final performance results will assist MDIFW determine potential development of a regular rainbow trout program and help aid future strain evaluations.

For more information, please contact:

Jamie Bray, Fish Culturist Supervisor
Palermo Rearing Station
200 Gore Road
Palermo, Maine 04354
Telephone: (207) 993-2361
Email: jamie.bray@maine.gov