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

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Plates 8. Selected photographs from the researchprogramme: Kenyan and Seychelles basket trap fishers;Epinephelus polyphekadion at the atoll spawningaggregation site in Seychelles; telemetry receiver in situat spawning aggregation site and tagging Siganus sutorin Kenya; and running ripe gonads in E. fuscogutattuscatches in Msambweni.
Chapter 7: Observations of spawning aggregations ofthe brown-marbled grouper, Epinephelus fuscoguttatus,in KenyaMelita Samoilys, Denis Macharia, Jan Robinson, George Waweru Maina andJude BijouxIntroductionThe brown-marbled grouper, Epinephelus fuscoguttatus (Epinephelidae) (Forsskål 1775) is widelydistributed throughout the Indo-Pacific region (Heemstra and Randall 1993) and is known to formspawning aggregations (Johannes et al. 1999; Pet et al. 2005; Robinson et al. 2008; Rhodes et al.2012). In the western Indian Ocean, it has been reported by fishers to form spawning aggregationsin Kenya and preliminary studies have verified the location of two aggregations (Samoilys et al.2006, 2007), but little is known about their spatio-temporal formation. The reproductive biologyof this species remains unstudied in eastern Africa, with the exception of reports of spawning in thenortheast monsoon (October to March) period (Nzioka 1979).Epinephelus fuscoguttatus is not considered an abundant grouper (Pears et al. 2006) and in Kenyait is rare in artisanal catches, with only 24 individuals recorded over a 6-month period in 2007 insouthern Kenya (Agembe et al. 2010). Due to its large size, it is relatively important to the biomassof groupers caught. In Kenya, it is targeted by speargun and handline, however catches are so smallthat they are not reported separately (WIOFish database (www.wiofish.org); McClanahan andMangi 2004).Global concerns over the status of Epinephelus fuscoguttatus populations led to a Near ThreatenedRed List classification by the IUCN Groupers and Wrasses Specialist Group in 2007 (IUCN 2011).Concerns over the status of this species in Kenya have arisen from our awareness of two spawningaggregations within the Diani-Chale Reserve on the south coast of Kenya, which is not under activemanagement and does not include no-take zones (Samoilys et al. 2007; Robinson et al. 2008a).Targeted fishing of these aggregations for the local tourism market is known and marketed catchesof E. fuscoguttatus have been observed with running ripe gonads in 2007 (MS pers. obs.) suggestingaggregation fishing. E. fuscoguttatus inhabits depths of up to 60m (Heemstra and Randall 1993)and may therefore be partially protected through a depth refuge (Tyler et al. 2009; Mangubhai etal. 2011; Rhodes et al. 2012) since fishers in Kenya have less access to the seaward reef slopes wherethese fish are likely occur. Boats are still largely non-mechanised (Samoilys et al. 2011a) and thewinds of the south-eastern monsoon (4-5 months) are prohibitively strong preventing easy accessto these sites. However, with technological developments, notably the use of outboard engines,increasing effort by new fishers and an open access fishery (Samoilys et al. 2011a), the vulnerabilityof E. fuscoguttatus in Kenya is likely to be increasing.There is strong evidence that targeted spawning aggregation fishing is rarely sustainable (Sadovy andDomeier 2005). This fact, combined with the life history characteristics of E. fuscoguttatus of slowgrowth, late maturity and long life (Pears et al. 2007) highlight the need to identify managementneeds for this species at and away from spawning sites vulnerable to fishing. This study was designedto verify the aggregation sites in the Diani-Chale Reserve on the south coast of Kenya, to describethe spawning behaviour of this species and to determine the seasonal and lunar periodicity ofaggregation formation. We also intended to track the movements of E. fuscoguttatus to and fromaggregations with acoustic tags, but were unsuccessful in capturing the fish. We document thisseparately (Appendix III) to aid in future research on tagging this species in Kenya.63
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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
Page 19 and 20: a fraction of spawning sites are pr
Page 21 and 22: Chapter 3: Targeted fishing of the
Page 23 and 24: verifying spawning aggregations, we
Page 25 and 26: ecorded from inshore close to the c
Page 27 and 28: (a)(b)Fig. 3. Spatial patterns ofca
Page 30 and 31: pooled sizes of the three spawning
Page 32 and 33: found S. sutor contributed up to 44
Page 34 and 35: 2011b). However, observations of fi
Page 36 and 37: MethodsTo identify seasonal and lun
Page 38 and 39: n=199Females GSI (mean ± SE)2.521.
Page 40 and 41: The estimate of size at maturity in
Page 42 and 43: This study was designed to verify S
Page 44 and 45: were selected. Fish selected for ta
Page 46 and 47: The number of traps increased on th
Page 48 and 49: Of the 9 tagged fish detected by re
Page 50 and 51: Fig. 7. Diel patterns ofdetection f
Page 52 and 53: Spawning aggregation site fidelity
Page 54 and 55: Chapter 6: Shoemaker spinefoot rabb
Page 56 and 57: anterior of the anus and below the
Page 58 and 59: A high percentage (80.8%) of depart
Page 60 and 61: arrivals and departures at these tw
Page 62 and 63: are typically applied for reef fish
Page 64 and 65: (a)(b)(c)Chapter 3, Figure 3. Spati
Page 66 and 67: (1)(2)(3)(4)(5)(6)Chapter 7, Table
Page 68 and 69: Chapter 12, Fig. 1 Fraction of fema
Page 72 and 73: MethodsStudy sitesThe study area wa
Page 74 and 75: which shelved gently ( ca. 25 o ) t
Page 76 and 77: Fig. 4. Lunar periodicity in number
Page 78 and 79: 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
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Spawning aggregation behaviour is c
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tiger grouper, Mycteroperca tigris:
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of protecting the normal residence
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• Since grouper males are afforde
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Fig. 2 Yield-per-recruit normalized
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The approaches identified above are
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during full moon periods. Siganus s
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model, many parameter estimates are
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ReferencesAbunge C (2011) Managing
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Cox DR (1972) Regression models and
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Grüss A, Kaplan DM, Hart DR (2011b
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Kaunda-Arara B, Rose GA (2004a) Eff
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Newcomer RT, Taylor DH, Guttman SI
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Sancho G, Petersen CW, Lobel PS (20
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Appendix 1. QuestionnaireMASMA SPAW
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8. Spawning aggregation knowledgeUs
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Example items KSh Furthest site Clo
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Appendix II. Experimental testing o
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Clove oil concentrationAt a concent
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Appendix III. Application of acoust
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