Eventually, the trail led me out of the grass- and shrub-covered sand hills and down onto Twilight Beach.

I’d looked forward to this but within an hour of beach tramping, I had grown bored, The sun's rays blinded me, the ceaseless wash of surf on my right grated like tinnitus, and the low dunes on my left blocked any view of the hinterland.

I didn't want to think about walking this beach for the next three or four days, so I tried not to. Instead, I began picking out any object that stood out against the sand and counting the steps until I reached it and then starting again. It is the most mind-numbing pursuit I know and I was to do it many times over the next few days.

Halfway down the beach, I saw a half-buried log. As I grew closer, I realised with sudden interest that what I had thought was the stump of a branch was in fact a fin.

I had never encountered a shark this close before. I dropped my pack and squatted a few feet away. I wondered if it was dead. But the enormous black eyes were lifeless and the body looked oddly deflated, like a half-empty football. A pool of bright red blood coagulated on the damp sand. Already, flies and other scavengers swarmed.

With a sense of primal awe, I stroked the skin and marvelled at how rough the cartilage felt and yet how exquisitely it fitted together. After a little consideration, I lifted the snout and saw how the jaw hinged forward to expose the rows of teeth. A beetle scuttled for safety down the tongue and out between the teeth onto the sand.

I felt both sickened and saddened. "My enemy, my friend," I thought. I guessed that a human, perhaps a sports fisherman or offshore trawler crewman, had taken the life of this magnificent animal.

A few lines from Blake's poem, "The Tiger" sprang to mind:

TIGER, tiger, burning bright

In the forests of the night,

What immortal hand or eye

Could frame thy fearful symmetry?

When the stars threw down their spears,

And water'd heaven with their tears,

Did He smile His work to see?

Did He who made the lamb make thee?

I let the jaws close gently, picked up my pack and walked on.

Over the next three days, I would encounter another half-dozen sharks on this beach, once two a few feet apart. A dead shark every 15 kilometres may not seem much but if they were humans, there would be a national outcry.

And a little part of me cried out because I am both predator and potential prey. I felt vulnerable.

And right now, there is absolutely zero chance of me taking a short, refreshing but potentially lethal swim in these waters.