Survey of Chek Jawa (22 Aug 01)

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	Vegetation Coverage (seaweeds and seagrasses) 1) Bare Area % 2) Seaweed ID and occurrence in random sampling 3) Seagrass ID and occurrence in random sampling 4) Other species independently collected outside the transects by Prof Lawrence Liao 5) Total composition of seaweed (by Division) 6) Observations Plant identification by Associate Prof. Lawrence M. Liao Seaweed Taxonomy Specialist, Department of Biology, University of San Carlos, 6000 Cebu City, Philippines Data collated by Joseph Lai from field records of sampling plots along 6 transect lines. Completed by 1 Oct 2001
	1) Bare Area % T1 T2 T3 T4 T5 T6 P1 92 71 20 59 54 27 P2 100 5 85 98 87 82 P3 5 75 20 85 97 97 P4 93 14 90 70 95 34 P5 37 8 20 60 63 95 P6 90 60 100 78 P7 39 30 20 74 P8 39 15 80 73 P9 90 89 P10 5  Total no. of plots: 45 2) Seaweed ID and occurrence in random sampling click on link for species locations, spatial distribution and specimen photos S/no. Name of seaweed Frequency occurrence (no. of plots) 1 Bryopsis pennata 1 2 Congracilaria babae (new record) 1 3 Gracilaria vanbosseae 1 4 Hypnea esperi 1 5 Hypnea spinella 1 6 Gracilaria edulis 2 7 Gracilaria tenuistipitata 2 8 Caulerpa sertularioides 3 9 Solieria robusta 3 10 Gracilaria changii 4 11 Gracilaria salicornia 4 12 Caulerpa lentillifera 5 13 Acanthophora spicifera 6 14 Chaetomorpha crassa 12 15 Chaetomorpha linum 14 16 Ulva reticulata 23 3) Seagrass ID and occurrence in random sampling click on link for species locations, spatial distribution and specimen photos S/no. Name of seagrass Frequency of occurrence (no. of plots) 1 Thalassia hemprichii 2 2 Halodule uninervis 2 3 Halophila beccarrii 5 4 Halophila minor 10 5 Halophila spinulosa 17 6 Halophila ovalis 24
	4) Other species Here is a list of 12 seaweeds and 1 seagrass that were independently collected outside the transects by Prof Lawrence Liao. 4.1) Seaweed 1. Avrainvillea amadelpha 2. Boodlea composita 3. Boodleopsis sp. 4. Bryopsis hypnoides 5. Caulerpa cupressoides 6. Caulerpa taxifolia 7. Chaetomorpha gracilis 8. Enteromorpha flexuosa 9. Gracilaria cacalia 10. Halimeda macroloba 11. Neomeris vanbosseae 12. Ulva pertusa 4.2) Seagrass 1. Halodule pinifolia 5) Total composition of seaweed (by Division) 5.1) Division Chlorophyta (Green Algae) 1. Avrainvillea amadelpha 2. Boodlea composita 3. Boodleopsis sp. 4. Bryopsis hypnoides 5. Bryopsis pennata 6. Caulerpa cupressoides 7. Caulerpa lentillifera 8. Caulerpa sertularioides 9. Caulerpa taxifolia 10. Chaetomorpha crassa 11. Chaetomorpha gracilis 12. Chaetomorpha linum 13. Enteromorpha flexuosa 14. Halimeda macroloba 15. Neomeris vanbosseae 16. Ulva pertusa 17. Ulva reticulata 5.2) Division Rhodophyta (Red Algae) 1. Acanthophora spicifera 2. Congracilaria babae (new record) 3. Gracilaria cacalia 4. Gracilaria changii 5. Gracilaria edulis 6. Gracilaria salicornia 7. Gracilaria tenuistipitata 8. Gracilaria vanbosseae 9. Hypnea esperi 10. Hypnea spinella 11. Solieria robusta 6) Observations The survey managed to record for Chek Jawa a total of 28 species of seaweeds, composing of 60.7% green algae and 11.3% red algae. A new record, Congracilaria babae, was collected from a plot within a transect. This is a parasitic red algae found on Gracilaria salicornia. No brown algae (Division Phaeophyta) were recorded during the survey. The Gracilaria genus accounts for 6 species -- an impressive figure for a single locality. Seagrasses scored an equally impressive total of 7 species. All 4 previously recorded species of Halophila in Singapore can be found within Chek Jawa itself, including the very rare Halophila beccarrii. Halophila ovalis, Ulva reticulata, Halophila spinulosa, Chaetomorpha linum, Chaetomorpha crassa and Halophila minor forms the dominant vegetation in the sandflat.