Grimsditsch et al Pemba Resilience Survey 2009 low res

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Detailed Results 4.6 Resilience indicators For each indicator, levels 1 to 5 were assigned according to local minimum/maximum levels and the distribution of values in between. A total of 55 variables were scored, that were grouped into the following factors: Group Explanation Factor Explanation Cover Benthic cover Benthic Benthic cover – combined estimates of hard and soft corals, and algae Coral Condition of coral community Current Current status shown by bleaching, disease, sexual recruitment and fragmentation of corals. Historic Past impacts to coral community as shown by evidence of past mortality, evidence of recover potential and size class distributions Ecological Broader ecological Negative Negative associates of corals – such as predators and epiphytes on coral surfaces factors that affect corals Positive Positive associates of corals, such as obligate feeders (butterflyfish) and invertebrates and fish in branching corals. Herbs Herbivorous fish populations Physical Environmetnal and habitat Acclimatization Past and present temperature dynamics that may protect corals by acclimatization/adaptive responses features that affect corals Cool &flush Degree of cooling/flushing of deeper and/or oceanic waters Shade &scrn Degree of shading or screening of corals by turbid water, reef slope, canopy corals, etc. Substrate Substrate quality, such as sediment type and thickness, amount of rubble. Connectivity Connectivity and larval supply Larvae Estimate of larval supply from contiguousreefs, separated reefs and distant reef systems Transport Currents providing transport of larvae and effect of barriers to dispersal. Anthropogenic Human Fishing Degree of fishing, shown by fish populations and/or other data pressures on Substrate Anthropogenic alterations to substrate – from sediment, reef sites damage, etc. Water Anthropogenic alterations to water quality – from runoff, pollution, etc. Each factor was scaled from 1 (poor conditions for corals) to 5 (good conditions for corals), and the sites ranked from highest overall resilience to the lowest. 31
Detailed Results Overall site resilience rankings 40 35 30 25 20 15 10 Anthropogenic Connectivity Fish groups Coral associates Coral Population Coral Condition Shade & screen 5 0 Misali Mandela Manta Njao Gap Simba Kokota Swiss Fundo Inner The Hole Msuka Bay Fundo Lagoon Fundo Outer Paradise Extremes & Acclimatization Cooling &flushing Benthic Misali ranked highest of the sites, followed by Mandela and Manta. Paradise and Fundo Outer ranked lowest. These results correspond well with hard coral cover (highest at Misali, Mandela and Manta but lowest at Paradise and Fundo Outer). As we shall see, the differences in resilience factors between healthy and degraded sites are mostly driven by factors relating to coral population (recruitment, fragmentation, dominant size classes and largest corals) and coral associates (branching residents, obligate feeders, competitors, bioeroders and corallivores). Coral Population Standard deviation of resilience factors Coral associates Cooling &flushing Benthic Extremes & Acclimatization Fish groups Coral Condition Shade & screen Anthropogenic Connectivity 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Standard deviation of resilience indicators between sites shows that the largest variations are caused by factors related to coral population and coral associates between degraded and healthier sites. Very little variation was found in connectivity between sites, as they are influenced by similar prevailing currents and there is little evidence to identify larval sources. Anthropogenic influences also did not vary greatly between sites- most sites are heavily fished or influenced by overspill effects of overfishing in neighbouring sites, while there is little overall effect from land-based pollution or nutrients. 32
Page 1 and 2: Coral Reef Resilience Assessment of
Page 3 and 4: Coral Reef Resilience Assessment of
Page 6 and 7: Executive Summary 1 Executive Summa
Page 8 and 9: Executive Summary 2. Tackle the ove
Page 10 and 11: The Study coral colony and coral co
Page 12 and 13: The Study Table 2.1. Sites surveyed
Page 14 and 15: The Study 7. Resilience indicators
Page 16 and 17: Major Findings on the site that is
Page 18 and 19: Major Findings rabbitfish, angelfis
Page 20 and 21: Major Findings 2. Tackle the overfi
Page 22 and 23: Detailed Results 4 Detailed Results
Page 24 and 25: Detailed Results % coral colonies 1
Page 26 and 27: Detailed Results 4.2 Coral communit
Page 28 and 29: Detailed Results 4.3 Coral populati
Page 30 and 31: Detailed Results Moderate Faviid Su
Page 32 and 33: Detailed Results 4.4 Crown-of-thorn
Page 34 and 35: Detailed Results Density 250m2 200
Page 38 and 39: Detailed Results Influence of resil
Page 40 and 41: Detailed Results Fundo Lagoon Msuka
Page 42: INTERNATIONAL UNION FOR CONSERVATIO

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