• 제목/요약/키워드: Biomass-based cohort analysis

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한국 남해안 보구치(Pennahia argentata)의 자원생태학적 특성치 및 자원량 추정 (Ecological Characteristics and Biomass of White Croaker Pennahia argentata Population in the South Sea of Korean Peninsula)

  • 전복순;이해원;강수경;이승종;오철웅
    • 한국수산과학회지
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    • 제55권5호
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    • pp.721-729
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    • 2022
  • We investigated the ecological characteristics and biomass of white croaker Pennahia argentata population in the South Sea of Korea using catch data from Danish seins fishery and biological data from 2018 to 2020. Survival rate (S), which was estimated using Pauly method (1984) was 0.361 per year, and the instantaneous coefficient of total mortality (Z) was 1.019 per year. The instantaneous coefficient of natural mortality (M) and that of fishing mortality (F) were estimated as 0.351 and 0.668 per year, respectively. At first capture, age was estimated to be 1.19 years and length at this age was 18.7cm. The annual biomass was estimated with a biomass-based cohort analysis using annual catch data between 1997-2020 in Korean water. The biomass of the white croaker declined sharply from 4,000 tons in 1999 to the lowest level of approximately 1,000 tons in 2004. Post 2004, the biomass started to increase gradually and reached approximately 7,000 tons. The amount of resources was 35.7%, 34.8%, and 16.5% at age one, two, and three years, respectively, and 86.9% of all captured white croaker individuals belonged to the age group of 1-3 years.

한국산 중하(Metapenaeus joyneri)의 자원생태학적 특성치 및 자원량 (Population Parameters and Biomass of the Shiba Shrimp Metapenaeus joyneri in Korean Waters)

  • 최정화;장대수;김정년
    • 한국수산과학회지
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    • 제39권4호
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    • pp.344-348
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    • 2006
  • The ecological characteristics and stock biomass of the Shiba shrimp, Metapenaeus joyneri, in Korean waters were determined, using fishery data from the Ministry of Maritime Affairs and Fisheries (MOMAF) and available length frequency data. The instantaneous coefficient of total mortality (Z) of M. joyneri was estimated to be 4.191year, and the annual survival rate (S) was 0.015. The estimated instantaneous coefficient of fishing mortality (F) for recent years was calculated to be 1.94/year. The age at first capture of M. joyneri was 0.71 years. Based on these parameters, the annual biomass of the M. joyneri stock was estimated using a biomass-based cohort analysis and data on the annual catch in weight at age for 1993-2004 in Korean waters. During the study period, the biomass of the shrimp peaked in 1994 at about 9,082 metric tons. Subsequently, it decreased to 500 metric tons in 1998.

한국 연근해 갈치의 자원평가 및 관리방안 연구 2. 한국 연근해 갈치의 자원량 변동 (A Study on the Stock Assessment and Management Implications of the Hairtail, Trichiurus lepturus Linne in Korean Waters 2. Variations in Population Biomass of the Hairtail, Trichiurus lepturus Linne in Korean Waters)

  • 장창익;손명호
    • 한국수산과학회지
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    • 제30권4호
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    • pp.620-626
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    • 1997
  • 본 연구는 한국 연근해 갈치의 연도별 연령별 어획량 자료를 사용하여 생체량을 기초로한 코호트 분석법 (Zhang, 1987)에 의하여 갈치의 $1970\~1988$년 자원량을 추정하였다. 연도별 자원량은 1975년 약 24만톤으로 가장 높은 수준을 보였으며, 1980년부터는 14만톤의 수준으로 떨어졌다. 성어자원량에 있어서는 1978년 약 5.5만톤의 최대수준을 보인 이후, 계속 감소되어 1980년 이후 약 9 천톤의 낮은 수준에 머물러 있다. 연령별 자원량의 경년 변동에 의하면 1970년대와 1980년대의 연령조성은 큰 차이를 나타내었다. 1980년대의 연령조성에서는 4세 이상의 대형어는 거의 나타나지 않고 있으며, $1\~3$세까지의 소형어 수준도 70년대 수준에 크게 못미치고 있다. 또 1973년 연급군이 비교적 탁월연급군으로 나타났다. 코호트 분석에 의해 추정된 1970년대와 80년대의 연도별 순간어획사망계수는 서로 유의성 (P<0.05)을 보여 80년대의 어획사망계수가 증가한 것으로 나타났다. 자원량에 대한 가입량에 있어서는 Ricker curve를 나타내 밀도종속적인 관계를 보여주고 있다.

