한수지 51(4), 435-443, 18 Original Article Korean J Fish Aquat Sci 51(4),435-443,18 상업어선의어군탐지기를이용한남극크릴 (Euphausia superba) 자원량추정 최석관 한인우 1 * 안두해 정상덕 윤은아 이경훈 국립수산과학원원양자원과, 1 전남대학교수산과학과, 전남대학교해양기술학부 Estimating the Abundance of Antarctic Krill Euphausia superba Using a Commercial Trawl Vessel Seok-Gwan Choi, Inwoo Han 1 *, Doo-hae An, Sang-deok Chung, Eun-A Yoon and Kyounghoon Lee Distant Water Fisheries Resources Research Division, National Institute of Fisheries Science, Busan 4683, Korea 1 Division of Fisheries Science, Chonnam National University, Yeosu 5966, Korea Department of Marine Technology, Chonnam National University, Yeosu 5966, Korea The Antarctic krill Euphausia superba is important commercially and ecologically as a basic component of the Antarctic Ocean ecosystem. To manage this resource, it is important to determine the distribution and standing of krill in the water layer. Acoustic methods can capture information about the entire water layer quickly. Acoustic surveys were conducted from March 3 to March 14, 17, using the commercial fishing boat Sejong (7,765 tons). Acoustic systems with a frequency of 38 khz and a khz commercial echo sounder (ES7, Simrad, Norway) were used and the acquired data were processed using post processing software. The density and standing of Antarctic krill were determined using the two-frequency difference method, using the characteristics of two frequencies. To compare the frequency difference of krill, the method using the frequency difference according to the krill length, recommended by the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) and the values extracted according to the krill length at survey stations where only krill were collected during the study period, were compared. The frequency difference ranges were 3.96-5.91 db and -3.~13.8 db, respectively. Key words: Antarctic krill, Euphausia superba, db-difference method, Two-frequency difference method, Abundance estimation 서론 (Euphausia superba),. (Hewitt and Demer, 1993; Kang et al., 1999; Everson, ; Kang et al., 5; Atkinson et al., 9; Jarvis et al., 1; Fielding et al., 14). (Commission for the Conservation of Antarctic Marine Living Resources, CCAMLR) 198,..,, https://doi.org/1.5657/kfas.18.435 Korean J Fish Aquat Sci 51(4) 435-443, August 18 This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial Licens (http://creativecommons.org/licenses/by-nc/3./) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Received June 18; Revised 3 July 18; Accepted 5 July 18 *Corresponding author: Tel: +8. 61. 659. 714 Fax: +8. 61. 659. 719 E-mail address: haninwoo89@gmail.com Copyright 18 The Korean Society of Fisheries and Aquatic Science 435 pissn:374-8111, eissn:87-8815
436 최석관ㆍ한인우ㆍ안두해ㆍ정상덕ㆍ윤은아ㆍ이경훈 (Lawson et al., 8; Cox et al., 11; Fielding et al., 14; La et al., 16), (Everson, 198; Miller and Hampton., 1989).,.,, (Choi et al., 16). 38 khz CCAMLR South Shetland island (Subarea 48.1). 재료및방법 조사해역및정점 South Shetland island, Bransfield strait, Elephant island m. 17 3 3 3 14 (7,765 tonnage). 4,, 9,7 km (Fig. 1). 1 knots,. 6, -3 knots. 음향시스템의구성및자료수집 38 khz (single beam) (ES7, Simrad, Norway). CCAMLR (Table 1). 6 mm, 13.7 mm Foote et al. (1987) (6 9. S, 59 4.6 W), single beam,. (Echoview V8; Echoview Software Pty Ltd., Australia). Latitude ( W) -6-6 -64, 1 mm. 잡음제거및주파수차이를이용한에코추출 Wang et al. (15). 1 m TVT (time varied threshold)., data range bitmap S v (volume backscattering strength), S v mask (De Robertis and Higginbottom, Table 1. Parameters of commercial echosounder for acoustic data collection Parameters ANTARTICA South Shetland Islands Longitude ( S) Elephant Island Subarea 48.1-66 -64-6 -6-58 -56-54 -5 Fig. 1. Acoustic survey line and trawl collection station for collection of Antarctic krill Euphausia superba sample. Setting Frequency (khz) 38 Ping duration (ms) 14 14 Ping interval (s) Data collection range (min.-max.) (m) -11-11 Bottom detection range (min.-max.) (m) 5-11 5-11 Display range (min.-max.) (m) -11-11 Calibration Theoretical value (db) -33.89-44.85
