Spring Stocking Activities
April - June
Spring activities at Craig Brook National Fish Hatchery are almost entirely devoted to fry. As the fry continue to develop, they slowly absorb their yolk sacs. When this is nearly complete, they are moved from the incubation trays into the rearing troughs. The majority of the fry that are reared at Craig Brook National Fish Hatchery are released unfed; they are able to subsist on the nutrients stored in their yolk sacs until they are released. Some fry will be kept on station as display fish, as domestic broodstock, or to be reared to a slightly advanced lifestage known as parr.
In April, the final preparations for stocking take place. All equipment is checked and repaired as necessary. Logistics for daily trips are finalized with our state partners, the Department of Marine Resources Bureau of Sea Run Fisheries and Habitat. Depending on weather, water flows and the development of the fry, some fry may be released during the last few weeks of April.
Fry stocking is the major activity for hatchery staff during the month of May. Fry are released nearly every weekday for the entire month. All in all, the hatchery releases close to 4 million fry annually! Some fry are transported hours and hundreds of miles before they are released into the streams. Again, depending on weather and water conditions, fry stocking may spill into the first few days of June.
Towards the end of May, our state partners begin operating a fish trap at the Veazie Dam on the Penobscot River. This trap is the source for all of Craig Brook National Fish Hatchery's Penobscot broodstock. Of the total run, only a portion is retained for broodstock. State of Maine biologists begin transporting broodstock to Craig Brook National Hatchery near the end of May and will continue through the spring to early fall. Penobscot broodstock are housed in four Swedish Pools, located between the boat launch and picnic area on Alamoosook Lake. For biosecurity reasons, the Swedish Pools are not open to the public.
In June, the hatchery staff turns to clean up. All fry stocking equipment is cleaned and stored until the next season. Remember all those incubation trays and troughs? Now is the time to drain and clean them.