While most of our work focuses on acoustic data to learn about the movement, distribution and population of harbor porpoises, I want to emphasize that we are not just dealing with numbers. These are curious, playful creatures with personality.
My talk will describe our research and findings. I will describe how our instruments work and explain about the high frequencies at which the porpoise echolocates. I will also share some of my experiences working closely with the rescued porpoises at Vancouver Aquarium.
I am grateful to the Vancouver Aquarium for letting me spend time at their facility recording the echolocations of their two rescued harbor porpoises. In this time, I found these porpoises would tease and play with me. After such an experience one could never go back to impersonally cataloging their characteristics.
The Harbor Porpoise Project was initiated in 2009 following my identification of instruments and techniques that could be used to monitor harbor porpoises, a species that state agencies found too difficult to monitor. Since that time the instruments have been tested, used and proven to be effective.
Through land-based observations and acoustic monitors, Pacific Biodiversity Institute has collected data that shows seasonal movement and distribution for the harbor porpoise. This data will be used in the coming year to request state agencies to adapt their management to be more protective of the porpoises and to petition for protected areas for calving. This work was presented at the 23rd Annual British Columbia Marine Mammal Symposium and written up in the Puget Sound Ecological Monitoring Program’s Marine Waters Report for 2014.
In 2014-5 the project has expanded monitoring which reaches from Saturna Island, British Columbia to the Hood Canal. This set of monitors in different habitats are demonstrating the harbor porpoise movement and distribution to show changes in seasonal presence. From data collected continuously over the entire past year at Burrows Pass, Rosario Strait and Admiralty Inlet, it appears that we can see movement from the more protected habitats on the east side of the Salish Sea in the winter to the more open waters of Admiralty Inlet in the summer. The three months of data from Saturna Island agrees with this finding. This finding is also supported by examining data from Dr. Anna Hall’s studies which show a peak of presence near Victoria, BC in the Haro Strait and Strait of Juan de Fuca in June and July.
Our analysis comparing land-based observations and acoustic monitoring at Burrows Pass has continued for five years. The seasonal cycle of higher presence in the winter than the summer is robust and comparable in the two sets of data. Since these sets of data are completely independent, this is strong confirmation of the validity of our work. We continue to see a diurnal cycle in the porpoise’s presence at Burrows Pass both winter and summer. In the fall of 2015, we began moving our monitors to other locations around the Fidalgo Island area and into the San Juan Islands where we will continue to look for examples for calving habitat.
Since 2009, we have been investigating the possibility for Photo ID work. About four likely identifications were made and a number of additional possible identifications were noted. The identifications may have included photographs from 2010 and 2012. At the present there are several animals that return regularly and for which we are collecting a set of photographs documenting this return. Two of these are recognizable by scars that are probably from a ship propeller. We will continue to watch for these animals.