ALEIPATA COMMUNITY-BASED MARINE BIODIVERSITY MONITORING REPORT
August 2007
Prepared by:
Juney Ward and Pulea Ifopo1
1 Marine Conservation Section, Division of Environment & Conservation TABLE OF CONTENTS
1. INTRODUCTION ...... 2
2. METHODOLOGY...... 2 - 5 2.1 Study Location and Sites 2.2 Survey Techniques 2.3 Quantitative Estimations
3. RESULTS ...... 5 - 19
A. Individual Site Analysis 3.1 Results of Current Survey 3.2 Comparison of the Average Fish Abundance of the Current survey with Previous Surveys
B. Overall Analysis
4. DISCUSSION ...... 19 – 21 4.1 Current Survey 4.2 Comparison of Fish Abundance within the NTZs from Previous and Current Surveys
5. CONCLUSION ...... 21
6. RECOMMENDATION ...... 21
7. REFERENCE ...... 21
8. ACKNOWLEGEMENT ...... 22
9. APPENDICES ...... 22 - 26 Appendix 1: List of targeted fish species/families Appendix 2: Benthic indicators and macro invertebrates Appendix 3: List of algae
1 1. INTRODUCTION
The Marine Conservation Section of the Ministry of Natural Resources and Environment has continued to manage the Aleipata District Marine Protected Area since it was handed over to the Government of Samoa in mid- 2004. Since then, all activities have been incorporated into the marine conservation section’s workplan and are continuing as of today.
Community-based Monitoring Program The community based monitoring program is conducted annually to assess the conservation status of the marine biodiversity within the MPAs, specifically for areas that have been identified as “No-Take Zones”. The monitoring program involves the local communities/volunteers whom are trained by the staff. This is so on a long term, the local people are able to assess and monitor their respective NTZs and provide updated quantitative feedback on the progress and status of their marine biodiversity.
The Aleipata District MPA Community-based Marine Biodiversity Monitoring survey was carried out from the 6 – 10 August 2007 by the district committee members, community volunteers and the staff of the Marine Conservation Section of the Division of Environment and Conservation.
Objectives The survey aims are: 1. To assess and determine the status of marine resources within respective NTZs.
2. To build the local skill and knowledge of the community volunteers on coral reef monitoring techniques.
2. METHODOLOGY
2.1 Study Location & Sites The Aleipata District MPA is located on the eastern coast of Upolu island covering an estimated area of 19.94 sq. miles. It extends across 11 coastal villages with the boundaries beginning at Tiavea village and ending at Lalomanu (Map 1). A total of nine NTZs were monitored and the other two were excluded because the area was not demarcated.
2 Map 1: The estimated area of Aleipata MPA is 19.9 sq. miles which includes inshore and offshore islands. Source: Juney Ward, 2007.
2.2 Survey Techniques Three defined path swims were predetermined by the survey team as transects within each surveyed site, 2 preferably along the outside edges and 1 in the middle of the site. Defined path swims are similar to belt transects, only the distance and direction of the swims are predetermined, thus eliminating the need for measuring tapes. However, a measuring tape was used in this survey to assist in coral health statistics.
Once the defined path swims were established, they were marked on the forms, and the surveyors would snorkel along the tape measure towards the referenced markers, while recording general observations and data within a 2m wide belt (Figure 1).
3
REEF / OUTER EDGE OF THE NTZ
1m 1m 1m 1m 1m 1m
Transect 1 Transect 2 Transect 3
SHORE / LAND MARKERS or REFERENCES
Figure 1: Diagrammatic illustration of the Defined Path Method used during the survey.
2.3 Quantitative Estimations The following are descriptions of criteria used to gather information during each swim.
2.3.1 Reef fish abundance Fish abundance of targeted fish families (Appendix 1) were recorded according to the:
1. 1st, 2nd & 3rd most abundant targeted fish families/groups. 2. Most common size of each of the most abundant targeted fish families/groups. 3. Total number of targeted fish species observed along each set path swim.
