WIOMSA-CORDIO spawning book Full Doc 10 oct 13.pdf

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The approaches identified above are entirely precautionary and ultimately there will be a needto tackle pertinent issues that are common to many small-scale coastal fisheries. Our model wasrestricted to annual fishing effort that was either unchanged or decreased after NTR establishment.However, conservation benefits may be considerably reduced if annual effort was significantlyincreased and the efficiency of fishing gears was improved after adoption of NTRs, which are likelygiven the trajectory of demand for fish in the region and globally (FAO 2012) and the fact thatfishing efficiency tends to increase over time (Hilborn and Walters 1992; Ruttan 2003; Grant andBerkes 2007). Thus, for spawning aggregation-based NTRs to be effective, the need for controls onfishing in non-protected areas cannot be ignored (Nemeth 2005; Rhodes & Warren-Rhodes 2005).122
Chapter 13: Conclusions and management implicationsJan Robinson and Melita SamoilysData-poor approaches for the assessment and management of marine resources are especiallyimportant to regions such as the WIO where the potential for long-term data collection andresearch are limited. The research programme reported in this book demonstrated the feasibilityof using basic information from spawning aggregation-based fisheries to systematically evaluatemanagement needs in data-poor contexts. This was achieved through a conceptual approach(Chapter 2) that involved estimation of key aggregation and fishery parameters (Chapters 3 to10), and the application of those parameters in a vulnerability assessment (Chapter 11) and a notakereserve (NTR) model for spawning aggregations (Chapter 12). We are confident that the fullapplication of this conceptual approach at any particular site, inclusive of the various methodologiesand tools, can enable an informed management process to be initiated within a short time framesuch as 2 years. As more information becomes available and if reserves are implemented, boththe vulnerability assessment and model can be further refined and incorporated in an adaptivemanagement cycle.Considering management measures that focus specifically on a population’s spawning behaviourshould be founded on knowledge that (i) the population aggregates for the purpose of spawning,and that (ii) the spawning aggregations are fished. This information was lacking at study sitesin East Africa and therefore research on verifying spawning aggregations and their fisheries wasrequired (Chapter 3, 5, 7, 10), highlighting how basic research on this phenomenon on themainland lagged behind that of Seychelles. However, by electing to work on the same species inthese two different areas of the WIO, we provided for valuable comparisons in the susceptibilityof conspecific populations to aggregation fishing, which were addressed semi-quantitativelyin the vulnerability analysis (Chapter 11) and are used qualitatively in this section to highlightmanagement implications.As in other tropical regions (Domeier and Colin 1997; Sadovy de Mitcheson et al. 2008), coastalfishers of the WIO exploit reef fish spawning aggregations, some on a commercial scale. Thoughthis study was confined to six populations and their associated fisheries, the practice of aggregationfishing is undoubtedly more widespread, as indicated by this and earlier MASMA studies (Robinsonet al. 2004; Samoilys et al. 2006; Robinson et al. 2007). For Siganus sutor, a shallow-water speciesof high fishery importance throughout the WIO (Everett et al. 2010; McClanahan and Mangi2004), it is highly likely that spawning aggregations are commonly targeted at all known andaccessible sites. While S. sutor is clearly more resilient to aggregation fishing (Robinson et al. 2011),extrinsic fishing pressures and drivers differ among fisheries in the region and highlight the needfor a case-by-case approach.This research programme confirmed regional similarities in aggregation dynamics among conspecificpopulations. For example, in southern Kenya, S. sutor migrates 2-4 kilometers to offshore reefs toform short-lived transient spawning aggregations around full moon within a protracted season(Chapters 3 and 5). Research results from multiple research approaches in Seychelles over the lastdecade (fisher knowledge surveys, reproductive biology, telemetry and UVC) show that S. sutoraggregate to spawn at specific sites a few days around the full moon during the north-easterlymonsoon season, providing strong evidence that this represents their sole mode of reproduction(Robinson et al. 2011; Chapter 6). Results from Kenya do not contradict this pattern but werefar less conclusive, a reflection of the more limited data obtained from the multiple approachesused in Kenya during this programme. Therefore, more detailed histological studies would bebeneficial to confirm whether or not the total annual reproductive output comes from aggregations123
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The designation of geographical ent
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Chapter 1: IntroductionJan Robinson
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limited, subsistence levels of expl
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NTRs for spawning aggregations usin
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al. 2003). Verification may include
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a fraction of spawning sites are pr
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Chapter 3: Targeted fishing of the
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verifying spawning aggregations, we
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ecorded from inshore close to the c
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(a)(b)Fig. 3. Spatial patterns ofca
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pooled sizes of the three spawning
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found S. sutor contributed up to 44
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2011b). However, observations of fi
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MethodsTo identify seasonal and lun
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n=199Females GSI (mean ± SE)2.521.
