CCAMLR

Understanding the relative contributions of different sources of mortality and survival in predator populations can improve ecosystem models and management of marine ecosystems.  Within the Antarctic bottom-up processes are widely cited for explaining penguin population declines, whereas for Antarctic fur seals, top-down processes are most cited as the primary driver for declining pup production.  This has led to an under emphasis of the role of bottom-up drivers for controlling fur seal production within the system.  We review the historical data in Antarctic pup production and provide annual pup production estimates from 2002-2012 for Cape Shirreff, Livingston Island.  Age-specific natality rates are provided as an indicator of bottom-up drivers and we contrast these with early season neonate mortality and leopard seal predation rates.  Fur seal pup production has undergone a dramatic declines in the last decade (12.1% per annum since 2002).  Since 1998, natality rate has also declined 14%, largely driven by poor recruitment and an aging population.  However, age-specific natality rate has also declined.  Predation rate has increased 4% per year since 2002.  We discuss the relative roles of bottom-up and top-down contributions to the decline in fur seals.      

Research during the last decade has revealed much about the early life history of Pleuragramm antarcticum, including confirmation of the first known nursery ground in Terra Nova Bay. However, there is still much unknown about larval fish distribution in the Ross Sea, Antarctica. During a United States National Science Foundation research cruise in the late austral summer 2013, we opportunistically sampled the icthyoplankton community at 17 locations in the western Ross Sea as well as one location in the central Ross Sea and one location in the far south of the eastern Ross Sea (in the Bay of Whales). Larval P. antarcticum made up more than 99% of the icthyoplankton in the western Ross Sea. Most of these fish had hatched during the current season. Length data from these fish obtained over the course of the cruise supports growth rates and hatching times consistent with reported hatching events in Terra Nova Bay. The most numerous abundances (3400+ in each tow) of larval P. antarcticum were found along the ice margin in the western Ross Sea, further suggesting the importance of sea ice to this species. Finally, a unique tow in the Bay of Whales revealed recently hatched P. antarcticum in mid-March, suggesting the presence of a potential eastern Ross Sea nursery ground. This late hatching period may be explained by latitudinal, climatic and oceanographic variations in this region.  

Three different trawls were used to sample Antarctic krill for the determination of demographic and abundance patterns around the South Shetland Islands during Austral summer 2014. A 60cm BONGO net (333 and 505 µm mesh), a 1.8m IKMT (505 µm mesh); and a pelagic ENGEL trawl (594m² mouth area, 10mm cod end liner) were used and their selectivities are compared. Despite very different apparent selectivities, length frequency distributions were generally similar. Median lengths based upon Empirical Distribution Functions (EDFs) for the three gears varied over about 7mm, with the BONGO net catching the largest range of krill (15mm to 60mm), while the ENGEL trawl captured the narrowest (27 to 61), and the size was shifted to larger animals. These differences suggest that tradeoffs between gear size and number of tows should be considered when designing fishery based sampling to augment research surveys using fishing vessels if research gear cannot be accommodated. The patterns of krill length frequency showed that krill collected in Bransfield Strait and Elephant Island areas of the South Shetlands in summer 2014 were about 42 mm in length (3yrs old), and few small (<25mm) krill (1 year old) were captured. The majority of krill were mature and in spawning condition.

As requested by CM 21-03, Annex 21-03/A, attached are the net diagrams and mammal exclusion devices included in the krill fishery notification submitted by China

Progressing from Stage 1 to Stage 2 of a feedback management strategy requires a better understanding of spatial overlap between predators and fishing activity. We provide estimates of the spatial overlap in Area 48, with particular emphasis on Subarea 48.1. We used habitat utilization data for penguins (Adélie, chinstrap, and gentoo) and pinnipeds (Antarctic fur seals, Weddell seals, and leopard seals) based on data from satellite and light-based geolocation tracking studies.  Catch data were restricted to the last 5 years, since this time period emphasizes the shift toward autumn and winter fishing in Subarea 48.1. In general, overlap of summer and winter foraging habitats with krill catches in Subarea 48.1 was observed for all predators. Overlap was highest for predators that used coastal SSMUs during the winter period, especially in the Bransfield Strait. Across years, predator distributions appeared to be more stationary and did not respond as rapidly (or on as large a scale) to conditions that might affect the distribution of fishing effort.  A comparison of CEMP parameters from two years with large differences in total catch in Subarea 48.1 suggests plausible local impacts on gentoo penguin recruitment and reproductive investment. We note that such impacts arose when CM-51-07 was invoked to close the fishery and that 55% (85,000 tonnes) of the allocation to Subarea 48.1 (155,000 tonnes) was taken from a single SSMU. We propose that 85,000 tonnes, based on observed overlap and likely impacts of such concentrated catch on predators, represents a useful upper limit for subdivision of catch among SSMUs and that a Subarea limit of 155,000 tonnes provides a catch consistent with the objectives of Article II of the Convention.

