I met my first Australian sea lion 57 years ago. Today I fear for this delightful animal

Eared sea lions, or, as most Australians call them, seals, must be about the sweetest, and most loveable of all sea creatures.

Man is their great enemy. Another is that incredible predator the great white shark, or white pointer, but whereas the white shark normally attacks only sick, old, or very slow sea lions, man in his usual fashion is generally not so discriminating.

Related: Population of Australia’s only unique seal has fallen by 60%, study finds

I met my first Australian sea lion on Dangerous Reef, out front Port Lincoln, South Australia. It was also on Dangerous Reef that I saw them butchered, probably for shark burley (bait). One minute they were watching with wide-eyed curiosity and the next they were being shot falling next to their startled pups. Man had once again triumphed ever the innocent and helpless. That happened about 57 years ago and has no doubt been happening ever since.

On 15 January 1975 the Australian sea lions on Dangerous Reef numbered about 60 or 80 animals. Six years before at the same time there had been 200 or more. I know because I counted them myself.

We had returned to the Dangerous Reef area with an Italian film team. The director, Bruno Valati, was making a one hour TV special on Australian marine life. My husband, Ron, had promised Bruno he would find hundreds of friendly sea lions on Dangerous Reef.

We were working from a Kangaroo Island fishing boat. Our skipper, Bill Zealand, anchored 200 yards from the main island in the Dangerous Reef formation, and all went ashore to film the above water segment on sea lions living in family groups.

This was when I first noticed the incredible depletion in the number of sea lions on the main reef, and also how afraid the remaining animals were.

Where had all the sea lions gone? Perhaps they had moved on, perhaps they had died out from natural causes, or perhaps they had, in the name of sport, become shark bait.

I have written this story hoping that other people may begin to understand how wonderful an unafraid wild creature can be.

We finished filming white sharks around Dangerous Reef and moved to Hopkins Island farther south, looking for sea lions in large numbers. Bruno wanted to film them underwater. Although he had some footage of the Dangerous Reef sea lions, it was very poor compared with what could be obtained using animals who were less afraid.

Captain Bill anchored his boat just out from a sunny sheltered cove. We all suited up. For us it was a fun dive, particularly after the white shark filming of the past few weeks. Being banged around in a little metal cage may be exciting but is hardly good fun.

On the tiny beach could be seen a family group of about 70 sea lions. Several seals appeared interested but showed no real alarm until we started to crawl from the water. The effect of our unexpected appearance was overwhelming, to say the least. The big brown bull bellowed a warning and about 30 excited sea lions galloped down the beach splashing around us. Surrounded by our new companions, we swam into deep water. At first I was nervous, for they came so close so fast that collision seemed inevitable, but it was only a game. I started to enjoy myself and take photographs.

They would also put their arms around each other in a very friendly fashion. In fact, they seemed one of the happiest and most loving family groups I had seen for a long time. It was the most wonderful dive.

We returned to Dangerous Reef every year for maybe 12 years always to film sharks and to visit the Sea lions both on Dangerous Reef and Hopkins Island. Every year there were fewer animals sunning themselves on the beach.

It was in the early 1980s while baiting out from Dangerous Reef that a fishing boat pulled alongside, and fisherman offered us a dead sea lion to use as bait. The animal had been shot. The fishermen told us the “stupid creature” had become entangled in their gill net (a common problem) and the easiest way to untangle them was to shoot them first.

We all were dismayed and most certainly wanted nothing to do with the dead animal.

Using Ron’s footage and TV interviews I had successfully had the killing of all seal lions in Australian waters banned. I know many eared seals fall prey to different natural causes but the introduction of man the hunter, the polluter, the uncaring has been the main cause of their decline.

Unless the government proclaims larger marine sanctuary areas around the remaining sea lion colonies I fear this delightful animal will become like the Tasmanian Tiger, only an image in a picture book.

• Valerie Taylor is a conservationist, photographer and filmmaker, and an inaugural member of the diving hall-of-fame. With her husband, Ron Taylor, she made documentaries about sharks and was credited with filming the live shark sequences for Jaws. Valerie still spends much of her time working for the protection of the marine world and its inhabitants. She is 85 years old