2.3.2 Benthic indicators and Macro-Invertebrates The monitoring looked at the following benthic indicators and macro- invertebrates (Appendix 2).
• Coral health: coral cover is estimated along each transect along with an estimation of live, dead and/or bleached and broken coral.
• Macro-Invertebrates: the total number of targeted invertebrates was recorded during each transect. Those included were:
¾ Crown of thorn starfish (COT) ¾ Gastropods (eg. turbo, ¾ Sea urchins trochus & top shells) ¾ Bivalves (eg. giant clams) ¾ Triton ¾ Holothurian ¾ Conch/Helmet shells 4
• Macro-Algae: the presence or absence of edible and non-edible macro algae were recorded for each transects (Appendix 3).
3. RESULTS
A. Individual Site Analysis
3.1 Results of Current Survey
3.1.1 Amaile NTZ
(a) Fish abundance The average number of targeted fish species within the Amaile NTZ was approximately 385. The dominant fish species recorded were the surgeonfish, mullet and parrotfish. Butterflyfish and groupers were the other abundant species recorded within the NTZ. The average size recorded for surgeonfish was around 13cm, for mullets the average size were 33cm while average size for parrotfish were 11cm.
(b) Coral health The estimated overall coral cover is 79%. Of this, the average percentage of live corals was estimated to be 60%, 11.33% are estimated to be dead and/or bleached and 7.67% are broken corals.
(c) Macro algae No edible seaweeds were recorded during the survey; however, other non edible seaweed species such as the Turbinaria ornata and Halimeda opuntia were recorded throughout the NTZ.
(d) Macro invertebrates Sea urchin species, the Echinometra mathaei (tuitui) and Diadema sp. (vaga) were very high in abundance. On average each transect counted approximately more than 350 sea urchins while counts of other species such as the Tripneustes gratilla were considered medium abundance with an average of 6 counts in each transect. Holothurians were also recorded very high in abundance especially Stichopus choloronotus (maisu) and Bohadschia argus, where approximately 50 were counted within each transect.
Giant clams, trochus and top shells were found present within the NTZ but in low abundance. There were no counts of other targeted invertebrates such as the triton, helmet shell and the crown of thorn starfish.
5 3.1.2 Samusu NTZ
(a) Fish abundance The average number of targeted fish species recorded in Samusu NTZ was estimated to be 276 where the dominant species were parrotfish, surgeonfish and wrasse. Other fish species abundant within the area included the butterflyfish, snapper, grouper and rabbitfish. The average size for the two dominant fish species were around 20cm while the average size of wrasses were 13cm.
(b) Coral health The overall coral cover was estimated to be 66% where the average percentage of live corals were estimated to be 43%, 15% are broken corals and 8% are dead and/or bleached corals.
(c) Macro algae No edible seaweeds were recorded except for other species of seaweed that are not consumed by the local community.
(d) Macro invertebrates There was very high abundance of the Stichopus choloronotus (maisu) holothurian in which each transect counted on average approximately 20 maisu. Sea urchins were very high in abundance, on average each transects counted around 120 of the Echinometra and Diadema species. One of the targeted holothurian, Synapta maculata (peva) was considered low in abundance. The crown of thorn starfish (Acanthaster plancii) was present but in low numbers, a total of 3 COTs were recorded throughout the area.
Other targeted invertebrates were not observed within the area. These included the trochus, top shells, triton, helmet shells and giant clams.
3.1.3 Utufaalalafa NTZ
(a) Fish abundance The average number of targeted fish species recorded was 37. The dominant fish species were the wrasse, surgeonfish and butterflyfish and all were on average less than 10cm in size. Other abundant fish species included emperors and rabbitfish.
(b) Coral health The area is predominantly seagrass comprising of the Halophila ovalis and Syringodium isoetifolium species. The overall coral cover was estimated to be 69%. Only fifty five percent of the area had live coral, 5% were broken coral and 9% were dead and/or bleached coral.
(c) Macro algae No edible seaweed was present within the area except for other species of algae that were found throughout the NTZ.
