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

(a)(b)Fig. 1. Map of (a) study site on the southern end of Unguja Island, Zanzibar and(b) village and reef areas where fishers and fishery were observed.Catch landings dataLandings of E. lanceolatus in Kizimkazi village were recorded on 36 different days between 13November 2009 and 26 February 2010 during which 64 individual E. lanceolatus were sampledfrom 43 catches. Sample records included: vessel type, number of fishers, gear type and size, fishinglocation, fish total length and body depth (to 0.1 m), and gonad colour and weight (to 0.5 kg).Sampled fish were too large to be weighed at the landing site and therefore total fish weightwas estimated approximately from fish lengths, based on a single 170 kg fish that was weighedin Zanzibar town. For reasons not clear, fishers were reluctant to sell us E. lanceolatus gonads,therefore, no samples were available for histological or macroscopic analysis. Instead gonads wereonly weighed and described by colour (red or white). Sampling effort was not stratified evenlyacross months or lunar phases, therefore, statistical differences should be interpreted with caution.Fisher knowledgeQuestionnaires (modified from the questionnaires used in Kenya, see Chapter 3) were used tointerview 17 fishers in Kizimkazi to gain knowledge of their fishing patterns in relation to E.lanceolatus and their knowledge of spawning aggregations, including their occurrence, location,and timing. These fishers were selected based on information collected during an earlier studythat identified them as the only fishers out of 150 fishers in Kizimkazi targeting E. lanceolatus. Inaddition, a focus group discussion (FGD) was held in February 2010 with 8 of the 17 fishers tofurther discuss their knowledge of the E. lanceolatus fishery and to cross check answers from priorinterviews.SCUBA observationsTwo SCUBA dives were carried out on the full moon of February 2010 on the offshore reef fishingsite where fishers reported catching E. lanceolatus. The dives were done to observe E. lanceolatus, tosee if they were aggregating and whether they were exhibiting any recognisable spawning-relatedbehaviour (Colin et al. 2003). The purpose of the dives was also to describe the reef topography ofthe presumed spawning site. Only two dives were done because the conditions were too dangerouswith bottom depths in excess of 40 m and very strong currents.94