`Date submitted [ to be completed by the Secretariat ]
`Language [ to be completed by the Secretariat ]
`Agenda
`
`Title
`
`Author(s)
`Affiliation(s)
`
`WG-EMM-05/12
`14 June 2005
`Original: English
`Agenda Item No(s): 3
`
`DESCRIPTIVE ANALYSIS OF HAUL DATA FROM F/V
`“ATLANTIC NAVIGATOR” IN ELEPHANT ISLANDS (48.1),
`SOUTH GEORGIAS ISLANDS (48.3) AND SOUTH ORKNEY
`ISLANDS (48.3) KRILL FISHERY (SUMMER 2004 - EARLY
`WINTER 2005).
`Oscar Pin, Hebert Nión, Elizabeth Delfino and Pablo Meneses.
`National Direction of Acuatic Resources from Uruguay (DINARA,
`Uruguay).
`Document status Scientific paper.
`
`
`ABSTRACT
`Data from individual hauls carried out by krill F/V “Atlantic Navigator” operating in three
`fishing zones were analyzed: Elephant islands zone (48.1), South Georgias islands zone
`(48.3) and South Orkney islands zone (48.2). The fishing season was extended from 19/2/04
`(summer 2004) to 7/4/05 (early winter 2005) with a total of 251 days of effective fishing.
`Descriptive study of the fishery operation was performed for the two fishing systems used:
`conventional fishing system (CON) and the continuous fishing system with air-bubbling
`suspension and suction of capture (CFS). Individual haul data were analyzed to describe
`differentialy catch rates (catch per day and catch per minute) of the three different fishing
`zones studied. The total catch registered was 41837 tonnes: 50% of this capture was obtained
`at South Orkney islands zone. The highest catch rate were calculated for the same fishing
`zone with CFS (293 kg/min) during summer 2005. The biggest krill size also corresponded to
`this zone and season: 50 mm total length. Sexual proportion determined when possible
`(summer 2005) was determined: males 64,59%, females 28,00% and immature individuals
`7,38%. Predominant colour of sampled individuals was determined IC for winter season 2004
`and IIC and IIB for summer to winter 2005. All data was recorded under the CCAMLR
`Scheme of International Scientific Observation (SC-CAMLR, 1993).
`
`Key words: krill fishing, Elephant islands, South Georgias islands; South Orkney islands,
`catch rate, conventional fishing, continuous fishing, krill size, krill colour.
`
`SUMMARY OF FINDINGS AS RELATED TO NOMINATED AGENDA ITEMS
`
`Agenda Item
`
`
`
`
`
`
`Findings.
`Item: Krill descriptive fishing from Elephant, South Georgias and South
`Orkney Islands.
`Findings: geographic ubication of fishery summer-winter 2004 and 2005,
`catch rate per day, catch rate per minute, fishing depth, modal total length,
`predominant colouration, comparative fishing systems conventional (CON)
`and continuous fishing (CFS).
`
`
`Submitted on the request of the Scientific Committee (SC-CAMLR-XXIII, paragraph 4.4)
`
`
`This paper is presented for consideration by CCAMLR and may contain unpublished data, analyses, and/or
`conclusions subject to change. Data in this paper shall not be cited or used for purposes other than the work of
`the CCAMLR Commission, Scientific Committee or their subsidiary bodies without the permission of the
`originators and/or owners of the data.
`
`AKER EXHIBIT 2002 PAGE 0001
`
`
`
`TITLE:
`“Descriptive Analysis of haul data from F/V “Atlantic Navigator” in Elephant
`Islands (48.1), South Georgias Islands (48.3) and South Orkney Islands (48.3)
`krill fishery (summer 2004 - early winter 2005).”
`
`
`
`Oscar Pin, Hebert Nion, Elizabeth Delfino and Pablo Meneses (*).
`opin@dinara.gub.uy; hnion@dinara.gub.uy
`(*) National Direction of Aquatic Resources from Uruguay (DINARA, Uruguay).