6
(d) Macro invertebrates Sea urchins and holothurians were very high in abundance. More than 241 holothurians were recorded and included Stichopus choloronotus, Stichopus horrens (sea) and Bohadschia argus.
All other targeted invertebrates were not observed within the area.
3.1.4 Satitoa NTZ
(a) Fish abundance The average number of targeted fish species within the Satitoa NTZ was approximately 97. The dominant fish species were the wrasse, surgeonfish and parrotfish. Other recorded fish species included the butterflyfish, trevally, grouper and mullet. The average size of the three most dominant fish species were less than 10cm.
(b) Coral health The area is mainly seagrass and the area of coral growth had approximately 35% live corals, 7% broken corals and 2% dead and/or bleached corals. The overall coral cover is estimated to be 44%.
(c) Macro algae Edible seaweed, Caulerpa racemosa (limu fuafua) and non edible seaweed was recorded present within the area.
(d) Macro invertebrates Very high abundance of holothurians were present, most of these were Stichopus choloronotus, Holothuria atra (loli) and Stichopus horrens. Echinometra and Diadema sea urchins were present in high numbers while Synapta maculata were recorded low in numbers. Other invertebrates were not recorded within the area.
3.1.5 Ulutogia NTZ
(a) Fish abundance The average number of targeted fish species recorded within the NTZ was approximately 123. The dominant species included the parrotfish with an average size of 10cm, surgeonfish and wrasse with average sizes of 7cm and trevally with an average size of 17cm. Other targeted fish species recorded were the grouper and butterflyfish.
(b) Coral health An estimate of the overall coral cover was 55%. On average, approximately 24% were live corals, 19% were broken corals and 12% were dead and/or bleached corals.
(c) Macro algae Only non edible algae were recorded within the NTZ. 7
(d) Macro invertebrates There was very high abundance of holothurians namely the Stichopus choloronotus, Holothuria atra and Stichopus horrens. Sea urchins were recorded but in medium abundance. There were no counts of other invertebrates within the NTZ.
3.1.6 Vailoa NTZ
(a) Fish abundance The average number of targeted fish species within the NTZ was 1,094. This was dominated by the parrotfish with an average size of 15cm, surgeonfish at an average size of 18cm and lastly the wrasse and butterflyfish with average sizes of less than 10cm.
Other abundant fish species recorded within the site were the goatfish, emperor, grouper, rabbitfish, trevally and snapper.
(b) Coral health The area that had coral cover an estimate of 78% was live corals and 12% were broken and dead and/or bleached corals.
(c) Macro algae The edible seaweed, Caulerpa racemosa and other non edible seaweeds were recorded within the NTZ. The red algae species were not observed in the area.
(d) Marco invertebrates Only 1 COT was found within the NTZ. Holothuria atra, Stichopus choloronotus, Stichopus horrens and Synapta maculata were observed very high in abundance. Sea urchins were also recorded very high in numbers which were mainly Echinometra and Diadema species. Two Tridacna squamosa and three cushion starfish (Culcita novaegiunea) were recorded, both were low in numbers.
3.1.7 Lalomanu NTZ
(a) Fish abundance The average number of targeted fish species was approximately 1,997. The dominant targeted fish species were the surgeonfish and parrotfish with average sizes of 18cm. Wrasse were the third most dominant species with an average size of 12cm.
Other abundant fish species recorded within the NTZ were the grouper, snapper, butterflyfish, emperor and soldierfish; these were just a few listed as there were numerous fish species in the area.
8 (b) Coral health The average percentage of live corals recorded within the NTZ was approximately 64%. The percentage of broken corals was 14% and those that were considered dead and/or bleached corals made up 17%.
(c) Macro algae No edible seaweeds were observed within the NTZ except for other algae that are not consumed by the local community.
(d) Macro invertebrates Sea urchins and holothurians were low in numbers, there were only 5 holothurians (Holothuria atra, Stichopus choloronotus) and sea urchins recorded for each transect. A total of three COTs were observed within the NTZ and 1 trochus shellfish.
