• The Journal of Fisheries Business Administration
• /
• v.46 no.2
• /
• pp.59-74
• /
• 2015

This study aims to estimate optimal harvesting production, fishing efforts, and stock levels of yellow croaker caught by the offshore Stow Net and the offshore Gill Net fisheries using the current value Hamiltonian method and the surplus production model. As analyzing processes, firstly, this study uses the Gavaris general linear model to estimate standardized fishing efforts of yellow croaker caught by the above multiple fisheries. Secondly, this study applies the Clarke Yoshimoto Pooley(CY&P) model among the various exponential growth models to estimate intrinsic growth rate(r), environmental carrying capacity(K), and catchability coefficient(q) of yellow croaker which inhabits in offshore area of Korea. Thirdly, the study determines optimal harvesting production, fishing efforts, and stock levels of yellow croaker using the current value Hamiltonian method which is including average landing price of yellow croaker, average unit cost of fishing efforts, and social discount rate based on standard of the Korean Development Institute. Finally, this study tries sensitivity analysis to understand changes in optimal harvesting production, fishing efforts, and stock levels of yellow croaker caused by changes in economic and biological parameters. As results drawn by the current value Hamiltonian model, the optimal harvesting production, fishing efforts, and stock levels of yellow croaker caught by the multiple fisheries were estimated as 19,173 ton, 101,644 horse power, and 146,144 ton respectively. In addition, as results of sensitivity analysis, firstly, if the social discount rate and the average landing price of yellow croaker continuously increase, the optimal harvesting production of yellow croaker increases at decreasing rate and then finally slightly decreases due to decreases in stock levels of yellow croaker. Secondly, if the average unit cost of fishing efforts continuously increases, the optimal fishing efforts of the multiple fisheries decreases, but the optimal stock level of yellow croaker increases. The optimal harvest starts climbing and then continuously decreases due to increases in the average unit cost. Thirdly, when the intrinsic growth rate of yellow croaker increases, the optimal harvest, fishing efforts, and stock level all continuously increase. In conclusion, this study suggests that the optimal harvesting production and fishing efforts were much less than actual harvesting production(35,279 ton) and estimated standardized fishing efforts(175,512 horse power) in 2013. This result implies that yellow croaker has been overfished due to excessive fishing efforts. Efficient management and conservative policy on stock of yellow croaker need to be urgently implemented.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.43 no.1
• /
• pp.18-24
• /
• 2010

The biochemical composition of wild and cultured yellow croaker, Larimichthys polyactis, was analyzed in this study. The moisture contents in wild and cultured yellow croaker was high: $75.2{\pm}1.60%$ and $79.5{\pm}1.95%$, respectively. The crude lipid contents of wild and cultured yellow croaker were low; moreover, the crude protein and ash contents did nol differ significantly (P>0.05). The total amino acid content of wild and cultured yellow croaker did not differ significantly; however, the cystine content of wild yellow croaker was higher than than of cultured yellow croaker. The essential /nonessential amino acid (E/NE) ratio in wild and cultured yellow croaker was $0.76{\pm}0.01$ and $0.77{\pm}0.02$, respectively. The free amino acid and extractive nitrogen contents of cultured yellow croaker were high and differed significantly. The water soluble vitamin ($B_1$, $B_2$, $B_6$, $B_{12}$, C and folate) and fat-soluble vitamin (A and E) contents did not differ significantly. expect for niacin. The niacin content of cultured yellow croaker was higher than that of wild yellow croaker. The fatty acid composition of wild and cultured yellow croaker did not differ significantly The sodium, magnesium, and copper contents in wild yellow croaker were relatively low. In comparison, the calcium, phosphorus and iron contents in cultured yellow croaker were relatively high. Overall, the biochemical composition of wild and cultured yellow croaker did not differ significantly.

