Guzman, H. Gomez, C. Guevara, C. Kleivane, L. Potential vessel collisions with Southern Hemisphere humpback whales wintering off Pacific Panama. Marine Mammal Science. Volume 29, Issue 4 629- 642, October 2013.
Vessel and Whale collisions are a common occurrence throughout the world’s oceans. There are many reports of baleen whales being hit or struck by vessels. This has increased more and more due to globalization as well as the immense amount of shipping that happens in all oceans. In Central America, both the northern and the southern hemisphere Humpback whales (Megaptera novaeangliae) migrate to the Pacific Panama, warm waters for the winter to mate.
This study was to evaluate the potential for collisions between vessels and humpback whales wintering off Pacific Panama by following movements of 15 individual whales using tagging with satellite transmitters and comparing the data to commercial vessel track data using the global Automatic Identification System (AIS). The type of data needed to answer this question was individual tracks of whales and vessels in the same region. Real time satellite transmitters and tags were used. The tags were speared into the area 2-5inches away from the back of the dorsal fin. The AIS data that was used provided ship to ship and ship to shore information including name and type of vessel, position, hour, dimensions, speed, heading etc.
Data processing and analysis was primarily taking the AIS data and using ArcGIS 10.0 to display the interactions of whales and vessels by defining time or day. Whale transmissions were processed using Satellite Tracking and Analysis Tool (STAT), which helped filter and edit locations and organize data into different categories of interest (bathymetry, transmission quality, speed and distances).
The use of tagging on animals is always a tricky one because in order to place a tag there is much human disturbance and a concern that the tagging itself will harm the individual whale. However, the information that is able to be collected is so important to the understanding of whales and the way that they live their lives. The use of a tag for spatial data is a fantastic idea and so is using the AIS system that is already in place and collecting all that data anyways. I think that the data collection processes were sufficient and it is always fun to see ArcGIS being used in a paper and Redlands being cited. The overlaying of the tracks of the vessels and the whales by time is very useful and would help give a great picture about the importance of reduced speeds and increased awareness that is needed in these waters all the time but especially in breeding season.