East Twin Lake
East Twin Lake in Salisbury, Connecticut has been one of the most managed and studied coldwater lakes in the state. It has a long history of fisheries management reacting to massive swings in fish community structure. East Twin Lake supported the most popular kokanee salmon fishery on the eastern seaboard through the late 1980s. Landlocked alewife were illegally introduced in the late 1980s and became abundant by the early 1990s causing a total collapse of the kokanee fishery due to competition for food (zooplankton).
Collecting kokanee salmon each fall has occurred for decades. In order to maintain the fishery, adult fish that are ripe for spawning are collected and transported to the Burlington State Fish Hatchery. At the hatchery, the fish are spawned, eggs incubated, and the resulting fry are raised until about 2 inches in length. Each May and June, the young kokanee are stocked back into the lake. To learn more about Connecticut's kokanee salmon fisheries, visit the webpage for the kokanee salmon program.
The Brown Trout Management
In 1993, the then Department of Environmental Protection (DEP) Inland Fisheries Division enacted special regulations in an attempt to increase the abundance of large brown trout and hopefully reduce or control the illegally introduced landlocked alewife. Based on previous work done in the Great Lakes, it was anticipated that the brown trout would prey heavily upon the alewives, and if successful, might allow the kokanee fishery to be restored. The new regulations on trout included a 14-22 inch protected slot length limit, and an extended closed season on all trout (season closed June 1 to the following Opening Day). Connecticut’s standard five trout per day creel limit remained in effect, but only one trout (all species) could exceed 22 inches in length. Initially, stocking was limited solely to brown trout, due to their superior ability to prey upon alewife.
The restrictive regulations at East Twin Lake effectively created an abundant population of very large holdover brown trout, but did not successfully reduce the alewife population. Consequently, it was determined that East Twin would be best managed for brown trout rather than kokanee because of the continued presence of alewives. Beginning in 1998, restrictive regulations on all trout at East Twin Lake were relaxed to provide a greater harvest of large brown trout that were then inhabiting the lake, while retaining the traditional put-and-take fishery for smaller trout. The restrictive 14-22 inch slot length limit for all trout was changed to a minimum length limit of 20 inches for brown trout, with a daily creel limit of one brown per day. Trout stocking was also changed, with approximately 30-50% of the allocation comprised of rainbow trout or a mix of rainbows and brook trout. Anglers could harvest five trout per day (5 rainbows/brooks or 4 rainbows/brooks and 1 brown trout ≥ 20 inches). The extended closed season was also removed, and changed back to the standard season (3rd Saturday in April through the last day of February).
With alewife re-established in 2020, the Fisheries Division has opted to once again pursue a trophy brown trout fishery. To accomplish this, Seeforellen strain browns are being stocked. Fishing regulations have been changed to allow anglers to take one brown trout per day, providing it is at least 22 inches. During ice fishing, anglers are allowed to use a total of 2 devices (not the normal 6).
Around this time (1998), zebra mussels (Dreissena polymorpha), another introduced aquatic nuisance species, were discovered in East Twin, further complicating the lake’s biological dynamics. Between the effects of the booming zebra mussel population and other contributing environmental factors, by 2008 the lake’s alewife population had totally collapsed along with the lake’s ability to grow holdover brown trout. Throughout this whole period in time, the Fisheries Division had been stocking the surplus kokanee salmon fry into the lake in hopes of one day reviving the population. Then in 2008, the first time in over 15 years, adult spawning kokanee were found in the lake -- bringing the management of East Twin Lake full circle back to a thriving kokanee fishery.
Please contact the Fisheries Division with any questions.
Content last updated January 2023