River Monsters (38 page)

Dave reckons these extreme conditions could be instrumental in sawfish survival here. Biologists think that the gravid females drop their live young (thirty inches long, with sheathed saws) in
the estuary, whereupon these are pushed into the river on the tide. Then, in the wet season, they just keep on going, away from the estuarine predators. As well as salties and bull sharks, these
include the northern river shark (
Glyphis garricki
), a fish superficially similar to the bull shark but with some distinct differences, in particular its smaller eyes, larger second dorsal
fin, and more acute-pointed teeth. Although fearsome looking and growing to possibly ten feet, this, like the sawfish, is a rarity. Only twenty have been recorded from here in the last ten years.
Nevertheless, while the science team put out nets in the shallows, in the brief window of slack water, I put out an eight-inch mullet for a
Glyphis
, surely the ultimate in forlorn hope, even
for an angler. All was quiet while the tide turned, and then a run in the shallows led to a big swirl on the surface when I tightened up. This turned out to be a threadfin salmon (
Eleutheronema
tetradactylum
), which is not a salmon at all but actually an elongated perch with a deeply forked tail, a mouth that opens to the diameter of its body, and bizarre finger-length tendrils
trailing between its pectoral fins, as if it has somehow incorporated a gene or two from an insect. Although prized for their taste, mine was too small to keep, so back it went, followed by a
recast into the deeper water of the basin where we were anchored.

The next time the ratchet whined, I connected to a much heavier fish, which plunged powerfully next to the boat once I had managed to shorten the line. I couldn’t see anything through the
opaque water, but a grey body and high dorsal fin breaking the surface told me it was a shark. Then I saw that the hook was just nicked into its left pectoral fin. I was using a circle hook, so its
hold was probably very tenuous. Luckily, I was using a light-action rod that gave gently to the fish’s lunges rather than resisting stiffly, but even so, we had some nervous moments before
Andrew, the boat’s skipper, managed to get both hands firmly around its tail. The hook fell out as we boated it, just as graduate student Jeff Whitty declared a positive ID for a
Glyphis
. We measured it at fifty-two inches, quickly put a numbered plastic tag in its dorsal fin – in case it should ever turn up again – and then released it. Before I knew it,
the needle was back in the haystack.

Once up the river, away from the estuarine predators, the sawfish pups’ safety is only relative. Ninety miles upstream at Camballin barrage, an abandoned irrigation dam that completely
blocks the passage of fish in the dry season, I caught some small catfish on camp supper leftovers and swung one out on a handline into the pool below the barrier. Like many catfish, you have to
handle these ones very carefully because of the three multibarbed spikes sticking out of their bodies – one on each pectoral fin and one on the dorsal fin. In the Congo the one-inch pectoral
spine of a small dead catfish impaled the end of my right-hand ring finger, and the pain was almost unbearable. So the thought of putting one of these fish in a human mouth doesn’t bear
thinking about. But fish have different notions, and our aboriginal rangers assured me that these spiky catfish are a good bait. Sawfish tend to be more active at night, so we’d unrolled our
waterproof canvas sleeping bags on a low beach, staying well back from the water as a token precaution against the saltwater crocs that have been seen here. Before zipping myself inside, I loosely
fixed an empty drink can on the line, and within minutes it went scuttling across the sand, catapulting me to my feet. On tightening my grip around the line, I felt a fast-moving fish, swimming
first this way and then that. In the light of my headlamp, a dorsal fin cut the water, but I could see no toothed rostrum. After a couple of minutes I slid a bull shark on to the sand, a stocky but
disconcertingly flexible yard-plus in length, and I caught two more in quick succession. No matter how familiar I am now with the bull shark’s osmotic control, to see them in such abundance
in completely fresh water still doesn’t quite compute.

There was also something about this place that was both disturbing and reassuring, something about a saw-snouted monster from the dawn of the Cenozoic and sharks from the far Jurassic swimming
under the reflection of a concrete dam. Underwater was not just another world; it was another time. And at night by this river you can feel the closeness of that other time, restrained by such a
flimsy rippling skin, and almost imagine that time and this time dissolving into each other to form something else that’s outside of it all. And indeed they do, in a way, when the drink can
rasps its message across the millennia and I pick up the line to feel the weight of time itself.

