Status of the fishery resources of Danajon Bank

Transcription

1 Status of the fishery resources of Danajon Bank First Workshop on the Formulation of the Danajon Bank Fisheries Management Plan 28 June 2005

2 Without fisheries management intervention? Demersal fish stocks (tons/km2) Habitat degradation Illegal fishing Destructive fishing Excessive fishing pressure

3 Current trend of demersal stock density decline t/km m m m m year Compilation of demersal stock density estimates based on various trawl surveys in the Philippines from 1948 to 1995

4 Estimates of demersal stock densities in selected fishing grounds of the Philippines Area Manila Bay San Miguel Bay Lingayen Gulf Carigara Bay Sorsogon Bay Year Stockdensity (t/km 2 ) Relative density (% of baseline) Warfel & Manacop 1950 Silvestre et al., 1987 Armada, 1994 Warfel & Manacop 1950 Vakily, 1982 Source Cinco et al., 1995 Soliman & Dioneda, 1997 Villoso & Aprieto, 1983 Ochavillo et al., 1989 Armada & Silvestre, 1981 Pura et al., 1997 Ordoñez et al., 1972 Cinco & Perez, 1996

5 With fisheries management intervention? Demersal fish stocks (tons/km2) Restore habitat Control illegal fishing Eradicate Destructive fishing Reduce fishing pressure

6 With fisheries management intervention? Demersal fish stocks (tons/km2) Restore habitat Control illegal fishing Eradicate Destructive fishing Reduce fishing pressure

7 Danajon Bank capture fisheries profile And the rest the coastal municipalities of Bohol

8 Number of fishers and fishing boats in Danajon Bank and the rest of Bohol 100 8, , ,953 Grand Total , , ,260 Sub-total ,256 Mabini Candijay ,048 Anda Guindulman Duero ,187 Jagna G. Hernandez Valencia Dimiao Lila Loay Alburquerque Baclayon ,634 Dauis ,655 Panglao Tagbilaran Cortes Maribojoc ,544 Loon ,006 Calape Rest of Bohol , , ,693 Sub-total ,670 Tubigon Clarin ,281 Inabanga ,000 Buenavista ,170 Getafe , ,476 Talibon ,176 Bien Unido ,492 Ubay ,093 C P. Garcia Danajon Bank % n % n % n MB NMB Fisher s MB NMB Fishers Fisher to boat ratio Density (count/km coastline) Counts Municipality

9 Coastal population

10 Fishers

11 Commercial fishing boats

12 Motorized fishing crafts

13 Non-motorized fishing crafts

14 All fishing gears

15 Gillnets and trammel nets

16 Hook and lines

17 Squid jig

18 Major Fishery resources exploited Anduhaw, Tamarong, Tulingan Lambay, Nokus, Lumayagan Danggit, Bolinao, Balo

19 Ten most important issues raised by municipal fishers in Bohol Province in 2003 Rank Blast fishing Drive-in nets(bahan, sagiwsiw, or dagoydoy) Baling/Sahid operations Issues Trawls and hulbot-hulbot operating in municipal waters Spear fishing with compressor Commercial fishing vessels operating inside municipal waters (ex. kubkub, likum) Decrease in fish catch attributed to overfishing Fishing with noxious substances, (cyanide, tubli, etc) Increase in the number of boats and fishers competing for limited resources in a limited area Ban of certain fishing operations (ex. Trammel nets, sudsud, whale shark fishing, manta fishing, baling, etc.) affects the livelihood of the community Fishing ground Rest of Bohol Danajon Bank TOTAL

20 Baseline data for Danajon Bank Information generated by the FISH Project for fishery resources management

21 Trawl survey (May 2004) Planed and actual fishing stations used during the trawl survey % jellyfishes, sea urchins and starfishes 5 0 Trawl Station Actual Trawl Route control 1 control 2 control 0 cont rol 3 control Average catch: Total catch = 4.54 kg/30min of trawling 1.33 kg/30min (excluding jellyfishes sea urchins and starfishes)

22 Estimation of biomass density Estimated demersal biomass density: 0.45 tons/km 2 Estimates of demersal stock densities from trawl survey in Danajon Bank compared to some selected fishing grounds of the Philippines Fishing ground Carigara Bay Lingayen Gulf Manila Bay San Miguel Bay Danajon Bank Year Biomass (mt/km 2 ) Armada & Silvestre, 1981 Pura, et al., 1997 Villoso & Aprieto, 1983 Ochavillo et al., 1989 Warfel & Manacop, 1950 Silvestre et al., 1987 Armada, 1994 Warfel & Manacop, 1950 Vakily, 1982 Cinco et al., 1995 Soliman & Dioneda, 1997 FISH, 2004 Source

23 Top 10 species/group caught during trawl survey Species/group Local name % Weight % Number 1 Leiognathus splendens dangay, potpot Saurida tumbil banghutin Arothron sp. butete Platycephalus indicus sunugan Upeneus tragula timbungan Loliginidae taroroton Apogon sp. 1 moong Scolopsis taeniopterus silay Loligo sp. taroroton, nokos Leiognathus rivulatus potpot Others

