CCAMLR

The current CCAMLR assessment method for the mackerel icefish (Champsocephalus gunnari) in sub‐area 48.3 employs the CMIX and GYM packages, which derives population numbers‐at‐age and projects these numbers forward under the given harvest control rule to set a two‐year TAC. One issue is the accurate identification of age cohorts from the survey data. In this paper we describe a length‐based approach that removes the problem of cohort determination. A stratified bootstrap technique (consistent with the current CCAMLR approach) is used to estimate the length distribution of the population from the survey data which, in conjunction with the bootstrapped survey biomass data, yields an estimate of the population numbers‐at‐length.

A comparison of this method and the existing age‐based CMIX/GYM methodology showed very good agreement in calculated yields for 2006, 2007 and 2009, and some differences for 2008 which were explained by an unusual length distribution from which it was difficult to reliably estimate age composition in CMIX. Using the 2009 survey data and the new methodology, we calculated a TAC according to the CCAMLR decision rules of 1577t and 933t for the 2009/10 and 2010/11 fishing seasons respectively. The respective estimates using the existing CMIX/GYM methodology were 1590t and 968t respectively

Le présent document synthétise les observations françaises en matière de pêche illicite pour l'année écoulée. Il propose une analyse des évolutions du phénomène et des axes d'amélioration de la lutte.

Le dispositif de surveillance des zones économiques exclusives (ZEE) françaises déployé par la France a été maintenu tout au long de l’année. Il s’est révélé efficace, et la pêche INN ne se manifeste plus dans les ZEE. Les relevages d’engins de pêche INN sont en diminution constante depuis 2004. La ressource durement éprouvée par la pêche INN dans les ZEE de Kerguelen et de Crozet est aujourd’hui sauvegardée. S’il existe une faible possibilité d’incursions passagères, elle demeure trop incertaine pour permettre d’affirmer que des prélèvements INN ont eu lieu dans les ZEE de Crozet et de Kerguelen.

La pêche INN continue de se manifester en zone CCAMLR dans les eaux internationales, avec cependant moins de vigueur que les années précédentes. Le schéma annuel de travail de la flottille INN semble aussi s’être modifié, avec une relative désaffection des bancs Banzare et Elan cette saison et une réorientation des activités illicites vers des haut fonds de moindre importance (Marion Dufresne seamont), plus disséminés (Bruce bank, Ob et Lena seamont), mais parfois en limite de ZEE de Kerguelen (Lameyde Ridge).

La tendance à utiliser le filet maillant est confirmée, tous les navires INN observés semblent utiliser cette technique de pêche.

La présence de moyens de surveillance portant les marques de la CCAMLR ne semble pas suffisante pour dissuader totalement les navires INN de poursuivre leurs activités. Cependant les éléments observés ces derniers mois montrent un net ralentissement des activités INN.

Se ha comprobado ya el cambio climático en la Antártida a nivel regional, notablemente, en la región de la Península Antártica.  Una de las manifestaciones más evidentes del cambio climático ha sido el colapso de las barreras de hielo; en total, se ha observado el retroceso de un 87% de los glaciares de la Península en las últimas décadas.  El colapso de la barrera de hielo originará la creación de nuevos hábitats marinos y la colonización biológica.  La colonización de estos hábitats podría simplemente incluir las especies de aguas contiguas a la barrera de hielo colapsada; no obstante, es posible que ocurran otros procesos más complejos ya que las aguas más cálidas pueden crear oportunidades para el retorno de las especies que estuvieron presente durante el último período interglacial, que fue más cálido que el período actual.  Además, la alteración en la dinámica del ecosistema podría permitir la introducción de especies exógenas a medida que el calentamiento del océano va eliminando las barreras fisiológicas que una vez aislaron al bentos antártico.  Ante la complejidad de las posibles interacciones y la necesidad de estudiar las mismas en ausencia de cualquier otra perturbación antropogénica, recomendamos que los lugares que se encuentran actualmente (esto es en 2010) bajo barreras de hielo en las Subáreas 48.1, 48.5 y 88.3 sean nombradas áreas marinas protegidas donde no se permita la pesca, y que a partir de ahora, los límites de estas áreas permanezcan fijos, aún si las barreras de hielo retrocedieran o se derrumbaran en el futuro.

Data on the main population of black petrel (Procellaria parkinsoni), which breeds on Great Barrier Island, were analysed. Three types of data were available. The most useful was abundance data, from which it was possible to infer that the population was probably increasing at a rate between 1.2% and 3.1% per year. Mark-recapture data were useful in estimating demographic parameters, like survival and breeding success, but contained little information on population growth rates. Fishery bycatch data from observers were too sparse and imprecise to be useful. The fact that the population is probably increasing shows that there is no evidence that fisheries currently pose a risk to this population. However, this does not imply that there is clear evidence that fisheries do not pose a risk to this population. The mean age of first breeding for black petrel is estimated to be 6.7 y. Before this, new adults spend an average of 1.2 y in the colony as pre-breeders, with only 3% skipping the pre-breeder phase. Of birds that appear in the study area as pre-breeders and survive to breed, only 68% do so in the study area. Once birds start breeding, their annual survival rate is 0.89, 80% breed each year, and of those, 77% are successful (i.e., produce a fledgling). Survival rates before the pre-breeder stage are not well determined because we can’t distinguish mortality from emigration (birds that breed in an area away from where they were hatched). Two recommendations for further monitoring of this population are: periodic repeats of the transect based abundance estimation last done in 2005 (to determine whether the population is increasing or declining); and the use of data loggers to improve our knowledge of the birds’ foraging range and thus help to identify fisheries that might be affecting this population. (New Zealand Aquatic Environment and Biodiversity Report, 51 (2010), ISSN 1176-9440)

Software is presented for the automated production of standardised image plots of spatially referenced data. While developed to satisfy the specific requirements of WG-FSA, the routines have been developed to be as generic as possible and may be useful for displaying a wide range of data. This software is submitted to be appraised by WG-SAM in the hope it may prove a useful tool within CCAMLR Working Groups for the display of spatially referenced data.