There were no records for other invertebrates within the NTZ.
3.1.8 Mutiatele/Namua NTZ
(a) Fish abundance The average number of targeted fish species was estimated to be 540. The dominant fish species recorded were the parrotfish, surgeonfish and butterflyfish. The average size recorded for both parrotfish and surgeonfish were 12cm and for the butterflyfish average sizes were 7cm.
Other abundant fish species observed within the NTZ were the grouper, soldierfish, rabbitfish and wrasse.
(b) Coral health The average percentage of live coral observed within the NTZ was approximately 59%, 9% were broken corals and 13% were dead and/or bleached corals. (c) Macro algae Only non edible seaweed was recorded within the NTZ.
(d) Macro invertebrates Holothurians were considered high in abundance in which Holothuria atra and Stichopus choloronotus were most abundant. Sea urchins, giant clams and trochus shellfish were low in abundance, on average there were less than 2 counts for each of the invertebrates observed.
No other invertebrates were recorded within the NTZ.
3.1.9 Saleaaumua NTZ Saleaaumua NTZ is a seagrass area (Halophyla ovalis and Syringodium isoetifolium) in which no targeted fish species, corals and edible seaweed were recorded within the NTZ during the time of monitoring.
9 3.2 Comparison of the Average Fish Abundance of the Current Survey with Previous Surveys
3.2.1 Amaile NTZ A comparative analysis for the average fish abundance was done for 2005, 2006 and 2007 as shown in Figure 2. A t-test was done and showed that there was no difference in the average fish abundance recorded for 2005, 2006 and 2007. In 2005, the average fish abundance recorded was 328 (±138), in 2006 the average was 1,658 (±2,572) and the average fish abundance in 2007 was 385 (±13).
Average Fish Abundance at Amaile NTZ
4500
4000 3500
3000 2500
2000 Average 1500
1000
500 0 2005 2006 2007 Years
Figure 2: Average Fish Abundance recorded in 2005, 2006 and 2007.
3.2.2 Samusu NTZ A comparative analysis for the average fish abundance was done for 2005, 2006 and 2007 as shown in Figure 3. A t-test was done and showed that there was no difference in the average fish abundance recorded for 2005, 2006 and 2007. In 2005, the average fish abundance recorded was 328 (±138), in 2006 the average was 1,658 (±2,572) and the average fish abundance in 2007 was 277 (±25).
10 Average Fish Abundance at Samusu NTZ 4500
4000 3500
3000
2500 Average 2000
1500 1000
500 0 2005 2006 2007 Years
Figure 3: Average Fish Abundance recorded in 2005, 2006 and 2007.
3.2.3 Utufaalalafa NTZ A comparative analysis for the average fish abundance was done for 2005, 2006 and 2007 as shown in Figure 4. A t-test was done and showed that there was no difference in the average fish abundance recorded for 2005, 2006 and 2007. In 2005, the average fish abundance recorded was 80 (±49), in 2006 the average was 24 (±7) and the average fish abundance in 2007 was 37 (±27).
Average Fish Abundance at Utufaalalafa NTZ
140
120
100
80
Average 60
40
20
0 2005 2006 2007 Years
Figure 4: Average Fish Abundance recorded in 2005, 2006 and 2007.
11 3.2.4 Satitoa NTZ A comparative analysis for the average fish abundance was done for 2005, 2006 and 2007 as shown in Figure 5. A t-test was done and showed that there was no difference in the average fish abundance recorded for 2005, 2006 and 2007. In 2005, the average fish abundance recorded was 302 (±178), in 2006 the average was 90 (±57) and the average fish abundance in 2007 was 98 (±58).
Average Fish Abundance at Satitoa NTZ 600
500
400
300
Average
200
100
0 2005 2006 2007 Years Figure 6: Average Fish Abundance recorded in 2005, 2006 and 2007.
