Fish Discard and Release Mortality Science

What is discard and release mortality?

Discard and release mortality occurs when fish or other animals are caught alive and then die after release. Severe injury or predation, such as being eaten by another animal at the water's surface after release, can cause immediate death. Stress or injury during capture or handling can leave a fish unable to effectively find or digest food, resulting in death at a later time.

Why does NOAA Fisheries care?

NOAA Fisheries works to ensure sustainable fisheries and protected species recovery by collaborating with fishermen and other partners to avoid bycatch and safely discard or release bycatch that cannot be avoided. Discard and release mortality is not the best outcome of fishing activities, because a discarded dead fish cannot be served up on someone’s dinner plate, and it can no longer have offspring to contribute to future fish populations.

What is NOAA Fisheries doing?

NOAA Fisheries created the Action Plan for Fish Release Mortality Science, in consultation with outside experts, to address the gaps in our understanding of fish discard and release mortality. We are working to reduce mortality, improve mortality estimates, and incorporate those improved estimates into stock assessments and management actions. With those goals in mind, we created an Action Plan for Fish Release Mortality Science.

What will the Action Plan do?

  1. Identify species, complexes, and/or fisheries that would benefit most from improved mortality rate estimates.

  2. Help develop improved mortality rate estimates.

  3. Support effective and efficient research to reduce discard and release mortality for high-priority species, complexes, and/or fisheries.

  4. Ensure that improved mortality rate estimates are effectively incorporated into existing management processes.

Why was the Action Plan developed?

The Action Plan builds upon work done in 2014, when NOAA Fisheries held a workshop with experts to produce a report. The report summarizes 15 years of NOAA Fisheries-funded discard and release mortality research, identifies data gaps, compiles estimates, and identifies criteria to help scientists and managers prioritize release mortality challenges.

SMART Tool RankingThe Action Plan includes a “simple multi-attribute rating technique” (SMART) tool that can help identify high priority stocks for discard and release mortality research. The SMART tool, which was tested at a 2015 experts workshop, can help a range of scientists and managers to more consistently prioritize research efforts. The SMART tool is an unbiased, repeatable, and quick assessment. It can easily be tailored to meet your needs by region, fish species, and fishery.

How have fishermen contributed?

Fishermen and managers have developed and promoted practices designed to reduce mortality. Please visit the FishSmart website for examples. Fishermen and scientists have also developed technological solutions, including devices like fish elevators and reverse hooks (see the NOAA Fisheries video).

NOAA Fisheries greatly appreciates these efforts, along with the efforts of the 2014 and 2015 workshop experts from state agencies, fishing clubs, regional fishery management organizations, non-governmental organizations, and U.S. and Canadian federal government and academic institutions. Without valuable input from our partners, including fishermen, we would not have an Action Plan and supporting report.

Action Plan for
Fish Release
Mortality Science

NOAA Fisheries worked with stakeholders like you to identify the best practices for estimating and reducing release mortality. Improved communication among scientists, managers, fishermen, and other stakeholders has been vital to the success of these efforts. We thank you for your input. The Action Plan for Fish Release Mortality Science is available below.

DRAFT Action Plan for Release Mortality Science

Action Plan for Fish Release Mortality Science


Click to Learn About Bycatch

A yelloweye rockfish (Sebastes ruberrimus) experiencing barotrauma.

A canary rockfish (Sebastes pinniger) experiencing barotrauma, a condition that occurs to some fish in deep water that are quickly brought to the surface. The rapid change in pressure causes their swim bladders to expand and their organs to shift. It is easy to recognize a fish experiencing barotrauma — you will often see the stomach ballooning out of its mouth and its eyes bulging. Fish experiencing barotrauma can have difficulty returning to depth. This can leave the fish vulnerable to birds and other predators.


Fish with distended swim bladders cannot descend to safety.Fish with
swim bladders
cannot descend
to safety.