Coffin Bay Dolphin Project: first fieldwork season and amazing experiences in a remote area of South Australia!

by Cecilia Passadore

After several months living in Adelaide planning our PhD’s projects and getting use to Australian culture, we started our fieldwork in the beautiful waters of Coffin Bay in September 2013.

We moved to this remote area located in Thorny Passage Marine Park, SA, aiming to reveal the secrets of the population of Burrunan dolphins inhabiting these waters. Cecilia (Uruguayan) is interested in knowing the amount of dolphins inhabiting Coffin Bay, how they use the different bays and in understanding the way the distribution of dolphins relates to the environmental conditions and the human activities performed here (such as boat traffic). Meanwhile, Fernando (Chilean) is looking at the social system and genetic relations of this population and the dolphins found along Eyre Peninsula. We (Fernando and Cecilia) work together in Coffin Bay with the help of enthusiastic volunteers that with good vibes share with us work and life in the field.

During 2013 we lived more than 3 months in the little town of Coffin Bay. During spring we were joined by two volunteers: Emilia from Uruguay and Isabel from Brazil with whom we lived unforgettable moments on the water and on land. That season the dominant language was ‘spanportglish’ consisting in a fun mixture of English with Portuguese and two particular types of Spanish (we have to state clear that is not the same the Spanish spoken in Uruguay ‘che’ with that thing that Chileans speak ‘po’).

During the 3 months we spent in the field for our first field season we were only able to survey the waters of Coffin Bay 26 times due to several days of strong winds and rain. During the surveys on the boat we follow zigzag transects that cover most of the bay and the different environments found within our study area. Once we sight a group we approach them to record the number of individuals, the amount of adults, calves and juveniles and their behaviour while we took pictures of the dorsal fins off all the individuals. We also collect environmental data such as sea surface temperature, salinity and turbidity. When we finish the survey, which sometimes can go up to 10 hours length, we go back to our house-station in Coffin Bay to do the hardest part of the work… spend several hours a day sitting in front of the computer entering the data collected, go through the hundreds of pictures taken and compare them with the individual catalogue of the population that we are building. Although that spring we spent more days on land that on the water, we managed to do more than 100 hours of survey and found over 130 groups of dolphins!!! Not bad, don’t you think? More than one group per hour, super fun!... Well, and after uncountable hours sitting in front of the computer we were able to identify at least 200 different individuals!!!

Interestingly, our preliminary analysis of our finding during 2013 suggest that most of the individuals were seen more than once. Investigating a bit deeper it seems that some individuals are always found in certain areas of the bay, so they have a high fidelity to restricted areas… But we still have a lot to study and we need heap of extra information to test our assumptions. We’ll see…