3.2.5 Ulutogia NTZ A comparative analysis for the average fish abundance was done for 2005, 2006 and 2007 as shown in Figure 5. A t-test was done and showed that there was no difference in the average fish abundance recorded for 2005, 2006 and 2007. In 2005, the average fish abundance recorded was 295 (±181), in 2006 the average was 156 (±102) and the average fish abundance in 2007 was 123 (±118).
12
Average Fish Abundance at Ulutogia NTZ
500
450 400
350
300 250
Average 200
150 100
50
0 2005 2006 2007 Years
Figure 5: Average Fish Abundance recorded in 2005, 2006 and 2007.
3.2.6 Vailoa NTZ A comparative analysis for the average fish abundance was done for 2005, 2006 and 2007 as shown in Figure 6. A t-test was done and showed that there was no difference in the average fish abundance recorded for 2005, 2006 and 2007. In 2005, the average fish abundance recorded was 750 (±229), in 2006 the average was 797 (±708) and the average fish abundance in 2007 was 1,094 (±557).
Average Fish Abundance at Vailoa NTZ 1800
1600
1400
1200
1000
800 Average 600
400
200
0 2005 2006 2007 Years
Figure 6: Average Fish Abundance recorded in 2005, 2006 and 2007. 13 3.2.7 Lalomanu NTZ A comparative analysis for the average fish abundance was done for 2005, 2006 and 2007 as shown in Figure 7. A t-test was done and showed that there was no difference in the average fish abundance recorded for 2005, 2006 and 2007. In 2005, the average fish abundance recorded was 2,654 (±1665), in 2006 the average was 2,278 (±867) and the average fish abundance in 2007 was 1,997 (±6).
Average Fish Abundance at Lalomanu NTZ 5000
4500
4000 3500 3000
2500
Average 2000 1500
1000
500 0 2005 2006 2007 Years Figure 7: Average Fish Abundance recorded in 2005, 2006 and 2007.
3.2.8 Mutiatele/Namua NTZ A comparative analysis for the average fish abundance was done for 2005, 2006 and 2007 as shown in Figure 8. A t-test was done and showed that there was no difference in the average fish abundance recorded for 2005, 2006 and 2007. In 2005, the average fish abundance recorded was 453 (±156), in 2006 the average was 251 (±134) and the average fish abundance in 2007 was 540 (±618).
14
Avergae Fish Abundance at Mutiatele NTZ 1400
1200
1000
800
Average 600
400
200
0 2005 2006 2007 Years Figure 8: Average Fish Abundance recorded in 2005, 2006 and 2007.
3.2.9 Saleaaumua NTZ A comparative analysis for the average fish abundance was done for 2005, 2006 and 2007 as shown in Figure 9. A t-test was done and showed that there was no difference in the average fish abundance recorded for 2005 and 2006; however, there was a change in 2007. In 2005, the average fish abundance recorded was 13 (±7), in 2006 the average was 17 (±21) and there was no records of targeted fish documented in 2007.
Average Fish Abundance at Saleaaumua NTZ 40
35
30
25
20
Average 15
10
5
0 2005 2006 2007 Years
Figure 9: Average Fish Abundance recorded in 2005, 2006 and 2007.
15 B. Overall Analysis The following is an overall result for each of the quantitative analysis made within the Aleipata MPA District.
1. Fish Abundance Figure 10 shows the mean number of targeted fish species within each surveyed site. Lalomanu, Vailoa and Mutiatele/Namua recorded the most abundant fish species with an estimate of more than 1,000 counts of targeted fish species.
2500
2000
1500
1000 Fish Abundance Value) Fish (Mean 500
0 Amaile Samusu Utufaalalafa Saleaaumua Satitoa Ulutogia Vailoa Lalomanu Mutiatele/Namua Surveyed Sites
Figure 10: The mean value of targeted fish species within the surveyed sites.
The overall abundant fish species that were recorded within the Aleipata NTZs were the surgeonfish and parrotfish (Figure 11). Wrasses and butterflyfish were the second abundant fish species observed. Other targeted fish species recorded were mullets, emperors, trevallies and rabbitfish.
