Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New survey techniques improve narwhal population estimates

08.04.2010
New aerial survey techniques lead to increased narwhal estimates

Improvements in aerial survey methods have led to increased estimates of narwhal populations in the eastern Arctic, according to a paper published Arctic, the journal of the University of Calgary's Arctic Institute of North America.

Previous estimates of narwhals were based on surface counts and covered part of their eastern Arctic summering range. They placed populations between 20,000 and 30,000. New estimates increase that number to over 60,000, says Pierre Richard, lead author and research scientist with the Canada's Department of Fisheries and Oceans.

Counting marine animals is notoriously difficult. "It's not like you're counting your cows as they are going through the gate," says Richard, who developed the survey techniques with a team of scientists from Canada, the U.S. and Greenland.

Not only are observers traveling in aircraft flying at 180 kilometers an hour, they also have to contend with inclement weather conditions which can hinder visibility. "The weather can turn on a dime and you are often waiting for the sweet spot between foggy conditions and high winds," he says.

In addition, many animals are submerged. Narwhals are renowned for their deep diving abilities. In the winter, they dive to depths of two kilometers and they can remain submerged for up to 25 minutes. "Only one-third of their time is spent at the surface," says Richard.

There is also the problem of narwhal sighting distance. "The further the animal is away from the observer, the less likely you are to observe it," says Richard. At other times, whale sightings are coming "so fast and furious" it is difficult to count them accurately.

Richard and his colleagues developed two new approaches to correct for some of these biases. Using dive data acquired from instrumented animals, they developed a method for estimating how many narwhals are submerged. They also created a process to estimate the proportion of animals that observers might have missed, even if they were at the surface.

The surveys, which were conducted in August between 2002 and 2004, also covered new territory. Narwhals summer in the High Arctic archipelago and northern Hudson Bay and winter in Baffin Bay and Davis Strait. Previous surveys had not covered all of their summering range. Richard and his colleagues extended data collection into the Gulf of Boothia and the east coast of Baffin Island. They were planning to fly over other areas, but were stopped by weather.

An accurate picture of narwhal populations is needed to set sustainable hunting quotas. Richard says that while his survey results show the narwhal population is larger than previously thought, management of the population should be exercised with caution. Survey results can be imprecise and there appear to be local stocks of narwhals that return each summer to specific areas within their range. This site fidelity suggests that stocks of narwhal occupying different summering areas should be managed separately, and that management of a stock should be based on the summer estimate of narwhals for that area only.

Richard's team will be waiting out weather again in 2010 to conduct further studies. This time, they hope to conduct newly designed surveys of Admiralty Inlet – if weather permits. During previous surveys, the area had been beleaguered by bad weather and sampling problems that put the accuracy of the area's narwhal estimate in question.

For media interviews with Pierre Richard contact:

Ruth Klinkhammer, Director of Communications, Arctic Institute of North America Tel: 403 220-7294, Email: r.klinkhammer@ucalgary.ca

This media release is part of the Promotion of Arctic Science, an Arctic Institute of North America project made possible with the generous support of the Government of Canada Program for International Polar Year. The mission of the Arctic Institute of North America at the University of Calgary is to advance the study of the North American and circumpolar Arctic and to acquire, preserve and disseminate information on physical, environmental and social conditions in the North. More information can be found at www.arctic.ucalgary.ca

Ruth Klinkhammer | EurekAlert!
Further information:
http://www.ucalgary.ca
http://www.arctic.ucalgary.ca

Further reports about: Arctic marine animals narwhal population

More articles from Ecology, The Environment and Conservation:

nachricht Joint research project on wastewater for reuse examines pond system in Namibia
19.12.2016 | Technische Universität Darmstadt

nachricht Scientists produce a new roadmap for guiding development & conservation in the Amazon
09.12.2016 | Wildlife Conservation Society

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Water - as the underlying driver of the Earth’s carbon cycle

17.01.2017 | Earth Sciences

Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

17.01.2017 | Materials Sciences

Smart homes will “LISTEN” to your voice

17.01.2017 | Architecture and Construction

VideoLinks
B2B-VideoLinks
More VideoLinks >>>