11th ICRS Abstract book - Nova Southeastern University

22.829
Commercial Topshell, trochus Niloticus Fisheries in The Pacific. Present Status,
Management Overview And Outlook For Rehabilitation
Kalo PAKOA* 1 , Kim FRIEDMAN 1 , Emmanuel TARDY 1 , Ferral LASI 1 , Mecki
KRONEN 1 , Aliti VUNISEA 1
1 SPC, Noumea, New Caledonia
In surveying coral reef fisheries as part of a Pacific-wide programme, the status of
trochus fisheries was recorded across more than 70 sites in 17 Pacific island countries and
territories. Surveys show that T. niloticus was present at 72% of sites, and that 67% of
sites had at one time received trochus through successful or unsuccessful introductions.
Historical records and current data show these fisheries to be highly productive, with
current status reflecting the differing harvesting regimes in place.
Shallow water snorkel and SCUBA assessments reveal stocks to be depleted at most
sites; the main aggregations within 92% of sites had a mean density below a suggested
threshold of 500 trochus ha -1 . However, there are examples of well managed fisheries,
and the prospect for recovery in fisheries under pressure still exists; 44% of depleted
fisheries had trochus at >500 ha -1 in at least one SCUBA survey station.
Catches also differed markedly between historical and current records. Virgin fisheries
were yielding 4000 trochus fisher -1 day -1 , whereas our records show fishers in seven
countries making multiple fishing trips (mean of 33 ±6SE trips yr -1 ) for small catches
(mean of 17 ±6SE trochus trip -1 ). In fact in non-regulated fisheries, 61% of these fishers
reported catches of