16 50
45
40
35
30
25
20
Abundance CategoryAbundance 15
10
5
0 Surgeonfish Mullet Parrotfish Butterflyfish Wrasse Emperor Rabbitfish Trevally
Targeted Fish Species Figure 11: The overall abundance of targeted fish species that were recorded within the NTZs.
Figure 12 summarizes the average sizes for the targeted fish species that were observed within the surveyed sites. The average size for mullets observed were less than 35cm in length. Surgeonfish, parrotfish, wrasse and trevally were estimated to be around 10cm to 15cm in length. Butterflyfish, emperor and rabbitfish were less than 5cm in length.
35
30
25
20
15 Average Size (cm) 10
5
0 Mullet Surgeonfish Parrotfish Butterflyfish Wrasse Emperor Rabbitfish Trevally Targeted Fish Species
Figure 12: Average size in centimeters of the most abundant targeted fish species. 17
2. Coral Health Assessment Almost all NTZs had high percentages of live corals except for the villages of Ulutogia and Satitoa which had approximately 25 to 35% of healthy corals. Vailoa and Lalomanu had the highest percentage of live corals, Vailoa had approximately 80% live corals and Lalomanu had an estimate of 65% (Figure 13). Less than 20% of each NTZ had broken coral and dead and/or bleached coral. 80
70
60
50
40
30 Percentage (%) Percentage 20
10
0 Amaile Samusu Utufaalalafa Satitoa Ulutogia Vailoa Lalomanu Mutiatele Surveyed Sites
Broken Corals Dead and/or Bleached Corals Live Corals Figure 13: Estimate of the coral health within each surveyed site looking at broken, dead and/or bleached and live corals.
3. Macro Algae (Seaweeds) Caulerpa racemosa (limu fuafua), an edible seaweed that is commonly utilized by the local people was observed in only two surveyed sites, these were Satitoa and Vailoa village. The red algae (limu aau) that is also consumed by people, was found only at Amaile NTZ. All NTZs were observed to have other non edible algae such as Sargassum cristaefolium, Sargassum polysystum, Padina boryana, Dictyota sp. and Halimedia opuntia to name a few.
4. Macro Invertebrates The following are invertebrates that were either observed or absent from the surveyed NTZs.
• Crown of thorn starfish COTs were considered low in abundance during the survey and were recorded at Samusu – 3, Vailoa – 1 and Lalomanu – 3.
18 • Sea urchins The two common species of sea urchins recorded in all NTZs were Echinometra mathaei (tuitui) and Diadema sp. (vaga). Both species were very high in abundance at Amaile, Samusu, Vailoa and Utufaalalafa. Satitoa NTZ had high abundance of sea urchins within their area and Ulutogia, Lalomanu and Mutiatele/Namua had medium abundance. Saleaaumua village did not record the presence of sea urchins.
Another targeted sea urchin species Tripneustes gratilla (satula/sava’e) was recorded at Amaile NTZ only.
• Holothurians The three observed holothurian species that were very high in abundance were Stichopus choloronatus (maisu), Holothuria atra (loli) and Synapta maculata (peva) found in almost all NTZs. Stichopus horrens (sea) and Bohadschia mamorata (fugafuga) were also observed in most of the NTZs. Lalomanu had the least abundance in holothurians.
• Giant clams Giant clams were only found present in three NTZs, these were Amaile – 2, Vailoa – 2 and Mutiatele/Namua – 1.
• Trochus and Top shell Trochus and top shells were low in abundance and found at Amaile – 4, Lalomanu – 1 and Mutiatele/Namua -1.
Other targeted invertebrates such as the giant triton and helmet shell were not observed in the NTZs at the time of monitoring.
4. DISCUSSION
4.1 Current Survey
4.1.1 Fish Abundance Estimations The targeted fish species included those that were considered in demand for food on a subsistence level and would be an indicator of the level of exploitation. The total number of fish species was the number of targeted fish species/families only and excluded other abundant fish families such as the damsel fish (Pomacentridae).
