Nobleboro & Newcastle Fishery
There is only one year of data available for repeat spawning rates for the Nobleboro and Newcastle fishery. This is a joint fishery conducted by two municipalities at one fishing location. The current municipal management plan for this fishery permits all river herring arriving at the fishway during the first week of the season free passage upstream. This fishery is one of two fisheries in Maine that currently allows continuous escapement of spawning fish throughout the season in addition to closed days, though traditionally they harvested seven days a week. Historically, Damariscotta Lake never had a run of river herring. The run began in 1806 with the constriction of a 42-foot high fieldstone fishway and an initial introduction of broodstock from the Sheepscot River. After local residents established the run, the fishing rights granted by the State of Massachusetts in 1810 permitted the fishery to occur seven days per week. Continuous escapement up the fishway occurred throughout the season. Estimated annual exploitation rates for this run ranged from 85-95 percent from the early 1800s through the 1984.
A tidal stream leads to the base of the fishway. Alewives arrive and depart the area downstream of the fishway based on the tidal stage in the river. During the height of the run the tidal stream and fishway are full of alewives attempting to ascend into Damariscotta Lake. The run is entirely alewife, with no blueback herring mixed in with the commercial catches. There is no spawning habitat for either species below the fishway due to high salinities.
Commercial fishermen did collect scale samples in 2009 and 2010 in addition to MDMR data collection efforts. The Maine Department of Marine Resources manages this pond for a commercial escapement of 35 fish per acre. The spawning escapement needs for this system are 153,335 river herring counted upstream by the harvester. The management plan returned enough fish to meet the target escapement developed for this system 85% of the time during the past 20-year period. The age and design of the previously existing fishway limited the numbers of river herring entering spawning habitat. A $400,000 fishway renovation started in 2007 improved escapement into spawning habitat.
A hydropower turbine is located at one of the lake outlets and produces a limited amount of hydropower during early spring and winter. The hydropower station does not operate during the downstream migration period for alewife or American eel (July – November). Operation during the 1960s and 1970s is unknown as are any associated adult or juvenile mortality rates.
Damariscotta Lake is an oligotrophic lake that produces small juvenile river herring compared to other lakes in the area. These juveniles start to emigrate from the lake in early July at total lengths as small as 42 mm. Work conduced at Damariscotta indicates that increased escapement levels negatively effect the numbers of juveniles produced within the lake. Increased stocking rates appear to lead to diminished yield per adult spawner.