Michael Tenorio Michael Trianni

Transcription

1 Michael Tenorio Michael Trianni

2 This project would not have been possible without the support of many over the years, and this presentation reflects their dedication Alvin Fitial Anthony Flores Bob Coldeen Danny Castro Frank Rasa Gayle Martin Jacinto Taman* Jaimie Nogis Jess Omar John Manglona JJ Kapileo Pete Tegata Larry Tenorio Rudy Pangelinan Roxon Kani

3 Short History of CNMI Sea Cucumber Fishery Target species Surf Redfish

4 The harvest of sea cucumbers is a major industry in the Indo-Pacific Region and now Worldwide as temperate species are now being exploited to meet demands in the Orient Estimated Asian Landings Tonnes Wet Weight 2000: 12, : 12, : 12, : 13, : 18, : 17, Choo PS 2008 FAO Tech Rpt

5 Development of the sea cucumber fishery in the CNMI Began on Rota in late basic data collection Trianni M Beche-de-Mer Info. Bull. 16: Moved to Saipan in June 1996 fishery dependent & independent data Trianni M Proceedings 9 th International Coral Reef Symposium, Bali, Indonesia. Planned movement to Tinian 1997 fishery independent survey- Survey resulted in the closure of fishery Trianni M & Bryan P Pacific Science Re-Survey of harvested areas on Saipan 2006 Trianni M., Tenorio M Asian Fisheries Science

6 Surf Redfish Habitat outer reef flats subject to strong waves and currents Can be found from the back reef to depths of 35 feet. Viable commercial populations from 0-20 feet

7 Prior to harvest on Saipan two No-take Sea Cucumber Reserves were established by regulation at Lao Lao Bay and Bird Island Fishery Monitored by collection of species specific catch, effort and location data as required by condition under the Division of Fish and Wildlife Export Permit

8 Saipan Fishery Monitored by Catch-Effort Statistics 250 CPUE # Depth Avg. CPUE #/day Depth of Harvest (feet) Week Fishery was halted in January 1997 due to declining catches

9 The post-harvest abundance was estimated using two approaches 1) Subjected catch-effort data to 3 depletion model estimators: Leslie Model: linear model DeLury Model: log-linear model Non-linear Leslie Model: objective function minimization These models provided estimates of initial abundance using CPUE, cumulative catch or cumulative effort

10 The post-harvest abundance was estimated using two approaches cont. 2) Conducted fisheries independent post-harvest survey Transects used to estimate remaining surf redfish densities in management units, then extrapolated through estimate of total habitat in management units

11 Abundance Estimate Results Total Surf Redfish Harvested in Fishery = 156,388 Estimate Initial Size # Remaining Leslie Model 172,482 16,094 DeLury Model 178,019 21,631 Non-linear Leslie Model 186,938 30,550 DFW Post-harvest Survey 189,365 32,977 As a result of these analyses fishery was terminated in June 1997 and a moratorium on sea cucumber harvest in the CNMI established in 1999.

12 2006 Re-Survey Sampling Technique 1) Utilize circle plot sampling method 2) Obtain estimates of precision at sample size for this method using un-harvested mean and variance from 1997Tinian survey 3) Consider management units as strata 4) Randomly select points in habitat to sample 5) Generate population estimate

13 A total of 522 samples Original image provided by D. McClarin,CRMO

14 Use handheld GPS to locate predetermined sample sites Circular plots (5.64 meter radius) Count, measure, and weight all surf redfish within the plot

15 300, , , ,000 Pre-Harvest 189, , , ,482 After 10 years 256, , , ,000 50,000 Post-Harvest 32,977 30,550 21,631 16,

16 Habitat 2006 Density/100m Density/100m 2 A BR A RS B C BR C RS D BR D RS E BR E RS

17

18 Conclusions 1. Sea cucumber populations can be fully recovered given spatial and temporal restrictions on harvest 2. Unsure of recovery rate during the time period Marks the first documentation of a recovered surf redfish population, and one of only a few recovered sea cucumber populations worldwide 4. Requirement of strict reporting essential to sea cucumber fisheries management and establishment of management measures are beneficial

19 Thank You Si Yu us Ma asi Ghilisow