PUKYONG

GUIDE OAK 국가리포지터리 부경대학교

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Abstract: Artisanal fisheries in Central America are fishing hammerhead shark as a target and/or non-target species with gillnets. Scalloped hammerhead sharks (Sphyrna lewini) migrates along the warm current waters as large schooling and seasonally aggregates at seamounts. In this study, a total of 4,677 samples of body lengths were collected from commercial fisheries in eleven ports and villages along the coast of Central America Pacific Ocean and analyzed from April to November 2009. The sizes ranged from 30 cm to 275 cm in length and more than 55 cm in height. The growth parameters were estimated to be K = 0.15/year, t0 = -0.57 year, L∞ = 366 cm. the estimates of total mortality (Z) was 0.919 /year, natural mortality (M) was 0.450/year, fishing mortality (F) was 0.469/year, and tc was 0.408 years. Biomass of S. lewini was estimated to be 54,230 mt in 2009 by the length based cohort analysis. The biological reference points for S. lewini were calculated that F35% and F40% were 0.267/year and 0.228/year, respectively. The acceptable biological catch (ABC) was estimated to be 4,782 mt when FABC was 0.115/year. This study is the first stock assessment for S. lewini carried out on the Central American region, which will provide more information on the population dynamics to assess the stock status and develop sustainable management plans for this species in future.

URI: https://repository.pknu.ac.kr:8443/handle/2021.oak/8899
http://pknu.dcollection.net/jsp/common/DcLoOrgPer.jsp?sItemId=000001965947

Table Of Contents: Tables of contents i
List of Figures iii
List of Tables v
Abstract vii
1. Introduction 1
1.1 Background 4
1.2 Research conducted of Sphyrna Lewini 6
1.3 Sharks fisheries in Central America 10
2. Data and methods 15
2.1 Research area 15
2.1.1 Fishing villages and fishing ports 15
2.2 Data 20
2.3 Methods 27
2.3.1 Biological parameters 27
2.3.1.1 Weight and length relationship 27
2.3.1.2 Growth parameters 28
2.3.1.3 Mortality 30
2.3.2 Biomass 31
2.3.3 Yield per recruit 34
2.3.4 Acceptable biological catch (ABC) 35
3. Results 41
3.1 Biological parameters 41
3.1.1 Weight and length relationship 44
3.1.2 Growth parameters 46
3.1.3 Mortality 50
3.2 Biomass 51
3.3 Yield per recruit 52
3.4 Acceptable biological catch (ABC) 56
4. Discussion 59
5. References 67
6. APPENDIX 78
6.1. APPENDIX A 78
6.2 APPENDIX B 84
6.3 APPENDIX C 91

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