Hearing in baleen whales

Credit: Maya Yamato, Woods Hole Oceanographic Institution

Here is an interesting article about hearing in large whales, a subject which is both very poorly understood and difficult to research. According to this study, it seems that minke whales have "a large, well-formed fat body" that connects the ears and provides a possible transmission pathway for sound from the environment to the inner ear:
http://www.sciencedaily.com/releases/2012/04/120417113640.htm?utm_source=feedburner&utm_medium=email&utm_campaign=Feed%3A+sciencedaily%2Fplants_animals%2Fdolphins_and_whales+%28ScienceDaily%3A+Plants+%26+Animals+News+--+Dolphins+and+Whales%29

Blue whales and the Melimoyu volcano

Credit: Susannah Buchan

A blue whale with the Melimoyu volcano backdrop, on the 19th of March 2012.

Orcas on my last day in Melimoyu!

Credit: Susannah Buchan

Credit: Sebastian Yancovic

Credit: Susannah Buchan

This was the biggest treat of all. I had never seen orcas, and here are three of them passing through Melimoyu Bay on my last day in Melimoyu, 20th March 2012.

Bottlenose dolphins!

Credit: Susannah Buchan

This was such a treat to see the open ocean morphotype of bottlenose dolphins moving through Melimoyu Bay and out to the open Corcovado Gulf. They are so energetic and impressive. Absolutely huge! These photos were taken in February 2012.

Dolphin high fives!

This summer I had a special encounter with some Peale’s dolphins that made all the frustration of this summer’s field season a whole lot better.

It was the perfect ending to a beautiful clear sunny day in the Corcovado. We went to Raul Marin in the Chucao to drop some friends off and on the way back managed to fit in two sampling stations, which we did in record time, because we now have the sampling routine down to a tee and because the sea was so calm: “como una taza de leche”, like a glass of milk. It was simply perfect working conditions.

Credit: Sebastian Yancovic

And on the way back, with a sun setting, as we left the Gulf behind and entered the channels, we came across a group of roughly 15 Peale’s dolphins celebrating the end of the day. There were energetic, vigorous and on for some bow riding. So I went up front and dangled off the side with my hand stretched out towards them. They were amazing to watch through the crystal clear and darkening waters of sun down. And so they weaved and flew into the air with incredible energy. They turned to one side and then to the other, making eye contact over and over again. I could see their pupils, the white of their eyes and their underbellies, and their sleek form through the grey waters of the austral channels. And then, to my outstretched hand, up they came! I felt the narrow firm edge of their dorsal fins and the perfectly smooth and solid wetness of their backs. 

The feeling of that touch and their immense grace still stays with me, such a wonderful end to a beautiful Melimoyu day.

Blue whale research in the Golfo Corcovado and Melimoyu: the 2012 field season

The Melimoyu site is owned by a for-profit conservation company called Patagonia Sur, which is setting up an exciting new research institute called the Melimoyu Ecosystem Research Institute, or MERI, and has lanched this venture with a flagship project on blue whale acoustics, which is where Dr. Rodrigo Hucke-Gaete (the principal investigator and my PhD supervisor) and I (the grad student!) come in. This project involves the installation of 6 acoustic buoys throughout the feeding ground, recording continuously over a 6 month period, to look at movements to and from and within the feeding ground. This project will provide Rodrigo and I with essential information over a time period (i.e. autumn/winter) and in places that we have not yet covered, and will add huge value to my on-going PhD research. I am of course delighted that the project is working out, that we have installed the buoys in January 2012.

Here is the buoy deployment team!: Fred Channel (buoy technician), Rodrigo Hucke (director Blue Whale Center), me, Tomas Montt (first mate), Matthew Westcott (captain!), Rafaela Landea (Patagonia Sur conservation coordinator) on board the Williwaw:

Credit: Rafaela Landea

After the buoy deployment trip, I spent February and March 2012 in Melimoyu working on the more oceanographic aspects of my research on board the Patagonia Sur boat “Chucao”, as well as providing visitors with some insights into blue whales and their feeding ground.

Credit: Sebastian Yancovic

Credit: Sebastian Yancovic

I arrived with my assistant Jaime Gutierrez (who was then replaced by Oliver Alarcon) at the beginning of February and we set up a wet lab and a dry lab from scratch in amongst the ecotourism facilities at Melimoyu. These are the very first MERI research facilities! And I have my supervisor Dr. Renato Quinones to thank for going all out with providing excellent oceanographic sampling equipment and human resources to make this happen. We also constructed a steel arm on board the Chucao from which to deploy our oceanographic sampling equipment. So I am really pleased with the research set up we now have at Melimoyu.

But as is often the case, this field season was a mixed bag. Getting out on the water and seeing whales has been tricky due to particularly bad weather and most critically due to very low whale sightings this year. Some years are just better than others, and it seems that the whales have preferred other grounds this year, or we have just not coincided with them as we did last year. But that is the nature of the game. And despite these issues, we have collected interesting samples that I am sure will yield interesting results.