At nearby Myroodah, the scientists deployed their net in some shelving shallows, and shortly after dark something swam into it, pulling a couple of net floats under. I went out to investigate
with them, in a hurry because a croc had been checking out the net earlier. Lifting the top cord, I felt a sudden strong kicking and, in the light of my headlamp, saw a flailing rostrum. The body
behind it looked over six feet long – too big to bring into the boat, so we gathered both ends of the net and towed the fish to shore. Grounded in the shallows, I could finally see the whole
fish. The rear half was just like a shark: sleek and elongated with an asymmetric, long-upper-lobed tail, and two high dorsal fins, although the body on which they were mounted was more
flat-bellied and triangular in cross section than cylindrical, as befits a bottom-hugging lifestyle. But forward of the first dorsal fin is where things got interesting – and strange –
as the body flattened and widened, merging smoothly with winglike pectoral fins. Two holes near the front of the head opened and closed, like black eyes blinking, and in front of them the real
eyes, unblinking, regarded us, their horseshoe-shaped irises edged with gold like tiny jewels. Forward from there was just a tangled mass of thick monofilament: graphic evidence of how vulnerable
these fish are to any kind of net. Normally, gill nets are selective, to a certain extent. Only fish of a certain size get stuck, whereas smaller fish pass straight through and bigger ones bump
into the meshes without their heads getting caught. But sawfish will get their rostrum teeth tangled in anything trailing near the bottom, and their thrashing only entangles them more. Seeing this
fish so comprehensively trapped, the global decline of sawfish became all too understandable. Even if they aren’t targeting sawfish (their fins are in demand for the disgraceful Asian
‘shark fin’ market), most commercial fishermen aren’t going to waste time and risk injury disentangling a live fish, only for it to swim back into their nets at a later date. The
use of a wooden club is a matter of simple economics.

Disentangling takes time and care. With Dave holding the tail and body, I carefully worked the net free of the rostrum teeth using a screwdriver, leaving the rostrum tip until last. To free the
final teeth, I was told to hold the end of the rostrum between thumb and forefinger, coming from the front, and to let go as soon as the net was clear. Then, giving its front end a wide berth, I
moved in to straddle the fish’s back, a position that is safe from the rostrum unless the fish manages to flip on to its side and flex its body, which it can double into a full circle, thus
touching its rostrum tip with its tail. A person trying to wrestle it in this position would risk getting a face full of rostrum teeth. Fortunately though, the fish telegraph their intentions by
tensing before they kick, so you know when to hang on more tightly. But this seven-footer just calmly sat there and allowed us to get on with measuring and tagging. Although its back was in the air
and its mouth was resting on sand, its spiracles were under the surface, and these simple flap valves on the top of its head were supplying clean water to the gills. I was struck by how similar
this arrangement is to that in rays, to which sawfish are more closely related than to sharks, despite the shark-like rear half of the body.

To attach the numbered tag, we punched a small hole in its cartilaginous dorsal fin and put the small disc of tissue thus obtained into a tube of alcohol for later DNA analysis. There are
roughly half a dozen sawfish species worldwide, but the precise number is not agreed upon. The ‘freshwater’ sawfish of Australia, Southeast Asia, and the coasts of the Indian Ocean is
very similar in appearance to the largetooth sawfish of the western Atlantic, and they may in fact be the same species. Finally, a finger-sized acoustic tag was fixed to the second dorsal fin. This
would transmit location and depth information to strategically placed hydrophones along the river’s course, anchored black capsules that are periodically retrieved in order to download their
electronic memory on to a computer. ‘It’s a chunk of change,’ said Jeff. ‘But the data’s more valuable.’ Of particular value is the fact that fish movements
revealed by this high-tech system are not influenced by the presence of a tracking boat.

One clear finding so far is a strong correlation between the strength of the wet season and the numbers of new sawfish pups that make it up into the middle reaches. Our visit followed a
particularly low flood season, and there were very few new recruits to the river’s sawfish population. Even though yard-long sawfish can swim in four inches of water, the chances are that
most didn’t make it much beyond the tidal zone, so they were polished off by the more abundant predators there. This new insight explains the team’s concern about a proposal to divert
the Fitzroy’s ‘surplus’ monsoon water south to supply the human population of Perth. If nobody else would miss it, the sawfish certainly would.

