Selected References

• Fish size-at-release effects -- bigger is better, sometimes
• Release habitat effects -- can make or break stocking success
• Release season effects -- choice of season can reverse size-at-release effect
• Acclimation effects -- can cut hatchery costs in half!!!
• Release magnitude effects -- more can mean more, but can also mean less!!!
• Cost effectiveness of fish size-at-release -- place your bets
• Transport stress effects
  

~ Sponsored by ~
NOAA NMFS
&
NOAA Aquaculture

Hatchery-Release Strategies

Developing Protocols Needed to Control Hatchery Impact on Fisheries

Decisions about release strategies have important consequences on the effectiveness of hatchery releases. SCORE scientists have shown that the decisions made about fish size-at-release, release habitat and microhabitat, acclimation, timing of releases, and release magnitude have direct effects on hatchery fish survival, growth, dispersal, recruitment to the fishery and cost-effectiveness of hatchery releases. Release magnitude can affect abundance of both hatchery (+ and -) and wild fish (-).

Without conducting pilot release-recapture experiments to examine release strategies, stocking to enhance fishery landings is a hit or miss proposition, with little or no opportunity for improvement. In contrast, SCORE scientists have used pilot release experiments to improve survival of stocked juvenile fishes by up to 90% (in-situ acclimation) and in some cases even orders of magnitude (choice of size-at-release, release habitat, seasonal timing).

Business owners don't stock their shelves before taking inventory to determine what sold well and what did not. Why should fishery managers stock the sea without knowing which release strategies worked well and which didn't? How much value could be gained by comparing the outcome of a range of release strategies?

Applying pilot release experiments and an adaptive management approach in Biscayne Bay, Florida's Fish and Wildlife agency turned a totally ineffective red drum stocking program into one that could be used to support a catch-and-release sport fishery in Miami.

Ask your hatchery manager -- how efficient are your stocking strategies, and what effect does stocking have on the fishery? Which habitats work well for stocking and which don't? Which size hatchery fish provides more bang for the buck (more fish in the fishery per dollar spent to rear them), tiny juveniles or larger juveniles? at some release sites and seasons, the answer is cheap small fish; at others, the small fish have no impact. Would you stock your store's shelves without even knowing what was selling and what was not?