Research
Background
Humpback whales were one of the main targets of commercial whalers in the 20th century and their populations were decimated. Humpback whales make seasonal migrations between low latitude wintering areas used for mating and calving and high-latitude feeding areas. Research by Cascadia Research has recently revealed that Central America is winter breeding ground for humpback whales that feed off the West Coast of the US in summer. Most of our past research has been conducted in Costa Rica but in the last 2 years we have discovered an area off Nicaragua that appears to be heavily used by whales.
The project has several objectives:
1) Determine the number of whales using waters off Nicaragua as a wintering area.
2) Determine the movement patterns and migratory destinations of these whales.
3) Evaluate if humpback whales seen in this area are engaged in behaviors and vocalizations that are similar to other North Pacific breeding grounds.
Options for different research tasks will be presented on a daily basis. There will also need to be some flexibility in our activities to respond to where we are finding whales and weather conditions. Boat surveys will be conducted in 24' fiberglass boats with an outboard engine. Participants will assist in the research by 1) helping to spot whales (searching a specific quadrant), 2) recording data including entries for effort, weather, and whale sightings 3) helping to obtain identification photographs, 4) assisting in the deployment and recover of hydrophones (to listen for whale song) and other instruments and 5) when a whale is sighted, recording group size, behaviors, and movement of whales.
Identification of individual whales using photographs of natural markings has revolutionized the study of many endangered whale species since its development 25 years ago. The underside of the flukes of humpback whales are highly varied and range from virtually all black to all white, with almost all animals having some distinguishing pigment patterns or marks. Additionally, the trailing edge of humpback flukes shows a series of scallops or notches that are extremely useful for identification.
We will also monitor the vocalizations of humpback whales using an underwater microphone called a hydrophone. The vocalization of humpback whales can carry great distances underwater and are often audible when whales are out of sight. These recordings therefore provide an independent indication of the presence of humpback whales. From our boat, participants will help deploy the hydrophone, record whales, and monitor for whales using a headset. When two boats are in the same area we will use the two hydrophones and our VHF radio to acoustically locate the position of the singing whale.