Project

The importance of Seychelles for blue whales, and other whales and dolphins

Species
  • Marine Mammals
Years funded
  • 2021
Status
  • Active
Project type
  • Research
Description

Jeremy wants to understand when blue whales and other whales and dolphins visit Seychelles, and how many visit when they do. He investigates what factors, like ocean currents or noise pollution, affect their presence and behaviour in these waters. To do this, he spends hours observing whales and dolphins from a boat to document their behaviour, where they move and what they do. He also uses their calls to identify when they arrive, whether they’re feeding or mating, and where they come from. This information can help identify new behaviours, or important areas that need protection.

The importance of Seychelles for blue whales, and other whales and dolphins

Jeremy Kiszka

Project leader
About the project leader

I am a biology professor at Florida International University and the director of the Marine Conservation Ecology Lab. Originally from France, I obtained my PhD from the University of La Rochelle in 2010, focusing on the ecological and behavioural relationships of several dolphin species around the tropical island of Mayotte in the Mozambique Channel. I study marine mammals (whales, dolphins and sirenians) and other large marine vertebrates (sea turtles and sharks) around the globe to understand how the marine ecosystem and human activities affect their behaviour and populations, and how they...

PROJECT LOCATION : Seychelles
Project details

Importance of the Seychelles for endangered blue whales and other cetaceans

Key objective

Our key objective here is to understand how important the Seychelles are for endangered blue whales, when, and why (feeding, reproduction, or both).

Why is this important

Several species of large whales have recovered from whaling, such as the humpback whale. However, others are still endangered, and we know very little about these animals. This is particularly the case for blue whales that are currently under threat from climate change and acoustic pollution. Ocean noise affects the ability of whales to undertake vital life history events, including reproduction, feeding, and travelling from feeding to reproductive grounds.

Background

In the open ocean, island archipelagos are often oases of life. They are characterized by steep underwater slopes that can generate oceanographic conditions that will promote the presence of nutrients and food for large marine predators such as sharks, tuna, whales and dolphins. In the western tropical Indian Ocean, Seychelles is characterized by a high abundance and diversity of whales and dolphins. Past surveys carried out throughout the southwestern Indian Ocean have shown that cetacean densities are the highest around Seychelles, with a high species diversity. The archipelago used to be a major whaling ground, particularly for Soviet whalers during the 20th Century. However, no dedicated research has been carried out to understand the importance of this region for endangered cetaceans, particularly blue whales or any other cetaceans, although Seychelles proposed the establishment of the Indian Ocean Whale Sanctuary in 1979 whereby the International Whaling Commission has banned all types of commercial whaling.  Studying whales and dolphins in their natural habitat can be challenging, particularly in areas where information is lacking. Listening to whales and dolphins using hydrophones (underwater microphones) is a great method to investigate which species are present, when, and what the animals do. It also gives us an idea of how many animals are present at the same time in an area of hundreds of kilometres (particularly for blue whales that can be very loud). We know very little about blue whales and other large whales in the tropical Indian Ocean, although we know several species occur and can potentially be abundant, particularly in Seychelles.

Aims & objectives

Using a combination of acoustic methods and visual boat-based surveys, we will aim at improving our knowledge on the abundance, behaviour, and critical habitat of blue whales and other cetaceans in Seychelles, particularly at D’Arros and St. Joseph. We will assess the importance of this region for cetaceans, and how human activities (particularly acoustic pollution) might affect them. For any project we do around the globe, we believe that training local students is a crucial element of the success of a long-term effort. Therefore, we will train students from Seychelles, bring them into the field, and involve them in the analysis of the data that we will collect at sea. Since the Seychelles population is often unaware of the presence of whales in the archipelago, we will develop outreach initiatives to raise awareness about the presence of whales in Seychelles.