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Transcript of REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND Some Good...
REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND
WWW.UNEPSCS.ORG
Some Good Practices in the Establishment of Refugia, Sanctuaries, and Fisheries Management Systems in
the Philippines
Some Good Practices in the Establishment of Refugia, Sanctuaries, and Fisheries Management Systems in
the Philippines
3.1
3.2
3.3
3.4
66 67 68 68 70 71 72 73 74 75 76 77 78 79 80 81
Year
Tro
ph
ic l
ev
el
of
ca
tch
REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND
WWW.UNEPSCS.ORG
Presentation Outline
• Establishing network of refugia and sanctuaries
• Species specific management interventions
• Some initiatives towards ecosystem approach
REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND
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Major areas of high larval count and presumed to have intense spawning (based on Magnusson, 1970 and Tan, 1970).
Celebes Sea
Sulu Sea
SouthChina Sea
PacificOcean
MindoroStrait
MalampayaSound
Lingayen Gulf
REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND
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LingayenGulf
ManilaBay
IlocosCoast
Batanes Islands
SubicBayZambales
MalampayaNo. Palawan
KIG
Lingayen Gulf
Manila Bay
Ilocos Coast
Subic Bay, Zambales
BatangasCoastMindoro
Strait
MalampayaSound
NorthernPalawan
KIG
CalamianesIslands
Map of western Philippines showing locations of main embayments (red squares) and other coastal areas of transboundary significance in the South China Sea.
REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND
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Candidate refugia sites in western Philippines
1. Bolinao, Lingayen Gulf
2. Masinloc, Zambales
3. Busuanga, Calamianes
REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND
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Participants in the various consultations
• Local Government Units
• Academe
• Regional Government Agencies
• Law Enforcers (Police, Coast Guard, Navy, Bantay Dagat)
• Fisherfolk Organizations
• Non-Governmental Organizations
• People’s Organizations
• National Committee Members
REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND
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REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND
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General tidal circulation in Coron Bay (Villanoy 2006).
Circulation pattern
REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND
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Simulated dispersal resulting from tidal circulation in Coron Bay (Villanoy 2006).
119.90 120.00 120.10 120.20 120.30
11.75
11.85
11.95
12.05Simulated dispersal
REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND
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Simulated dispersal with wind effects typical of April (Villanoy 2006). Red ellipses indicate areas where settled particles originate from several sources. Grey lines indicate possible but weak dispersal, apparent only after 30 days.
119.90 120.00 120.10 120.20 120.30
11.75
11.85
11.95
12.05Simulated dispersal
REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND
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Density (no./100m3) distribution of fish eggs in Coron Bay in April 2004 (Campos 2004)
119.90 120.00 120.10 120.20 120.30
11.75
11.85
11.95
12.05
0 to 0.01 0 .01 to 25 25 to 100 100 to 250 250 to 6596
Fish EggsFish eggs distribution
REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND
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Density (ind./100m3) distribution of fish larvae in Coron Bay in April 2004. (Campos 2004)
Fish Larvae
119.90 120.00 120.10 120.20 120.30
11.75
11.85
11.95
12.05
0 to 0.01 0.01 to 10 10 to 25 25 to 50 50 to 182
Fish larvae distribution
REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND
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119.90 120.00 120.10 120.20 120.30
11.75
11.85
11.95
12.05
0 to 0.01 0.01 to 2 2 to 25 25 to 65
Yolk Sac
Distribution of yolk sac larvae in Coron Bay in April 2004 (Campos 2004)
Yolk sac larvae distribution
REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND
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Marine sanctuary sites
REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND
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Candidate mangrove refugia
REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND
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• Close season during spawning season
4th 5th and 6th day after the new moon
monthly for the entire year or for a few months only
• Banning of fine meshed gears catching rabbit fishes
• Banning of selling of rabbit fishes during close season
Closed Season for rabbit fish, Siganus canaliculatus
REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND
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Siganus canaliculatusSiganus canaliculatus
Closed Season for rabbit fish, Siganus canaliculatus
REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND
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all gears
0
10
20
30
40
50
60
5/1/
045/
2/04
5/3/
045/
4/04
5/5/
045/
6/04
5/7/
045/
8/04
5/9/
045/
10/0
45/
11/0
45/
12/0
45/
13/0
45/
14/0
45/
15/0
45/
16/0
45/
17/0
45/
18/0
45/
19/0
45/
20/0
45/
21/0
45/
22/0
45/
23/0
45/
24/0
45/
25/0
45/
26/0
45/
27/0
45/
28/0
45/
29/0
45/
30/0
45/
31/0
46/
1/04
6/2/
046/
3/04
6/4/
046/
5/04
6/6/
046/
7/04
6/8/
046/
9/04
6/10
/04
6/11
/04
6/12
/04
6/13
/04
6/14
/04
6/15
/04
6/16
/04
6/17
/04
6/18
/04
6/19
/04
6/20
/04
6/21
/04
6/22
/04
6/23
/04
6/24
/04
6/25
/04
6/26
/04
6/27
/04
6/28
/04
6/29
/04
6/30
/04
7/1/
047/
2/04
7/3/
047/
4/04
7/5/
047/
6/04
7/7/
047/
8/04
7/9/
047/
10/0
47/
11/0
47/
12/0
47/
13/0
47/
14/0
47/
15/0
47/
16/0
47/
17/0
47/
18/0
47/
19/0
47/
20/0
47/
21/0
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22/0
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47/
28/0
47/
29/0
47/
30/0
47/
31/0
4
date
Sig
anid
s ca
tch
(kg)
Catch monitoring data from various gears catching rabbit fish in Danajon Bank from May to July 2004
new moon
Closed Season for rabbit fish, Siganus canaliculatus
REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND
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Major seagrass areas
REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND
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Proposed temporal seagrass closed areas
REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND
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• Size limits (12 cm carapace width?)• Minimum crab gillnet mesh size of 10 cm (4 inches)• Prohibit selling and buying of berried females• Impounding berried females (7 days?)• Zoning of crab fishing gears
Size limit on blue crab, Portunus pelagicus, and ban on harvesting of berried individuals
12 cm
REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND
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Crab gillnet
0 10 20 30
0.0 - 0.9
1.0 - 1.9
2.0 - 2.9
3.0 - 3.9
4.0 - 4.9
5.0 - 5.9
6.0 - 6.9
7.0 - 7.9
8.0 - 8.9
9.0 - 9.9
10.0 - 10.9
11.0 - 11.9
12.0 - 12.9
13.0 - 13.9
14.0 - 14.9
15.0 - 15.9
16.0 - 16.9
17.0 - 17.9
18.0 - 18.9
19.0 - 19.9
Crab liftnet
0 10 20 30
0.0 - 0.9
1.0 - 1.9
2.0 - 2.9
3.0 - 3.9
4.0 - 4.9
5.0 - 5.9
6.0 - 6.9
7.0 - 7.9
8.0 - 8.9
9.0 - 9.9
10.0 - 10.9
11.0 - 11.9
12.0 - 12.9
13.0 - 13.9
14.0 - 14.9
15.0 - 15.9
16.0 - 16.9
17.0 - 17.9
18.0 - 18.9
19.0 - 19.9
Crab pot
0 10 20 30
0.0 - 0.9
1.0 - 1.9
2.0 - 2.9
3.0 - 3.9
4.0 - 4.9
5.0 - 5.9
6.0 - 6.9
7.0 - 7.9
8.0 - 8.9
9.0 - 9.9
10.0 - 10.9
11.0 - 11.9
12.0 - 12.9
13.0 - 13.9
14.0 - 14.9
15.0 - 15.9
16.0 - 16.9
17.0 - 17.9
18.0 - 18.9
19.0 - 19.9
Length at maturity
Size limit on blue crab, Portunus pelagicus, and ban on harvesting of berried individuals
REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND
WWW.UNEPSCS.ORG
REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND
WWW.UNEPSCS.ORG
REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND
WWW.UNEPSCS.ORG
REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND
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Length frequency distribution of Plectropomus leopardus in Calamianes in 1998 (Mamauag et al. 2002)
500g - 1,000g
2 - 4 years old
Lm
Immature Super spawners
Minimum and maximum size limit for red grouper, Plectropomus leopardus, in Calamianes
REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND
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Length frequency distribution of sexual development stages of Plectropomus leopardus in Calamianes (Mamauag 1997)
Sex Selectivity?