• Development and Reproduction
• /
• v.23 no.1
• /
• pp.73-78
• /
• 2019

To clarify the cytogenetic features of the chicken grunt, Parapristipoma trilineatum, small yellow croaker, Larimichthys polyactis, and brown croaker, Miichthys miiuy, in Jeju, Korea, karyotype analysis was performed. The karyotype of chicken grunt and brown croaker consists of 24 pairs of telocentrics [2n=48, fundamental number (FN)=48], and small yellow croaker consists of 3 pairs of submetacentrics and 21 pairs of telocentrics (2n=48, FN=54). No evidence of polymorphism, including aneuploidy or sex-related heteromorphic chromosomes, was found in any specimens examined in this study.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.48 no.1
• /
• pp.10-19
• /
• 2012

The mesh selectivity of a drift net for yellow croaker (Larimichthys polyactis) was examined in field experiments with six different net mesh size (40, 45, 50, 55, 60 and 65mm) from April to December, 2008 in the coastal areas of Jeollanam-do in Korea. The total catch of 6,748 consisted of yellow croaker (n=6,310; 89.1% of total catch), common mackerel (n=158; 5.6%) and other species (n=280; 9.6%). The selectivity curve for yellow croaker was fit by the models of selectivity curve in SELECT method. The optimal mesh size for 50% retention for minimum landing size (191mm) of yellow croaker was estimated as 49.6mm-51mm by selectivity curves. And the bi-normal model for the selectivity curve was found to fit the data best.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.42 no.5
• /
• pp.518-522
• /
• 2009

The mesh selectivity of drift gill net for yellow croaker (Larimichthys polyactis) was examined in field experiments with six different net mesh size (40, 45, 50, 55, 60 and 65 mm) from April to December, 2008 in the northwestern coastal waters of Gageo-do, Korea. The total catch of 8,091 consisted of yellow croaker (n=7,574; 89.5% of total catch), common mackerel (n=162; 4.8%) and other species (n=355; 5.8%). The selectivity curve for the small size yellow croaker was fit by Kitahara's method to the polynomial equation S(R)=exp{($-0.552R^3$+$4.927R^2$-11.591R+9.320)-6.717}. The optimal mesh size for 50% retention for minimum landing size(191mm) of yellow croaker was estimated as 51.1 mm. This is very similar to the current drift net mesh size used in Gageo-do.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.55 no.3
• /
• pp.198-205
• /
• 2019

The small yellow croaker (Larimichthys polyactis) is one of the representative high-class fish species in Korea. The catch of small yellow croaker in adjacent water fisheries has been continuously decreasing from 59,226 tons in 2011 to 19,271 tons in 2016. The small yellow croaker is caught by gillnet, stow net and bottom trawl, among which about 55~65% is caught by gillnet. For the sustainable use of small yellow croaker, the fishing power of small yellow croaker drift gillnet is very important. Therefore, the change of fishing power index were analyzed to identify the development of the vessel and gear technology that may have improved the fishing efficiency of the small yellow croaker drift gillnet fishery from 1960s to 2010s. Gross tonnage and horse power per fishing vessel was increased annually. The mesh size was 75.0 mm in the 1960s, but reduced to 60.6 mm in the 1980s and to 51.0 mm in the 2000s. In the 1960s, it was hauled out by manpower. However, the net hauler were modernized and supply rate was also increased since 1970. Due to the mechanization of the net hauler, the number (length) of used net gradually increased from 1.5 km in the 1960s to 7.5 km in the mid-1980s and to 15 km in 2010. Colour fish finders and positioning system were introduced and utilized from the mid-1980s. Surveys on the supply and upgrading of fishing equipment utilized visiting research. Therefore, the relative fishing power index in the small yellow croaker drift gillnet fishery increased from 1.0 in 1980 to 0.8 in 1970, to 1.1 in 1990, to 1.6 in 2000 and to 1.9 in 2010. The results are expected to contribute to reasonable fisheries stock management of the small yellow croaker drift gillnet fishery.

