T-NASS Status Report December 2007
Dedicated cetacean shipboard sigthings surveys were conducted from 7 vessels (1 Faroese, 3 Icelandic, 2 Norwegian) from June 25 to August 6, 2007 while dedicated aerial survey were conducted from 5 planes (3 Canadian, 1 Greenlandic, 1 Icelandic) between June 20 and October 1, 2007 with a total a total of 79 observer positions. In addition, ten observers were placed on fishery surveys occurring simultaneously to TNASS in adjacent areas, the ICES Redfish survey in the Irminger Sea (one Russian and one German vessels), MarEco survey on the Mid Atlantic Ridge (one UK vessel) and Norwegian Pelagic survey in the Norwegian sea (two Norwegian vessels). Russia participated also by sending observers both to the shipboard and the shipboard extension survey.
Line transect methods and/or cue counting, when possible with a double platform setup, were used to collect visual data. Passive acoustic data were also collected from five of the vessels (the three Icelandic, the Faroese and the MarEco vessels), with emphasis on recording of sperm whale acoustic signals.
For the first time, a trans North Atlantic survey was achieved, adding to the NASS area, areas to the west of Greenland and the eastern coast of Canada. The 12 platforms of the core survey covered over 54.000 nm of transects in effort in an area of about 1.8 mill. sq.nm, spanning from the Eastern Barents Sea to the East coast of Canada and from 78ºN in the north to 52ºN in the east and 42ºN in the west to the south. This represents the largest coordinated whale survey today. TNASS observers placed on opportunistic surveys (MarEco, ICES Redfish and Norwegian pelagic) added a supplementary effort of 5,253 nm, in the Irminger Sea, the Norwegian Sea and the Mid Atlantic Ridge.
Cetacean encounters numbered in total over 3.000 with an apparent variation in frequency between blocks and areas. Nineteen cetacean species were observed, with overall fin whale, common minke whale, humpback whale, white beaked dolphin and harbour porpoise as the preliminary top five species in numbers of sightings. Other marine megafauna like seals and large shark and fish species were also recorded. The only bird survey conducted in coordination with T-NASS was carried out from the MarEco vessel.
T-NASS was coordinated in timing, coverage (spatial contiguity) and methodology both with the European CODA survey (Cetacean Offshore Distribution and Abundance in the European Atlantic, coordinated by the Sea Mammal Research Unit, University of St. Andrews), and the American SNESSA survey (Southern New England to Scotian Shelf Abundance survey, coordinated by the National Marine Fisheries Service, NMFS, Woods Hole), conducted respectively to the South East and South West of the TNASS core area. The coordinators of CODA and SNESSA are members of the T-NASS Planning Committee, which will also coordinate and supervise the analysis of the data. The Scientific Committee of the International Whaling Commission endorsed T-NASS at its 2006 meeting and plays an advisory role to the project. T-NASS is a component project of the International Polar Year (#1136), as a sub-project of the umbrella project ESSAR - Ecosystem Studies of Sub-Arctic and Arctic Regions (#155).
The present status of the project is data entering and validation, and analysis is started for some areas and species. Abundance estimates will first be calculated from the data collected using standard line transect method, followed by double platform analysis when data is sufficient and later spatial modelling. Assessment of trends will be done by comparison with the earlier NASS surveys. A coordination and co-operation is planned with CODA and SNESSA, especially in terms of spatial modelling. The next T-NASS meeting is planned for April 2008, previous to the NAMMCO Scientific Committee Meeting, so T-NASS results can be presented there.
Line transect methods and/or cue counting, when possible with a double platform setup, were used to collect visual data. Passive acoustic data were also collected from five of the vessels (the three Icelandic, the Faroese and the MarEco vessels), with emphasis on recording of sperm whale acoustic signals.
For the first time, a trans North Atlantic survey was achieved, adding to the NASS area, areas to the west of Greenland and the eastern coast of Canada. The 12 platforms of the core survey covered over 54.000 nm of transects in effort in an area of about 1.8 mill. sq.nm, spanning from the Eastern Barents Sea to the East coast of Canada and from 78ºN in the north to 52ºN in the east and 42ºN in the west to the south. This represents the largest coordinated whale survey today. TNASS observers placed on opportunistic surveys (MarEco, ICES Redfish and Norwegian pelagic) added a supplementary effort of 5,253 nm, in the Irminger Sea, the Norwegian Sea and the Mid Atlantic Ridge.
Cetacean encounters numbered in total over 3.000 with an apparent variation in frequency between blocks and areas. Nineteen cetacean species were observed, with overall fin whale, common minke whale, humpback whale, white beaked dolphin and harbour porpoise as the preliminary top five species in numbers of sightings. Other marine megafauna like seals and large shark and fish species were also recorded. The only bird survey conducted in coordination with T-NASS was carried out from the MarEco vessel.
T-NASS was coordinated in timing, coverage (spatial contiguity) and methodology both with the European CODA survey (Cetacean Offshore Distribution and Abundance in the European Atlantic, coordinated by the Sea Mammal Research Unit, University of St. Andrews), and the American SNESSA survey (Southern New England to Scotian Shelf Abundance survey, coordinated by the National Marine Fisheries Service, NMFS, Woods Hole), conducted respectively to the South East and South West of the TNASS core area. The coordinators of CODA and SNESSA are members of the T-NASS Planning Committee, which will also coordinate and supervise the analysis of the data. The Scientific Committee of the International Whaling Commission endorsed T-NASS at its 2006 meeting and plays an advisory role to the project. T-NASS is a component project of the International Polar Year (#1136), as a sub-project of the umbrella project ESSAR - Ecosystem Studies of Sub-Arctic and Arctic Regions (#155).
The present status of the project is data entering and validation, and analysis is started for some areas and species. Abundance estimates will first be calculated from the data collected using standard line transect method, followed by double platform analysis when data is sufficient and later spatial modelling. Assessment of trends will be done by comparison with the earlier NASS surveys. A coordination and co-operation is planned with CODA and SNESSA, especially in terms of spatial modelling. The next T-NASS meeting is planned for April 2008, previous to the NAMMCO Scientific Committee Meeting, so T-NASS results can be presented there.
