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

More documents

Recommendations

Info

Behaviour and appearanceDescription4. Male aggression Assumed to be males, based on the behaviour, but they arenot in male colouration. Two behaviours were observed:i) One individual chases another away from its area, swimmingrapidly and chasing for up to ca. 10 m. Assumed to bemales fighting over territories.ii) Two individuals circling tightly head to tail, moving veryslowly; as one moves away (possibly a submissive response),the other uses its lips to hit (which is audible) the other fishon the caudal peduncle area. Some individuals were scarredwith superficial wounds, while others were more severe. Forexample, one fish had a badly torn upper lip. These injurieswere assumed to be from male-male aggression.5. CourtshipMale in spawning colours (see 2) swims slowly close to afemale (see 3), and turns sideways to the female and shakesits whole body, while swimming slowly past her. The actionwas sometimes repeated to the same female within 10 to 15minutes of the first encounter.6. Suspended in the water columnStationary or moving slowly, well above substrate by at least1m. At KW, two individuals were seen hovering around 3m above the bottom in the same area where other fish wereaggregating. This behaviour continued for 5-10 minutes. Thefish were assumed to be male, but were not displaying malecourtship colours. This is assumed to be a pre-spawning action.Table 2. Frequency of spawning related behaviour in spawning months (December-February) and non-spawningmonths (July-August). Data are the number of individuals observed exhibiting the behaviour within the set census(30 min count + 10 min. observations). * = numbers refer to a pair of fish. Numbers in parenthesis refer to behaviourdescribed in Table 1. NM=new moon; FM=full moon.MonthColourchange (2)Gravidfemale (3)Male-malechase (4i)*Male-malehead to tail(4ii)*Courting (5)*Dec NM 31 11 7 1 3 5Jan NM 7 5 2 0 5 0Feb NM 7 6 2 0 3 0Jan-Feb FM 2 2 0 0 1 0Jul-Aug 0 0 0 0 0 0Suspension inwater column(6)70
Fig. 6. Size structure of E. fuscoguttatus population on the KM spawning aggregation site during spawning months(November-February) and non-spawning months (July-August) based on underwater estimates of fish sizes to 5cm.Samples are pooled data for each month, total numbers of fish shown in Fig. 3.Fish size and sex ratios of spawning aggregationsTwelve pairs of E. fuscoguttatus were observed courting and in all but one case the male was largerthan the female. The modal size class of courting fish was 81-85 cm TL for males, and 71-75 cmTL for females. Since it is possible to sex males when they are in male colouration or showingmale-male aggression (Table 1), an approximate value for the proportion of males in an aggregationwas calculated. This ranged from 7 to 64% with a mean of 35% (±7.3% SE). Consistently higherproportions of males in aggregations (mean = 46%) were observed during the December newmoon, when most spawning-related behaviours were recorded (Table 2). Size frequency plots ofthe aggregations show that the minimum sizes of aggregating fish were 56-60 cm TL (December)and the maximum size was 96-100 cm TL (November) and that the largest fish (>85cm TL) werepresent only during the months of November, December and January (Fig. 6).Fishers’ information on spawning aggregations and their timingEight of the 32 fishers interviewed provided information on E. fuscoguttatus spawning aggregationsthat matched criteria for determining spawning aggregations (see Methods). More than one fisher71
Page 4:
The designation of geographical ent
Page 9:
Chapter 1: IntroductionJan Robinson
Page 12 and 13:
limited, subsistence levels of expl
Page 14:
NTRs for spawning aggregations usin
Page 17 and 18:
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 70 and 71: Plates 8. Selected photographs from
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 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 130 and 131:
The approaches identified above are
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
show all

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

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?