[MARMAM] FW: New publication: Abundance and distribution of sperm whales in the Canary Islands: Can sperm whales in the Archipelago sustain the current level of ship-strike mortality?

andrea fais andreika3 at hotmail.com
Tue Apr 5 08:23:08 PDT 2016








Dear colleagues,
we are pleased to announce the publication of the following article:
Abundance and distribution of sperm whales in the Canary Islands: Can sperm whales in the Archipelago sustain the current level of ship-strike mortality? 
Authors: Andrea Fais, Tim P. Lewis, Daniel P. Zitterbart, OmarÁlvarez, Ana Tejedor, Natacha Aguilar Soto
Abstract:Sperm
whales are present in the Canary Islands year-round, suggesting that the
archipelago is an important area for this species in the North
 Atlantic. However, the area experiences one of the highest
reported rates of sperm whale ship-strike in the world. Here we investigate if
the number of sperm whales found in the archipelago can sustain the current
rate of ship-strike mortality. The results of this study may also have implications
for offshore areas where concentrations of sperm whales may coincide with high
densities of ship traffic, but where ship-strikes may be undocumented. The
absolute abundance of sperm whales in an area of 52933 km², covering the
territorial waters of the Canary Islands, was estimated from 2668 km of
acoustic line-transect survey using Distance sampling analysis. Data on sperm
whale diving and acoustic behaviour, obtained from bio-logging, were used to
calculate g(0)=0.92, this is less than one because of occasional extended
periods when whales do not echolocate. This resulted in an absolute abundance
estimate of 224 sperm whales (95% log-normal CI 120-418) within the survey
area. The recruitment capability of this number of whales, some 2.5 whales per
year, is likely to be exceeded by the current ship-strike mortality rate.
Furthermore, we found areas of higher whale density within the archipelago,
many coincident with those previously described, suggesting that these are
important habitats for females and immature animals inhabiting the archipelago.
Some of these areas are crossed by active shipping lanes increasing the risk of
ship-strikes. Given the philopatry in female sperm whales, replacement of
impacted whales might be limited. Therefore, the application of mitigation
measures to reduce the ship-strike mortality rate seems essential for the
conservation of sperm whales in the Canary Islands. 
The article is available at : http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0150660
On behalf of the authors, Andrea Fais: 		 	   		  
 		 	   		   		 	   		  
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.uvic.ca/pipermail/marmam/attachments/20160405/696802b0/attachment.html>


More information about the MARMAM mailing list