The great goby mudflat desertion
It is entirely possible that I have stumbled upon a little-known gap in scientific knowledge.
While researching this piece about the disappearance of mudskippers on the mudflats out-front of my adopted city of Cairns in northern Australia, I discovered a bemusing lack of certainty about the humble goby.
Having asked Google to tell me how many known species of mudskipper there were on the planet, most of the academic studies that popped up listed between 19 and 42. One seemingly optimistic researcher suggested 300-plus.
So, I’m concluding until otherwise corrected that the profile of the little mud-burrowing amphibians is too low for science to have bothered with a definitive call on their variations.
All of which has become somewhat academic on the mudflats of the Cairns esplanade – because the mudskippers seem to have abandoned the place.
By definition, mudskippers like mud – they love to cavort in it; usually the tropical and sub-tropical stuff. But not, it seems, if something messes with their ‘ooze-o’ cocktail.
Just a few years ago, you could see thousands of Boleophthalmus birdsongi and Boleophthalmus caeruleomaculatus (apparently the most common mudskipper species around Cairns) from the esplanade boardwalk. But for reasons yet to be explained, they have all but disappeared from that location.
I took the accompanying pic of a whimbrel with what might have been the last of our gobies (a birdsongi, surely) in March 2016. Esplanade regulars say there have been other isolated sightings, but I have yet to receive conclusive proof.
This mystery is clearly something for academic minds to unravel. Meanwhile, I proffer the likely culprits as tropical storms and the Cairns Regional Council’s stupid beach creation project, which introduced vast amounts of sand to the foreshore in a short time and drastically altered the structure of the mud.
Mudskippers like to dig deep burrows into soft substrates and seek refuge there from predators and extreme environmental conditions. They also lay their eggs inside their burrows.
But mudskippers aren’t good at breathing underwater, so they gulp air and carry it down into their retreats, where it is released into special chambers. This apparently provides the male (who protects the eggs) and the eggs themselves with a moist, oxygen-rich environment.
All they ask is for some decent quality mud to flap around in, and to be left in peace!
©Tony Neilson, Natural Images 2018