Dolphins of the Bay Discovering the bottlenose dolphins of North Patagonia ELS VERMEULEN . HILDA SUÁREZ . ALEJANDRO BALBIANO “We ourselves feel that what we are doing is just a drop in the ocean. But the ocean would be less because of that missing drop.” Mother Teresa of Calcutta (1910-1997) Table of Contents 2 Introduction Prologue Ever since I was a child, I have dreamed of working with 3 What is a cetacean? dolphins, my favourite animals. But it wasn’t until I was 20 4 Getting to know the dolphins that I saw my first wild dolphin. I will never forget it. It was a bottlenose dolphin, also known in Argentina as “tonina”. of the Gulf of San Matías The love I feel for these animals has cultivated the need to protect 5 The bottlenose dolphin them deep within me, seeking to ensure they are able to live in a healthy and peaceful environment. This passion motivates me 6 How do we study bottlenose dolphins? to learn about dolphins and study them in the wild, and is why 7 What do we know about the bottlenose I became a marine biologist. Besides, it is the perfect excuse to be around them all day long! Dolphins dolphins of the Bay of San Antonio? Studying the bottlenose dolphins in the Bay of San Antonio 8 Bottlenose dolphin tales I (Province of Río Negro, Argentina) has only deepened my passion further. During the years I have spent around these dolphins, not 9 Bottlenose dolphin tales II only have I begun to understand their life as a species, but of the Bay 10 Behaviour I have also begun to know each one of them individually, all with their different stories. This is how I have come to learn that they 11 Cooperative feeding are very intelligent creatures. I have discovered that, besides the need for food and protection, they need to interact with their 12 Threats I family and friends, to be part of a group, have fun, play and take 13 Threats II care of their young. However, unfortunately I have also noticed how human actions can be a serious threat to them and I’ve 14 How can we protect the bay become aware of how much they need our care and protection. and its dolphins? This is why I want to share with you, throughout the pages of this book, what I have learned from the dolphins of the Bay of San 15 Reflections by the sea Antonio, since we can only protect what we love and we can only 16 Catalogue love what we know. I want to introduce you to the dolphins that live in this bay: Tulumba, Hilda, Yaco, Nereo and many more, so that you can understand them, know them, love them and take ORIGINAL TITLE care of them too. Las Toninas de la Bahía: descubriendo a los delfines Els Vermeulen de Patagonia Norte AUTHORS Els Vermeulen, Hilda Suárez & Alejandro Balbiano TRANSLATION Acknowledgements Paula Goñi Firstly, I want to thank Alejandro Cammareri for all the years we EDITING have worked together, and the Marybio Foundation, which I have been Giles Crosse part of and which has made my work in the area possible. I also want DESIGN Discovering the bottlenose dolphins to thank all the surrounding neighbours who have given me their María Agustina Méndez & Raúl Méndez support during all these years of work, especially to Claudio Barbieri, PHOTOGRAPHY Mariela Pazos, Jorge Baraschi, Hernán David, Mauricio Faillá, and of North Patagonia Alejandro Cammareri, Els Vermeulen Federico Hollmann. Furthermore, I would like to thank those who have & Alejandro Balbiano helped me with the scientific analysis and my PhD: Ludo Holsbeek, SCIENTIFIC ADVICE PhD; Stefan Bräger, PhD; Krishna Das, PhD; and Pedro Fruet, MSc. Els Vermeulen My investigation project would have never been possible without EDITORIAL DESIGN the financial support of Marybio Foundation, the Cetacean Society Graciela Arnoldi International and Trigon N.V. Special thanks to Bill Rossiter and Cetacean Society International Published in Argentina, 1st edition for financing the translation of this book. ISBN: 978-987-29700-1-7 eBook Contact: [email protected] 2014 DOLPHINS OF THE BAY 1 Introduction What is a cetacean? The Bay of San Antonio is privileged, as its protected differences of more than 16º C between summer and Cetaceans are mammals, just like us, but are adapted movement in water and allows them to swim at great speed. coasts and shallow waters are inhabited by unique species. winter. Another characteristic of the area is the large tidal completely to an aquatic life. The word “cetacean” has a dual Instead of arms, they have flippers, and they don’t have hind The southern right whale, migratory birds such as the red range and the existence of large quantities of food, both