`
`
`
`ABSTRACT
`
`Data from individual hauls carried out by krill F/V “Atlantic Navigator” operating in
`three fishing zones were analyzed: Elephant islands zone (48.1), South Georgias
`islands zone (48.3) and South Orkney islands zone (48.2). The fishing season was
`extended from 19/2/04 (summer 2004) to 7/4/05 (early winter 2005) with a total of 251
`days of effective fishing. Descriptive study of the fishery operation was performed for
`the two fishing systems used: conventional fishing system (CON) and the continuous
`fishing system with air-bubbling suspension and suction of capture (CFS). Individual
`haul data were analyzed to describe differentialy catch rates (catch per day and catch
`per minute) of the three different fishing zones studied. The total catch registered was
`41837 tonnes: 50% of this capture was obtained at South Orkney islands zone. The
`highest catch rate were calculated for the same fishing zone with CFS (293 kg/min)
`during summer 2005. The biggest krill size also corresponded to this zone and
`season: 50 mm total length. Sexual proportion determined when possible (summer
`2005) was determined: males 64,59%, females 28,00% and immature individuals
`7,38%. Predominant colour of sampled individuals was determined IC for winter
`season 2004 and IIC and IIB for summer to winter 2005. All data was recorded under
`the CCAMLR Scheme of International Scientific Observation (SC-CAMLR, 1993).
`
`Key words: krill fishing, Elephant islands, South Georgias islands; South Orkney
`islands, catch rate, conventional fishing, continuous fishing, krill size, krill colour.
`
`
`RESUMEN
`
`Se realizó el análisis individual de datos provenientes de lances realizados por el
`krilero B/P “Atlantic Navigator” que operó en tres differentes zonas de pesca: islas
`Elefante (48.1), islas Georgias del Sur (48.3) e islas Orcadas del Sur (48.2). La
`temporada de pesca se extendió desde 19/2/04 (verano 2004) a 7/4/05 (invierno
`temprano 2005) con un total de 251 días de pesca efectiva. Se realizó el estudio
`descriptivo de la operación de pesca de los dos sistemas utilizados: pesca
`convencional (CON) y pesca continua con suspensión por burbujeo de aire y succión
`de la captura (CFS). Los datos de los lances fueron analizados individualmente para
`describir en forma diferencial las tasas de captura (captura diaria y captura por
`minuto) de las tres diferentes zonas de pesca estudiadas. La captura total registrada
`fue de 41837 toneladas: 50% de esa captura fue obtenida en la zona de las islas
`Orcadas del Sur. La mayor tasa de captura fue calculada para la misma zona de
`pesca con CFS (293 kg/min) durante verano 2005. La talla más grande de krill
`
`
`
`1
`
`AKER EXHIBIT 2002 PAGE 0002
`
`
`
`también correspondió a esta zona y estación: longitud total de 50 mm. La proporción
`sexual, cuando fue posible (verano 2005), se determinó según: machos 64,59%,
`hembras 28,00% e individuos inmaduros 7,38%. El color predominante de los
`individuos muestreados fue determinado en IC para invierno 2004 y en IIC y IIB
`paea verano a invierno 2005. Todos los datos fueron registrados bajo el Esquema de
`Observación Científica Internacional (SC-CAMLR, 1993).
`
`
`
`MATERIAL AND METHODS
`
`Introduction.
`
`From March 2004 to April 2005 the krill fishery performed by the F/V “Atlantic
`Navigator”, from Vanuatu, was observed by uruguayan Scientific Observers of the
`National Direction of Aquatic Resources (Uruguay). This krill fishing vessel (KF/V)
`operated in the CCAMLR Statistical Area 48, carring out exploratory fishing in the
`subareas 48.1 (Elephant
`Islands surroundings), 48.2 (South Orkney
`Islands
`surroundings) and 48.3 (South Georgias Islands surroundings).
`
`The main krill fishing season occurs during the austral winter from Georgias Islands to
`the southern Orkney and Elephant Islands during spring and summer when the ice
`decreasing allows the fishing operations in high latitudes. All data obtained by the
`Scientific Observers have been analyzed (geographical position, duration, catch and
`effort per haul) and all the not consistent records were eliminated. The proportion of
`deleted or missing records was approximately 8%.
`
`
`Database description.
`
`Data obtained by the Scientific Observers were registered and communicated under
`the CCAMLR Scheme of International Scientific Observation (SC-CAMLR, 1993)
`including haul date and geographical position, net shoot time, fishing start and end
`time and haul end time.