24 Bottom-set longline survey (June 2004) Catch per unit effort: 4.77 kg/run

25 Comparison of CPUE of bottom-set longline used for test fishing in the focal areas. Focal area Danajon Bank Coron Bay Lanuza Bay Tawi-Tawi Bay Average catch per operation Standard deviation Number of hooks 1,

26 Top 10 species/group caught during bottom-set longline survey in Danajon # Species Local name % Weight % Number 1 Therapon jarbua bugaong Lethrinus lentjan katambak Nemipterus hexodon lagaw Congridae obod Lutjanus chrysotaenia manilan-on Pentapodus setosus siwsiw Epinephelus sexfasciatus pugawo Gymnothorax sp. bakasi, panangitan Muraenidae obod Alutera monoceros saguksuk Others

27 Fish trap survey (June 2004) Contr ol Fishpot sites Catch per unit effort: 1.06 kg/run

28 Top 10 species/group caught during the fish trap survey # Species Local name %Weight %Number 1 Monocanthus chinensis saguksuk Thalamita sp. kubaw Pentapodus setosus siwsiw Upeneus tragula timbungan Helotes sexlineatus gonggong Scolopsis taeniopterus silay Upeneus sp. timbungan Octopus sp. tabugok Paracentropogon sp. bantol Pentapodus caninus salinggukod Others

29 Catch and effort monitoring (May to July 2004) Grid map and catch and effort monitoring points in Danajon Bank

30 Summary of CPUE from catch and effort monitoring in Danajon Bank (May-July 2004) compared to other FISH Project areas and similar fishing grounds Fishing gear Local name (in Danajon Bank) Danajon Bank 2004 Coron Bay 2004 Lanuza Bay 2004 Tawi- Tawi Bay 2004 San Miguel Bay 2001 San Pedro Bay Bottom set gillnet palunod, palugdang Drift gillnet palutaw, paanod Set gillnet w/plunger dumbol Bottom set longline palangre, kitang Multiple handline bira-bira, undak Simple hook & line pasol Squid jig ulang-ulang; pangnokos Crab liftnet sapyaw (sa lambay) Fish corral bungsod, tower Crab pot panggal panglambay Fish trap bubo Scissor net sudsud Handspear pana Stationary liftnet bintol Baby trawl palakaya

31 Fishing frequency of all fishing gears

32 Average CPUE of all fishing gears

33 Gillnet fishing frequency

34 Hook and line fishing frequency

35 Danish seine fishing frequency

36 Trawl fishing frequency

37 Threats to fisheries

38 Blast fishing Internal hemorrhage Intact coral reef Coral rubble

39 Cyanide fishing An estimated 65 tons of cyanide are sprayed each year on Philippine coral reefs alone Source: A field test in the Philippines in 1980 showed that two exposures to cyanide three months apart can completely kill the exposed reef area (Barber, C.V. & V.R. Pratt. 1998) Fish are approximately one thousand times more sensitive to cyanide than humans Cervino et al

40 Effect of cyanide on corals Coral specimens exposed to 600 mg/l CN-: (a) Acropora millepora control, (b) A. millepora 24 h after exposure; (c) Heliofungia control, (d) Heliofungia 72 h after exposure; (e) Trachyphillia geoffrio control, (f) T. geoffrio fully bleached 3 weeks after exposure (Cervino et al. 2003).

41 Effect of cyanide on corals The relationship between the cyanide dose and mortality or zooxanthellae density in colonies of Pocillopora damicornis 12 days after exposure to various cyanide doses. PC = Parent Colony controls, HC = Handling Controls ( stfish/news/lrf/3/2jon es.html)

42 Fine mesh nets among gillnets Number cm (stretched) Fine mesh pukot panglambay pang-anduhaw palunod, patugkad pukot palaran pangmangsi

43 Other fine mesh nets % 20 0 baling kurantay lawag sapyaw length bolinao sapyaw lawag kurantay baling gear palundag patuloy undak pasol lawag % ave. mesh size: #25-28 target: bolinao Round haul seine, Lawag length anduhaw lawag pasol undak patuloy palundag gear

44 Other fine mesh nets Stationary liftnet, New Look Fish corral, Bungsod, tower ave. mesh size: #22-28 target: small pelagics ave. mesh size (bunt): #16-20 target: pasayan

45 Other fine mesh nets Otter trawl, Palakaya Danish seine, Liba-liba ave. mesh size (codend): 1.7 cm target species: pasayan ave. mesh size (codend): <3 cm target species: demersal spp.

46 Other fine mesh nets Beach seine, Baling Pushnet, Sudsud ave. mesh size (codend): <3 cm target species: nearshore, demersal spp.

47 Other fine mesh nets dynamite spear w ith compressor crab gillnet Bottom set gillnet Drift gillnet simple hook and line Handspear trammel net stationary liftnet Bottom set longline Fish trap set gillnet w ith plunger Average sizes of danggit expressed in pieces per kilogram caught by different fishing gears used in Danajon Bank. Drive-in gillnet En c irc lin g g illn e t Fish corral Barrier net Beach seine otter traw l scissor net filter net danish seine Unfriendly fishing gears? Pieces per kg

48 Active and commercial fishing gears Ringnet Baby Ringnet Danish seine Baby Trawl

49 Thank you