• Animal cells and systems
• /
• v.14 no.1
• /
• pp.45-51
• /
• 2010

Genetic variation was surveyed at the mitochondrial control region (766bp) to test for the presence of genetic stock structure in the small yellow croaker, Larimichthys polyactis from the Yellow and East China Seas. Individuals of the small yellow croaker could not be distinguished on the basis of its location, as demonstrated using the neighbor-joining (NJ) method, unweighted pair-group method, arithmetic average (UPGMA) and the minimum spanning network (MSN). Analysis of molecular variance revealed no significant differences among collections of the small yellow croaker taken from the four locations (two locations each in Korea and China). Neutrality tests and a mismatch distribution analysis indicated that this species has recently expanded. Our findings suggest either that the small yellow croaker has a high migration capability that enables it to overcome the effects of genetic drift, or that this species expanded relatively recently and has not yet had sufficient time to differentiate.

• Korean Journal of Environmental Biology
• /
• v.38 no.4
• /
• pp.507-517
• /
• 2020

Several methods including morphometric analysis were used to distinguish small yellow croaker (Larimichthys polyactis) from yellow croaker (Larimichthys crocea), which have very similar external shapes. Morphometric analysis showed four considerable differences (p<0.05) among the total 48 morphometric dimensions, but no differences were seen in the classical dimensions (p>0.05). Rather, significant differences were seen in two truss dimensions: Insertion of dorsal fin base - origin of pectoral fin base and origin of anal fin base - origin of pectoral fin base, and two head part dimension: most anterior extension of the head - above of eye and above of eye - posterior aspect of operculum(p<0.05). However, the yellow croaker had higher values than the small yellow croaker in the other three morphometric dimensions except for the head part dimension of above of eye - posterior aspect of operculum of the four morphometric dimensions (p<0.05). The X-ray photographs indicated that the small yellow croaker (45.1±2.34°) had 8.4% more curved vertebral column than the yellow croaker(38.4±1.82°). A diamond-shaped cranium was found when the skin was peeled off from both fish but the commonly held fact that only the small yellow croaker has a diamond-shaped cranium is not accurate. Our results confirmed that the two fish could be definitely distinguished by their external body shape.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.49 no.4
• /
• pp.440-448
• /
• 2013

Estimations on population ecological parameters of the small yellow croaker, Larimichthy polyactis in Korean waters, were calculated using catch data based on coastal and offshore drift gillnet fishery and biological data from 2010 to 2012. The population ecological parameters included survival rate, instantaneous coefficient of natural and fishing mortality and age/length at first capture. The survival rate (S) of the small yellow croaker was estimated to be 0.20 from catch curve method. The instantaneous coefficient of natural mortality (M) was estimated to be 0.46/year with Alverson and Carney method. The instantaneous coefficient of total mortality (Z) was 1.611/year, used to be transformed the survival rate and the instantaneous coefficient of fishing mortality (F) were 1.153/year. The length at first capture ($L_c$) was 19.1cm by Pauly method, and the age at first capture ($t_c$) was 1.303 years of the small yellow croaker by the coastal and offshore drift gillnet fishery.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.41 no.5
• /
• pp.346-352
• /
• 2008

Yellow croaker (Larimichthys polyactis) is a major target species of large pair trawl fishery in the East China Sea. To standardize catch per unit effort (CPUE) of yellow croaker for the large pair trawl fishery, generalized linear model (GLM) was applied to evaluate and eliminate the influence of the explanatory factors (year, month, horse power and gross tonnage of vessel) on daily catches per boat collected and compiled by National Fisheries Research and Development Institute (NFRDI) from 1990 to 2007 at the fishery auction places of Busan, Masan and Incheon in Korea. Results of GLM showed that all of the factors significantly influenced on CPUE, explaining 36% of the total deviance. The standardized CPUE indicated that the abundance of yellow croaker in 2000's was 1.7 times higher than the CPUE in 1990's.