Coastal Ecosystems Research Foundation

Baja Expedition 2000

Blue whales observed off Isla San Fransisco, Baja California Sur, Mexico, February 21st, 2000.

by: William Megill

Last Modified: 26 March 2000

Introduction

The blue whale, Balaenoptera musculus, is the largest animal ever to exist on earth. Once relatively abundant, the species was almost wiped out by commercial whaling during the 1960's and 1970's. Today, remnant populations exist in all oceans, but the two best studied populations are the ones off the east & west coasts of North America. The Mingan Island Cetacean Study (http://www.rorqual.com) has been working with the Atlantic whales, both in the Gulf of St. Lawrence and in the Gulf of Maine, and has recently begun work on blues further north, off Iceland, Greenland & Baffin Island. They have also been working in the Sea of Cortez since the mid 1980's, and, in collaboration with several research groups, including the Cascadia Research Collective (http://www.CascadiaResearch.org) and researchers from the Centro Interdisciplinario de Ciencias Marinos (Instituto Politecnico Nacional), in La Paz, BCS, Mexcio, have begun to piece together the natural history of the blue whales of the northeast Pacific. The following document is the Coastal Ecosystems Research Foundation's (http://cerf.bc.ca) first contribution to that collaboration.

Methods

The photographs presented here were taken while the author was on holiday in the Sea of Cortez. We were travelling from Los Islotes to Isla San Fransisco, when we encountered a large group of blue whales (estimated group size: 18; area of encounter: ~3 square miles). Photographs were taken from the roof of a 50' reconverted fishboat using a 600mm lens, and from a 22' panga using a 100-300mm zoom lens. The camera used was a Canon EOS 630, and film was Kodak Ektachrome 100 slide film. Whales' locations were recorded using a handheld GPS unit, and notes taken of roll and frame numbers.

Results

The 79 photographs taken are catalogued below. Because of weather, number of whales, evasive whale behaviour, and a shortage of time, no attempt was made to photograph both sides of each whale, or keep track of individuals. The ID numbers below are therefore temporary until the right and left sides can be matched conclusively through comparison to other workers' catalogues, or until the animals are spotted again in later years.

Left Sides	Right Sides	Flukes
B00001L	B00001R	B00001F
B00002L	B00002R
B00003L	B00003R
B00004L	B00004R
B00005L	B00005R
B00006L	B00006R
B00007L	B00007R
B00008R

Discussion

The photographs presented here are from a single encounter on a single day in one very small area of the Sea of Cortez. It is the author's hope that these data (and more like them in the years to come) will help fill in one more gap in our limited knowledge of the biology of the blue whale.

Thank you to Doug Schmid & SCOPE, Long Island, NY, USA, for inviting me to join them in Baja California Sur,
and to Baja Expeditions, SA de CV, La Paz, BCS, Mexico, for logistical support. Thank you also to Julie Scott-Ashe, who did most of the matching.