What constitutes a pristine environment? Pristine by definition means ‘original’ but the word original in relation to planet Earth can only be applied from a given point in time.
Ten thousand years ago, sea levels were sufficiently low to allow us to walk from PNG to Tasmania over a landmass known as Sahul. There was no Sydney Harbour and you could walk east of our current coastline for many kilometres before finding the ocean.
The Gulf of Carpentaria, on face value, would seem to be a ‘pristine’ environment but there is irrefutable evidence of a massive, human-made, erosion/siltation event having occurred there since the end of the last ice age.
It is believed that the Aboriginal practice of fire stick farming, over thousands of years, had a similar effect to our modern-day land clearing. It allowed huge quantities of earth to be washed into the sea on a scale that makes our efforts look like a toddler’s tinkle in a sandpit.
The rivers of the Gulf were believed to have once flowed deep and clear. Some fossil evidence even suggests that it may have harboured large Lutjanus species, the likes of black bass.
Pristine, in relation to humans, can also mean ‘unspoilt’. So, can we assume that if humans dramatically alter an environment to its betterment, then it remains pristine?
Our perception of pristine is borne of the misguided concept of ‘the balance of Nature’. Since the beginning of life millions of species have evolved and then perished, only to be replaced by more critters evolving to meet the constantly changing (often violently) geographical and atmospheric conditions. Where’s the balance in that?
The only law that can be applied to this planet is one of constant change. The bit that really matters to us humans is the rate of change.
My point to all this is that when humans decide to build a city the size of Sydney on Sydney Harbour, things are going to change. But change isn’t necessarily a bad thing and it’s going to happen anyway.
There’s no point in trying to compare our major city waterways with, so-called, pristine environments. In my short lifetime I’ve witnessed the futility of this.
When I was a kid in the 1960s and ’70s, Sydney Harbour was all but a write- off. Pollution and commercial activity were at all-time highs and with increasing commercial and recreational fishing, the Harbour was really suffering.
I was also fishing little Boambee Creek, just south of Coffs Harbour, that we considered to be pristine. There was no pollution and the fishing was sensational with countless flatties, bream, whiting, crawling mud crabs and even a few mangrove jacks.
Over the next 20 years I witnessed a complete turnaround. Development, both industrial and domestic, encroached on Boambee. Fishing pressure, rec and commercial (and illegal) increased.
We could watch the crab poachers with their spotlights from my granddad’s waterfront home every night in holiday time. I was devastated in the early ’90s to hear that that, for a time, Boambee had been declared the most polluted waterway on the North Coast, failing EPA pollution tests for the entire 1990 swimming season. The quality of the fishing plummeted.
Meanwhile, Sydney Harbour was making a big comeback. Industry was stopped from using it as an open sewer, sewage outlets were diverted well offshore, stormwater was cleaned up, kingfish traps were banned and salmon canneries were closed.
The water cleaned up and the fishing improved dramatically. The recent removal of all commercial fishing from Sydney Harbour has set the scene for the creation of a piscatorial wonderland.
Given the choice of fishing either of these two waterways now, the Harbour would win hands down.
I suppose my point is that just because humans have changed a waterway dramatically doesn’t mean that the fishing can’t be good. The Harbour is a classic example that high-density human population and exceptionally good fishing can coexist if we make the effort.
Assuming that we don’t take them out faster than they can regenerate, fish are a renewable resource.
Commercial fishing isn’t so bad if it’s done properly. Unfortunately, it usually isn’t.
But not everything humans do to a waterway is bad news, even if only by default.
Dams and weirs, while they have their downsides, have been great news for freshwater fish, especially once we rectified our oversight on the small matter of fish ladders.
In fact, dams are now strongholds for some species populations to the point that dams are keeping them off the critically endangered species list.
And what about all our bridge pylons, jetties, moorings, channel markers, wrecks marinas and breakwalls?
While I’m not suggesting that they replace habitat losses like seagrass, they create new and hopefully equally beneficial habitats for a bounty of juvenile and adult species.
The range and quantity of species around the Harbour’s yacht moorings is flourishing over what would otherwise be a featureless, fishless sand bottom.
We see as a stand of fairly unattractive boat moorings, fish simply perceive it as reef. The average swing mooring block has a diameter of about 1.5m and stands about 1m high. Cover this in marine growth and drop 30 of them in a bay and you have, by default, a substantial artificial reef.
A big stand of moorings encrusted in marine life also has the advantage of discouraging commercial netters
Kingfish love the shade created by big channel markers. It gives them, and us, a reference point in what would otherwise be featureless, open water.
The anticipation of casting to structure, human-made or otherwise, is a lot more inspiring than blind casting.
Besides being great shade and shelter from predators and current, our marinas and other structures must represent a massive addition to the food chain.
The banning of tributyl tin-based antifouling paints has resulted in a dramatic increase in inter-tidal shellfish. Tributyl tin was so effective that not only would nothing grow on the hull but even within 10m of the boat. A quick scan of our marinas today reveals a smorgasbord to rival the Tokyo fish market.
Not all pollution is bad for all species. It’s interesting to note that while the numbers of some species increased at the old North Head sewer outlet after it was moved offshore, there was also a decline in other species. And likewise at the new outlet.
Clearly, some species were benefiting from the ‘nutrients’ the outlet provided.
Northern beaches rock and beach legend Big Al Bellissimo is adamant that the blackfish and drummer fishing was better when the ‘poo pump’ was nearby.
Blackfish don’t eat poo but they thrived on the increased weed and algae growth it encouraged.
Fish scraps are classified as ‘kitchen pollution’ by the NSW Maritime Authority and, by law, in Sydney Harbour, you have to take them home and put them in the bin.
Theoretically you cannot fillet a freshly caught fish on the Harbour and throw the frame back.
But we all know that this ‘pollution’ creates a dramatic increase in fish populations, particularly bream, around boat ramps and cleaning tables.
In the right doses, phosphate run-off into waterways from the likes of golf courses and turf farms can actually benefit bottom-end food chain critters and hence the whole system.
Sydney Harbour presents the angler with an environment altered, both good and bad, by humans. But, overall, it is now fishing at a standard that anyone under 60 years old cannot recall.
Lap it up – but look after it!Reads: 776