This is a companion paper to Kinzey et al. (2014), who extended the integrated stock-assessment framework for Antarctic krill (Euphausia superba) to assimilate multiple sources of survey data and estimate krill growth.  Kinzey et al. (2014) fitted stock-assessment models to survey data that were pooled at annual, seasonal, and monthly time scales.  The data were from research cruises conducted by Germany (RMT8 net samples from 1981 to 1989), the U.S. AMLR Program (IKMT net samples from 1992 to 2013 and acoustic biomass estimates from 1996 to 2011) and Peru (IKMT samples from 2014).  Results from three of the models provide a robust picture of changes in the krill population.  An annual model fitted to IKMT data collected during the austral summer and another annual model fitted to data from all surveys estimated similar absolute biomasses and changes in biomass.  A seasonal model estimated similar changes in biomass but lower absolute biomasses than the two annual models.  A monthly model estimated different changes in biomass but predicted absolute biomasses that were similar to those from the seasonal model.  All four models fitted the observed data reasonably well, but the monthly model failed basic simulation testing.  Together, results from the two annual models and the seasonal model suggest that inter-annual variations in cohort strength have dominated krill dynamics in Subarea 48.1.  Long-term trends (either decreasing or increasing) in krill biomass have not been apparent over the past 30+ years.  Differences in scaling of biomass estimates between the annual models and the more highly resolved models suggest substantial uncertainty in absolute abundance.  Management strategies that are based on absolute estimates of biomass (rather than relative estimates of biomass) may therefore be biased, possibly leading to harvests that are inconsistent with the objectives of the Convention.  We propose that WG-EMM consider how the integrated assessment framework can be used to provide management advice for the krill fishery.

In accordance with CM 21-03, Annex 21-03 A, attached are the net diagrams and mammal exclusion device diagrams referred to in the krill fishery notifications for 2014/15 submitted for the three Norwegian vessels (Juvel, Saga Sea and Antarctic Sea).

Records of 14 trematode species, collected from bottom fishes from the western and northern parts of the Ross Sea, are given. Trematodes Otodistomum cestoides van Beneden, 1871, Lecithaster micropsi Zdzitowiecki, 1992, Neolepidapedon trematomi Prudhoe et Bray, 1973, Postlepidapedon opisthobifurcatum Zdzitowiecki, 1990, Discoverytrema gibsoni Zdzitowiecki, 1990, D. markowskii Gibson, 1976, Macvicaria muraenolepidis Zdzitowiecki, 1990, Helicometra rakusai Zdzitowiecki, 1997 and Proctophantastes sp. are recorded from the Ross Sea for the first time. Proctophantastes sp. differs from other species of Proctophantastes Odhner, 1911 by the morphology of the ventral equatorial ridge of the ventral sucker.

The South Orkney Islands Southern Shelf Marine Protected Area was established by CCAMLR in 2009 (CCAMLR-XXVIII paragraph 7.1; CM 91-03) with the objective of contributing towards the conservation of biodiversity in Subarea 48.2, and to the development of a representative system of protected areas across the Convention Area. At the time of its adoption, the Commission agreed to review CM 91-03, based on advice from the Scientific Committee, at its regular meeting in 2014 and at subsequent five-year periods (CM 91-03, paragraph 9). Based on assessments described in the draft MPA Report and draft MPA Research and Monitoring Plan submitted to this Working Group (WG-EMM-14/xx and WG-EMM-14/xx), we suggest that the grounds for protection of the South Orkney Islands Southern Shelf as described in CM 91-03 remain the same as at the time of its designation. We therefore suggest that there is no requirement for new management or administrative measures at this time, or for any changes to the existing measures specified in CM 91-03.

The South Orkney Islands Southern Shelf Marine Protected Area (SOISS MPA) was established by CCAMLR in 2009 (CCAMLR-XXVIII paragraph 7.1; CM 91-03), with the objective of contributing towards the conservation of biodiversity in Subarea 48.2, and to the development of a representative system of protected areas across the Convention Area. In 2013, a preliminary draft MPA Report was developed for the SOISS MPA (WG-EMM-13/10), based on the report structure proposed in WG-EMM-12/49. The Working Group recommended that WG-EMM-13/10 should be revised to form three separate documents (WG-EMM-13 paragraph 3.22):

i)    Management Plan

ii)    Research and Monitoring Plan

iii)   MPA Report

This draft MPA Report contains: a description of the region (including evidence used to designate the MPA); details of regional and specific MPA objectives; results of research and monitoring undertaken since designation of the MPA; requirements for new research and monitoring; a summary of activities undertaken within the MPA; an assessment of the achievement of MPA objectives, and an assessment of the impact of activities on the MPA, including analysis of current and potential threats.

It has been agreed that WG-EMM would be the appropriate working group with primary responsibility with respect to reviewing and updating the content of MPA reports (SC-CAMLR-XXXI paragraph 5.34). We have therefore developed this draft MPA Report for consideration by the Working Group, and would welcome discussion and feedback on its structure and content.