I wasn't on board when Joan and Elisa found the dying newborn, but I support their choice of documenting the event without trying to intervene.
I'm quite sure that they would have done their best to help the baby, should there be any space for meaningful action. But I agree with them that there wasn't any.
Below, I try to explain why.
The fate of the baby dolphin was rather unpredictable. While he obviously had problems, these were of unknown origin and they could have been of temporary nature. We did not know whether the newborn could recover and what was going to happen next. Only towards the end of the observation it became apparent that he was going to die.
Capturing a dolphin in deep open waters cannot be expected to be easy, also considering that adult dolphins were consistently preventing the baby from approaching the resarchers' boat too closely. The likely reaction by the newborn to approaching human swimmers under those circumstances could be avoidance and increased distress.
The researchers on boat had no veterinary experience and carried no medical equipment. The best they could do (provided that they managed to capture the bay dolphin) was keeping him at the surface. This, however, was expected to result in additional stress and overheating, thus increasing rather than decreasing the risk of mortality. Wild dolphins have been reported to die of stress when handled and the risk may be particularly high if the handled animal is already distressed or ill.
Attempts to capture the newborn may have elicited aggressive behaviours by its presumed mother and/or by other adult dolphins, exposing humans to unknown but potentially significant risks, particularly in deep and murky waters. The presence of swimmers was also likely to disrupt the behaviour of the whole group, possibly jeopardizing the repeated and obvious attempts by other dolphins to assist the newborn. This, again, was thought to increase rather than decrease the risk of a potentially fatal outcome.
President, Tethys Research Institute