CCAMLR

Predictionofspecies’distributionsiscentraltodiverseapplicationsinecology,evolutionandconservationscience.Thereisincreasingelectronicaccesstovastsetsofoccurrencerecordsinmuseumsandherbaria,yetlittleeffectiveguidanceonhowbesttousethisinformationinthecontextofnumerousapproachesformodellingdistributions.Tomeetthisneed,wecompared16modellingmethodsover226speciesfrom6regionsoftheworld,creatingthemostcomprehensivesetofmodelcomparisonstodate.Weusedpresence-onlydatatofitmodels,andindependentpresence-absencedatatoevaluatethepredictions.Alongwithwell-establishedmodellingmethodssuchasgeneralisedadditivemodelsandGARPandBIOCLIM,weexploredmethodsthateitherhavebeendevelopedrecentlyorhaverarelybeenappliedtomodellingspecies’distributions.Theseincludemachine-learningmethodsandcommunitymodels,bothofwhichhavefeaturesthatmaymakethemparticularlywellsuitedtonoisyorsparseinformation,asistypicalofspecies’occurrencedata.Presence-onlydatawereeffectiveformodellingspecies’distributionsformanyspeciesandregions.Thenovelmethodsconsistentlyoutperformedmoreestablishedmethods.Theresultsofouranalysisarepromisingfortheuseofdatafrommuseumsandherbaria,especiallyasmethodssuitedtothenoiseinherentinsuchdataimprove.

Australia has developed the “Field identification guide to Heard Island and McDonald Island (HIMI) benthic invertebrates: a guide for scientific observers aboard fishing vessels”. This Fisheries Research and Development Corporation (FRDC), Australian Fisheries Management Authority (AFMA) and industry funded production is first of its kind for the region, and is intended to be used as both a training tool prior to deployment at-sea, as well as for use by trained observers to make accurate identifications of invertebrate by-catch when operating in the HIMI region. Based on available data, this publication will include instructions to observers for collection of benthic organisms at sea, quick-reference pictorial guides to invertebrate phyla, common species and CCAMLR identification codes, and detailed identification notes for each phylum including representative images for more than 400 benthic organisms identified from the HIMI region thus far. This guide will enable observers to gather invertebrate by-catch data at higher taxonomic resolutions.

Following on from earlier analyses presented to WG-EMM, meta-analyses of life-history characteristics and their relationships with physical and chemical variables were undertaken for habitat-forming invertebrates other than cnidarians. Particular focus was placed on bryozoans and sponges which are known to form important biogenic habitat in the Southern Ocean. Data were extracted from a global database of life-history characteristics. Bryozoans showed a strong negative relationship between growth rate and age and a strong positive relationship between growth rate and temperature. A multiple regression model suggests that Southern Ocean bryozoans may take more than 50 years to recover following disturbance. Demosponges showed a strong positive relationship between maximum size and age while there were too few data for glass sponges for robust analysis. Most sponges from the Antarctic showed no or very slow growth over considerable periods and it is hypothesised that they will take many decades or even centuries to recover from disturbance particular in areas where natural disturbance is low.

A global database of life-history characteristics, including growth rate, age, maximum size and reproductive parameters, was established for benthic, habitat-forming taxa and associated physical and chemical variables, including depth, temperature, oxygen concentration, salinity and nutrients. The metadata fields are described. At present more than 850 records representing more than 650 taxa from 29 higher taxonomic groups have been incorporated into the database. The database can be used to investigate relationships between and among life-history characteristics and habitat variables. Members are encouraged to contribute additional data and collaborate with analyses.

Publicly available bathymetry and geophysical data can be used to map geomorphic features of the Antarctic continental margin and adjoining ocean basins at scales of 1:1-5 million. These data can also be used to map likely locations for some Vulnerable Marine Ecosystems. Seamounts over a certain size are readily identified and submarine canyons and mid ocean ridge central valleys which harbour hydrothermal vents can be located. Geomorphic features and their properties can be related to major habitat characteristics such as sea floor type (hard versus soft), ice keel scouring, sediment deposition or erosion and current regimes. Where more detailed data are available, shelf geomorphology can be shown to provide a guide to the distribution in the area of the shelf benthic communities recognised by Gutt (2007). The geomorphic mapping method presented here provides a layer to add to benthic bioregionalistion using readily available data.

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.