in origin, from the Latin cetus, meaning large sea creature, limbs. Instead, they have a muscular tail which helps them knot and several species of dolphins are just some of them. its clear waters and its sandy beaches and rocky coasts. and the ancient Greek ketos, meaning sea monster. swim powerfully and most of them have a fibrous dorsal But why do they choose this area to spend part of their All of these unique characteristics make the Bay of San Like all mammals, cetaceans are “warm-blooded” fin, which helps them stabilise their bodies in the water. lives? Antonio the ideal home for a group of bottlenose dolphins, animals, which means they have mechanisms that allow Because they have lungs, they must come to the surface to Located in the north-west of the Gulf of San Matías, many of which remain in the area the entire year. It is them to maintain a constant body temperature, in spite of breathe and hold their breath while swimming underwater. in the Province of Río Negro, Argentina, the Bay of San one of the best places to observe them within their natural temperature variations in the environment. Furthermore, They are excellent divers though, a very important ability Antonio is 20 km long, 10 km wide and no more than 30 habitat, which gives us an excellent opportunity to study they have lungs through which they breathe atmospheric when it comes to hunting fish! They also give birth and metres deep. The region is not only famous because of its their lives, habits and behaviour. And as if that were not air and produce milk to feed their calves, which grow and nurse their calves underwater, and they never have more shallowness and lack of strong currents, it is also well known enough, due to the enormous decrease in bottlenose develop inside the womb of their mother. than 1 calf at a time. for having the warmest waters of the entire Argentine dolphin sightings in other areas, the Bay of San Antonio But, besides the characteristics shared with other Although it may seem hard to believe, the ancestors of coastline, with maximum temperatures around 24º C in may be one of the last remaining homes within Argentina mammals, cetaceans have some special features that enable cetaceans were land mammals that walked on 4 legs. The summer. In winter, temperatures drop considerably, with for this species. them to live in water. These adaptations are related to both first real cetaceans appeared on Earth around 55 or 60 their anatomy and function. Let’s look at some examples. million years ago and were called Archaeoceti. They were Cetaceans’ bodies feature a hydrodynamic shape which, similar to the large cetaceans with teeth that live today, but together with their short and rigid necks, improves their they became extinct almost 30 million years ago. They breathe through their blowhole; Their neck bone is formed 1 or 2 holes on the top of their head of 7 vertebrae, as in all mammals, similar to the nostrils but they are fused in almost of other mammals. all cetaceans. The Gulf of San Matías is located in the north of Patagonia. It is The Natural Protected Area of the San Antonio bay, outlined by Punta Bermeja (Province of Río Negro) and Punta Norte created in 1993 by the Río Negro (Peninsula Valdés, Province of Chubut). It is the second largest gulf in Argentina, Province Law No. 2670, protects one of the most with an area of approximately 18,000 km2. It has an average depth of 100 metres, important places for migratory birds The tail or caudal fin is boneless with a maximum depth of around 200 metres. in the south-west Atlantic. They do not have external ears Fore limbs or flippers function and fibrous. It features a horizontal (ear lobes), instead they use as oars to change direction and position to push them along a small slit located aid stability when swimming. while swimming. just behind each eye. Southern right whale. Red knots. In order to differentiate cetaceans from fish we must pay attention to 2 characteristics: the tail and their way of breathing. Cetaceans generally do not have Cetaceans have a horizontal tail, which moves up and down, and blowholes on the top of their head. Fish have a vertical tail, hair. Instead, they are covered which moves from side to side, and gills on both sides of their head. in a thick layer of blubber (fat) under their skin which keeps them warm. Blubber. Skin. DOLPHINS OF THE BAY 2 DOLPHINS OF THE BAY 3 La Plata Dolphin or Franciscana With a length of 1.3 to 1.7 metres, this is the smallest dolphin in the gulf Getting to know and one of the smallest dolphins in the world.