The species most severely affected by incidental mortality in longline fishing operations share a common life-history strategy and include seabirds, turtles, sharks and rays and sunfish. They are all k-selected species, meaning that are generally longlived (have low natural adult mortality), breed slowly and/or have low recruitment into the breeding population. This life history strategy makes these species especially vulnerable to over-exploitation at even relatively low mortality rates. Increases of even one or two percent in adult mortality due to longline fishing can lead to substantial population decreases (Weimerskirch et al. 1997). These factors combined with the small global populations of some cases make these species extremely vulnerable to even small numbers of mortalities to adults due to longline fishing.