`
`Defining the studied variables, considering the hauls of the conventional fishing
`system (CON) many definitions from Trathan et al. (1998) were used: a) shoot time:
`time at the start of shooting the net por each trawl; b) fishing start time: time at which
`shooting was completed and the net began to fish; c) fishing end time: time at which
`hauling started and the net stopped fishing; d) fishing period: time between the start
`and end of fishing.
`
`Considering the not-conventional system of continuous fishing with air-bubbling
`suspension system (CFS), the same variables were used but considering the fishing
`effort by the fishing period definition strictly: time between the start and end of
`effective fishing. Also the total catch per haul (kilograms), catch rate per day (kg/day)
`and catch rate per minute (kg/min) were registered. The fishing depth of the net and
`the bottom depth in the moment of the catching were determined by ecoic register
`(sonar and net-sonde) of the fishing unit.
`
`
`
`2
`
`AKER EXHIBIT 2002 PAGE 0003
`
`
`
`
`
`
`Analysis of records, fishing gear and methodology.
`
`KF/V “Atlantic Navigator” carried out two different methodologies and fishing gear: a)
`convential fishing system with pelagic net (CON); b) not-conventional system of
`continuous fishing system, with pelagic net with air-bubbling suspension and
`continuous suction of catch (CFS). Both methods were alternatively used, depending
`on the following factors: a) distribution, density and behaviour of krill concentrations;
`b) meteorologic and oceanographic conditions (ice-pack aggregations that prevent
`from fishing); c) fishing master decisions; d) krill catch processing capacity of factory.
`
`Capture methodology of krill included the following stages: a) ecoic-searching and
`definition of swarms or krill concentrations; b) fishing methodology election, including
`conventional exploratory hauls for cuantitative and qualitative estimation of capture; c)
`catch by CON system or CFS.
`
`The ecoic equipment used were Simrad ES500 Ecosonde and Sonar Simrad SR 240.
`
`Pelagic nets were used by two different modalities: a) trawling net for conventional
`pelagic krill fishing, mesh 22 mm in the bottom (copus), 74 m to 95 m of superior and
`inferior scoffer (burlon), 22 m to 30 m of vertical opening, 800 to 1000 meshes
`“diamond” oriented, polivalent type Egersund doors with 14 square meters of surface
`and 3500 kg of weight; b) pelagic net similar to the cited one but adapted to
`continuous fishing, with a thin hose for suspension of krill concentrations in front of
`the net mouth by air-bubbling, and another thick hose for suction of the krill catch
`(width 22 cm).
`
`Both fishing methodologies used the prevention dispositive named RIST, which
`consisted on a metallic grid before the net mouth that prevented against incidental
`capture of medium and big organisms (big pelagic fishes, birds and marine mammals)
`from the net. This dispositive showed to be much effective in that objective.
`
`
`Fishing season and fishing periods.
`
`The fishing season studied was extended from 19/2/04 to 7/4/05, with interruptions
`between fishing periods. The season started on summer of the year 2004 and
`finished on early winter of the year 2005. The fishing zones were: Elephant Islands
`zone (Observer Ebol Rojas) 19/2/04-4/3/04; South Orkney Islands zone (Observer
`Eduardo Mujica) 23/4/04-14/5/04 and 25/3/04-1/4/04; Elephant Island zone 30/5/04-
`8/6/04 and South Georgias Islands zone (Observer Pablo Meneses) 11/6/04-25/7/04;
`South Georgias Islands zone (Observer Danae Canepa) 23/9/04-20/10/04; South
`Orkney Islands zone (Observer Elizabeth Delfino) 28/1/05-26/2/05 y 10/3/05-7/4/05.
`
`
`
`
`
`
`
`3
`
`AKER EXHIBIT 2002 PAGE 0004
`
`
`
`Fishing vessel.
`
`Krill fishing vessel “Atlantic Navigator” was registered in Port Vila (Vanuatu). Distintive
`call YJQS7. Ship type: pelagic stern trawler; 6759 TRB; 96.20 m length; 18.5 m width;
`loading capacity 2630 m3; Motor Warsilla 2 x 3290 KW. Acustic equipment on board
`Simrad ES500 Sonde, Sonar Simrad FS903 and SR240. GPS Northstar 915X.
