Scale loss and mortality in angled-and-released eastern sea garfish (Hyporhamphus australis)

Butcher, P. A., Broadhurst, M. K., Hall, K. C., Cullis, B. R., and Nicoll, R. G. 2010. Scale loss and mortality in angled-and-released eastern sea garfish (Hyporhamphus australis). – ICES Journal of Marine Science, 67: 522–529. The eastern sea garfish (Hyporhamphus australis) is an endemic Australian marine teleost that is angled in large numbers throughout its distribution. Most fish are retained, although some are released, mainly because of size-grading in response to bag limits. Owing to their fragility, there are concerns that few released fish survive. To investigate this assumption, 185 angled and 90 control eastern sea garfish were released in groups of five into holding cages, then monitored for up to 24 h. One control and 93 angled fish died, providing an adjusted angled mortality rate of 49.2%. All fish that ingested their hooks (n=7) subsequently died. Generalized linear mixed models for the remaining mouth-hooked garfish revealed that mortalities were mainly caused by scale loss (p