Once they reach the size of this netted one, however, sawfish can hold their own. This fish had the whole tip of its right pectoral fin missing: a crescent-shaped cut some eight inches long and
still not completely healed – bearing witness to a nonfatal encounter with a bull shark. It also had crocodile tooth-marks in its head and flank, but these had bounced and slid across its
tough hide, failing to penetrate. There are also reports of sawfish injuring people in self-defence when cornered in shallows or caught in a net. I even read in a newspaper archive that a flailing
fifteen-footer off Darwin managed to hole a wooden fishing dinghy, and this certainly gave me pause for thought as I prepared to go after one with a line.

Most line fishermen in these waters are after barramundi (
Lates calcarifer
), a scaled-down Nile perch lookalike that is prized for its flesh and dramatic, leaping fight. A couple of times
at night I almost jumped out of my skin as this predator nailed a surface-swimming baitfish from below, making a sound like a rock falling into the water as it snapped open its cavernous mouth. But
anyone fishing with live- or dead-bait on the bottom, rather than a lure, may hook a sawfish. And, sadly, some fishermen will kill an accidentally caught sawfish and throw it up on to the bank to
rot rather than attempt to unhook and return it. We found three yard-long sawfish dead beside one pool – a significant dent in a precarious population. Therefore, targeting them with a rod or
a handline is illegal. But because I was working with the scientific team, hunting specimens for them and under their supervision, I had the rare chance to experience this legendary creature on the
end of a line.

But I almost didn’t want to. Catching a fish used to be a very private thing for me, and somehow catching my first sawfish under camera lights with a scientific team standing by to process
it didn’t excite me as much as the prospect of a solitary encounter. And failure is normally private too – perhaps that was it. Then I snapped out of it. The unique circumstances were
in fact all part of being here. I took my mind away for a moment and reminded myself that fishing is about challenge, and that challenge should be welcomed and sought, not feared and avoided. It
was time to finish the chapter that had started so strangely all those years ago in the middle of the Amazon.

For a couple of hours, as the riverbank dimmed into moonlit dark, both lines hung lifeless, and I fished with little confidence. Then, suddenly, one line was running out. But when I engaged the
drag and tightened, nothing was there. And there was no more activity that night. The next night I moved to a different spot, from where I could cast into an eleven-foot hole. Again, baitfish were
scarce – just a handful of tiny mullet. Shortly after dark I missed a screaming run but somehow lost the bait. But when the next four-inch mullet was taken, I connected to a heavy fish. Out
in the dark I could feel it scything from side to side, punctuated by heart-stopping jags as something raked the leader. It felt a bit like a stingray, lashing the line with its barb. But although
Australia has big river rays – previously believed to be the same as those I’d caught in Thailand but just recently shown to be a separate species – I somehow knew this was a
sawfish.

Although I could tell it was a good-sized fish, on my heavy gear it tired quickly. Inside a couple of minutes it was aground on the mud-and-rock bank at my feet, its rostrum in the air. What to
do now? One swipe could sever the taut line even though my hard fluorocarbon leader had lasted the fight so far. I yelled into the darkness for help, and soon Travis, one of our aboriginal rangers,
was there, coolly hooking the final two tusks with his second and third finger to immobilise the rostrum. Then the whole team was there and we pulled the fish on to the mud for measuring and
tagging, all the while keeping a constant eye out behind us for crocs in case one came to investigate the commotion. With the data logged, I then had the chance, while squatting astride the fish
with my hands lightly holding its head, to savour the moment.

Here at last was the fish that had been swimming around in my head for the better part of twenty years. At seven feet long and with that double row of fearsome tusks glinting in the flashlight
beam, it was certainly a monster in terms of appearance and size. But in my whole time here I had found no evidence of this creature ever using that weapon wilfully against people. Even so, humans
judge others, both human and nonhuman, by appearances, and our first reaction is to recoil from such outlandish beasts. It’s not a measured intellectual response but a visceral one, and it
helps us to survive in a hostile world. But sometimes we get it wrong, and in the case of the sawfish I had been as guilty as anyone of being misled by my preconceptions. Maybe I wanted to believe
that it was a homicidal flesh ripper and I was disappointed to find that it wasn’t because that in some way diminished my capture. But in truth I liked the twist to this tale, and as I let it
go, I felt we somehow now shared our own private joke. Sure, if you’re a mullet or a bony brim, you should be very afraid. But from the human perspective, this animal is a gentle giant
– more sinned against than sinner.