`Control system Skanti. Net sonde Scanmar.
`
`
`
`RESULTS
`
`Fishing seasons and number of fishing days.
`
`Haul based data considered in this analysis included from summer 2004 to the early
`winter 2005. The cited fishing season was divided by the geographical locations or
`fishing zones: CCAMLR Subareas 48.1, 48.2 and 48.3 (Table 1). The total number of
`effective fishing days was 251 in all zones studied.
`
`Table 1. Fishing zones, season and number of days of effective krill fishing.
`
`
`CCAMLR
`Zone
`48,1
`48,1
`48,2
`
`Fishing
`zone
`Elephant Islands
`Elephant Islands
`S.Orkney Islands
`
`48,2
`
`S.Orkney Islands
`
`48,3
`
`S.Georgias Islands
`
`Period
`Febr.-March 2004
`May 2004
`April-May 2004
`Jan-Febr-March-April
`2005
`June-July-Aug-Sep-
`Oct-Nov 2005
`
`Season
`summer-fall
`winter
`winter
`
`Nº fishing
`days
`10
`15
`22
`
`summer-fall-winter
`
`59
`
`winter-spring
`
`145
`
`
`
`Elephant Islands zone. The fishing season is determined by both the presence of the
`krill concentrations in the zone and the of ice aggregations or packs that prevent from
`fishing operations. The fishing activity in this zone happened during February and
`March 2004 (late summer and fall). Scarce exploratory hauls were performed on May
`2004 (winter).
`
`South Georgia Islands zone. The fishing season in this zone usually commences on
`the latter part of May and ends in August-September. In this case, the season started
`in the middle of June and ended in November 2004 (winter and spring).
`
`South Orkney Islands zone. Exploratory fishing was performed during April and May
`2004 (winter) in this zone but the main fishing activity was performed from January to
`April 2005 (from summer to early winter) when the ice aggregations ended all
`possible fishing operation.
`
`
`
`
`
`
`4
`
`AKER EXHIBIT 2002 PAGE 0005
`
`
`
`Description and location of the fishery.
`
`Elephant Islands zone. The fishery operated over a wide area along the islands,
`specially on the northern edge of the continental shelf, with little fishing activity close
`the islands (specially in winter) or over extremely deep water. The average bottom
`depth at fishing was 531 m. The average fishing depth was 34 m in summer-fall and
`85 m in winter 2004; and 65 m in late winter-spring 2005. This fact confirms the
`previous observations done that during winter time and early fall, the krill
`concentrations usually remain in deep waters depending on the oceanographic
`conditions. The geographical location of the main catches were made on the
`sorroundings of Lat. 60º 56’ S – Long. 56º 36’ W.
`
`South Georgia Islands zone. The fishery started over the northern edge of the
`continental shelf but along the season the fishing activity spread out to the western
`zone. The fishing movement was irregular because of the continuous exploratory
`activity in the main “fishing grounds”. The average bottom depth at fishing was 883 m
`(130 m – 4362 m). The average fishing depth was 156 m in middle winter 2004, and
`64 m in late winter and spring 2005. The geographical location of the main catches
`were made on the sorroundings of Lat. 53º 53’ S – Long. 38º 54’ W.
`
`South Orkney Islands zone. The fishery operated firstly at the northwestern zone
`making exploratory fishing in early winter 2004, with catches on Lat. 60º 21’ S – Long.
`46º 52’ W. Subsequently the fishery operated on the main “fishing grounds” from
`summer to early winter 2005: the “big canyon” (60º 22’ S – 46º 33’ W) and the “small
`canyon” (60º 30’ S – 46º 06’ W) nearer the island. The main catches there were made
`on the sorroundings of Lat. 60º 27’ S – Long. 45º 12’ W and 60º 24’ S – Long. 46º 03’
`W. The average bottom depth at fishing was 459 m. The average fishing depth varied
`from 60 to 100 m in summer 2005; 130 m in fall 2005 and 150 to 200 m in winter
`2005.
`
`
`Operative time of the day
`
`The vessel operated with the conventional hauls system (CON) mainly un daylight
`hours (80% were between 8.00 h -17.00 h). Conventional hauls at all fishing locations
`were of short duration (1h 10’ per haul), with 7 or 8 hauls per day. The approximative
`time at CON were 30’ shoot time; 35’ haul end time. The time needed to shoot the net
`and the time needed to haul the net were approximately constant all over the fishing.
