The NASS2015 surveys resulted in 21,277 nm of survey effort covering an area of approximately 1,200,000 nm2. Additional surveys are planned for summer 2016 in the Jan Mayen area, Norwegian Sea and coastal Iceland. The analyses of cetacean distribution and abundance are ongoing and will be available in fall 2016.
This map shows the surveyed tracks during NASS2015.
Planning for the NASS2015 started in 2011. The following are excerpts from the survey proposal.
The specific objectives for NASS 2015 are:
To obtain unbiased abundance estimates of
i) pilot whales around Faroe Islands useful for assessing the sustainability of the hunt
ii) minke whales in West Greenland, around Iceland, Jan Mayen and Svalbard and the central Norwegian sea
iii) fin whales southwest of Iceland
1. The survey will be focused on abundance estimates from areas and species that are important for providing robust abundance estimates useful for management
2. The following species are identified as primary target species: long-finned pilot whales, minke whales and fin whales. It is, however, assumed that the survey will also provide robust estimates of humpback whales, sei whales and to some extent also smaller cetaceans.
3. It should be attempted to include Canada and Russia and neighboring countries in surveying parts of the Atlantic to extend the coverage
4. The survey is planned for 2015 to ensure sufficient time for preparations
The geographical extent of the planned survey is shown in Figure 1. In addition to areas covered in the past the following new areas were considered of primary importance for a NASS 2015 survey:
1. The East Greenland shelf from Kap Farvel to about 80° N where significant numbers of baleen whales have been detected by platforms of opportunity in recent years;
2. The area between Iceland and Jan Mayen is important for minke whales and could be the sink for minke whales not encountered in recent surveys in Iceland. It will not likely be included in the Norwegian mosaic surveys in 2015 and should be surveyed in NASS2015 to ensure a coherent coverage with coastal Icelandic and East Greenland surveys;
3. Intensified survey coverage will be established around the Faroe Islands based on ‘home range’ information from ongoing satellite tracking experiments of pilot whales instrumented on the Faroe Islands.
Areas of secondary importance that would be important to include if options appear for including survey effort by neighboring countries (i.e. Canada and Russia):
1. The offshore areas between the Labrador coast and the shelf areas of West Greenland that has not been surveyed in the past;
2. Areas south of the Irminger Sea and generally south of 55° N where sei whales and pilot whales occur;
3. Areas north of 70° N in West Greenland where recent catches of minke whales have been taken;
4. Areas between east Iceland and Norway depending on the Norwegian mosaic survey effort;
5. Areas in the northeast Barents Sea, Pechora Sea where Russian surveys have indicated increased presence of cetaceans.
Proper coverage of all areas of primary importance will ensure that unbiased estimates are obtained. The use of double-platforms will further reduce the bias of the estimates. Both approaches are critical for achieving a survey that will be of long-term value for the management of whales in this area. Coverage of areas of secondary importance will, depending on the applied survey methods, provide additional abundance estimates and data on distributional changes. Combined, such a large-scale survey will be able to detect major shifts in abundance caused by ongoing climatic perturbations in the North Atlantic. Finally the survey will provide critically important information on several of non-target species and provide abundance estimates for some of those.
An example of how the results of the survey will be fundamental to the interpretation of observed changes in abundance is the minke whales around Iceland. A significant decline in abundance in coastal areas of Iceland was detected in the T-NASS 2007 survey compared with previous surveys. However, critical areas north of Iceland and along the East Greenland coast were not included in the survey effort in T-NASS 2007. It is therefore impossible to say if the decline represents a catastrophic drop in population abundance or if it constitutes a shift in occurrence, perhaps in response to oceanographic changes. In the survey planned for 2015 all areas will be covered and major shifts in abundance should be detectable.
The primary areas of focus for the 2015 survey extend about 1,740,000 nmi² (Fig. 1).
Figure 1. Extension of the TNASS 2015 and associated surveys. The size of the areas is estimated to be 235.529 km² for Northeast Greenland, 726044 km² for the Jan Mayen area, 2860193 km² for the Iceland area, 934722 km² for the Norwegian area, ~768235 km² for the Faroe Island area, 233659 km² for the East Greenland area and 225285 km² for West Greenland.
Individual NAMMCO member countries plan to conduct national surveys in 2015 and these are generally planned to be similar to those of the T-NASS 2007 survey.
Greenland will conduct an aerial survey of West Greenland shelf area from Kap Farvel to Uummannaq in August–September 2015. No ship surveys are planned because of lack suitable survey ships and unfavorable weather conditions that require large effort during small windows of good survey conditions. Greenlandic scientists will ensure analysis and presentation of the survey results.
Norway conducts a series of mosaic surveys covering different part of the North Atlantic each year. According to the schedule of the mosaic surveys Norway will cover the central Norwegian Sea. Analysis and presentation of results are also covered by Norway.
Faroe Islands will provide a survey platform that will cover the areas traditionally covered by the Faroe Island, so that trends in abundance in reference areas can be followed.
Iceland will provide 2–3 survey platforms that will cover the areas traditionally covered by Iceland (see Fig.1) and Icelandic scientists will participate in survey design, survey execution and analysis and presentation of results.
In 2015, Norway surveyed the Norwegian Sea and part of the Jan Mayen area by ship. These areas will also be re-surveyed in 2016 to ensure full coverage of both areas. The abundance estimates generated by these surveys will be combined with the estimates from the other Norwegian 'mosaic' surveys to get an estimate for the total areas that are surveyed by the Norwegians.
The survey was conducted on the vessel Fisktrans, and took take place from 22 June to 30 August.
The Norwegian survey was carried out on the Fisktrans.
The survey design for the Icelandic aerial survey in 2015. The red lines indicate the planned transects.
The aerial survey was conducted on board a Partenavia, and focussed on coastal areas. The observers used a newly-constructed device to help measure accurate angles, which is important for calculating the density of whales on the survey area.
|Observers on the Icelandic aerial surveys headed out for a day of counting whales. Photos: Dan Pike|
|Dan Pike using the new geometer to record angle measurements to the sightings of whales.|
The Icelandic ship-based surveys were conducted on two ships sailing at about the same time.
R/V Árni Fridriksson
This research vessel conducted a combined cetacean and fisheries (redfish and mackerel) survey from 10 June - 8 August 2015, with just a few days off during that time.
|R/V Árni Fridriksson. Photo: Marine Research Institute, Iceland|
R/V Bjarni Saemundsson
The R/V Bjarni Saemundsson surveyed for cetaceans from 9 June until 26 July 2015, with only 4 days break.
|R/V Bjarni Saemundsson. Photo: Jon Pall Asgeirsson
The ship-based survey began in early July 2015 on the vessel Høglkettur, and continued until early August. The focus of this survey was counting pilot whales, but all marine mammals were be documented.
An important part of the pilot whale abundance estimate is getting accurate group size estimates. It can often be difficult to see how many whales are in a group from the vantage point of the ship. To help out with this problem, in 2015 the Faroes survey used a drone to fly over groups of whales that they encountered and took aerial video of the group. Researchers will then use this video to see how many whales were in the group and compare this to how many the observers said was in the group.
The vessel Høglkettur, which was used for the survey in the Faroe Islands.
The survey team also towed a hydrophone to record any vocalizations.
The Greenlandic aerial surveys were conducted during August and September 2015 using a Twin Otter aircraft.