The social organisation of the mixed groups of females and young probably has substantial survival significance for this species. Calves are born into these groups, and members of the group, in addition to mothers, may play important roles in caring for calves during their long period of dependence. Mating takes place when males visit social groups and mating opportunities may be a factor limiting population growth in some areas.
Obviously, because of the larger number of animals involved, a greater number of whales are potentially disturbed when whale watchers visit social groups. Concern was also expressed that it would be harder for a social group of whales to avoid the attention of whale watchers because of their large size and the presence of calves.
The vulnerability of calves in mixed groups was a matter of particular concern to many of the participants. Calves may be left alone at the surface when adults dive and these calves are inquisitive and are known to approach vessels. It may not be in a whale's long term interests for a calf to become habituated to boats or to humans. Watkins recounted an instance of a calf being caught in the propellers of an oceanographic research vessel which it had been investigating while the boat was hove to. The relative ease with which they can be approached and the fact that they don't dive but remain accessible at the surface, can make calves the targets of whale watching operations.
Clearly there are many biologically important activities which take place in sperm whale mixed social groups and while this may make them inherently more interesting to watch, it also increases the potential harm that serious disturbance might cause.