Twenty-seven sites within the Saguenay–St. Lawrence Marine Park coordination zone (Québec, Canada) host active seabird colonies. These hold approximately 23,000 breeding pairs of 8 species (4 larids, 3 alcids and the Double-crested Cormorant [Phalacrocorax auritus]), 4 of which are close to the upstream limit of their breeding range in the St. Lawrence. Due to their abundance and distribution, the Herring Gull (Larus argentatus) and the Double-crested Cormorant are undoubtedly the most representative members of this group in the study area. The numbers of most of the 8 species have fluctuated significantly since the mid-1970s, but are now relatively stable. However, in recent years, there has been a rapid increase in the Common Murre (Uria aalge) population and a decline in that of the Black Guillemot (Cepphus grylle), which has dropped to a very low level. Recommendations are made for the conservation and management of this bird community.