It’s a puzzle that has a group of Auckland Council’s ecologists and their contractor from Wildlands stumped.
While checking out Grafton Cemetery’s (also known as Symonds Street Cemetery) seldom visited gully system one evening recently looking for bats, the team stumbled across an exciting find.
At the bottom of the gully lies a little stream called the Waipāruru which once used to run out to the ocean but is now swathed by motorway asphalt. All that remains is a shortened 200m channel within the reserve where the stream inexplicably stops and disappears, soaking forlornly into the ground.
It’s against this background the ecologists, finding no bats, turned their flashlights nonchalantly into the stream’s many empty pools.
They were astonished when at first a head appeared, then the unmistakable sinuous form of a shortfin eel broke cover from beneath a log.
More whooping and hollering followed when further upstream another appeared, this one perched beneath a log and reluctant to reveal itself.
Still another fish is found, this one a banded kōkopu fabled for their climbing exploits as juvenile whitebait.
Two eels, similar in size, and a solitary kōkopu occupying the best habitat this little stream has to offer. But how on earth did they get here?
The two seasoned freshwater ecologists Nick Goldwater and Matt Bloxham have witnessed the otherworldly climbing exploits of juvenile eels returning to freshwater, scaling seemingly impassable obstacles to reach the habitat of their forebears.
But for these three fish, there is no question, the journey is seemingly an impossible one. Nobody has an explanation, though one must exist. But all agree the journey, however unlikely, must have been a fraught one.
Amid the celebration and incredulity comes the sad realization that for these fish, the story begins and ends here.
The banded kōkopu, all alone, will make a living from the bountiful supply of insects for a few years yet, as will the eels.
But if they are to breed, these two eels must return to the ocean. Yet the exit strategy for these fishy fellows and the chance of being joined by more is confounded by this virtual dead end!
The ecologists are now plotting to make their stay an enjoyable one.
There’s better habitat on the cards and the stream outlet will be excavated in the hope others may join these three.