CCAMLR

Cold seeps and hydrothermal vents can be detected by a number of oceanographic and geophysical techniques as well as the recovery of characteristic organisms. While the definitive identification of a seep or vent and its accompanying fauna is seldom unequivocal without significant effort. We suggest an approach to identifying associated VMEs in the CCAMLR region that uses the results of scientific surveys to identify confirmed features while documenting a series of criteria that can be used by fishing vessels to reduce the accidental disturbance of seep communities.

Implementing measures to avoid significant adverse impacts to vulnerable marine ecosystems (VMEs) requires a specific list of the taxa that are considered vulnerable. New Zealand identified an interim list of taxa to monitor in fishery bycatch in the Ross Sea as part of its 2008 benthic fisheries impact assessment. The rationale for including or excluding each taxonomic group is described relative to the group’s fragility, longevity, organism size, and spatial distribution. Additional considerations such as organism mobility, community diversity, endemism, taxonomic resolution and presence in fishery bycatch are also important considerations. Thirteen coarse-resolution taxonomic groups consistent with FAO guidelines are identified as vulnerable to bottom longline fishing activities in the Ross Sea region, including two indicator-only taxa.

Protecting vulnerable marine ecosystems (VMEs) from significant adverse impacts caused by fishing activities requires knowledge of the distribution of those communities relative to the fishing footprint. If high fish catch rates are associated with habitats where VMEs are found, impacts from fishing are more likely to occur than if VMEs are distributed randomly with respect to fishing locations. This study used the catch of VME indicator organisms reported during the 2008/09 Ross Sea longline fisheries to look for a correlation between fish catch rate and VME indicator organism catch rate on a set-specific basis. Analysis of the data available showed that vessel and longitude were significant factors in predicting the VME indicator organism catch rate. Toothfish catch, when forced into the model, showed a very weak (r2 = 0.02) but statistically significant relationship with VME indicator organism catch. With current data there is no functional relationship between toothfish catch and VME indicator organism catch.

This paper reviews, reanalyzes and contributes new data pertinent to understanding genetic connectivity in benthic invertebrates at differing spatial scales in Antarctica. This information is valuable for understanding the potential resilience of benthic communities under threat from bottom fishing. Genetic connectivity allows insight into the realized dispersal of organisms, i.e. the likelihood of new recruits arriving from surrounding areas. Despite the wide distribution patterns shown by many marine organisms in Antarctica, population genetics analyses indicate that benthic marine invertebrates rarely show connectivity across major regions. Even taxa that have long-lived larvae, and therefore great dispersal potential, show unexpected genetic structure. Breaks to gene flow are most likely facilitated by distance and deep-water barriers. A number of organisms exhibited genetic homogeneity within isolated island regions e.g. South Georgia, the South Orkneys, Bouvet Island. The exception to this was the Antarctic Peninsula, where the Bransfield Strait may represent a distinct region. If representative protected areas are created within areas known to house genetically distinct populations, conserving genetic diversity would be maximized. However, further thought must be given to protecting areas that might maintain genetic connectivity across major regions, which would essentially act as stepping-stones for gene flow. At present, the available data is very incomplete, and an understanding of the generality of these patterns is limited.

Analysis of VME data collected in 2008/09 by UK vessels and national and international observers onboard was carried out to explore evidence of VMEs in the Ross Sea. 2008/09 data corroborated areas in 88.1I, E and F identified in our previous analysis of data collected by observers on UK vessels between 2005 and 2007 on benthic taxa recovered from longlines. A new area was identified within 88.1K, not previously detected. A second objective was to determine whether a relationship could be established between VME Indicator Units and CPUE data collected in 2008/09, in order to understand better the meaning of our historical CPUE data. Although a positive (exponential) association was apparent between VME Indicator Units and CPUE (bits/1000 hooks), there were insufficient data at high levels of VME Indicator Units (corresponding with the levels at which notifications to the Secretariat were triggered) to determine a meaningful relationship beyond a suggestion that 5 VME Indicator units was approximately equivalent, on average, to 25 bits/1000 hooks. As expected, heavy large taxa (e.g. gorgonians) triggered 5 VME Indicator Units at lower CPUEs than 25 bits/1000 hooks, and small lighter taxa (e.g. hydrocorals) triggered VME Indicator Units at higher CPUEs. Accounting for different benthic taxa might improve the application of the VME Indicator Units as a means of highlighting potential VME risk areas.

Dense coral-sponge communities on the upper continental slope off George V Land have been identified as a Vulnerable Marine Ecosystem in the Antarctic. The challenge is now to understand their likely distribution. The CEAMARC survey of 2007/2008 found these communities at sites on the upper slope in depths of 570 – 950 m. Based on these results we propose some working hypotheses to explain their distribution. Icebergs scour to 500 m in this region and the lack of such disturbance is probably a factor allowing growth of rich benthic ecosystems. In addition, the richest communities are found in the heads of canyons. We suggest two possible oceanographic mechanisms linking abundant filter feeder communities and canyon heads. The canyons in which they occur receive descending plumes of Antarctic Bottom Water formed on the George V shelf and these water masses could entrain abundant food for the benthos. Maps of water properties measured during the Collaborative East Antarctic Marine Census (CEAMARC) survey provide some support for this idea. Another possibility is that the canyons harbouring rich benthos are those that cut the shelf break. Such canyons are known sites of high productivity in other areas because of a number of oceanographic factors, including strong current flow and increased mixing, and the abrupt, complex topography. These hypotheses provide a framework for the identification of areas where there is a higher likelihood of encountering these Vulnerable Marine Ecosystems.

The present paper describes trawl systems, discharges and systems for obtaining green weight of krill onboard the three Norwegian krill fishing vessels, Saga Sea, Juvel and Thorshøvdi