Field Work
The right whale population at Península Valdés, Argentina has grown from an estimated 580 whales in 1971 to around 3,000 whales today, but its future is not secure.
Human activities are degrading the whales' habitat. Existing problems include entanglement in ropes from a seed mussel industry, increased boat traffic, potential human development of the whales' preferred bays, the extension of oil fields that currently exist 200 km to the south of the peninsula, and the creation of a hydropower plant that would create a channel between the two bays embraced by the Península which would have a major impact on the ecology of the region.
One of the most surprising problems we study stems from the greatly increased refuse disposal that has resulted from the rapid growth of Puerto Madryn, the major city in the area. The food that is discarded has subsidized the population of Kelp gulls. One result of this is that young gulls have learned to feed on the skin and blubber of live whales when the tides cover their major food source, mussel beds. This causes the whales to spend about one third of their time, and presumably a similar amount of their energy (stored in their blubber) fleeing gull attacks.
A growing interest among Argentines in the right whales that calve off their shores gives hope for the population's future. Ocean Alliance's branch in Argentina, the Instituto de Conservación de Ballenas (www.icb.org.ar) is working to educate Argentines about the whales and to increase popular support for solving the problems that face their whales so that the people of Argentina become a key force in persuading the government to protect both the whales and their calving bays.
Current Research Activities
* We do annual aerial surveys of the waters around Península Valdés to photograph the different patterns of white spots on the whales’ heads and from those photographs, we identify the whales as individuals.
* We measure the annual increase in the number of known-age whales in the population in order to get a better estimate of juvenile survivorship and how long right whales live.
* We study juvenile right whales in order to understand the activity patterns through which they pass as they join the ranks of successful reproductive adults.
* We study the acoustic characteristics of the areas in which these whales spend most of their time so as to be able to make sure that such characteristics are incorporated into future plans to protect their habitat.
* We investigate the role that sound plays in maintaining groups of whales.
* We collect tissue samples from live whales and the bodies of dead, stranded whales. We analyze these samples for genetic factors, contaminant concentrations and stable isotopes.
* We constantly update the computer-assisted whale identification system on which our work depends.
* We investigate relationship between the body condition of mothers and the activity patterns of their calves.
* We study the effect that attacks by Kelp gulls have on calf activity and survivorship (the gulls have learned to feed on skin and blubber that they bite out of the whales’ backs).
While Ocean Alliance has a wide range of research activities relating to right whales, there are two areas within which our current efforts are focused:
Continued Aerial Surveys
Data from long-term aerial surveys has provided baseline information on changes in distribution and reproductive patterns of the whales. These surveys allow us to monitor the status and distribution of the population. The changes we observe can serve to alert us to problems the whales are encountering. The data we collect each year helps to develop a more complete picture of the lives of these whales. Beginning in1971 and every year since, Ocean Alliance has made annual aerial surveys of the right whale population at Península Valdés. Flying along the 495 km perimeter of the peninsula, we have photographed the identifying patterns on the heads of every whale we encounter and noted the whale's location, behavior and companions.
Gull Harassment at Península Valdés
Gulls molest the right whales at Península Valdés by diving onto the whales' backs and biting out pieces of skin. In one region we have studied, as much as 35% of a whale's day is spent fleeing attacks by the gulls. The whales respond by increasing their swimming speed, and making postural changes that allow their backs to remain submerged. The whales are fasting during the months they are at the peninsula, and we are concerned that the gulls may drive the whales from the best nursery areas. It seems logical that this would diminish the amount of milk left for her calf, which would affect the calf’s survival. By studying the harassment of whales by gulls, Ocean Alliance will be able to provide management authorities at the peninsula with the data they need to intervene on the whales' behalf.
