Biophysical Survey of Mafia Island Marine Reserves

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Several areas of coral reef habitat have been observed within the borders of NIMR. The major areas of scleractinian coral are on the western and southern sides of Nyororo Island, along the reef drop-off extending from the north-west of the reserve area down to the north-east, on deeper reef sites in the eastern section of the reserve, and in scattered patches within the lagoonal area at the centre of the reserve. These consist of a range of reef types supporting differing coral communities. Along the western side of Nyororo Island, and in parts along the shallow areas of the northern reef edge, are branching Acropora dominated communities. These communities are typical of those found in more exposed environments with higher levels of water flux. The deeper sites in the eastern section consist primarily of very large massive corals. Massive growth forms also tend to dominate the reef framework on the lagoon and back reef sites, but the communities here also support other coral species and include columnar and branching forms. a) Benthic Composition The reef habitats observed on the reef flat and slope on the western side of the island (Site 2) have the highest exposure to anthropogenic influences. This is manifested in some damage occurring, particularly on the reef flat, with large areas of broken branching and foliaceous coral. However, this site still has high levels of scleractinian coral cover (Figure 4), especially on the deeper parts of the reef and on areas further away from the fishing camp, and supports an abundant fish population. As with all the reef areas assessed, there is a high coverage of soft corals (Figure 4). The scleractinian coral community on this reef consists primarily of branching Acropora as well as large areas of foliaceous corals (Figure 5). Bleaching, primarily of branching Acropora species on the shallow reef flat, was observed on two visits. Water temperature during this period was an average of approximately 34°C. In addition, some bleached colonies had suffered partial mortality, most likely as a result of the bleaching event.
Average percent cover (+/- SE) 35 30 25 20 15 10 5 0 All hard coral Dead Coral Bleached Coral Soft Coral Sponge Other Benthic Organisms Seagrass Macroalgae Turf algae on coral rock Turf algae on rubble Crustose Coralline Algae Nutrient Indicator Algae Rock Rubble Sand Silt Other Figure 4. Average percent cover (+/- SE) by benthic type across all transects completed at site 2, Nyororo. Average percent cover (+/- SE) 14 12 10 8 6 4 2 0 Massive Branching Columnar Submassive Foliaceous Encrusting Solitary Tabular Figure 5. Average percent cover (+/- SE) of scleractinian coral by growth morphology across all transects completed at site 2, Nyororo. Site 3 (NW Reef) at NIMR is located on the seaward side of the northern most reef edge that extends from the north of Nyororo Island down to the east of the reserve
Page 1: Frontier Tanzania Environmental Res
Page 4 and 5: Suggested Technical Report citation
Page 6 and 7: Executive Summary Major Findings
Page 8 and 9: price it fetches may be contributin
Page 10 and 11: IV. RESULTS A. Nyororo Island Marin
Page 12 and 13: I. INTRODUCTION Project Aim To cond
Page 14 and 15: The reserves were established under
Page 16 and 17: III. METHODS A. Field Methods 1. Re
Page 18 and 19: Ground Proofing Methodology (Low Re
Page 20 and 21: Invertebrate Abundance Invertebrate
Page 22 and 23: Commercially Targeted Fish The meth
Page 24 and 25: Indian Ocean Bird wrasse Gomphosus
Page 28 and 29: area, the most extensive continuous
Page 30 and 31: Average abundance (+/- SE) 30 25 20
Page 32 and 33: Average abundance (+/- SE) 3 2.5 2
Page 34 and 35: stop off or shelter. Boats from the
Page 36 and 37: 2. Coral Reef Habitat a) Benthic Co
Page 42 and 43: 68% 5% 18% 2% 0% 1% 0% 6% 0% 0% Tha
Page 44 and 45: on Mbarakuni. At times of good weat
Page 46 and 47: edge is visible at around 10m deep.
Page 50 and 51: 97% 0% Figure 28. Average percentag
Page 52 and 53: c) Invertebrate abundance Invertebr
Page 54 and 55: lobster fishing. A foreign financed
Page 56 and 57: (Chaetodon trifascialus) are closel
Page 58 and 59: transects. Commercial fish species
Page 60 and 61: damage at present, but if further u
Page 62 and 63: VI. Appendices Appendix 1. Fish spe
Page 64 and 65: Whitespotted Epinephelus Grouper ca

Biophysical Survey of Mafia Island Marine Reserves

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