Lalomanu, Vailoa, Mutiatele/Namua, Amaile and Samusu had high mean values of targeted fish species while Utufaalalafa, Satitoa and Ulutogia had lesser numbers. The low numbers within Utufaalalafa, Satitoa and Ulutogia was probably due to the fact that these sites had limited areas that had good coral growth within a large NTZ thus these were the only areas that targeted fish species were observed. Saleaaumua NTZ recorded no targeted fish species within the area during the survey which was probably due to the area being a seagrass site and the monitoring being done during low tide.
19
The most abundant fish species were from families Acanthuridae (surgeonfish), Scaridae (parrotfish), Labridae (wrasse) and Chaetodontidae (butterflyfish) which were mostly juvenile (<15cm in length). This could be an indicator that the NTZs offer a sanctuary for juvenile fish before allowing them to move to deeper waters.
4.1.2 Coral Reef Health Assessment Estimation of coral cover was not taken into account; however, estimates of broken, dead and/or bleached and live corals were recorded. The highest estimation of broken and dead and/or bleached corals was observed at Ulutogia, Lalomanu, Vailoa and Samusu although bleaching was observed to be minimal. The high percentage of coral breakage is most likely due to illegal fishing activity within the NTZs, strong waves overturning and breaking the corals and people treading on corals during swimming or during reef gleaning which is done by the local women.
Overall, all the surveyed NTZs except for Saleaaumua which is a seagrass area had high percentage of live corals indicating the success of the marine protected areas. The highest live corals were observed at Vailoa, Lalomanu, Amaile and Mutiatele/Namua which estimated 50 – 80% healthy corals.
4.1.3 Macro Algae Presence The edible Caulerpa racemosa (green algae) and Halymenia durvillei (red algae) was recorded present only within Satitoa, Vailoa and Amaile NTZ. However, all surveyed sites observed other species of seaweeds.
4.1.4 Macro Invertebrate Abundance The crown of thorn starfish was recorded present in Samusu, Vailoa and Lalomanu NTZs. Although COTs were found within these areas they were found in low numbers which might suggest that COTs pose minimal impacts on the reefs.
Sea urchins were high in abundance in most of the surveyed areas. This high abundance of sea urchins can be detrimental as they can contribute to bioerosion by grazing on turf algae growing on hard substrates used by other reef organisms. Saleaaumua NTZ did not record the presence of sea urchins during the survey which is probably due to the area being more a seagrass site with no coral growth.
The three holothurian species that were observed in high numbers in almost all the NTZs were Stichopus choloronatus, Holothuria atra and Synpata maculata. Stichophus horrens is the most harvested holothurian for consumption and was recorded at Utufaalalafa, Satitoa, Ulutogia and Vailoa. The presence of this holothurian species suggests that there are minimum impacts or harvesting by the local women who do reef gleaning.
20 Giant clams, trochus and top shells are some of the depleted resources; however, they were found present at Amaile, Vailoa, Lalomanu and Mutiatele/Namua. Although in low numbers the presences of them is a good indication that the NTZs are serving its purposes of recruiting and stocking depleted resources.
The absence of other targeted invertebrates such as the giant triton and helmet shell suggests that these resources are still depleted stocks within the area.
4.2 Comparison of Fish Abundance within the NTZs from Previous and Current Surveys
Based on the graphs presented in Section 3.2, most villages have showed either an increase or decrease in the 2007 survey compared to 2003 and 2006. However, statistical analysis proves that the majority of the NTZs have no significant changes except for Saleaaumua where they experienced a decrease in their fish abundance in the 2007 survey. This could be due to a number of reasons such as the timing of the 2007 survey which was conducted during low tide where as the past surveys were done during high tide. Other factors could be that the NTZ is mainly seagrass and during the monitoring time we were unable to see the targeted fish species. Despite the fact that statistical analysis shows no changes within the NTZs, the communities have noticed changes. People within the respective NTZs have noticed more fish especially the juveniles suggesting that the NTZs are providing shelter for many juvenile fish to recruit and an improvement on the state of their corals which suggests a steady recover of corals within the NTZs.
