River Monsters (40 page)

There are recent stories that seem to support this. In 1971 eight-year-old Carol Davis was paddling in a stream near the small town of Maheno when an eel grabbed her ankle and started pulling
her towards deeper water. Eels can swim backwards, so it must have felt like a dog attached to her leg that only let go when the girl’s older sister came to her aid.

I heard another tale from Brian Coffey who, in the 1970s, was an ecologist working with a diving team doing maintenance on the Arapuni dam. Working with lights in one hundred feet of water, they
would often see a huge head looming out of the murk, or part of a snakelike body, but never the whole animal owing to the poor visibility. Although large eels are invariably female, they christened
their shadowy companion ‘Horace’ and amused themselves on long saturation dives by occasionally tugging a workmate’s fin or bumping him on the shoulder. One day two divers were
decompressing, ten feet down, clipped to the grille over the turbine intake, when one of them saw the eel’s tail against the dam wall . . . and whacked it with his hammer. Understandably, the
eel bolted, colliding with the other diver, Ian Sutherland, and breaking two of his ribs. The severity of this injury confirmed Horace’s monstrous size – until the next day, when she
was found dead on the surface. Her head was indeed very large, but her body, although nearly a foot across at its thickest point, was only four feet long. ‘She was a fat slug of a
fish,’ said Brian. ‘She was probably the only big eel in there.’

He speculates that she was imprisoned in the lake, unable to follow her migrating instinct. So she stayed there and kept growing. This could be why some eels reach a very large size: old-style
dams or steep banks block their way to the sea, allowing no easy exit. However, even for eels that aren’t imprisoned, there is no set size or age at which they migrate. Some stay in fresh
water long after their contemporaries have left. I asked Brian if that was the biggest eel the divers saw. He said that in Lake Wanaka, before it was fished commercially, they’d spotted eels
with the same body mass as themselves.

Another diver, Clint Haines, was searching for a friend’s boat propeller one hundred feet down on the bottom of Lake Rotoiti near Nelson on South Island when a ‘huge’ eel swam
towards him. Within moments others joined it, one of which grabbed one of his dive fins. Panicking, he dropped his torch and kicked for the surface. His wife, who was waiting in a boat above, says
the eels pursued him to the surface, and Clint was screaming to get out of the water. He had come up so fast from deep water that he collapsed with the bends. Mr Haines had seen forty-pound eels
caught from the lake and estimated these fish were about eighty pounds.

For my first look at a New Zealand longfin, I went to the Mangawhitikau cave system near Waitomo, in North Island. Here, in near-total darkness in a river that runs through subterranean tunnels
in the limestone, lives an individual known to Te Pare as ‘the caretaker’, but that is more popularly called Gollum. Normally the only illumination comes from dim constellations of
glowworms on the cave roof, so you’d expect a bright torch beam on the shallow clear water plus the vibrations that six people dragging film kit make to cause some alarm to anything living
there. But the effect was exactly the opposite. A black shape a yard long slid through the shallow water to meet me, clearly in expectation of my offering. The water was so clear, she appeared to
be gliding through air. I could easily see the pronounced dome of muscle on top of her head that all large longfin females have, the reason for their vicelike bite and a feature that disappears
prior to their final migration, when they stop feeding. I dangled a finger-sized strip of goat meat in front of her, and she appeared to locate it by smell rather than vision before sipping at it
and then taking it with a loud slurp. This was a great opportunity to get some underwater footage, but the next time she approached she ignored the meat and went for the camera, biting the lens and
chewing its strap. Perhaps she was responding to minute electrical currents and thought it was some kind of rival or competitor on her patch. Interestingly, there were other eels down there, but
none in what appeared to be her territory. The only one nearby was a two-footer that I saw pulling itself tail-first into a cranny between loose rocks a good six inches above the water line. As it
did so, I heard echoes of Cook’s words: ‘He said that they burrow in the ground.’ Clearly the big one was not used to upstarts in her patch, so we removed the camera and tried to
regain her confidence, and eventually we had her crawling half out of the water on to the base of a smooth low stalagmite. She seemed to be curious about me, as though there was some kind of
intelligence there, and I wondered how she experienced her world and whether she remembered her journey here, swimming along an underground river.

