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Inclusion of the Banggai Cardinalfish Pterapogon kauderni in Appendix II.
Proponent: The United States of America.
Summary: The Banggai Cardinalfish Pterapogon kauderni is a small coral reef fish endemic to a restricted
region of Indonesia. It has been harvested substantially for the international ornamental aquarium trade
since 1995 and possibly in smaller numbers before then. Its range is restricted to 27 Indonesian islands in
the Banggai Archipelago and to Luwuk harbour in central Sulawesi. The total extent of natural occurrence
of the species is around 5 500 km2, which is extended slightly by artificial introductions to nearby areas.
The total extent of suitable habitat is estimated to be only 34 km2. The Banggai Cardinalfish is a sedentary
fish living in small stable groups that remain closely associated with various living benthic substrates
including sea urchins, sea anemones, branching corals and mangrove roots. Despite its small size, short
life span and early age at first maturity, the Banggai Cardinalfish nonetheless has a relatively low fecundity
due to limited brood size and prolonged male mouth brooding. It is also vulnerable to overexploitation due
to its limited dispersal abilities (it has no pelagic larval stage) and consequently has the highest degree of
population subdivision ever documented for a marine fish: populations occurring on reefs within the same
island are genetically differentiated from each other.
There are an estimated 2.4 million individual Banggai Cardinalfish in the wild based on data from 2004.
Since the early 1990s, exports of this species appear to have increased. Recent figures indicate an
annual export of some 400 000 to 480 000. Data for the period 2001–2004 suggested annual exports of
around
700 000–900 000 fish, which were estimated by extrapolating shorter-term export figures.
However, these figures
may be overestimates if there is substantial inter-annual variation in exports (there
are currently no data to determine this). Export figures may substantially underestimate the number of
fishes collected if, as is suggested by various sources, there is a high level of post-capture mortality.
There is some anecdotal information suggesting that the frequency of collection by traders and the
number of traders visiting individual villages in the region have been recently declining, but whether this
reflects dwindling abundance of Banggai Cardinalfish or other factors remains unclear. Baseline
population information is not available to indicate whether the status of the species as a whole has
changed since the main export trade began in 1995. Falling prices per fish suggest that there remain
enough accessible stocks to satisfy current demand. However, several spatial and temporal studies have
demonstrated the severe localised impact of harvesting Banggai Cardinalfish for the aquarium trade;
observations indicate harvesting reduces the size of sub-populations and reduces the number of fish per
group, a factor that is likely to lead to further declines and inhibit population recovery. All observed
declines of individual sub-populations are recent and have been as high as 100% over three years.
The
extremely limited capacity for this species to recolonise areas that have been depleted by harvesting for
the trade has also been demonstrated. Protection of sub-populations from fishing pressure has been
associated in some cases with increased population densities. There has been substantial development of
local conservation strategies for the Banggai Cardinalfish in recent years with considerable involvement of
local stakeholders. Efforts are being focussed on the development of four marine protected areas (which
still await implementation), increasing capacity for “in-situ” grow-out of juvenile fish and improving
husbandry techniques to minimise post-capture mortality. There is also some evidence that a sustainable
system of rotational harvest could be effective in preventing over-harvesting of Banggai Cardinalfish.
Further investigations are required to determine whether “in-situ” breeding and rotational harvesting can
be considered as sustainable strategies.
This species is proposed for inclusion in Appendix II under Resolution Conf. 9.24 (Rev. CoP13) Annex 2a
criterion B because of marked recent declines in populations driven by harvesting for the international
aquarium trade and the inherent vulnerability of this species to overexploitation.
Analysis: The Banggai Cardinalfish is a localised species that is harvested intensively for the international
aquarium trade. While the exact levels of recent exports are not known and the most recent population
estimates are from 2004, there is little doubt that a significant proportion of the total population of this
species is exported from Indonesia each year. Higher levels of fishing pressure are associated with both
marked recent declines in localised population size and a reduction in individual group size. The limited
geographic range, small-scale isolation of sub-populations, low fecundity, and extremely limited dispersal
mean this species is inherently vulnerable to overexploitation. It thus seems likely that the species meets
the criteria for inclusion in Appendix II as set out in Annex 2a of Resolution Conf. 9.24 (Rev. CoP13).
