Résultats de la recherche

1. Using ecosystem monitoring data to detect impacts

   impacted by activities such as fishing. This paper discusses a range of methods for inferring such impacts ... an observed value in an unimpacted system, or (ii) the frequency of values below a fixed reference ... probabilities of Type I and Type II error can be evaluated analytically for these methods, which facilitates ... point. The second approach allows inference criteria based on changes in this frequency rather than by ... : Method 4 with inference based on changes in frequency: the observed proportion of years in an n-year ... if at ≤ acrit in two or more years of a four-year refer- ence period. Summary of methods: anomalies ... two out of three successive years. The reference period for Method 3 was also three years. Results ... anomaly as an impact (albeit based on only two observations). Even the higher reference points identify ...

   Science Journal Paper : CCAMLR Science, Volume 17 (CCAMLR Science, Volume 17) : 197–212 : Auteur(s): Hill, S.L., J. Forcada, P.N. Trathan and C.M. Waluda

2. Analysis of haul data from the South Georgia krill fishery

   establish the time required for each phase of the fishing operation. The times associated with shooting and ... hauls were generally small, suggesting that little effort was spent searching for fishable swarms beyond ... Georgia suggests that fisheries-based indices may be of value for management purposes, consequently ... focused, operating in a limited area along the shelf edge on the northern coast of the island. Each day ... operating in different years. Most vessels from Poland and Ukraine operated for just a single year, while ... . For example, in 1994 two vessels from Japan left on the same day (vessels 2 and 3). Within their ... (nominally for June and July at 54O00'S; 35"30fW), a two-sample T-test based on 10 daylight hours (hours ... recorded data from individual hauls. For ease of reference, each vessel was assigned an individual ...

   Science Journal Paper : CCAMLR Science, Volume 5 (CCAMLR Science, Volume 5) : 9–30 : Auteur(s): Trathan, P.N., I. Everson, E.J. Murphy and G.B. Parkes

3. Further computations of the consequences of setting the annual krill catch limit to a fixed fraction of the estimate of krill biomass from a survey

   ), as a function of the fraction of the biomass estimate which is set as the catch for a 20-year period ... a summer harvest. However, the imposition of an upper bound of 1.5 yr-1 on the effective annual ... et al. (1992) put forward an extension of the harvesting model of Beddington and Cooke (1983) to ... over the ranges of uncertainty for a number of model parameters. Results are provided for the ... any year, an upper bound of 1.5 yr-l is placed on the effective annual fishing mortality for fully ... biomass estimate which is set as the catch for a 20-year period. Three possible fishing seasons are ... drawn at random from pre-specified distributions for each simulation of a 20-year period of harvesting ... ) requested that statistics be provided for a 10- as well as a 20-year period of harvesting. Calculations ...

   Science Journal Paper : CCAMLR Science, Volume 1 (CCAMLR Science, Volume 1) : 81–106 : Auteur(s): Butterworth, D.S., G.R. Gluckman, R.B. Thomson, S. Chalis, K. Hiramatsu and D.J. Agnew

4. Krill (Euphausia superba Dana) resources and distribution in the Wilkes Land area in the seasons 1986 to 1989

   mainly focused on the search for exploitable krill aggregations. Two research vessels were simultaneously ... account an area to the north of the edge of the continental slope. Each subarea was described in terms of ... was considered as the most valuable for the krill fishery. Krill aggregations were most frequently and ... for Fisheries 3 The annual period used is the split-year 1 July to 30 June. Split-year is denoted by ... for exploitable krill aggregations. Two research vessels were simultaneously involved in the survey ... 1986 50 12.2 1000 50.0 20 to 21 April 3 1986 300 3.5 158 47.5 24 to 30 April 4 1987 127 14.0 1510 ... : Assessments ofkrill resources for subarea ill (64°40' to 66°20'S, 143° to 1500 E). Sequential Period of Area ...

   Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/7 (Selected Scientific Papers, SC-CAMLR-SSP/7) : 149–162 : Auteur(s): Dolzhenkov, V.N. and V.P.Timonin

5. Results of Soviet investigations of the distribution and ecology of pelagic squids (Oegopsida) in the Southern Ocean

   description is also suggested for M. hamiltoni, the data on which come only from beaks found in sperm whale ... was increased by two or three dozen specimens mostly identified as the little-studied Alluroteuthis ... Antarctic, two hypotheses are suggested: all squids migrate to the Antarctic in the summer seasons from the ... specimens of that total were identified as Brachioteuthis riisei. In recent years (1978-1984) the collection ... habits of sperm whales in the Southern Ocean for 13 years were snmmed up, the scope of material on M ... web. Such description is also suggested for M. hamiltoni, the data on which come only from beaks ... years ( 1978-1984), the collection was increased by two or three do%en specimens taken during ... the mantle is up to 20 cm. There are no data on the feeding habits. H. eltaninae is characterised as ...

   Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/2 (Selected Scientific Papers, SC-CAMLR-SSP/2) : 79-111 : Auteur(s): Lubimova, T.G.

6. Defining smaller-scale management units to further develop the ecosystem approach in managing large-scale pelagic krill fisheries in Antarctica

   define predator units. The derived conceptual model is then used to formulate an approach for developing ... local restrictions on harvesting are necessary, as well as the overall requirements for the monitoring ... the principles and approach required for developing small-scale management units to take account of ... predators’ needs when managing the fishery for Antarctic krill. It provides a theoretical foundation for ... conceptual model is then used to formulate an approach for developing fi sheries on prey species, notably ... of predators in an ongoing management framework for a fully developed fi shery (Constable et al ... been resolved, despite early consideration of the options that could be used to provide for an ... subdivided in Area 48 to better account for the needs of predators (SC-CAMLR, 2000a). An important issue to ...

   Science Journal Paper : CCAMLR Science, Volume 9 (CCAMLR Science, Volume 9) : 117–131 : Auteur(s): Constable, A.J. and S. Nicol

7. Bias in the estimation of krill yield from using a deterministic formulation of the median unexploited spawning biomass

   method for correcting this bias in the level of escapement. The GYM uses an unbiased estimate of the ... needs to be estimated prior to each trial in order for it to be based on the parameters for that trial ... median unexploited spawning biomass Abstract / Description:  Two Monte Carlo simulation models, the krill ... for estimating yields according to decision rules that relate spawning stock status to the median ... perio . Table 2: Escapement of spawning biomass at the end of 20 and 30-year projections for different ... and for three levels of y - 0.15, 0.2 and 0.4. Projections for 20 years and 30 years were undertaken ... : The probability of depleting the spawning biomass during 20-year projections for different levels of y ... spawning biomass after 20 and 30 years relative to median So in each run with no fishing was 1.099 and ...

   Science Journal Paper : CCAMLR Science, Volume 5 (CCAMLR Science, Volume 5) : 1–8 : Auteur(s): Constable, A.J. and W.K. de la Mare

8. Movement and growth of tagged Dissostichus eleginoides around South Georgia and Shag Rocks (Subarea 48.3)

   experimental pot fishing in 2000 and 2001, and have been at liberty from one to two years. Four fish were ... at 42°S after about one year at liberty from some opportunistic tagging carried out on a toothfish ... tagged and recaptured from the same longline vessel in 2002 after up to two months at liberty. The fish ... strontium chloride or oxytetracycline that places a permanent chemical marker on the otolith indicating the ... an approximate spring balance measurement that does not provide useful data for growth comparisons ... released during experimental pot fi shing in 2000 and 2001, and have been at liberty from one to two years ... seas area on the Patagonian Shelf at 42°S after about one year at liberty from some opportunistic ... ‘T-bar’ tags indicating a reward for the return of the tag on recapture as well as address, fax and ...

   Science Journal Paper : CCAMLR Science, Volume 10 (CCAMLR Science, Volume 10) : 101–111 : Auteur(s): Marlow, T.R., D.J. Agnew, M.G. Purves and I. Everson

9. Quantifying movement behaviour of vessels in the Antarctic krill fishery

   analyses demonstrate the need for high-quality year-round data on all vessels participating in the krill ... /haul, and the travel distance decreased as the catch level increased; this pattern was most obvious for ... number of fishing grounds within this area. The same patterns were observed for vessels from other ... nations, but were less clear. The study suggests the movement trends for Japanese vessels could form the ... krill fishery is essential for an ecosystem-based approach to managing the effects of fishing on ... of each haul, assuming 60 n miles for one degree latitude and 30 n miles for one degree longi- tude ... been made within a 30 n mile radius by the total number of haul pairs. For this calculation, travel ... bins from 0 to 30 tonnes (and greater). The predictor variable, x, was defined as the mean catch for ...

   Science Journal Paper : CCAMLR Science, Volume 16 (CCAMLR Science, Volume 16) : 131–148 : Auteur(s): Kawaguchi, S. and S.G. Candy

10. Low breeding success of the Adélie penguin at Béchervaise Island in the 1998/99 season

    , foraging trip duration and diet suggests that the death of chicks during the guard stage was due to an ... fewer local trips and both sexes spent longer at sea than in years of higher breeding success. Meal ... seven days during mid-January each year at longitude 60°E. Chick Growth (CEMP A7) About 30 chicks ... respectively (Table 3). 20-24 Feb 1 25 Feb-l Mar I 2-6 Mar Mean foraging trip durations for males and ... Bechervaise lsland except 1994/95 for both males and females. Two-way ANOVA following normalisation of the ... two factors for which insufficient temporal data Irvine et al. presently exist in the Mawson ...

    Science Journal Paper : CCAMLR Science, Volume 7 (CCAMLR Science, Volume 7) : 151–167 : Auteur(s): Irvine, L.G., J.R. Clarke and K.R. Kerry

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