2012. Review of Significant Trade - Cites

Tridacna spp.
A number of actions were proposed in the Solomon Islands aquaculture development plan
(Ministry of Fisheries and Marine Resources, 2009) which included maintaining a ban on the
export of wild Tridacnidae and supporting production of hatchery-based clams on village
farms.
It was reported that between 1997-2001, over 60 000 Tridacnidae specimens (consisting of
T. gigas, T. derasa, T. squamosa, T. maxima, T. crocea and Hippopus hippopus) were exported
from 25 village farms in the Solomon Islands (Ministry of Fisheries and Marine Resources,
2009). However, the production of hatchery-reared individuals for grow-out on village
farms was disrupted in 1999-2000 and 2000-2003 as a result of ethnic tensions
(Ministry of Fisheries and Marine Resources, 2009). The village farming systems were
described as “simple, low-cost and low-input operations” (Hean and Cacho, 1999).
More recently, Tridacnidae farming in Solomon Islands was reported to be supported by the
WorldFish Center and funded by NZAID (Ministry of Fisheries and Marine Resources,
2009). Farming activities were reported to concentrate on T. derasa, with plans to expand the
production to cover other species as well (Ministry of Fisheries and Marine Resources, 2009).
The export rates of aquaculture-produced specimens were expected to increase in the future,
although the attractiveness of aquaculture production to private investors was considered
limited due to conflicts related to the customary rules on sea access rights and ownership in
Solomon Islands (Ministry of Fisheries and Marine Resources, 2009).
C. Species reviews
Tridacna crocea Lamarck, 1819: Solomon Islands.
Biology: Tridacna crocea was reported to be the smallest Tridacna species (Rosewater, 1965),
with a maximum length of 15 cm, although not usually exceeding 11 cm
(Kinch and Teitelbaum, 2010). Hamner and Jones (1976) recorded annual growth rates of
2 cm in the first year and 1.5 cm in the second and third years, after which the growth rate
was reported to decline.
The species is typically found deeply burrowed in coral substrate, in lagoons that experience
runoff of fresh water, and it appears to be well adapted to lower salinity levels
(Hamner and Jones, 1976; Hart et al., 1998; Kinch and Teitelbaum, 2010). According to
Kinch and Teitelbaum (2010), it is sometimes found in very shallow waters, and can occur in
depths up to 20 m in clear waters.
Distribution in range State: T. crocea has a wide distribution, ranging from Australia to
Japan, and from Vanuatu to Indonesia (Mollusc Specialist Group, 1996).
The species was considered widespread in the Solomon Islands (Govan, 1988; Wells, 1997),
and has been found in reasonable numbers in most parts of the country (Hviding, 1993).
However, in a 2004 survey of key invertebrate species conducted at 66 sites in the main
island group of the Solomon Islands, excluding the remote islands and atolls, T. crocea was
found at only 24 per cent of the studied sites, being significantly less frequent than T. maxima
or T. squamosa (Ramohia, 2006).
Population trends and status: T. crocea was categorised as Lower Risk/least concern in the
IUCN Red List, although it was noted that the assessment needed updating
(Mollusc Specialist Group, 1996). Wells (1997) described it as “reasonably abundant”
throughout its range, although many populations in Southeast Asia were considered to be in
decline.
Within Solomon Islands, Hviding (1993) regarded it abundant and in some localities, very
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