`
`Time interval between consecutive hauls was variable depending on the searching of
`krill concentrations, behaviour of krill swarms under different oceanographic
`conditions, time of the day, weather conditions (including ice-packs aggregations),
`the processing capacity of the factory and the experience of the fishing master
`(human factor). Considering the continuous fishing and suction of catch system
`(CFS), the searching and the catching were almost a simultaneous process at krill
`fishing. At CFS the delayed time was variable depending on the same factors cited.
`The CFS operated during daylight as well as night.
`
`
`
`
`5
`
`AKER EXHIBIT 2002 PAGE 0006
`
`
`
`Considering both CON and CFS fishing systems the trawling velocity of the net
`registered was approximately 2 knotts (1,1 – 3,4 knotts) at effective fishing.
`
`
`Total catch by fishing zone
`
`The total catches of krill completed 41836800 kg. The catches were determined by
`fishing zone: Elephant Islands zone 9,86 %, South Georgia Islands zone 40,14 % and
`South Orkney Islands zone 50,00 % (Table 2).
`
`Table 2. Total catch by season and fishing zone.
`
`
`
`
`
`summer-fall
`2004
`3680400
`
`
`
`Total catch (kg)
`winter
`summer to winter
` 2004
`2005
`445000
`
`16793000
`
`5293000
`19946423
`
`
`
`
`
`
`
`
`Total
`(kg)
`4125400
`16793000
`20918400
`41836800
`
`Fishing zone
`Elephant Islands
`S. Georgias Islands
`S. Orkney Islands
`All zones
`
`
`Catch rate per day and catch rate per minute
`
`Catch rate per day was calculated for each season and fishing zone considering both
`fishing systems CON and CFS (Table 3). Also, catch rate per minute was calculated
`for same seasons and fishing zones (Table 4).
`
`Table 3. Catch rate per day by season and fishing zone.
`
`
`Catch rate
`(kg/day)
`
`summer-fall 2004 winter 2004
`28655
`204697
`
`183143
`
`
`
`Fishing zone
`Elephant Islands
`S. Georgias Islands
`S. Orkney Islands
`
`
`
`Table 4. Catch rate per minute by season and fishing zone.
`
`
`
`
`
`
`Catch rate
`(kg/min)
`
`summer-fall 2004 winter 2004
`43,4
`104,6
`
`117,5
`
`
`
`Fishing zone
`Elephant Islands
`S. Georgias Islands
`S. Orkney Islands
`
`
`
`
`
`summer to winter 2005
`
`
`210996
`
`
`summer to winter 2005
`
`
`293,1
`
`
`
`6
`
`AKER EXHIBIT 2002 PAGE 0007
`
`
`
`Modal length, length-frequency distribution and sexual proportion of krill
`
`The krill specimens were measured by CCAMLR standards, that is the total body
`length from the front of the eye to the tip of the telson, to the nearest milimetre below
`(CCAMLR Scientific Observer Manual, Part III: S3-1, 1998). The hauls were
`sistematically sampled with n = 300 individuals. Total length (mm) and total weigth
`(gr) were determined for each specimen considering both sexes in common (except
`for South Orkney Islands zone samples in summer 2005). The modal length was
`determined for each fishery season and fishery zone considered (Table 5).
`
`Table 5. Modal length (mm) and maximum and minimum length sampled by season
`and fishing zone.
`
`
`
`
`
`summer-fall 2004
`41 (29-50)
`
`
`
`
`Modal length (mm)
`(max.-min.)
`winter 2004
`34 (26-70)
`40 (30-56)
`38 and 48 (29-60)
`
`
`summer to winter 2005
`
`
`50 (19-51)
`
`Fishing zone
`Elephant Islands
`S. Georgias Islands
`S. Orkney Islands
`
`
`The length-frequency distribution for both sexes was determined for the Elephant
`Islands, South Georgias Islands and South Orkney Islands zones in winter season
`2004 (Figures 1, 2 and 3) and for South Orkney Islands zone in the extended season
`summer, fall and early winter 2005 (Figure 4).