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한국 동해안 기름가자미(Glyptocephalus stelleri)의 자원평가 및 적정어획량 추정 (Stock Assessment and Optimal Catch of Blackfin Flounder Glyptocephalus stelleri in the East Sea, Korea)

  • 손명호;양재형;박정호;이해원;최영민;이재봉
    • 한국수산과학회지
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    • 제46권5호
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    • pp.598-606
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    • 2013
  • The blackfin flounder Glyptocephalus stelleri is a commercially important species in the East Sea of Korea, but its catches and biomass have decreased gradually in recent years. This study estimated the optimal catch (acceptable biological catch, ABC) for the effective management of this species by estimating population ecology parameters and the stock biomass of blackfin flounder in the East Sea of Korea. The estimated instantaneous coefficient of total mortality (Z) of blackfin flounder was 1.0542/year, the survival rate (S) was 0.3485, and the instantaneous coefficient of natural mortality (M) was 0.3637/year. From the values of S and M, the instantaneous coefficient of fishing mortality (F) was calculated to be 0.6905/year. The age at first capture was 1.304 years, and the total length was 11.5 cm at that time. On the basis of these parameters, the annual biomass was estimated by a biomass-based cohort analysis using annual catch data in weight by year for 1991-2012 in the East Sea of Korea. The annual biomass peaked in 1997 at about 12,800 mt and then subsequently declined continuously to a level of 10,500 mt in 2004 and to 9,800 mt in 2011 and 2012. The maximum sustainable yield and $F_{0.1}$ were estimated as 3,547 mt and 0.3595/year, respectively. Using these estimations, the ABC was estimated to be 3,571 mt in tier 5, 3,397 mt in tier 4, and 2,622 mt in tier 3.

한국 연근해 도루묵, Arctoscopus japonicus의 자원량 추정 (Biomass estimation of sailfin sandfish, Arctoscopus japonicus, in Korean waters)

  • 이성일;양재형;윤상철;전영열;김종빈;차형기;최영민
    • 한국수산과학회지
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    • 제42권5호
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    • pp.487-493
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    • 2009
  • Available ecological and fishery data of sailfin sandfish, Arctoscopus japonicus, was examined to ascertain its population dynamic parameters in Korean waters. The instantaneous coefficient of total mortality (Z) was estimated to be 1.361/yr, and annual survival rate (S) was 0.256. The estimated instantaneous coefficient of natural mortality (M) was 0.482/yr, and the instantaneous coefficient of fishing mortality (F) for recent years was calculated to be 0.879/yr from Z and M values. Age at first capture was estimated to be 1.958 years. These parameters, in conjunction with catch landings data between 1991 and 2008, were used to estimate annual biomass using a biomass-based cohort analysis. The biomass of A. japonicus was estimated at approximately 7,600 mt in 1991, but since 1994 decreased to below 4,000 mt by 2001. After 2002 they started to increase gradually, and showed the level of more than 5,000 mt in recent years.

개체군 체장자료를 이용한 연령조성 추정 (Inference of Age Compositions in a Sample of Fish from Fish Length Data)

  • 김규한;현상윤;서영일
    • 한국수산과학회지
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    • 제51권1호
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    • pp.79-90
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    • 2018
  • Fish ages are critical information in fish stock assessments because they are required for age-structure models such as virtual population analysis and stochastic catch-at-age models, whose outputs include recruitment strengths, a spawning stock size (abundance or biomass), and the projection of a fish population size in future. However, most countries other than the developed countries have not identified ages of fish caught by fisheries or surveys in a consistent manner for a long time (e.g.,>20 years). Instead, data about fish body sizes (e.g., lengths) have been well available because of ease of measurement. To infer age compositions of fish in a target group using fish length data, we intended to improve the length frequency analysis (LFA), which Schnute and Fournier had introduced in 1980. Our study was different in two ways from the Schnute and Fournier's method. First we calculated not only point estimates of age compositions but also the uncertainty in those estimates. Second, we modified LFA based on the von Bertalanffy growth model (vB-based model) to allow both individual-to-individual and cohort-to-cohort variability in estimates of parameters in the vB-based model. For illustration, we used data about lengths of Korean mackerel Scomber japonicas caught by purse-seine fisheries from 2000-2016.

한국근해 참조기의 자원량 변동에 관한 연구 (A Study on Fluctuations in Biomass of Small Yellow Croaker, Pseudosciaena polyactis, off Korea)

  • 장창익;김용문;유신재;김종관;안순모
    • 한국수산과학회지
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    • 제25권1호
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    • pp.37-44
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    • 1992
  • 한국근해 참조기 자원의 연도별 연령별 어획량 자료를 사용하여 생체량을 기초로한 코호트 분석법(Zhang, 1987)에 의하여 참조기의 1970-1988년 자원량을 추정하였다. 연도별 자원량은 1974년 약 10만톤으로 가장 높은 수준을 보였으며, 1981년부터는 2-3만톤의 수준으로 떨어졌다. 성어자원량에 있어서는 1974년 약 5만톤의 최대수준을 보인 이후, 계속 감소되어 낮은 수준에 머물러 있다. 연령별 자원량의 경년변동에 의하면 1970년대와 80년의 연령조성은 큰 차이를 나타내었다. 1980년대의 연령조성에서는 5세 이상의 대형어는 거의 나타나지 않고 있으며, 1세-4세까지의 소형어 수준도 70년대 수준에 크게 못미치고 있다. 1968, 1972 및1978 연급군이 비교적 탁월연급군으로 나타났다. 코호트 분석에 의해 추정된 연도별 순간어획사망 계수에 있어서도 1980년대는 70년대 수준의 2배가 되는 것으로 나타났다. 성어자원 량-가입 량 관계는 직선식으로 적합되었다.

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