5. CONCLUSION
Generally, the 2007 survey showed that almost all the surveyed NTZs indicated an increase in the percentage of live corals, numbers of targeted fish species, presence of edible seaweed and targeted macro invertebrates eg, giant clams. This gives an indication that areas claimed as “no take” are showing signs of recovery and recruitment which suggest success.
6. RECOMMENDATION
• To re-mark of all NTZs with sticks instead of buoys as it is expensive to replace buoys. This needs to be done so that all NTZs are monitored in 2008.
• It was suggested that Saleaaumua NTZ be shifted where the coral reef is located to determine the status of their reef.
21 • To simplify the monitoring and redesign methods for future community based surveys and analysis.
7. REFERENCE
Aleipata District Marine Protected Area. 2002. Aleipata Permanent Baseline and Community-based Monitoring Report. Ministry of Natural Resources and Environment (Apia, Samoa): 39-85.
Division of Environment and Conservation. 2005. Coral Bleaching Assessment Report-Aleipata Marine Protected Area. Ministry of Natural Resources, Environment and Meteorology: Apia, Samoa.
Division of Environment and Conservation. 2005. Community-based Monitoring Report: Aleipata District Marine Protected Areas. Ministry of Natural Resources and Environment. Apia, Samoa.
8. ACKNOWLEDGEMENT
We would like to extend our thanks and gratitude to the dedicated team of volunteers and the Aleipata District MPA committee members whom took time to assist the DEC Marine Conservation Team. We would also like to acknowledge Mele, Siaosi and Natapu for their efforts and participation that allowed us to fulfill and complete the monitoring program at Aleipata.
22 Appendix 1: Targeted fish families/ groups.
Family Name Species Acanthuridae Surgeonfish, Unicornfish, Tangs Carangidae Trevallies Elasmobranchii Sharks Labridae Wrasses Lethrinidae Emperors Lutjanidae Snappers Mugilidae Mullets Pomacanthidae & Chaetodontidae Angelfishes & Butterflyfishes
Scaridae Parrotfishes
Serranidae Groupers
Fish Size Abundance categories used in estimates of abundance of numerically dominant fish species and the median abundance value used for population.
Category Range Number of Fish Median Number 1 1 – 60 30
2 61 – 250 155 3 251 – 1000 625 4 1001 – 4000 2500 5 4001 – 16000 10000
Fish Size categories and their corresponding maximum and median lengths.
Size category Maximum Size (cm) Median Size (cm) Limatusi (finger) 10 5 Tapulima (wrist) 20 10 Tulilima (elbow) 50 25 Tau’au (shoulder) 80 40
Macro-invertebrate abundance categories used in estimating the presence of dominant macro-invertebrate species.
Category Numerical Description Category 1 1 to 5 Low Category 2 6 to 10 Medium Category 3 11 to 20 High Category 4 >20 Very High
23 Appendix 2: The following plates are pictures of some of the targeted invertebrates surveyed during this survey.
Mespilia globulus Echinometra mathaei
Plate 4: Species of sea urchins found in the Safata District MPA.
Actinopyga mauritiana Holothuria atra Stichopus horrens
Plate 5: Sea cucumbers and other holothurians targeted during this monitoring survey.
Turbo chrysostomus Trochus maculatus Turbo setosus
Trochus pyramis Cypraea mauritiana Cypraea tigris
Plate 6: Gastropod species.
24
Cassis cornuta Charonia tritonis
Plate 7: Helmet shell (Cassis cornuta) and Giant triton (Charonia tritonis).
Tridacna maxima Hippopus hippopus Tridacna squamosa
Plate 8: Giant Clam Species
25 Appendix 3: The following plates are pictures of some of the algae (seaweed) surveyed during this survey.
Halimeda opuntia Caulerpa racemosa Padina boryana
Sargassum polysystum Turbinaria ornata Red coralline algae
Plate 3: Pictures of some of the macro algae species found in the Safata District MPA.
26