Credit: Sebastian Yancovic

Credit: Sebastian Yancovic

These low blue whale sightings are no doubt linked to what I have seen in my krill net trawls: distinctly low numbers of krill and high numbers of gelatinous zooplankton like salps, ctenophores and jellyfish. This is a very  different picture from last year, where I was getting thousands of krill in my net and seeing up to 6 blue whales feeding at one time in one feeding patch. So there are oceanographic and ecological cycles over scales that we do not understand that greatly affect the plankton species of the feeding ground and therefore the presence of whales. And I must say that even though it has been disappointing to not see what we saw last year, I am still fascinated by what is going on and eager to understand why some years are krill-abundant and others not so much. So I am looking forward to coming back in winter and to studying the feeding ground with or without whales in sight. And I am also really excited about getting the acoustic buoy data back and comparing what I have seen over the summer with whale presence or absence as determined from the acoustic buoy data.

So this is an exciting year for blue whale research! And I am extremely grateful to those who have and are funding and supporting this work. In particular, my supervisors Renato and Rodrigo have been incredible and visionary, as have the Patagonia Sur team. Also, my field assistants, Jaime and Oliver, have been amazing and a huge wealth of knowledge.

Credit: Wilfredo Alarcon

Throughout my time working in the south of Chile, I have never kept a diary and have been pretty terrible at communicating what I am doing and experiencing. So after much hassling from family, friends and colleagues, I thought I should start posting some short pieces on the work I am and have been doing in this beautiful and remote part of our world. This piece is a little longer and sums up how I got here and what the hell I am doing here.

I arrived in Chile in 2007 with some acoustic recording equipment very kindly lent to me by my master’s thesis supervisor at the University of St Andrews, Dr. Luke Rendell, who I had been working with up until then on sperm whales in the Mediterranean. This all came about after meeting a Chilean up a mountain in Scotland: now my firm friend Max Bello. Max was one of the founders of the Blue Whale Centre, or Centro Ballena Azul, a Chilean NGO dedicated to blue whale and marine ecosystem protection in the south of Chile, headed by Dr. Rodrigo Hucke-Gaete, a professor of ecology at the Austral University of Chile. In 2001 Rodrigo lead an expedition down to the Corcovado Gulf and discovered the blue whale feeding and nursing ground that we now know. Additionally, I was lucky enough to get financial backing from One World Wildlife, a UK based NGO, who has supported this project over the years, even though there was no clear promise of results at first.

Credit: Susannah Buchan

So I arrived in South America for the first time, to the fishing village of Melinka, with no notion of where Chile was, no Spanish and some acoustic equipment to work with Rodrigo and try to see if we could start a new line of research at the Centro Ballena Azul in blue whale bioacoustics, i.e. the study of blue whale vocalizations and songs. I was supposed to stay for 5 months, and that was 5 years ago.

Credit: Susannah Buchan

Credit: Susannah Buchan

Over the past five years I have spent long and tedious hours, mixed in with mind blowing and life changing moments, recording the sounds of the Corcovado Gulf off an artisan fishing boat. All my moments surrounded by blue whales, feeding or singing or exploring the depths of the waters of southern Chile, have seemed eternal and have changed me forever. And during this time, we have successfully recorded the songs of the Corcovado blue whales, which have yet not been described in the scientific literature. This work is helping Rodrigo and I better understand the population identity and movements of Chilean blue whales to and from their feeding ground, all within a conservation perspective to protect this endangered species. This work is also now the main focus of my PhD studies in oceanography and blue whale ecology at the University of Concepcion, where I have the great good fortune to be supervised and supported by Dr. Renato Quinones, who oversees the oceanographic aspects of my research, while Rodrigo oversees the blue whale biology aspects of my thesis.                                                                                                                       

Credit: Cesar Guala

Returning to oceanography, which I studied as an undergraduate, has brought me back to examining more ecological aspects of the Chilean blue whales and their feeding ground. In particular, last year I started trawling for krill to try to understand the distribution of krill throughout the feeding ground and therefore understand the movements of blue whales within their feeding ground, between the various feeding patches. This work is related to the acoustic work which elucidates blue whale movements to and from the feeding ground. The occurrence of these relatively
predictable feeding patches is because krill has a patchy, non-uniform distribution throughout the Corcovado Gulf that is driven by oceanographic processes that occur in this complex ocean environment, where Subantarctic waters mix with terrestrial waters within the channels and between the islands of Southern Chile.

And so all this brings me to Melimoyu and a change of location for the 2012 field season. On the other side of the Corcovado Gulf from Melinka, Melimoyu is a completely different setting. It is a total immersion in the terrestrial wilderness of the Southern Chilean mainland, at the foot of the Melimoyu volcano, with its glacier, rivers and waterfalls, and pristine temperate rainforest like I have never seen before. Such a treat!