Résultats de la recherche

1. Improving estimates of Adélie penguin breeding population size: developing factors to adjust one-off population counts for availability bias

   presented for the collection and development of data to adjust counts of Adélie penguins made at any time in ... point one week after the peak in egg laying, consistent with Standard Method A3 of the CCAMLR Ecosystem ... illustrated using data collected at the Béchervaise Island CEMP site in 2007/08. Estimates of the breeding ... , breeding-age penguins that failed to return to the breeding site in that breeding season, nor pre-breeding ... foraging and relieve the males from their incubating duties, who in turn leave the breeding sites to ... undertaken ‘on the same day each year…when about two-thirds of chicks have entered crèches’ in the same ... 1 Nov 16 1 Dec 16 1 Jan 16 1 Feb 16 0. 0 0. 2 0. 4 0. 6 0. 8 1. 0 0 10 20 30 40 50 60 ... Camera 2 16 1 Nov 16 1 Dec 16 1 Jan 16 1 Feb 16 0. 0 0. 2 0. 4 0. 6 0. 8 1. 0 0 10 20 30 40 50 ...

   Science Journal Paper : CCAMLR Science, Volume 17 (CCAMLR Science, Volume 17) : 229–241 : Auteur(s): Southwell, C., J. McKinlay, L. Emmerson, R. Trebilco and K. Newbery

2. Management and uncertainty: the example of South Georgia

   :  Decisions on fishery management are often made with some degree of uncertainty in scientific advice. Such ... to consider ways in which CCAMLR can improve its ability to take decisions in the face of uncertainty ... uncertainty. The question is addressed specifically in terms of the fishery of Notothenia rossii around South ... in the 1980 year-class (paragraph 20 of the report). - 346 - Accepting that the decline in ... , and the small numbers from the 1966 to 1969 year-classes observed in later years would not be ... mortalities in the years 1976 to 1983 (excluding 1980) of 0.2 to 0.6. The only year during this period in ... (1969/70, 1970/71 and 1980/81). Some of these features could be explained by year-to-year changes in ...

   Science Journal Paper : Selected Scientific Papers, SC-CAMLR-SSP/3 (Selected Scientific Papers, SC-CAMLR-SSP/3) : 341-353 : Auteur(s): Gulland, J.A.

3. Comparison of two methods to assess fish losses due to depredation by killer whales and sperm whales on demersal longlines

   depredation occurs on fish in the marine environment. This is the case for killer whales (Orcinus orca) and ... aimed at providing two indirect methods of assessment of depredated biomass over an 11-year period (2003 ... to 2013), accounting for spatial variations of depredation levels. In the first method, fishing data ... second method used the differences in the proportion of grenadiers (Macrourus spp.) between non ... , represented less than 20% of all cells (Cd + Cu). Out of 145 cells in total, 83 were used for killer whales ... the Crozet Islands EEZ per year. Although access to Patagonian toothfish on longlines is limited in ... communi- ties co-exist with elephants? A five-year case study in East Caprivi, Namibia. Biol. Cons., 93 ... whales and 19 cells cg in the presence of killer whales and sperm whales together as both data in the ...

   Science Journal Paper : CCAMLR Science, Volume 22 (CCAMLR Science, Volume 22) : 1–14 : Auteur(s): Gasco, N., P. Tixier, G. Duhamel and C. Guinet

4. A first step towards modelling the krill–predator dynamics of the Antarctic ecosystem

   ecosystem Abstract / Description:  The history of human harvests of seals, whales, fish and krill in the ... hypothesis of a krill surplus in the mid-20th century is described, and the information on population and ... ) species. The model commences in 1780 (the onset of fur seal harvests) and distinguishes the Atlantic ... /Indian and Pacific Ocean sectors of the Southern Ocean in view of the much larger past harvests in the ... statistically significant increase (about 5% per year) in minke whale recruitment dur- ing the period from ... , seems certainly plausible. More recent trends in whales and seals in the Antarctic More than 30 ... given in the appendix. Crabeater seals have hardly been harvested, but 750 animals were taken per year ... of krill in region a in year y; ra is the intrinsic growth rate of krill in region a; Ka is the ...

   Science Journal Paper : CCAMLR Science, Volume 13 (CCAMLR Science, Volume 13) : 217–277 : Auteur(s): Mori, M. and D.S. Butterworth

5. A hybrid approach to acoustic classification and length estimation of krill

   the acoustic estimates of species and sizes to net samples collected during three surveys conducted in ... animal measurement. For small school- ing organisms, such as euphausiids, this criterion is seldom met ... estimated confi dently in the interval (amin – amax) where 100|δ| < 20%, for a given dΔ. The mean length ... (Table 1). The limits of each size class can be established by a per- centage error < 20% in the radius ... of species and sizes to net samples collected during three surveys conducted in the Ross Sea under ...