남극크릴의음향자원추정 437 7)., data range bitmap,. erosion filter 3 3, dilation filter. dilation filter 7 7 data range bitmap S v mask, median 7 7, select mask median 7 7 S v data range bitmap,. m 5 m, 5 m. detect schools, Cox et al. (11) Table khz -38 khz. 38 khz. ( MVBS, mean volume backscattering strength) MVBS TS (target strength) TS. 38 khz khz. Fig..,. 5 ping 5 m (SC- CCAMLR-XXVII, Anedex8, Paragraph35; CCAMLR 8; WG-EMM-16/38 16). Table. Setting a parameter to detect Antarctic krill Euphausia superba schools Default schools parameter Maximum horizontal link Maximum vertical Minimum candidate height Minimum candidate length Minimum school height Minimum school length Data threshold Default value 15 m 5 m 3 m 1 m 3 m 15 m -7 db Noise 38 khz 38 khz raw data Cleaned 38 khz Resample by ping 38 khz S V difference -38 khz (db) S v (min-max) (SC-CCAMLR-XXIX, Annex 5, CCAMLR 1; Fielding et al., 11), (PDF 95% ). 크릴의밀도및현존량평가 khz raw data Cleaned khz Resample by ping khz Fig.. Flow chart of acoustic data processing using db difference method at 38 khz and khz. khz 1 n.mile, 5 m. n.mile (S A, area backscattering coefficient; m nmi - ), S A (NASC, nautical area scattering coefficient). 1 n.mile C (conversion factor). C (, m ) (w, g). = s A C 185 ( g )WhereC = f (l ) i i m f i (l i ) Noise khz (1) f i l i i. - CCMALR Kaiyo Maru (SC-CCAMLR-XIX, Annex4, Appendix G, CCAMLR, ). w =.36 1-6 l 3.314 () (mg), (mm). 1991 CCMALR khz TS (Greene et al., 1991). (L) = 4 1 TS(L)/1 = 4 1-15.3+34.85log(L)/1 = 4 1-1.5 L 3.485 (3) (index k)
438 최석관ㆍ한인우ㆍ안두해ㆍ정상덕ㆍ윤은아ㆍ이경훈 (index j) (index i). -6 Euphausia superba Salpa thompsoni >5 (kg/h) <1 <3 ρ j = 1 N j SAi C i (W 1 ) i =1 i (4) L <6 9 Nj L j = i=1 (W 1 ) i j. S Ai i, C i i., l ^ t W 1 l ^ t. Latitude ( W) -6 T1 T W 1 = lat - lat- ^alt (5) lat 1%, 1 nm W 1.. W j = L j (6) 1 Lj j=1 N. j ( J ) (7). J = j ρ j (7) (VapComp j ) j. VarComp j = ω j ( ρ j - ρ k ) (8) k [ (1), Jolly and Hampton, 199] (9). ρ k = 1 Nk ω j j=1 ρ j (9) k [Var ( ρ k )] Var ( ρ k ) = ω j=1 j ( ρk - ρj ) -1 ( Nk ) j=1 ω j=1 j ( ρk - ρj ) (1) ( -1), k % (CV k ) -64-64 -6-6 -58-56 -54 Fig. 3. Data about fish caught and collected in each survey station. The top right legends shows the distribution of the resource. CV k =1 Var ( ρ k ) (11). (B ) (1). ρ k B = N Ak k=1 ρ k (1) B (13) (14). 결과 트롤채집조사 Longitude ( S) Var (B )= N VarCompk (13) k=1 CV B =1 Var (B ).5 (11) B 5 m 1,., 1 5,469 kg, 5,469 kg 5%,
남극크릴의음향자원추정 439 Latitude ( W) -6-6 T1 AVG.=46.9 SD.=4.1 T AVG.=41.6 SD.=4.9 Frequency (%) 18 16 14 1 1 8 6 4 5 ping 5 m T1 T -3-5 - -15-1 -5 5 1 15 5 3 SV difference -38 khz (db) Fig. 4. Size distribution by station of Antarctic krill Euphausia superba fishing by trawls. Frequency (%) -64-64 -6-6 -58-56 -54 1 1 8 6 4 N= 4 Avg.±SD = 44.3±5. mm 14,85 kg 1% (Fig. 3). (CPUE, catch per unit effort; kg/h) 1 5,469 kg/h, 11,844 kg/h. 1 34.4-56.5 mm (Avg. SD=46.9 4.1 mm), 3.-54. mm (Avg. SD=41.6 4.9 mm), 1 (Fig. 4). 3.-56.5 mm (Avg. SD=44.3 5. mm) 47. mm, PDF (probability density function) 95% 34.-54. mm (Fig. 5). 크릴의주파수차이 Longitude ( S) 95% = 34-54 mm.1.8.6.4.. 5 3 35 4 45 5 55 6 65 Length (mm) Fig. 5. Size distribution of Antarctic krill Euphausia superba catch at all station. PDF, probability density function. 1% PDF Fig. 6. The difference between frequency 38 khz and khz for trawls survey station T1 and T. SV, volume backscattering strength. 5 ping 5 m, 1 Fig. 6. 1 5%, 5%,, ( ) 1-1.1 ( 4.9), 4.5 ( 6.5)., 1 db db, 5% 1,. 1% (5-95% ) -3.~13.8 db. 크릴의시 공간분포및밀도추정 1% SV (volume backscattering strength) -3.~13.8 db. -3.~13.8 db South Shetland island West 6 (Fig. 7). Fig. 8 South Shetland island West 6 5 g/m,.9 g/m (CV=31.55%), 83,45 (Table 3). 고찰,,,