`
`
`Length-frequency distribution
`Elephant Islands Zone, winter 2004
` (KF/V Atlantic Navigator)
`
`n = 7560
`
`12
`
`9
`
`6
`
`3
`
`0
`
`% Frequency
`
`18
`
`22
`
`26
`
`30
`
`34
`
`50
`46
`42
`38
`Total length (mm)
`
`54
`
`58
`
`62
`
`66
`
`70
`
`
`Figure 1. Length-frequency distribution of krill, Elephant Islands zone, winter 2004
`(KF/V “Atlantic Navigator”).
`
`
`
`
`7
`
`AKER EXHIBIT 2002 PAGE 0008
`
`
`
`Length-frequency distribution
`South Georgias Islands Zone, winter 2004
` (KF/V Atlantic Navigator)
`
`n = 5399
`
`12
`
`9
`
`6
`
`3
`
`0
`
`% Frequency
`
`18
`
`22
`
`26
`
`30
`
`34
`
`50
`46
`42
`38
`Total length (mm)
`
`54
`
`58
`
`62
`
`66
`
`70
`
`
`Figure 2. Length-frequency distribution of krill, South Georgia Islands zone, winter
`2004 (KF/V “Atlantic Navigator”).
`
`
`
`Length-frequency distribution
`South Orkney Islands Zone, winter 2004
` (KF/V Atlantic Navigator)
`
`n = 11617
`
`12
`
`9
`
`6
`
`3
`
`0
`
`% Frequency
`
`18
`
`22
`
`26
`
`30
`
`34
`
`50
`46
`42
`38
`Total length (mm)
`
`54
`
`58
`
`62
`
`66
`
`70
`
`
`Figure 3. Length-frequency distribution of krill, South Orkney Islands zone, winter
`2004 (KF/V “Atlantic Navigator”).
`
`During winter 2004 in Elephant Islands zone showed a defined modal length at 34
`mm with bigger individuals up to 70 mm (n = 7560). The South Georgias Islands
`
`
`
`8
`
`AKER EXHIBIT 2002 PAGE 0009
`
`
`
`zones showed a not so defined modal length at 40 mm and less dispertion of values
`(n = 5399). The South Orkney Islands showed two modal lengths at 38 mm and 48
`mm (n = 11617), probably inicating a mixture of diferent length-classes.
`
`
`Length-frequency distribution
`South Orkney Islands Zone, summer-winter 2005
` (KF/V Atlantic Navigator)
`
`n = 13858
`
`12
`
`9
`
`6
`
`3
`
`0
`
`% Frequency
`
`18
`
`22
`
`26
`
`30
`
`34
`
`50
`46
`42
`38
`Total length (mm)
`
`54
`
`58
`
`62
`
`66
`
`70
`
`
`Figure 4. Length-frequency distribution of krill, South Orkney Islands zone, summer to
`winter 2005 (KF/V “Atlantic Navigator”).
`
`
`During the following summer to winter 2005 in South Orkney Islands zone showed a
`defined modal length at 50-51 mm with the smallest individuals sampled of 19 mm (n
`= 13858). The sexual proportion in the samples was determined only for this zone
`and season because classification between sexes of specimens by gonadic
`identification was only possible when the individuals were sexually mature.
`
`
`Table 6. Sexual proportion from South Orkney Islands zone, summer to winter 2005.
`
`
`Sexual proportion
`64,59%
`28,00%
`7.38%
`
`Specimen
`Males
`Females
`Immature individuals
`
`
`Feeding and colouration types
`
`The colouration types of krill were determined by using methodology and the coloured
`illustrations from CCAMLR Scientific Observers Manual (Figure 1, Part III: S3-1,
`1998). Specimens from Elephant Islands zone were almost all classified under IC
`condition from fall to winter 2004, indicating low feeding intensity. Late winter from
`South Georgias Islands zone showed 67% of specimens making a transition from the
`
`
`
`9
`
`AKER EXHIBIT 2002 PAGE 0010
`
`
`
`IC to a predominant IIB condition. Specimens from South Georgia Islands zone
`showed a predominant proportion of IIB and IIC condition, indicating a higher feeding
`intensity during summer and fall 2005.
`
`Table 7. Colouration types proportion (%) sampled by season and fishing zone.