   Science Journal Paper : CCAMLR Science, Volume 11 (CCAMLR Science, Volume 11) : 33–58 : Auteur(s): Azzali, M., I. Leonori and G. Lanciani

6. An overview of Southern Ocean zooplankton data: abundance, biomass, feeding and functional relationships (submitted to the 2008 Joint CCAMLR-IWC Workshop)

   for differences in the extent of identification of early larval stages. Likewise, the time of year ... between the Antarctic sectors, but latitudinally it is maximal in the Polar Frontal Zone and declines to ... in size structure and abundance. Other issues are specific to polar environments, for example, lipid ... in global literature compilations. Likewise, stenothermy (narrow temperature tolerance) means that ... one-half of those above. A change in the view of SO copepods in the last 20 years has followed an ... of 330, 202 and 76 μm in the Polar Frontal Zone. 0 20 40 60 80 100 0 100 200 300 400 500 ... rather than differences in method or time of year of sampling. Large-scale distribution Appendices 1 ... have instead compiled data from multiple cruises at different times of year, albeit in different ...

   Science Journal Paper : CCAMLR Science, Volume 19 (CCAMLR Science, Volume 19) : 171–218 : Auteur(s): A. Atkinson, P. Ward, B.P.V. Hunt, E.A. Pakhomov and G.W. Hosie

7. Seabird interactions with longlining operations for Dissostichus eleginoides around South Georgia, April to May 1994

   -seven line sets were observed and 98 deaths of seabirds were recorded over 20 sets; no deaths occurred ... ) predominating. Grey-headed albatrosses, whose populations (at South Georgia are in serious decline, were ... disproportionately affected in relation to their numbers near the fishing vessel; giant petrels may be ... disproportionately affected in relation to the size of their breeding population at South Georgia when compared to ... each species in the vicinity of the ship was recorded every 30 minutes. Of the 20 sets for which ... Georgia (sets 5 to 15) during night-time setting. These occurred in aggregations of 20 to 30 birds ... albatrosses could save the lives of 30 300 albatrosses and enable fishermen to save $4.9 million in bait ... , flying in and diving at the line within 30 m of the stern. Birds were submerged for up to five seconds ...

   Science Journal Paper : CCAMLR Science, Volume 2 (CCAMLR Science, Volume 2) : 111–121 : Auteur(s): Ashford, J.R., J.P. Croxall, P.S. Rubilar and C.A. Moreno

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

   :  Data from individual hauls carried out by vessels operating in the South Georgia krill fishery between ... focused, operating in a limited area along the shelf edge on the northern coast of the island. Each day ... several hauls were undertaken by each vessel (average 7.9 in 1993,9.9 in 1995, and 7.0 in 1996), with ... variability are discussed in relation to previous attempts to model fisheries data and to derive suitable ... operating in different years. Most vessels from Poland and Ukraine operated for just a single year, while ... starting in April (1 year), May (5 years) or June (1 year), and ending in August (1 year), September (2 ... years), October (1 year), November (1 year) or December (1 year). In recent years the end date of the ... undertaken. In each year the first (Q1) and third (Q3) quartiles were equidistant about the median, with ...

   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

9. Effects of recruitment variability and natural mortality on generalised yield model projections and the CCAMLR decision rules for Antarctic krill

   proportional recruitment of krill. In this study, krill sampling data for empirical size frequencies were ... . The annual proportions of krill less than 36 mm in length to the total captured in net samples in four ... proportional recruitment in the CCAMLR study areas was similar to the variability in other krill studies and in ... the annual size distributions of krill in penguin diets. Simulations with either no fishing, or with ... years and CCAMLR criteria calculated both for any given year in all years, and for only the final year ... individuals less than 36 mm in all areas and legs that were sampled suggest it was a year with relatively ... - tus in the final year of simulations in each of the 10 001 trials. The CCAMLR criteria were slightly ... ratio of the spawning biomass in the final year to the pre-exploitation median spawning biomass (the ...

   Science Journal Paper : CCAMLR Science, Volume 20 (CCAMLR Science, Volume 20) : 81–96 : Auteur(s): Kinzey, D., G. Watters and C.S. Reiss

10. The effects of monitoring procedures on Adélie penguins

    loss. There was a slight reduction in return rates of birds banded for more than one season, but no ... incubation period resulted in increased foraging trip durations and reduced breeding success. Attachment for ... single or multiple foraging trips post-hatching caused no significant increase in foraging trip durations ... . No reduction in fledging rates of chicks from nests of stomach-lavaged birds was detected over two ... (TIRISTM, Texas Instruments, USA), 30 mm long and 3 mm in diameter, implanted under the skin of the neck ... Clarke and Kerry and/or banded birds present in 1991/92 returned the next year. When the second figure ... loss in King penguins has been estimated at 22% during the first year after banding (Weimerskirch ... returned to the colony as two-year-olds (1993/94 summer). Ainley et al. (1983) reported that 30% of all ...

    Science Journal Paper : CCAMLR Science, Volume 1 (CCAMLR Science, Volume 1) : 155–164 : Auteur(s): Clarke, J. and K. Kerry

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