I suspect that I am somewhat of a curiosity compared to the normal recipient of an SOSF grant. Firstly, at the age of 65 I am probably older than most, although hopefully not the oldest! Secondly, I am no longer a full-time research scientist. And thirdly, I am resurrecting aspects of a project that consumed me more than 40 years ago when I was a young PhD student. Working at the Durban Aquarium between school and university, I quickly cottoned on to the fact that I liked sharks, and that to become a field biologist was my thing. I also knew quite a lot about the bull shark Carcharhinus leucas, which was the main culprit for a spate of shark encounters off Durban’s beaches in the 1960s. What fascinated me was that this shark could enter fresh water. So, when at university the head of department said that sharks and rays were intolerant of fresh water, I happily pointed out the error of his ways. Thus the idea of a PhD was born – how do cartilaginous fish species such as the bull shark and sawfish adapt to fresh water?