In the late 1970s, I literally underwent a sea change. After spending time as a deckhand on a mate’s boat I decided commercial fishing was the life for me. All my energy went into fishing so I could fund a carefree life of adventure – snorkelling and diving on the Great Barrier Reef.

Life and work was good, but I figured out a way to make it even better. I spent a year building a fishing boat with long-range capability that was large enough to house myself, my wife and our first daughter. We could now spend months out at sea, eliminating the time and expense of a daily commute to fishing spots, as well as our living costs.

Before dawn each day I’d be up trolling for mackerel and trout. There would be a break to process the morning’s catch, before another opportunity to fish for, say, red emperor. When the weather was bad, we’d take refuge at one of the islands to repair equipment, catch bait, have a snorkel and enjoy the scenery.

Every so often, we’d dock back in Port Douglas; population 400. Back then, it was northernmost town from which you could still buy ice and sell fish. It was also quiet enough that you could stop at any time of the day in the middle of the road for a leisurely chat.

There was no conversation about the health of the reef, because we took its health for granted. The fish were there and we could go out and catch them to our heart’s content.

To me, fish were something pretty to look at underwater and delicious to eat. It was as simple as that. However, in the early 1980s I’d upgraded to an 18-metre commercial fishing boat that could also be chartered to take out guests. I secured such work for the fledgling Great Barrier Reef Marine Park Authority, CSIRO and some of the earliest tourism charters. The more I spoke to researchers, the more I realised how little I knew about my workplace.

Each scientist I spoke to was a fountain of knowledge on something I’d only ever given a cursory thought to. Each one would enthusiastically tell me why a particular sea creature behaved the way it did, what it ate and what ate it and how they fit into the bigger picture. All of a sudden, science and research was exciting because it provided an exclusive insight into the underwater world I immersed myself in when diving or snorkelling.

It also made me aware of how many gaps there were in the research. It was difficult for researchers to get out in the field because travelling out to the reefs wasn’t cheap. Most scientists I spoke to were lucky to spend two weeks of their year in the water. The rest of their time was devoted to writing grant applications, teaching or in the office.

This provided me with the inspiration for a new business venture. By now, I’d returned to land with my wife Linda and two young children. I was taking visitors out on fishing or diving tours but the boats weren’t always full. If I offered spots to researchers for free, those who were coming along to fish or dive would also get exclusive access to an expert guide on the wonders they were seeing – and the researchers would have all hands on deck to help with tagging sharks or photographing whales. It was win-win.

It was around this time that we all started to notice changes. Those researchers were observing rapid changes in the coral and sea life of the reef. Meanwhile, fish became harder to catch, and as a diver I observed the first infestation of crown of thorns starfish. I started asking questions – and found out about run-off from farms and industry, water quality and fishing impacts.

When the first mass coral bleaching event occurred in 1998, I saw first hand how the colour and beauty of the reef that my business had always banked on could be wiped away. Initially, this didn’t affect business. We redirected visitors to spots that weren’t affected, and over time the reefs recovered.

Then it happened again. And again. This year, we’re experiencing the worst mass coral bleaching event in the reef’s history, which no one can ignore. Yet still there are tourism operators who worry that if they speak out, and express concern, then negative publicity could have a short-term impact on tourism numbers.

I am worried too – but it’s the long-term health of the reef and the viability of our entire industry that keeps me up at night. Over time, I’ve become painfully aware that there are decisions being made outside of my community that are defining not only my business, but the entire reef tourism industry and our children’s future.

The Great Barrier Reef is in danger. It can’t survive as we know it if ocean temperatures and acidity – driven by climate change – keep rising.

The viability of my business – and the livelihoods of 69,000 other Queenslanders – rely entirely on the health of the reef. In a tourist town like Port Douglas that’s 80% of our jobs. We’ve got so much skin in the game. If we can’t step up and protect the reef then the science shows we will lose it.