Biophysical Survey of Mafia Island Marine Reserves

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Commercially Targeted Fish The methodology for data acquisition of targeted fish abundance was slightly modified from that of reef fish data. This was due to the habits and characteristics of the target fish which display a lower affinity with the benthos over which they reside. Data were collected by a pair of SCUBA divers swimming underwater along the reef at a constant depth for fifteen minutes, noting the abundance of all target fish they saw. Commercially targeted fish searched for is shown in Table 5. GPS start and end positions were taken for all commercial targeted fish survey dives. Table 5. Fish species list used for collection of abundance of commercially targeted data collection. Common name Latin name Common name Latin name GROUPER EMPEROR Peacock Grouper Cephalopholis argus Spangled Emperor Lethrinus nebulosus Sixspot Grouper Cephalopholis sexmaculata Blackspot Emperor Lethrinus harak Coral Hind Grouper Cephalopholis miniata Longface Emperor Lethrinus olivaceus Saddleback coral Grouper Plectropomus laevis Bigeye Emperor Monotaxis grandoculus Whitespotted Grouper Epinephelus caeruleopunctatus Other Grouper Any other grouper species Other Emperor Any other emperor species SNAPPER Thumbprint Spinecheek Scolopsis bimaculatus Blackspot Snapper Lutjanus ehrenbergi Red Snapper Lutjanus bohar JACKS / TREVALLYS Carangidae Bluelined Snapper Lutjanus kasmira KINGFISH / TUNA Scombridae Other Snapper Any other snapper species PARROTFISH Scaridae SWEETLIPS SURGEONFISH Acanthuridae Black Sweetlips Plectorhinchus sordidus RABBITFISH Siganidae Slatey Sweetlips Diagramma pictum GOATFISH Mullidae Oriental Sweetlips Plectorhinchus orientalis BARRACUDA Sphyraenidae Blackspotted Sweetlips Plectorhinchus gaterinus TRIGGERFISH Balistidae Goldspotted Sweetlips Plectorhinchus flavomaculatus NEEDLEFISH Belonidae Other Sweetlips Any other sweetlips species FUSILIERS Caesionidae SHARKS / RAYS Carcharhinidae/Dasyatidae
As with the other data collection methods employed for this report, divers swam at a constant depth, following contours of the reef rather than a specific bearing. Data were collected at a range of depths, as with the transect methodologies, to allow differences across the depth gradients to be observed. In some cases, fish appear on both the reef fish census, and on the commercial fish census, highlighting their importance within the reef community. Some species listed in Table 5 have been identified only to family level for simplicity of the survey method and to ensure data accuracy. 3. Seagrass Habitats Shallow seagrass beds (< 2m deep) within the inner and outer lagoon areas were assessed. Inner lagoon sites were located within 300m of the island shoreline and outer lagoon sites were within 300m of the reef edge. In addition deep (> 4m) seagrass habitats were assessed for fish abundance where they were found to be particularly extensive. A minimum of four lagoon sites were selected at each island, two inner and two outer. Each site consisted of 10 points chosen to form a grid pattern within an area extending to 250m². Each of the 10 points selected had the centre point GPS marked. Four 1m² quadrats were thrown out from the centre point at 90° to each other, within a 10m diameter circular area. Each quadrat area was visually inspected for substrate and benthos composition based on estimates of percent cover. Invertebrate species present, and their abundance, were also recorded. Fish abundance on the deep seagrass beds was also assessed for some sites. Fish were recorded in 22 different categories (Table 6) during 5 minute swims over seagrass habitats on given bearings. Types and density of seagrass species were also recorded. Sites were studied where accessible and extensive seagrass habitats were found at depths of 4m or deeper. Table 6. Fish species list used for collection of abundance of fish species found on seagrass habitats. Common name Latin name Common name Latin name Damselfish SIGANIDAE Rabbitfish SIGANIDAE Goatfish MULLIDAE Surgeonfish ACANTHURIDAE
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 24 and 25: Indian Ocean Bird wrasse Gomphosus
Page 26 and 27: Several areas of coral reef habitat
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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