The third step is to determine which fishing factors cause significant mortality or impairment in fish condition. Statistical hypothesis testing is performed with data for condition measures and mortality. The laboratory studies identify important factors for mortality but do not produce direct estimates of escapee and discard mortality. Further studies may be performed in the field based on the laboratory results to estimate bycatch mortality. Relationships between fishing conditions and bycatch mortality may be modeled from limited experimental work. Future bycatch mortality could then be predicted from knowledge of fishery conditions.

Our research has shown that fish size and species may modify the effects of potential mortality factors.  If these factors are of interest, then experiments can be conducted which use various sizes of fish and different species.  See Davis (2002) for further information on size and species effects.    

For further information on bycatch mortality factors see articles (Olla et al., 1997; Olla et al., 1998; Davis et al., 2001; Davis and Olla, 2001; Davis and Olla, 2002; Davis and Parker, 2004; Davis and Schreck, 2005; Lupes et al., 2006; Milston et al., 2006).

Steps for Studying Bycatch Mortality in the Laboratory
[ Step 1] [ Step 2 ] [ Step 3 ] [ Step 4 ] [ Step 5 ] [ Step 6 ]

Research Topic 1: Fish and Environment

Research Topic 2: Fish Habitat

Research Topic 3: Bycatch Mortality

Research Topic 4: Fishing Gear

Last updated 27 March, 2009