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

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Induction time is defined by the total time taken from a) to d), i.e. from placement of fish intoanesthesia solution to time removed from anesthesia for suturing.TaggingPrior to tagging the fork length (FL) of the anaesthetised fish was measured using a measuringboard. The fish was then placed upside down in a soft canvas cradle suspended in an aerated shallowglass aquarium making sure the head was under water. Ssing a surgical scalpel a shallow incisionwas made through the ventral body wall slightly above the anus and about 2/3 distance below thelateral line (Plate 1a). A dummy acoustic transmitter tag was inserted gently at a steep angle ina posterior upward direction to avoid damage to the gonad (Plate 1b). The incision was suturedwith two stitches, each with two knots using ½ cycle 3-0,2 metric nylon-polyamide sutures. Totalincision time was recorded. The fish was returned to a bucket of fresh aerated sea-water to observeits recovery. It was then returned to the fish holding bucket strapped to the side of the boat withthe other fish. Total time for holding the fish from capture in the basket trap was restricted to 1hr. Additional untagged fish were retained as controls and also so that the tagged fish were keptin groups. This was important during release to enable them to swim together to the bottomand orient themselves easily. For the indoor experiment with 5 fish, fish were sacrificed after theexperiment to dissect and examine the sutures.Plate 1. a) Siganus sutor showing the position of the suture relative to lateral line; b) dissected fishshowing good placement of dummy transmitter tag below ripe gonad.SurvivalFive fish tagged with dummy transmitter tags were returned to one trap by gently pouring themin a bucket of water down through the trap entry funnel, together with nine untagged fish. Fiveother fish put through the anaesthesia and suturing procedure, but with no dummy tags inserted,were returned to sea in a second basket trap. The traps were placed on the sea bed where the fishwere captured and the entry funnel blocked with a stone so that they could not fish. Traps were leftovernight, and fish survival was checked the following day.Recovery and assessment of fish conditionInitial recovery from the anaesthesia was observed in an aerated bucket on the boat and thenin the holding bucket beside the boat. In the indoor experiment this was restricted to the 80 lcontainer. Recovery was defined as moving with caudal fin in normal vertical position. For thefield experiment survival of tagged fish was assessed within 24 hrs at which point the traps wereretrieved and the tagged fish brought to shore to assess the condition of the fish. This continuedfor 4 hrs in an aerated large plastic container indoors. Fish were then sacrificed to dissect them toinspect the placement of the tag in the body cavity, to measure the incision length and to examinethe suture wound.Results and DiscussionRetention timeFish that were removed from the anaesthesia solution after 0 sec or 30 sec soon started to recoverwhen in the tagging cradle, as seen in movement of caudal and pectoral fins. With retention times>1 min, 3 of the 5 fish did not start to recover from the anaesthesia while undergoing the suturing.148
Clove oil concentrationAt a concentration of 20 mg/l, S. sutor continued to swim slowly in the bucket and did not becomeanesthetised for over 3 minutes, therefore no trials were done with this concentration of clove oilsolution. Increasing the concentration to 40 mg/l brought the induction time for anesthesia to 3:01min. Increasing the concentration to 45 mg/l or 50 mg did not improve the induction time (Table1). However, observations of fish beginning to recover while still undergoing the suturing, as seenin the caudal and/or pectoral fins starting to move, showed that there was a difference between 40-45mg and 50mg. At 50 mg/l, fish did not start recovering while still undergoing suturing whereasthey did when anesthetised with 40 or 45mg/l.Table 1. Induction and recovery time (mean ± standard deviation) for different clove oilconcentrations.Clove oil concentration 40 mg/l (n=<strong>10</strong>) 45 mg/l (n=3) 50 mg/l (n=2)induction time (mins) 3:01±0.461 3:15±0.034 3:00±0.053recovery time (mins) 4:00±0.003 6:46±0.077 *12:01±0.296* one fish took 7 min., the other took 17 min. and was very stressed.Induction and recoveryFish took a longer time to be anaesthetised and to fully recover as the concentration was increasedfrom 40 to 50 mg/l (Table 1). This may be because the 45 mg/l and 50 mg/l were tested indoorswhere the chances of stress were higher due to handling fish in confinement.Suturing and tag insertionThe time taken to complete the suturing ranged from 01:30 min to 04:30 min, improving withpractice over time. A steady process completed within 2 minutes was considered the optimal time.Periods of 3-4 min, however, did not seem to have an adverse affect on the fish - all fish survived.Bruising was apparent around the suture wound immediately after surgery. However, by the nextday this bruising had diminished and faded.Average suture length for the field experiment was 2.0±0.271 cm (n=<strong>10</strong>) and 1.6±0.217 cm(n=5) for the indoor experiment. We strived to minimise the length of suture (relative to tag sizeand diameter) to improve the chances of the wound healing (Plate 2a). Sutures of greater than2 cm appeared loose after 21 hours and therefore we recommend that they have more than twostitches. We recommend a suture length of
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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
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eported aggregations forming betwee
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The sizes of E. fuscoguttatus aggre
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Materials and methodsStudy area and
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TL. All fish tagged were considered
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Lunar timing of arrivals and depart
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Fig. 8. The presence and absence of
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aggregation fishing. This critical
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Chapter 9: Persistence of grouper (
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ResultsBetween 2003 and 2006, the c
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Fig. 2. Mean (± standard error, SE
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A few species (e.g. Epinephelus gut
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(a)(b)Fig. 1. Map of (a) study site
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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: Appendix II. Experimental testing o
Page 159 and 160: Appendix III. Application of acoust
Page 161 and 162: 153
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