Exploitation
The Banggai Cardinalfish is highly-prized in the aquarium trade (Allen 2000, Vagelli and Erdmann 2002, Kolm and Berglund 2003). It has been heavily exploited by the aquarium trade since its rediscovery in 1994. Despite claims that captive breeding has been successful, most aquarium specimens are still captured in the wild. Fishes are collected, mainly with nets, and held in floating nets until purchased by fish buyers who visit individual fishers at least 3 to 4 times a month. Collectors are paid a small sum (ca. US $0.01 to 0.025 in 2001) per fish by buyers who, in turn, sell to exporters for US $ 0.10 to 0.12 a fish (Vagelli and Erdmann 2002). Since 1999, the fishery has expanded from Banggai Island and Bandang Island to villages in the Bokan area, on Bangkulu Island, Labobo Island, and Peleng Island, with most collection occurring near their own villages. By 2001, at least 17 villages and 230 fishermen were involved in the P. kauderni trade (Lunn and Moreau 2004). An estimated minimum of 600,000 to 700,000 individuals were collected per year by local fishers prior to 2001 (Vagelli and Erdmann 2002, Lunn and Moreau 2002); current harvest rates are believed to exceed 700,000 to 900,000 fish/yr (Vagelli 2005).
P. kauderni are shipped primarily by boat from the Banggai Archipelago to national exporters via Tumbak and Manado and to a Bali exporter via Palu, and also direct to Bali exporters. An estimated 115,000 fish/month were transported on the Tumbak–Manado route, 3,000/month along the Palu to Bali route, and up to 10,000 fish/month were sent direct to Bali in 2001 (Lunn and Moreau 2004). These numbers are close to earlier estimates of 50,000 to 60,000 fish/month arriving in North Sulawesi for exportation, with total estimated trade for 2000 and 2001 of 700,000 fish (Vagelli and Erdmann 2002). Transhipment mortality is high because of lengthy travel times, usually 18 to 48 hours by boat (Vagelli and Erdmann 2002); no data on mortality from collecting or holding prior to transhipment appears to be available. The high mortality rate contributes to the disparity in prices paid to fishers and buyers (Vagelli and Erdmann 2002). A minimum of four aquarium fish export companies operate in Bali; others exist in Kendary and Manado (Sulawesi). he majority of P. kauderni captured in the Banggai Archipelago are destined for the international aquarium trade, with most exported to the United States, Europe and Asia. Wabnitz et al. (2003) and Lunn and Moreau (2004) further document the aquarium trade.
In addition to the estimate of number of individuals collected and shipped reported in the assessment, trade surveys carried out by Lunn and Moreau (2004) suggest that a minimum of 118,000 Banggai Cardinalfish were sold each month by fishers in the Banggai Islands. Trade volumes are in all likelihood greater as this estimate only includes fish bought by Tumbak- and Palu-based buyers, not taking into consideration individuals collected and shipped from alternate locations, or lost to pre-sale mortalities in fishers’ holding cages (Lunn and Moreau 2004).
A recent study showed that, despite the use of non-destructive fishing methods, the fishery had a negative effect on fish density when sites with high fishing pressure were compared to sites with low fishing levels (Kolm and Berglund 2003). Fishing also had a significant effect on group size (halving of average group size where sites with high and low fishing pressure were compared), which may lead to strong negative impacts on individual fitness in the future (referred to as the Allee effect in the scientific literature) (Stephens et al. 1999, Stephens and Sutherland 1999, Kolm and Berglund 2003).
In addition to more detailed trade statistics to accurately reflect real trade volumes, regular monitoring of the fishery should be undertaken, particularly as studies seem to indicate that the expansion of the trade to new, previously unexploited areas is underway, moving outwards from Banggai Island to all of the major islands in the area. Lunn and Moreau (2003) also highlight that the pool of potential fishers could be large, particularly given that obstacles to entering the fishery appear to be minimal and alternative livelihood opportunities limited.