`
`
`
`
`
`summer-fall
`2004
`IC: 100
`
`
`Colouration types
`proportion (%)
`winter 2004
`
`IC: 100
`IC: 5, IIB: 67, IIIC: 27
`
`
`
`
`
`
`summer to winter 2005
`
`
`
`summer-fall IIB: 68, IIIC: 27, IVC: 5
`fall-winter IC: 1, IIC: 66, IIIC: 26, IVC: 6
`
`Fishing zone
`Elephant Islands
`S. Georgias Islands
`S. Orkney Islands
`
`S. Orkney Islands
`
`
`
`Depth of pelagic fishing
`
`Average depth of the pelagic net showed more superficial fishing during summer
`seasons: 34 m in Elephant Islands zone and 86 m in South Orkney Islands zone.
`Considering winter seasons the net fished deeper in all zones (Table 8).
`
`Table 8. Average depth of fishing (m) by season and fishing zone.
`
`
`Average depth of
`fishing (m)
`winter 2004
`85 m
`156 m
`69 m
`
`
`summer to winter 2005
`
`
`summer-fall 86 m
`fall-winter 150 m
`
`
`
`
`summer-fall 2004
`34 m
`
`
`
`
`
`
`
`Fishing zone
`Elephant Islands
`S. Georgias Islands
`S. Orkney Islands
`S. Orkney Islands
`
`
`
`DISCUSSION
`
`Operational description of fishing
`
`Standard hauling data registration was not enough for defining the time required to
`find an appropiate swarm for fishing within a concentration layer of krill. Searching
`time of krill should be splited out into primary searching time (PST) and secondary
`searching time (SST) as defined by Butterworth (1988).
`
`Considering the continuous fishing system with suspension by air-bubbling and
`suction of catch (CFS), the searching and the catching can be considered a
`simultaneous process at krill fishing. It was observed that during winter time (or under
`special oceanographic conditions) the krill concentrations layed deeper (from 160 m
`to 200 m) than in summer and summer-fall time (60 m to 100 m). That fact obliged the
`use of conventional hauls (CON) and prevented from fishing with air-suspention of
`
`
`
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`AKER EXHIBIT 2002 PAGE 0011
`
`
`
`catch (CFS), which showed to be more effective in depths from 30 m to 150 m
`(depending on the longitude of the suction-hose and the air-hose).
`
`The catch rates obtained for fall and early winter 2004 in Elephant Islands and South
`Orkney Islands zones were relatively slower than the rates from 2005 season,
`probably because the CFS were in experimental development phase. That is, a lot of
`time and effort were spent on reparation and adaptation of the fishing gear.
`
`
`Catch size usually is determined by the volume needed that the catch does not
`deteriorate before processing. Japanese and Soviet Union
`fleets generally
`determined this point in less than 8 tonnes per haul (Trathan et al. 1998). With the
`conventional fishing system (CON), the time needed to ensure that objetive was
`determined by both the krill concentration at fishing and the processing capacity of
`the factory. Considering the continuous fishing system (CFS), the distinction is
`useless because the fishing is a full-time process limited only for the activities such as
`searching for krill concentrations or by the factory processing time. The biggest catch
`rate were registered at South Orkney Islands zone with the CFS (293 kg/min): this
`system allowed a larger fishing period with less time spent in searching of krill and/or
`shooting and hauling of net time.
`
`Critical qualities of CON and CFS fishing systems should be fine-scale described and
`analized in order to define the easiest and cheapest fishing operation and the best
`quality of the final product at the factory.
`
`Considering both fishing systems CON and CFS prevented from almost any other
`species incidental catches, showing to be almost 100% effective in krill fishing and
`not other unwanted effect in the ecosystem. Some scarce catches of young
`specimens of
`icefish Champsocephalus sp. (Pisces, Channichthyidae) were
`registered. Some incidental captures of antarctic sea-lion Arctocephalus gazella
`(Mammalia, Pinnipedia) were registered, but in all cases (12) the specimens were
`released alive. The prevention dispositive RIST showed to be effective in general on
`its purpose.
`
`Classification between sexes of krill by gonadic identification was only possible during
`summer and fall of 2005 at Orkney islands fishery samples, because the individuals
`studied were sexually mature. From early winter 2005 the classification was not
`possible.
