I have just been looking at a new paper which is extolling the virtues of green zones in Moreton Bay. It is by Olds et al. (2014) "Marine reserves help coastal ecosystems cope withextreme weather" Global Change Biology 20: 3050-3058. In it they say that coral reefs in green zones in Moreton Bay survived and recovered from the 2011 floods much better than reefs outside the green zones, and they reckon this is due to fishers taking herbivorous fish from the areas that remain fishable. The species they are talking about are blue barred parrotfish (Scarus ghobban) and surgeonfish/Australian sawtail (Prionurus microlepidotus), and they also mention happy moments (Siganus fuscescens). Populations of these were apparently higher in the green zones prior to the flood, and they are trying to say that fishing has affected the recovery of the reefs outside the green zone after the floods.
I am not convinced, as I have never heard of anyone targeting any of these species in the bay. Instead, is it possible that the green zone reefs recovered better because the better reefs were chosen as green zones in the first place, so the result could be basically due to site selection bias as they did not do surveys of herbivorous fish before/after green zone declaration ? (i.e. they may have always been higher in numbers in the green zones because the green zones had more coral in the first place - protecting the best places makes for a self fulfilling prophecy later down the track....). Does anyone have any information on whether they know any people taking these parrotfish, surgeonfish and happy moments in the bay, or not ? If so, please post up so we can see what the state of play is.
In contrast, another recent paper by Wegner et al. (2015) Effects of reduced water quality on coral reefs in and out of no-take marine reserves in Conservation Biology looked at the effects of the 2011 and 2013 floods on coral reefs in the Keppel Islands and found the reefs suffered greatly and that the green zones had either no effect or a reverse effect - with macroalgal cover higher in the no take areas. I would expect no protection from floods by MPAs , but I did not expect them to make things worse - so do these two studies just cancel each other out ? Or are the researchers in Moreton Bay actually reporting a site selection artifact because no one actually targets the fish they think are saving the corals down here ?
More than likely yet another case of a set of data/statistics being interpreted or manipulated by someone with an agenda. I do know that historically there has been targeting of happy moments by commercial tunnel netting for export markets but I do not know to what extent. There may be some accidental by-catch of parrot and surgeonfish but in 25 years of fishing in the bay I personally have never caught either. I have seen one parrot but no surgeon.
Thanks Scottar. Any ideas where the pros have been tunnel netting happy moments ? Would be hard to tunnel net on a coral reef I think.... Worth noting everyone we are talking about the true parrotfish, which have beak-like teeth and tend to eat coral etc, not tuskfish (which some people still call parrot, but tuskies have peg like teeth and eat a wide array of food items, including lures and baits).
Many years ago b4 the green zones I helped a pro netter net the lazaret and the corner just up from the old Platypus. At the platypus he recognised that there was a school of happy moments which he netted for crab bait.
Sorry Ben, no exact location but my understanding was north of Peel Island. I have seen large (about a kilo) happy moments caught off the Amity Point Jetty from time to time on rod and reel.
Ben, I've fished the reefs around the bay for 30 years and have never caught a surgeon fish let alone kept one. On very rare occasions have caught/ seen one of those wrasse but never kept one, too small. People fishing the reef are, as you know, targeting snapper and sweeties and the like typically using 4/0 and bigger hooks, so these species with their tiny mouths are pretty damn difficult to catch. You might foul hook one on rare occasions but that would be it.
See zillions of happy moments at times at Peel and nearby reefs. Coughs a few, but again they are hard to hook on 4/0's.
I know now for a fact, having been deeply involved in the fight against the last rezoning, that some reefs were selected specifically because of their outstanding condition (eg Myora), which when you consider that they had been fished for the past 50 years, it's ironic that they needed to be turned into GZ's to protect their pristine condition....... Some rediculously flawed logic in there somewhere.
PM sent to you with more info that I hope will help.
Note to self: Don't argue with an idiot. They will only bring you down to their level and beat you with experience....
Having dived and speared (I only ever take a bream for tea, and the odd painted cray) the reefs in front of Reddy/Scarb for many years, I may be able to add some info.
I dunno about the green zones, as I never go in them with the spear, but the fringing reefs do hold juvenile Parrots. This year I saw more than any other year. Still not a heap, but more than previous years. They're definitely there. Never saw an adult model, though. Have never seen a surgeon or happy moment in those parts.
Interestingly, this winter was also the most barren in terms of life. Very difficult to even find bream at times. Almost as many Slateys as bream. There was also a massive overgrowth of a plant-like weed that I haven't seen in recent years. Plague proportions. May have something to do with local conditions, though, as the amount of diveable days were far less, and the water temp stayed warmer than normal.
Cuzza
I cant possibly see how fishermen could have any measurable impact on these species as they are at best an incidental catch.
Logic would dictate that if the GZ were working as intended we would see an increase in size and number predatory fish such as groupers and Cods and a consequential decrease in Herbivorous fish due to predation.
Parrot get caught from time to time by the prawn-danglers at various places around Amity point. A lot of happy moments (none that I have seen were too big though) in the area as previously mentioned. Never seen a surgeonfish get taken by line, but they're there (everywhere when snorkelling).
Never seen a surgeon in the bay and only ever caught a couple of juvenile parrot while jigging for bait around the wrecks at Curtain arty.
Democracy: Simply a system that allows the 51% to steal from the other 49%.
I've also seen plenty of Surgeon fish in the bay while snorkelling and caught plenty of almost legal parrot fish off Cooks Rocks, Scarby, Mud and Peel. Also landed 2 nice parrot near Goat last year. A few years ago we use to catch a lot of Happy Moments chasing yellowtail for bait on the shallow reefs off Redcliffe, often needed to move spots to avoid them.
~~~><))))*>
Caught one of these (surgeon fish) today in the bay. Put up a great fight. Estimate around the 2kg mark. Was hoping it was a snapper when it first took off. There was a small school of them, all around the same size.
Oh, caught a blue barred parrot fish in the same spot also.
When I first started out fishing around Peel and the like, (yes using prawns and smaller hooks, I now know better!) I was catching parrot and tusk, not heaps but more then a few legal fish.
Cant say it makes a difference one way or the other, but you never now how large an effect a seemingly small action can have.
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