We report on progress towards developing a Minimum Realistic Model for investigating trophic relationships between Antarctic toothfish (Dissostichus mawsoni) and four groups of demersal fish in the Ross Sea, Antarctica. These demersal fish are known to form a part (in some cases a substantial part) of the diet of Antarctic toothfish of a size commonly taken by the Ross Sea fishery and are also taken as bycatch by the fishery: (1) macrourids (especially Whitson’s grenadier, Macrourus whitsoni); (2) icefish (especially Chionobathyscus dewitti); (3) deep sea cods (especially violet cod, Antimora rostrata); and (4) eel (moray) cods (Muraenolepsis spp.). Changes to the abundance of Antarctic toothfish due to fishing could affect these prey groups and the trophic relationship between these groups and toothfish. A Minimum Realistic Model is the most appropriate modeling approach to investigate what changes in the abundances of these four demersal fish prey/bycatch groups in the Ross Sea are possible, and what changes in the trophic relationships between Antarctic toothfish and these prey groups may occur. Feedback on the model is sought. Work on this model will continue through 2010 and 2011 and will be presented to CCAMLR in due course.

In 2008-2009 New Zealand developed an impact assessment framework to estimate the likely impacts of bottom longline fishing on vulnerable benthic invertebrate taxa, termed Vulnerable Marine Ecosystems (VMEs), consistent with the requirements of Conservation Measure 22-06 (Bottom fishing in the Convention area). The impact assessment framework was subsequently endorsed within CCAMLR for routine application by Members submitting notifications of their intent to participate in new or exploratory fisheries using bottom fishing gear (SC-CAMLR XXVIII, paragraph 4.247 v–vii), and was applied to estimate the cumulative historical bottom fishing footprint of all fisheries in the CCAMLR area. The Scientific Committee called for additional work to address remaining uncertainties about the nature and extent of bottom fishing impacts on potential VMEs (SC-CAMLR-XXVIII paragraph 4.251). The purpose of this paper is: i) to estimate impacts on VMEs per unit effort using a simulation approach with explicit incorporation of uncertainties in the input assumptions; ii) to examine the application of the impact assessment framework at different spatial scales, and implications for the validity of the underlying structural assumptions of the assessment framework; and iii) to express impact estimates in a spatially explicit manner with reference to areas of distinct environmental characteristics arising from a benthic bioregionalisation of the Ross Sea region (Sharp et al. 2010). We conclude that bottom fishing impacts on VME taxa in the Ross Sea are low.

An important management objective for CCAMLR in the high seas region of the Antarctic is to develop appropriate methods of monitoring and managing impacts of bottom fisheries on vulnerable marine ecosystems (VMEs). We describe a spatially explicit production model that can be used to investigate a range of simple scenarios for simulating the effect and management of benthic impacts from longline fishing effort. Simulations were carried out under a range of productivity assumptions, impact, and spatial scale, with and without management by areal closures. Further, the management action simulated considered a range of areal closure radii and bycatch trigger thresholds. We conclude that spatially explicit production models can provide a useful tool for the investigation of impacts of fishing effort on benthic organisms. They have the advantage that they are relatively simple to construct, run, and interpret. In general, the results of the simulations suggested that management action of areal closures in the Ross Sea region are likely to result in an improved outcome over scenarios where there was no management action, but that the size of effects under the plausible models was often very small. We also note that further work on these simulations are required — including investigating how changes in the distribution of future fishing may result in alternative impacts or how different assumptions of the underlying distributions of benthic organisms may influence the results. However, as the size of these impacts in the scenarios tested were small, we recommend that research be focused, at least in the short term, to provide observational or experimental data necessary to constrain important model parameters, to reduce uncertainty and provide more plausible scenarios.

Bathymetric data are currently used inter alia to define management boundaries, implement conservation measures, allocate catch among areas, estimate spatial impacts due to fishing, and inform ecosystem-based management through bioregionalisation. Several data sources for bathymetric data exist, and these sources improve with time through additional data collection and improved analytical methods. We developed an algorithm to summarize bathymetric point data (x,y,z) for the Ross Sea region to provide a transparent and citable method to derive standard summary statistics for use by CCAMLR. This is especially important because of the multinational use of such data. The method is applicable to the entire Southern Ocean, but is currently applied only to the Ross Sea region. We have obtained publically available bathymetric data, created a spatial database, and have developed scripts for defining polygons of user-specified bathymetric areas, calculating the areas of those polygons, and displaying them as contour maps. As data sources improve, this process can update the summary statistics as needed in a comparable and transparent manner.