`
`
`
`CONCLUSIONS
`
`1) Total catches of the total fishing season were 41836,8 tonnes corresponding to
`251 days of effective fishing, which 50% proceeded from South Orkney Islands zone,
`from summer to winter 2005.
`
`2) Conventional fishing system seemed to be more effective in deep waters (deeper
`krill concentrations in winter from years 2004 and 2005): 69 m – 156 m. Continuous
`fishing system with air-supension and suction of the catch (CFS) seemed to be more
`
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`AKER EXHIBIT 2002 PAGE 0012
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`
`
`effective in more superficial waters (summer 2004 and summer-fall 2005): 34 m – 86
`m.
`
`3) Highest catch rate was registered with CFS, in South Orkney Islands zone, during
`summer-fall 2005: 293,1 kg/min.
`
`4) Catch rates per day and per minute calculated by season and fishing zone showed
`the smaller values for Elephant Islands zone (summer and fall 2004) with 28655
`kg/day and 43,4 kg/min; and the biggest values for South Orkney Islands zone
`(summer and fall 2005) with 210996 kg/day and 293,1 kg/min.
`
`5) The modal total length of krill determined for Elephant Islands zone was 41 mm in
`summer and fall 2004. The modal total length determined for South Georgias Islands
`zone was 40 mm in winter 2004. The same length determined for the Orkney Islands
`zone was 50 mm from summer to winter 2005.
`
`6) Specimens were predominantly in IC colour condition in winter 2004 but making a
`seasonal transition through a predominant IIC and IIB colour condition in summer and
`fall 2005 (probably related to a higher feeding intensity).
`
`7) The range of average fishing depths were registered from 34 m in Elephant Islands
`zone to 156 m in South Georgias Islands zone.
`
`
`
`ACKNOWLEDGEMENTS
`
`The authors are grateful to the Scientific Observers Danae Canepa, Fernando Area,
`Eduardo Mujica and Ebol Rojas, that with their professional work on board the KF/V
`“Atlantic Navigator” made this paper possible.
`
`
`
`BIBLIOGRAPY
`
`Butterworth, D.S. 1988. A simulation study of krill fishing by an individual Japanese
`trawler. In: Selected Scientific Papers, 1988 (SC-CAMLR-SSP/5). CCAMLR,
`Hobart, Australia: 1-108.
`
`
`CCAMLR Scientific Observer Manual. 1998-2002. CCAMLR, PO Box 213, North
`Hobart, Tasmania 7002. Australia.
`
`
`FAO 1985. FAO Species Identification Sheets for Fishery Purposes. Southern Ocean
`(CCAMLR Convention Area Fishing Areas 48, 58 and 88), Vols I and II.
`Prepared and published with
`the supportof
`the Commission
`for
`the
`Conservation of Antarctic Marine Living Resources (Eds: Fischer, W. and J.-C.
`Hureau). FAO, Rome.
`
`
`
`
`
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`
`
`
`SC-CAMLR. 1993. Report of the Twelfth Meeting of the Scientific Committee (SC-
`CAMLR-XII). CCAMLR, Hobart, Australia.
`
`
`Siegel, V., U. Damm and V.A. Sushin. Catch per unit effort (CPUE) data from the
`early years of commercial krill fishing operations in the Atlantic sector of the
`Antarctic. CCAMLR Science, Vol. 5 (1998): 30-50.
`
`
`Sushin, V.A. and K.E. Shulgovsky. 1999. Krill disrtibution in the Western Atlantic
`sector of the southern ocean during 1983/84, 1984/85 and 1987/88 based on
`the results of soviet mesoscale surveys conducted using an Isaacs-Kidd
`midwater trawl. CCAMLR Science, Vol. 6 (1999): 59-70.
`
`
`Trathan P.N., I. Everson, E. J. Murphy and G.B. Parkes. 1998. Analysis of haul data
`from the South Georgia krill fishery. CCAMLR Science, Vol. 5 (1998): 9-30.
`
`
`Watkins, J.L. 1999. A composite recruitment index to describe interannual changes in
`the population structure of Antactic krill at South Georgia. CCAMLR Science,
`Vol. 6 (1999): 71-84.
`
`
`
`
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