An update on Baja 2002 observations following data analysis.
We have completed data analysis of our 2002 Loreto; Baja field season and can now give you a brief overview of our observations.
A total of 42 blue whales were photo-identified, of which 24 were known, 13 unknown, and 5 for which the pictures were of too poor a quality to be included in the catalog. We observed only 2 cow and calf pairs.
Included amongst the known individuals were; BB005 Riffe, BB009, BB063, BB052 and BB152 who are all females known since the early 1980s.
BB084 Machete also seen since 1982 was also photographed, however we do not know the sex of this individual at the moment.
One individual particularly caught our attention: BB036 first seen off Loreto in 1991 with a calf (BB037). BB036 seen 11yrs before is our first blue whale grandmother, because BB037 was sighted in 1997 with her own calf. Blue whales are thought to reach sexual maturity at around 10 years of age, which has been confirmed by BB037.
Certain calves first observed with their mothers in the Sea of Cortez seem to have become regular visitors to the Loreto area. This the case of BB254 first seen flanking its mother in 1999 and seen again on its own in 2000 and 2002.
Another young blue whale (BB257) photographed in 2002 was first sighted as a calf in 1998 and this year's sighting was the first since then.
The Sea of Cortez photo-ID catalog contains more than 300 blue whales, of which approximately 16% are calves, however few have been re-sighted. The Sea of Cortez is known to be a nursery for a certain number of Northeast Pacific blue whales and from generation to generation females return to these waters with their calves.
Our fieldwork since 1983 has enabled us to gain a long-term perspective and to detect successive generations of female blue whales that return to the Loreto area. We thank all of you who have supported our work in the Sea of Cortez and who allow us to continue the research off Loreto by participating in research sessions. Your support is invaluable and indispensable if we are to continue to learn about blue whale ecology in this interesting region.