With the Snapper closure in full swing since starting on Tuesday, reports of snapper, pearl perch and teraglin jew releases have been pleasing to hear. Though it has been brought to the attention of both fisheries offices and researchers of the Rocky Reef Fin Fish Fishery, that anglers are finding it increasingly difficult to return a fish to the ocean if it has an inflated swim bladder or a condition called barotrauma.
Barotrauma results from the expansion of gases in the swim bladder of fish that are pulled up from the bottom. The effects and severity of barotrauma increase with depth of capture and susceptibility varies between species. All reef fish have the swim bladder organ and bottom dwelling species are mostly affected by barotrauma but it can also affect freshwater fish caught in deep lakes.
The symptoms of barotrauma include a swollen stomach that is hard when touched, stomach pushed out through the mouth or gill cover, eyes bulging out of sockets, bubbles in the blood when bleeding and scales standing away from the body (like the bristles of a brush). If barotrauma is not treated then released fish may have difficulty with orientation and swimming below the surface making them vulnerable to predation from large fish such as sharks or from birds.
Local Charter Operators are very familiar with techniques in minimising barotrauma and curing it once the fish is at the surface and reveals the symptoms. However, the average novice or occasional angler may not be familiar with the best steps to take. If anglers in Queensland are going to make this total snapper ban worthwhile, then it's imperative we are aware of the best handling methods and release method for fish like snapper, which have a swim bladder. Noosa Cat-Ch Offshore Fishing Charter operator Gary Froome fished Sunshine Reef last weekend and reported excellent catches of coral trout, as pictured with Phil, Andrew, Luke and Matt proudly displaying their catch. They exercised care and caution when handling undersize fish and no-take species, while also taking steps to minimise barotrauma in their catches.
Brigid Kerrigan from Fisheries Queensland recommended on local radio this week that any angler fishing in waters over 20m deep needs to handle the fish with great care in retrieving the fish. "Bring it up, don't race it up from the bottom which stresses it - gives the maximum chance of survival", says Brigid. If you decide that the fish is not one you wish to keep, or it is below the 35cm limit or it's banned like snapper are at present, then slow retrieval is necessary.
But there is a fine line between minimising barotrauma and having a retrieval so slow that you lose the fish. Brigid agrees that anglers do need to move at a pace which avoids losing the fish to sharks for example but still maintains that all efforts need to be taken to help the snapper population.
The other option which is widely used around the world is the process of venting the swim bladder with a venting tool or surgical needle. The fish needs to be displaying all the abovementioned symptoms of barotrauma. It is best to vent the fish as quickly as possible with a minimum of handling. If the fish's stomach is protruding out of the fish's mouth, do not attempt to push it back into the fish's body. Many anglers think the nest move is to pierce this, but it will only lead to eventual death.
Expelling the swim bladder gases will allow the stomach to return to its normal position within a few hours. Hold the fish gently but firmly on its side and insert a venting tool at a 45-degree angle approximately one to two inches back from the base of the pectoral fin. Only insert the tool deep enough to release the gases - do not skewer the fish. The sound of the escaping gas is audible and deflation is noticeable.
Venting tools are very hard to come by in Australia but are widely available in America. You can find them occasionally on eBay but many local anglers have resorted to using a surgical needle in it's place. The photo featuring a venting tool being used on a red emperor from the 2010 trip to Swain Reefs. This venting tool was fantastic to use but was an import from USA, yet to be available in Australia unfortunately.
So between now and 31 March 2011 the interim closure will hopefully reduce the fishing pressure on snapper. Please follow the rules and release snapper, pearl perch and teraglin while also taking steps to vent swim bladders as much as possible.
A venting tool being used to expel air from a red emperor's swim bladder.
Noosa Catch Fishing Charters took Phil, Andrew, Luke and Matt to Sunshine Reef where they brought home a feed of coral trout.
While fishing around Old Woman island Ed Vanderloy had the fight of his life when this 18kg Spanish mackerel took his floating pilchard.