Changes in a coral reef fishery along a gradient of fishing pressure in an Indonesian marine protected area

Abstract

Human population growth, rising incomes, and increased commercialization of marine resources promote demand for reef fish, yet few studies in Indonesia have examined how artisanal fisheries are influenced by the socio‐cultural conditions that contribute to their exploitation. This study examined artisanal fisheries of Karimunjawa National Park, Java, to understand how the condition of an artisanal fishery was related to socio‐cultural factors, along a gradient in fishing pressure. A total of 8674 fishes landed in Karimunjawa by fishers using four artisanal fishing gears were examined to understand how the condition of the artisanal fishery (standard and infinite fish length, trophic level and weight) related to fishing gear use, village fishing grounds, management, human population size, human population density and estimated fishing pressure. Depletion in fish lengths and trophic structure were found at or above 46 fishing trips day‐1 km‐2, suggesting that fishing pressure is a key factor driving fishery catch structure. When catch characteristics were examined in relation to the fishing pressure estimates from each village, negative correlations were found between inshore fishing pressure (no. trips day‐1 km‐2) and all four fish catch characteristics, but owing to small sample sizes (n = 5), only the effects on trophic level were significant. Fishery closures had limited impact on fish characteristics, and lack of any effect of spatial controls on fishing also supports the notion that fishing pressure and the types of fishing gears used, most likely driven by human population densities, are the greatest drivers of reef fish catch characteristics in the Karimunjawa fishery. In the absence of support for fishery closures from local fishing communities or adequate enforcement of fishery closures, targeted gear or species management strategies that limit impacts on large‐bodied fish and aim to conserve key species may be more effective in improving the size and trophic structure of fish populations. Copyright © 2013 John Wiley & Sons, Ltd.

Herbivorous fish rise as a destructive fishing practice falls in an Indonesian marine national park

“…This decrease is contrary to expectations given that muroami fishing involves a patron–client relationship, and we anticipated its cessation would result in an increased number of self‐employed fishers shifting to more traditional gears (e.g., spears; Campbell et al. ). In our case, economic drivers (e.g., elevated fuel price) may have prevented an increase in spearfishing landings (all authors, personal observation ).…”

“…), levels of compliance may have remained low and hence zoning may not reflect the spatial distribution of fishing pressure throughout the Park (Campbell and Pardede , Campbell et al. ).…”

“…Nominally herbivorous fish have been heavily exploited in Karimunjawa National Park (Campbell et al. ), and monitored with a high taxonomic resolution since 2006 (Pardede et al. ).…”

“…As nominally herbivorous fish reach sizes in excess of 1 m, they are heavily harvested throughout the Indo-Pacific and Indonesia (Cinner et al 2005, Campbell et al 2014, Ford et al 2016. Rarely are nominally herbivorous fishes afforded specific bans or catch limits, but they can be protected through spatially explicit fishery regulations .…”

“…Nominally herbivorous fish have been heavily exploited in Karimunjawa National Park (Campbell et al 2014), and monitored with a high taxonomic resolution since 2006 ). Yet, temporal patterns of this key group have not been investigated throughout the full extent of the monitoring program.…”