Prepared by Annie Douglas. Email: email@example.com
Since 1996 Cascadia Research, the Oceanic Society and Elderhostel have collaborated on winter season surveys of southern Costa Rica for humpback whales. Primary goals for this project have been to document presence of northern hemisphere humpback whales in Costa Rican waters and obtain identification photographs of individual whales. These data as well as survey data from other projects in Central America (see Cascadia’s Nicaragua trips) are used to examine aspects of humpback whale use of coastal Central America such as habitat preference, general behavior, number of animals, and timing of migration. A secondary goal is to record presence of other marine mammal species in the study area; these data are shared with Costa Rican researchers for photo-identification of resident species, and to determine local species abundance.
From 23-27 January 2008, Frank Garita of Asociacion Ambiental Vida and I led a group of 10 Elderhostel volunteers on daily surveys of the waters off the Osa Peninsula, Costa Rica. Our operations were based at the Drakes Bay Wilderness Resort. Each day we would meet at the dock, load the equipment into two boats (cameras, hydrophones, datasheets, thermometer and lunch), and set out to look for whales and dolphins. Volunteers had the opportunity to help with all aspects of the data collection; duties included filling out sighting and effort data, listening with a hydrophone for whale or dolphin vocalizations, taking sea surface and air temperature, as well as being ready to take photographs of whales or dolphins for photo identification.
During this trip we had 35 encounters with marine mammals, and a total of 277 animals, including 6 humpback whales. The number of humpback whales encountered over the week was lower than expected for this time of year, however valuable identification photographs were taken of three animals, and we documented a cow/calf humpback pair in Golfo Dulce. One whale that we encountered singing off Isla Ballena was determined to be CRC # 10649. This whale has been encountered in Costa Rica 1998, 2000, 2002, 2005 and in 2006 Costa Rica and Nicaragua, and in California in 1992, 1994, 1995 and 2001. We made a short recording of this whale’s song, and found that it had been recorded singing in 2000 and 2005. The two other whales photographed did not match the current Central America catalog; these flukes will be compared to the larger catalog of west coast whales in the months to come.
Other species-Identification photographs were taken of a small group of false killer whales, and these photographs will be compared to existing catalogs of false killer whales sighted along Central America. Photographs of spotted and bottlenose dolphins were also acquired, and these will be compared to Central America catalogs, as well as reviewed for evidence of interaction with fisheries.
Humpback whale female and calf off Drake’s Bay, 2008. Photo by Al Hermann.
False killer whale off Drake’s Bay, 2008. Photo by Frank Garita.