Michael Andrew Bigg (December 22, 1939 – October 18, 1990) was a Canadian marine biologist who founded modern research on killer whales (orcas). With his colleagues, he developed new techniques for studying these apex predators off British Columbia and Washington, conducting the first population census of the animals anywhere in the world. Bigg's work in wildlife photo-identification enabled the study of individual killer whales over years and decades, including their travel patterns and their social relationships within their family groupings (pods), and so revolutionized the study of cetaceans.

Michael Andrew Bigg was born in London in 1939. In the aftermath of World War II, his family emigrated to the west coast of Canada when he was eight years old. In his youth, Bigg enjoyed exploring the British Columbia wilderness. According to his father, newspaper publisher Andy Bigg, Michael's early life experiences ingrained in him an immense love of nature. Bigg attended Cowichan Senior Secondary School (now Quw'utsun Secondary School) in Duncan, and then the University of British Columbia in Vancouver, where he studied falcons, water shrews, and harbor seals. His PhD, awarded in 1972, was based on the reproductive ecology of harbor seals.

In recent decades, the public has come to appreciate and be fascinated by killer whales. However, before the mid-1960s, killer whales were widely feared as dangerous, savage predators, a reputation based on rumor and speculation. In the waters of the Pacific Northwest, the shooting of killer whales was accepted and even encouraged by local governments and moreover by other governments throughout the world. During the mid-'60s and early 1970s, a change in global opinion saw the development of public & scientific awareness of the species, starting with the first live-capture and display of a killer whale known as Moby Doll that had been harpooned off Saturna Island in 1964 and the impact of scientific research on this animal.

Between 1962 and 1973, at least 47 killer whales from the British Columbia and Washington coasts were captured for display in captivity, and at least 12 more whales died during capture attempts. It was assumed that the killer whale population in these waters numbered in the thousands; however, as a standard wildlife-management practice for "harvestable" animals, the Canadian government determined that a census should be done. In 1970, Bigg became head of marine mammal research at the Canadian Department of Fisheries and Oceans Pacific Biological Station in Nanaimo and was given the task of the census.

Bigg's first technique was to send 15,000 questionnaires to boaters, lighthouse keepers, fishermen, and others who frequented the British Columbia coast, asking them to record killer whale sightings in one day. No other animal census of this kind had been performed anywhere in the world. The results of the survey taken on July 27, 1971, indicated that the number of killer whales in the British Columbia region of the area was at most 350, drastically fewer than had been assumed. Similar surveys in the following two years and subsequent work with photo-identification techniques (described below), substantiated the results.

In 1976, Bigg submitted his report, indicating that the rate of captures from such a small population was unsustainable and recommending restrictions on the capture of killer whales from Canadian waters. The U.S. National Marine Fisheries Service conducted a killer whale survey in the Washington coast, which also yielded low numbers, and public opinion had begun to turn against whale capture. Since then, no killer whales in British Columbia or Washington waters have been taken for captivity, with the exception of Miracle, a young killer whale that had been discovered starving and with bullet wounds. Killer whales for aquarium display continued to be taken from Iceland until 1989, when that country banned further captures. Since that time, killer whale populations at marine parks have been in decline with only a few small-scale captures that have occurred in Argentina, Japan, and Russia.

In the early 1970s, Bigg and his colleagues discovered that individual killer whales can be identified from a good photograph of the animal's dorsal fin and saddle patch taken when it surfaces. Variations such as nicks, scratches, and tears on the dorsal fin, and the pattern of white or grey in the saddle patch, are sufficient to distinguish killer whales from each other.

Although it had been recognized that some animals could be identified from obvious distinctive features such as scars, Bigg and his colleagues discovered that the dorsal fin and saddle patch area of every killer whale was sufficiently distinctive to allow the individual to be reliably identified at sea using photographic techniques. The technique enabled the local population of killer whales to be counted each year rather than estimated. It also allowed longitudinal study of individual whales, their travel patterns, and their social relationships in the wild, and revolutionized the study of cetaceans. Just a few years previously, whale research had meant studying captive or dead animals, and the study of living wild whales had been virtually nonexistent.