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The estimate of size at maturity in
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This study was designed to verify S
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were selected. Fish selected for ta
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The number of traps increased on th
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Of the 9 tagged fish detected by re
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Fig. 7. Diel patterns ofdetection f
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Spawning aggregation site fidelity
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Chapter 6: Shoemaker spinefoot rabb
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anterior of the anus and below the
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A high percentage (80.8%) of depart
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arrivals and departures at these tw
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are typically applied for reef fish
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(a)(b)(c)Chapter 3, Figure 3. Spati
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(1)(2)(3)(4)(5)(6)Chapter 7, Table
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Chapter 12, Fig. 1 Fraction of fema
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Plates 8. Selected photographs from
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MethodsStudy sitesThe study area wa
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which shelved gently ( ca. 25 o ) t
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Fig. 4. Lunar periodicity in number
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Behaviour and appearanceDescription
Page 80 and 81: eported aggregations forming betwee
Page 82 and 83: The sizes of E. fuscoguttatus aggre
Page 84 and 85: Materials and methodsStudy area and
Page 86 and 87: TL. All fish tagged were considered
Page 88 and 89: Lunar timing of arrivals and depart
Page 90 and 91: Fig. 8. The presence and absence of
Page 92 and 93: aggregation fishing. This critical
Page 94 and 95: Chapter 9: Persistence of grouper (
Page 96 and 97: ResultsBetween 2003 and 2006, the c
Page 98 and 99: Fig. 2. Mean (± standard error, SE
Page 100 and 101: A few species (e.g. Epinephelus gut
Page 102 and 103: (a)(b)Fig. 1. Map of (a) study site
Page 104 and 105: Fig. 2. Number of E. lanceolatus ob
Page 106 and 107: was having any impact on the popula
Page 108 and 109: A spawning aggregation is said to o
Page 110 and 111: Chapter 11: Evaluation of an indica
Page 112 and 113: Table 1 Aggregation fisheries asses
Page 114 and 115: the lists of Jennings et al. (1999)
Page 116 and 117: with the more vulnerable labrids an
Page 118 and 119: The remaining serranid populations
Page 120 and 121: Spawning aggregation behaviour is c
Page 122 and 123: tiger grouper, Mycteroperca tigris:
Page 124 and 125: of protecting the normal residence
Page 126 and 127: • Since grouper males are afforde
Page 128 and 129: Fig. 2 Yield-per-recruit normalized
Page 132 and 133: during full moon periods. Siganus s
Page 134 and 135: model, many parameter estimates are
Page 136 and 137: ReferencesAbunge C (2011) Managing
Page 138 and 139: Cox DR (1972) Regression models and
Page 140 and 141: Grüss A, Kaplan DM, Hart DR (2011b
Page 142 and 143: Kaunda-Arara B, Rose GA (2004a) Eff
Page 144: Newcomer RT, Taylor DH, Guttman SI
Page 147 and 148: Sancho G, Petersen CW, Lobel PS (20
Page 149 and 150: Appendix 1. QuestionnaireMASMA SPAW
Page 151 and 152: 8. Spawning aggregation knowledgeUs
Page 153 and 154: Example items KSh Furthest site Clo
Page 155 and 156: Appendix II. Experimental testing o
Page 157 and 158: Clove oil concentrationAt a concent
Page 159 and 160: Appendix III. Application of acoust
Page 161 and 162: 153
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