Managing fishing gear to encourage ecosystem-based management of coral reefs fisheries

Abstract

We present fisheries landing data from two poor tropical countries, Papua New Guinea (PNG) and Kenya, and show that each gear type has a unique and consistent partitioning of the species and functional groups it targets. Partitioning by gear can be used to influence ecological processes and 
\nbiodiversity on coral reefs and to respond to disturbances such as coral bleaching. Hook and line capture a higher proportion of top carnivores and piscivores and target species with low susceptibility to coral bleaching. Traps, drag nets, and spear guns capture mostly herbivores and omnivores and target the highest proportion and number of fish species that are moderately susceptible to the impacts of coral bleaching. The use of specific gears can be actively managed to encourage the recovery of select functional groups and adaptively managed under conditions such as high erect algae cover, sea urchin dominance, low coral cover, and coral bleaching. We present a simulation and conceptual model that examine projected effects of 
\nthe gear and effort on the yields in the coral reef ecosystem and suggest a mechanism for how this model might be practically implemented. Spear guns are predicted to have the highest diversity and yields of catch, but can also result in decline in herbivorous fishes, which has serious consequences for recovery and resilience of the system. Further understanding of fishing gear effects on specific fish functional groups at a broader selection of reef locations will be valuable in developing adaptive gear-based management in a changing climate.