After three days in North Island, the crew and I got up at 5 a.m. and caught a flight to Christchurch on the South Island. From eighteen thousand feet, the geology of the land is made clear in a
way that it isn’t at ground level. Erosion has sharpened the mountains into serrated ridges, between which the rivers flow, gnawing away at the rock and depositing it on the flat coastal
plains. Looking down, I thought of the elvers making their way against current and gravity, intimately penetrating the land like a swarm of parasites.

But they are a gift to the land. Although their life cycle is a mirror image of the salmon’s, which grow to adulthood in the sea and then fertilise the rivers with their dead bodies, eels
still bring nutrients from the sea, packed into the bodies of multitudes of elvers. As is the nature of things, most of these will not make it to the top of the food chain. In the past the Maori
harvested them, as they were a vital protein source, and they are still fished today. I went to see fishermen on Lake Ellesmere who dig blind channels to trap migrating adults, which can be handled
safely because they’ve stopped feeding so they don’t bite. The fishermen’s catch is exported to Europe and Southeast Asia, and although eel numbers are way down on historical
levels, New Zealand is about the only place left in the world with a viable eel fishery, thanks to taking conservation measures in good time. All longfins over nine pounds have to be returned. Once
they reach the sea, though, their peregrinations are as mysterious as those of the European eel, but biologists think they breed over a thousand miles away, south of Tonga, from where the ocean
currents bring the young back home.

Not far from Lake Ellesmere, in Christchurch, is the National Institute of Water and Atmospheric Research (NIWA) and the laboratory of Don Jellyman, their principal freshwater fish scientist. He
showed me recent pictures of the biggest eel he’d seen in a long time: a ‘feeder’ measuring four feet, eleven inches and weighing just under thirty-one pounds that was trapped
from a stream running into the lake. In part, the maximum size of any fish species depends on how long they live – and eels are extraordinarily long-lived. I watched as Don dissected out a
tiny flake of bone from inside an eel’s head, an otolith, or ‘ear stone’. These lie in nerve-lined cavities and give the eel information about its orientation and movement.
Equally significantly, they grow throughout life, producing clear growth rings, where growth stops each winter, that are visible under a microscope. The oldest eel that Don has aged was 105 years
old. He doesn’t dismiss the possibility of them growing to eight feet and a weight of over one hundred pounds.

This dissection also yielded information about the eel’s diet. Inside its stomach was another, small eel, already well digested. But the surgical gloves on my hands were not worn for
reasons of squeamishness. A splash of longfin blood on the lips or eyes can cause inflammation, and only three teaspoons, if it were injected, has enough toxin to kill a person.

From Christchurch we drove across the southern Alps to Hokitika on the west coast, on the trail of the biggest living freshwater eel known about anywhere in the world. Four years before, so
we’d heard, one of the longfin eels in the aquarium here had been netted and measured at over seven feet. This is close enough to the dimensions Cook gave to substantiate that part of his
report, and it would potentially look like a devourer of men to anyone in the water. My job was to get into the tank and verify its size, hopefully without confirming its liking for human prey.
This would mean netting it again and this time weighing it, which wasn’t done last time.

The circular tank was some ten feet deep, and my first surprise was the sheer number of eels in it. Instead of one fat individual lying on the bottom, there must have been more than fifty,
mostly in and around a large tree root. In the centre a stone-clad column housed the filter unit, and a close look revealed portions of eel tail protruding from holes in this where, despite its
underlying structure of bolted steel mesh, they had forced entry. Accurately gauging the size of the eels that were visible through the curved, distorting glass was difficult, but they were
undoubtedly large and thick bodied. I put the longest ones at five feet, which meant the big one must have been hiding.

