To address the question about changes in export numbers of BCF by seasons, I am presenting information from a paper by Lunn and Moreau (2004) published in Coral Reefs Vol. 23:244-351 The title of the paper is "Unmonitored trade in marine ornamental fishes: the case study of Indonesia's Banggai cardinalfish (Pterapogon kaudneri).
The authors did not attempt to estimate population numbers in the Banggaii Islands but did mention an estimate of 1.7 million BCF for central Sulawesi (including the Banggai Islands and other areas) arrived at by Vagelli (2002).
Lunn and Moreau (2004) conducted their study in the north and central provinces of Sulawesi form 7 March to the 1st of April 2001. It consisted of 44 structured interviews in Bahasa Indonesian at 11 information gathering meetings wiht 76 people in Manado, Bitung, Tumbak, Luwuk (situated on the Island of Sulawesi) and 22 villages of the Banggai Islands, in addition to many informal conversations with locals in each of these places and another 25 villages of the Banggai regions.
The local trade in BCF began in 1992, with traders from Tumbak and Bali coming by boat to the Banggai Islands...Local fishers started independently collecting the BCF for sale to outside buyers in 1995, when regional fishing regulations changed to prohibit people living outside the Banggai district to fish in the area without purchasing government permits.. Since 1999, the trade has expanded from its original focus on Banggai Island and nearby Badang Island to include more villages in the Boken area, on Bangurung Island, Labobo Island and, to a limiited extent, Pelang Island (islands considered part of the Banggai archipelago).
In the Discussion section Lunn and Moreau (2004) noted that their trade survey suggests a minimum number of 118,000 BFC sold each month by fishers in the Banggai Islands at the time of their study (2001). Actual capture and trade volumes could be much higher. They noted that their estimate included only fish bought by Tumbak and Palu-based buyers, without considering the likely significant number of fish taken on the alternate trade routes described, or lost to pre-sale mortalities in fishers' holding cages. They stated "we expect that the Tumbak-Manado route was the most important on at the time of our study."... Our monthly estimate of numbers leaving the Banggai Islands on Tumbak boats is consistent with Vagelli and Erdmann's (2002) estimate of 50,000 -60,000 arriving in north Sulawesi for export each month in early 2001 (figure obtained by interviews with N. Sulawesi traders)."
Then, Lunn and Moreau (2004) go on to state "Neither estimate, however accounts for the potential annual variation in trade volumes through North Sulawesi, which certainly exists. All primary buyers interviewed conceded that purchasing trips could be cancelled if orders or funds were lacking, or if the weather was particularly rough, while secondary buyers noted that demand for the BCF dropped (albeit unpredictably) during the nothern hemisphere's summer. While fishers themselves noted no seasonal differences in buyer's visits, they did report waits of 3 weeks, and occasionally up to 6 months between visits from buyers. Affirming our expectation that significant inter-annual variation exists in the trade is the fact that recent assessments of total population size place the number of BCF at roughly 1.7 million (Vagelli 2002). If our estimated minimum trade volume remained constant throughout the year, this would suggest an unrealistically high annual fishing mortality in excess of 83% during 2000-2001."
Hence, Lunn and Moreau (2004) were questioning their own annual estimates of the numbers of BCF leaving the Banggai archipelago. They also cautioned that Indonesian export statistics did not help in confirming the number of BCF traded annaually. The noted that the failure of Indonesian government trade statistics to reflect real trade volumes was one reason for the establishment of the Global Marine Aquarium Database (GMAD) set up by the UNDP-World Conservation Monitoring Center (situated in the UK). However, they noted that GMAD only recorded 10,307 BCF imported from Indonesia in 2001, while "our field estimates suggest that even assuming very high morality rates of 85% from time of capture to import, at least 17,000 fish should be on record as having arrived at aquarium wholesalers (presumably this means wordwide) in a single month of that same year."
So, Lunn and Moreau (2004) gestimated that the total number of BCF reaching importers wordwide was about 204,000. Using the GMAD number seems ridiculously low (10,307 for all of 2001).
They concluded that more monitoring was needed to get better estimates etc. A multi-faceted management approach, combining well-conceived trade regulations with such community-based and industry-supported initiatives, might offer the best opportunity to conserve this species (BCF) and its marine ecosystem, while also preserving fishers' livelihood options.
Peter