50
0g -
1,0
00
g
Lm
Immature
Super spawners
Minimum and maximum size limit for red grouper, Plectropomus leopardus, in Calamianes
REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND
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Ban on harvest of berried lobster
REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND
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Rastrelliger kanagurta
0 50 100 150 200
ring net
danish seine
dynamite
Multiple handline
Surface set gillnet
Drift gillnet
simple hook and line
Set gillnet for rays
Rastrelliger brachysoma
0 20 40 60 80 100
Bag net
ring net
dynamite
danish seine
Set gillnet forrays
Naturalpoisons
Surface setgillnet
Multiplehandline
Drift gillnet
Ban on fine meshed fishing gears catching juveniles
REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND
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r oph
ic le
vel
Tr o
phic
leve
l
PhytoplanktonPhytoplankton
Top predatorsTop predators
Prey fishPrey fish
ZooplanktonZooplankton
. . . . . . .... .. .. .. .. .. .. .. *.*. .. .. ... . ..*.*.
*.*.*.*.*.*.
*.*.*.*.*.*.
10% 10%
10% 10%
10% 10%
*.*.
44
33
22
11
Trophic level: the concept
REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND
WWW.UNEPSCS.ORG
1 Pelagic piscivoresbawo, talakitok, kubal-kubal, balila, bat-og, lapis, tangigi, diwit
2 Soft-bottom piscivores ubod, tiki-tiki, sunugan, banghutin
3 Reef-associated piscivores ahaan, islawan, awman, panangitan, gawot, pugapo
4 Squids nokos taroroton, bisaya, kubotan, buko-buko
5 Soft-bottom zoobenthos feeders
moong, sapsap, caraballas, samook, bogo, timbungan, asoos, bugaong
6 Reef-associated zoobenthos feeders
pakol, ngisi-ngisi, kyampaw, lipti, labayan, lupit, katambak, tad, lagaw, tuwas, silay
7 Blue crabs lambay, kasag
8 Shrimps pasayan, locon, lunhan, bulit
9 Pelagic planktivores tamarong, tikab, anduhaw
10 Sardines hilos-hilos, mangsi, gilang, maubgas
11 Coastal planktivores guno, bolinao, libgao, solid
12 Demersal herbivores banak, gisaw, molmol
13 Rabbitfish danggit, kitong, samaral
14 Sergestids uyap
Trophic groups
REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND
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pasayan (shrimps)
lambay, kasag (crabs)
banak, gisaw (algal grazers, herbivores)
bawo, talakitok, tangigi (pelagic piscivores)
ahaan, awman, pugawo (reef piscivores)
Tro
phic
leve
l
1
2
3
4
potpot, moong, timbungan
(soft-bottom zoobenthos feeders)mangsi, gilang
maubgas (sardines)
bolinao, guno (coastal planktivores)
AlgaeDetritusPhytoplankton
Zooplankton
Average trophic level = 2.89
REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND
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A Collapse of management regime
Increase of trawls, Danish seines, and blast fishing activities
B Partial/haphazard management interventions
Removal of all illegal and destructive gears and effort redistributed indiscriminately
C Appropriate management options in place
Removal of all illegal and destructive gears and effort redistributed appropriately
Simulation
REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND
WWW.UNEPSCS.ORG
-5%
0%
5%
10%
15%
20%
25%
30%
0 1 2 3 4 5 6
Year
% c
hang
e in
bio
mas
s
No management
Partial management
Sound management
Trend in harvestable biomass in years following intervention
REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND
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0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
Soft-bottom zoobenthos feeders
Blue crabs
Sardines
Pelagic piscivores
Reef-assoc. zoob. feeders
Coastal planktivores
Squids
Pelagic planktivores
Shrimps
Rabbitfish
Demersal grazers/herbiv.