While the crew prepared lights and worked out camera angles, I lay on my back and did some breath-hold exercises, working up to three and a half minutes, followed by one breath-hold of two
minutes while walking around. I tried to relax mentally, to push away thoughts of being nipped out of curiosity, of teeth catching in neoprene, of a panicked fish pulling further into cover . . .
but I knew my pulse would shoot up under water, cutting my time right down to thirty or forty seconds. On top of that, the water was icy. When I lowered myself in, the cold went right through my
three-millimetre wetsuit and knocked the breath out of me, making my body immediately demand extra oxygen. I tried to breathe evenly through the snorkel while scoping out the eels from the surface,
and then – no point delaying any more – I made the most complete exhalation possible, followed by a deep intake from the diaphragm, and dived down.

Immediately I felt uncomfortable. Despite my fascination with fish, there is something about eels that disturbs. I think it could be the fear of anything snakelike, which is hard-wired into all
of us. The thought occurred to me that I was going into an underwater nest of vipers, but I pushed it aside and tried to look for the big one–or, rather, the big girl, I reminded myself.
Somehow the knowledge that these were all females made the situation feel less threatening, although I didn’t pause to question the logic of that. For their part, the eels regarded me with
curiosity, turning towards me when I approached but drawing away when I got too close. Three of them, Medusa-like, had their heads and half their bodies protruding from the root mass. With
subsequent dives I gained confidence, but the cold was working through me. From this viewpoint I could see what wasn’t visible from the outside: that several eels were hidden between the
boulders of the perimeter wall. One of these looked bigger than the rest, with its head looking out from one hole and its tail sticking out of another. I wondered how territorial these fish were,
whether the bigger individuals muscled the others out of the best, most secure lies. This could explain why I hadn’t seen the big one. And if a seven-foot eel can stay hidden in a small tank
of clear water, how would you ever find such a fish in the wild?

After running to the shower, where I gushed hot water inside my wetsuit, I asked one of the aquarium workers when the big eel had last been seen. Not since it had been netted, he said. It had
some kind of growth on its head, so they hadn’t put it back. I had been hunting a phantom. As for its size, he directed me to one of the other staff, who couldn’t remember.

‘But it was significantly bigger than these ones,’ I prompted.

‘Not really,’ she replied.

So where had the reported seven-footer come from? Nobody knew. I’d found a real case of spontaneous generation.

But we still had the net and my 230-pound scales, so we decided to go after the biggest one we could see. This turned out to be ‘Number 7’, so called because of a pronounced downward
kink in her neck, like an arthritic grandmother. Seeing that she was lying in an open area of the bottom, I dived down and scooped her head into the meshes, but her broad tail wouldn’t fold
inside, so I supported it in the crook of my arm as I surfaced, hoping she wouldn’t wake up to what was happening and reverse out. Hands above me took the net’s handle, and there she
was, lying quietly on the damp mat that we’d laid out–before grabbing the edge of our wooden platform with her tail and pulling herself back into the water. But by then we had the data
we needed: a length of exactly five feet, and a girth of eighteen inches, giving a weight of thirty-five pounds – an impressive fish, but well short of the size we were hoping for.

Although the seven-footer had vanished on our approach, we then heard stories of ‘huge eels’ in some dredge ponds nearby from the days of the gold rush. But there was no time to
check these out because we had a flight to catch. At the check-in desk they told us not to hand back our hire vehicles just yet. Because of low cloud, there was some doubt whether the incoming
twenty-seater would be able to land. At length, we took off through squally clouds, climbing steeply to clear the Alps. But the worst lurching and rattling came on the other side when we flew
between windswept clumps of cloud with the flat coastal plain beneath us. One of our crew heard the passenger behind him praying.

The next stop was Invercargill at South Island’s southern tip, where I met Vic Thompson, the manager of an eel processing plant that sends eels on aerial journeys as far as Billingsgate
market in London. The biggest eel he has seen out of the water was a fifty-two-pounder, squeezed into one of his fyke nets when he was a commercial fisherman. But he’s seen two shapes in the
water that were bigger than that: one that he first thought was a log that took a bait his uncle fished and nearly pulled him into the water, and another close to the length of his ten-foot boat.
He’s also seen eels attacking sheep, overpowering them in a stream where the banks were too slippery for the animals to escape. The eels burrowed into one sheep’s anus, ripped out the
intestines, and ate the internal organs.