ARLINGTON, Va. — August 28, 2014 — The following was released by the Atlantic States Marine Fisheries Commission:
The Atlantic States Marine Fisheries Commission is pleased to announce the release of the River Herring Ageing Workshop Report. The report is the 8th in a series of publications focusing on improving consistency among state and federal laboratories on how fish age samples are collected, processed, and read. Fish age and growth information are key components of stock assessments. Age and length data are the basis for determining how fast a fish grows, how long it lives, when it matures, and how big it is at each age. This information is used by fishery scientists and managers to develop harvest strategies that allow the population to successfully replace what was removed by fishing and natural causes. Age data also provide important information on the age structure of a fish population and whether that age structure is changing over time.
With the growing emphasis on river herring monitoring and management activities along the Atlantic coast, there has been an increased need to evaluate the consistency of age estimates provided by each agency for future stock assessments. At the workshop, biologists from Maine through North Carolina met to compare methodologies of preparing age structures (scales and otoliths) and the criteria used to estimate ages. The goal of the workshop was to improve the quality and standardization of ageing practices to support precise age estimates among laboratories.
Prior to the workshop, biologists conducted a blind study where they exchanged blueback herring and alewife otoliths and scales and provided age estimates using their own ageing protocols. When the estimates were compared at the workshop, it was found that biologists which followed the same protocols had similar estimates, while biologists that followed different protocols or were simply new to ageing samples often had vastly different estimates. Participants discussed potential reasons for the differences in observed ages and developed recommendations to improve ageing practices, the most important being the adoption of a coastwide protocol to serve as the standard for ageing river herring. Exchange results, recommendations, and the ageing protocol are included in the workshop report, which can be found at http://www.asmfc.org/files/Science/RiverHerringAgeingWorkshopReport_August2014.pdf. For more information about fish ageing, visit the Commission website at http://www.asmfc.org/fisheries-science/research or contact Jeff Kipp, Stock Assessment Scientist, at 703.842.0740.