Reef-associated piscivores
Soft-bottom piscivores
Octopus
Other crabs
Sergestids
2005 2007 2010
Group 2007 2010
Sardines - 54% - 66%
Octopus - 40% - 65%
Pel. piscivores - 19% - 23%
Rabbitfish - 18% - 25%
Shrimps - 4% - 7%
2007 2010
Overall harvestable biomass 3.35 t/km2 3.28 t/km2
% change + 0.8% - 1.4%
Group 2007 2010
Blue crabs + 23% + 25%
Coast.planktivores + 17% + 16%
Other crabs + 16% + 13%
Soft-bottom zoob. feeders
+ 14% +14 %
No management
REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND
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0.00 0.25 0.50 0.75 1.00 1.25
Soft-bottom zoobenthos feeders
Blue crabs
Sardines
Pelagic piscivores
Reef-assoc. zoob. feeders
Coastal planktivores
Squids
Pelagic planktivores
Shrimps
Rabbitfish
Demersal grazers/herbiv.
Reef-associated piscivores
Soft-bottom piscivores
Octopus
Other crabs
Sergestids
2005 2007 2010
Group 2007 2010
Pel. piscivores + 134% + 136%
Reef piscivores + 124% + 135%
Octopus + 120% + 133%
Soft-bottom pisci. + 105% + 120%
Squids + 102% + 117%
Rabbitfish + 97% + 97%
Shrimps + 35% + 53%
Group 2007 2010
Overall harvestable biomass 4.03 t/km2 4.16 t/km2
% change + 21.3% + 25.1%
Group 2007 2010
Blue crabs - 69% - 75%
Pel. Ppanktivores - 69% - 90%
Sergestids - 15% - 19%
Partial management
REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND
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0.0 0.2 0.4 0.6 0.8 1.0
Soft-bottom zoobenthos feeders
Blue crabs
Sardines
Pelagic piscivores
Reef-assoc. zoob. feeders
Coastal planktivores
Squids
Pelagic planktivores
Shrimps
Rabbitfish
Demersal grazers/herbiv.
Reef-associated piscivores
Soft-bottom piscivores
Octopus
Other crabs
Sergestids
2005 2007 2010
2007 2010
Overall harvestable biomass 3.92 t/km2 3.90 t/km2
% change + 18.0% + 17.3%
Group 2007 2010
Pelagic plank. - 95% - 100%
Reef-assoc. zoob. Feeders
- 10% - 18%
Group 2007 2010
Octopus + 143% + 162%
Pel. Pisci. + 127% + 121%
Squids + 124% + 129%
Rabbitfish + 80% + 80%
Soft-bottom pisci. + 77% + 78%
Sardines + 65% + 60%
Reef-assoc. pisci. + 54% + 59%
Crabs + 23% + 26%
Sound management
REVERSING ENVIRONMENTAL DEGRADATION TRENDS IN THE SOUTH CHINA SEA AND GULF OF THAILAND
WWW.UNEPSCS.ORG
• Collapse of management regime will lead to overall decline of the harvestable biomass
• Partial management will lead to the biggest overall increase in the harvestable biomass but drastic decline of important commodity like the “blue crab”
• Sound management will lead to a moderate increase in the harvestable biomass but increase in the desirable species especially the carnivores
Summary of results of simulation