44 최석관ㆍ한인우ㆍ안두해ㆍ정상덕ㆍ윤은아ㆍ이경훈 Latitude ( W) -6-6 -64 Swarm (-3.~13.8 db) 6 5 3 4 1 15 7 8 9 1 18 19 16 17 Longitude ( S) 11 1 13 14 3 1 4 NASC (m /nm ) <5 <1 Fig. 7. Spatio-temporal distribution of Antarctic krill Euphausia superba using the difference between frequency khz and 38 khz (-3.<ΔMVBS -38kHz <13.8dB). (Demer and Renfree, 8; Choi et al., 16). split beam 4, single beam., single beam,, (Fig. 9). Choi et al. (16) ES7 EK6 1 khz 3.59 db 38 <5 <1, <,, -66-64 -6-6 -58-56 -54-5 Mean density (g/m ) 7 6 5 4 3 1 Swarm -3.~13.8 db 1 3 4 5 6 7 8 9 1 11 1 13 14 15 16 17 18 19 1 3 4 Transects (St.) =.9 g/m A = 9,7 km B = 83,45 ton Fig. 8. Density of Antarctic krill Euphausia superba using the difference between frequency khz and 38 khz (-3.<ΔMVBS - 38kHz <13.8dB). khz.85 db, db S v 1 khz 38 k 1 db 9.4%. Hz, 38 khz.5 db, khz.34 db db. (ICES, 7), CCAMLR,. m, Ichii 8 Theoretical value (db) = -33.89 Measurement value (db) = -33. ~ -36.64 8 Theoretical value (db) = -44.85 Measurement value (db) = -46. ~ -48.9 6 6 Ping time (N) 4 Ping time (N) 4-37 -36-35 -34-33 -3 38 khz TS Value (db) -64-6 -56-5 -48-44 khz TS Value (db) Fig. 9. Theoretical value and Measurement value of single beam calibration. TS, target strength.
남극크릴의음향자원추정 441 et al. (1998). Kang et al. (5), South Shetland island West 44.9 g/m, South Shetland island South 3.3 g/m, Elephant island 11.3 g/m, Reiss et al. (8) Elephant island, South Shetland island. South Shetland island 37.7-58.3 g/m (Ichii et al., 1998; CCAMLR, ; Hewitt et al., 4). South Shetland island, Elephant island, South Georgia, (Table 4). Azzali et al. (4) -38 khz 5.77-1.7 db, Euphausia pacifica copepods, db< MVBS-38 khz<3 db (Sato et al., 15)., Euphausia pacifica SV -38 khz 3.9-13.3 db, DWBA, 1-3 mm 8-3 db (Kim et al., 16)., 38 khz. TS, TS. stochastic distored wave born approximation (SDWBA) TS- (3.96-5.91 db) SV (-3.~13.8 db). SDWBA db, SV 16 db,.,, khz 3.96-5.91 db, -3.~13.8 db (Fig. 1). Kang et al. (1999) IKMT (isaacs-kidd midwater trawl), amphipods, copepoda, salps. (Salps thompsoni). 1 5%.. Salps thompsoni TS 38 khz -75.7, -74. db, khz -7.8 db TS -38 khz -3 db (Wiebe et al., 9). Table 3. The density and resources in the total survey area of Antarctic krill Euphausia superba MVBS Mean (g/m ) CV (%) Nominal area (km ) Area Density (tonnes) Variance component (tonnes ) -3.1~13.8.9 31.55 9,7 83,485.38 693,949,3.33 ΔMVBS, mean volume backscattering strength; CV, coefficient of variation. Table 4. The Antarctic krill Euphausia superba density comparison in previous studies Survey area Survey data Frequency (khz) Mean density (g/m ) References South Shetland Island 1991-38, 1, 1.-6. Hewitt et al., 3 South Shetland Island Nov 1998 38 17.-4.19 Kang et al., 1999 South Shetland Island and South Orkney Island Nov-Dec 38, 1 3.5 Kang et al., 5 South Shetland Island Feb 6.37 Cox et al., 11 Elephant Island 1981-1997 38, 1 8.7-1.5 Brierley et al., 1999 Elephant Island Jan-Mar 199 1 9.63-11.7 Hewitt and Demer, 1993 South Georgia 1981-1997 38, 1 5.9-95. Brierley et al., 1999 South Georgia, Southern Ocean 1997-1 38, 1,.74-137.3 Fielding et al., 14 South Georgia Oct -Dec 5 3 18.7-89.5 Saunders and Brierley, 7 Scotia Sea Jan-Feb 38, 1, 1.44 Hewitt et al., 4 Weddell Sea Jan-Feb 1 38, 1.6-61.6 Brierley et al., East Antarctica Jan-Mar 6 38, 1, 1. Jarvis et al., 1
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