What to do about the influx of carp after the floods and as it seems forever after
One solution is to eat them
European carp victim of prejudice. Here is why they get a bad rap.
Off-flavour taint of aquaculture products, including around European carp is a global issue reducing consumer confidence in the farmed produce (as well as the wild caught carp of our lakes and rivers). As they are taken up via the gills of fish, and deposited in the lipids (fats) of the animal. If the fish are not purged, resulting undesirable muddy earthy flavour taint can be tasted by consumers. These undesirable flavour and odour is caused by the terpenoid compounds namely geosmin and 2-methylisoborneol, produced as secondary metabolites by certain bacteria including the cyanobacteria and actinomycetes. Geosmin is a neutral oil, with an approximate boiling point of 270 C, which contains carbon and hydrogen, but no nitrogen. It undergoes a reaction with acid (vinegar is an acid) to give odorless geosmin, a neutral oil, with an approximate boiling point of 230 C, which contains only carbon and hydrogen. 2-methylisoborneol, is also reduces to an odorless compound with acid
A study on the reduction of off-flavour compounds that cause “earthy” and “musty” organoleptic sensorial characteristic in fresh water systems was conducted. These compounds include geosmin and 2-methylisoborneol (MIB), which are produced as metabolites by some algal and bacterial species. Drinking water and aquaculture commodities affected by these compounds become undesirable to consumers, and market values tend to drop significantly. Triple distilled water samples spiked with approximately 1 μg Kg-1 geosmin and 1 μg Kg-1 2-methylisoborneol were dehydrated through acidification using two different food grade organic acids (acetic and citric acid), at different concentrations: 0.1, 1.0 and 4.0% (w/w). Levels of geosmin and MIB reduction were determined using Solid Phase Microextraction (SPME) and Gas Chromatographic/Mass Spectroscopic (GCMS) analyses. Results showed that acidification treatments of the off-flavour compounds using varying concentrations of acetic and citric acids significantly reduced the concentrations of geosmin and MIB in the samples. Treatments with 1.0% citric acid and 4.0% acetic acid significantly reduced the concentration of geosmin to concentrations as low as 0.07±0.03 and 0.09±0.01 μg Kg-1 respectively, while the reduction of MIB to concentrations of around 0.05±0.01 μg Kg-1 was achieved at a minimum concentration of 0.1% of either acid used. Previous studies reported that products of the dehydration process of geosmin and MIB produce non-odourous products such as argosmin, and 2-methylenebornane and 1-methylcamphene respectively.
Armed with this kind of knowledge, we can begin a journey to reduce the impact of carp in our waterways by putting a dent in their population, and start educating the public on how to eat them. They do it in the northern hemisphere. Treating them like repulsive vermin has put up a wall of ingrained prejudice, so deep in our Aussie culture and it will be hard to overcome.
This tells us that the expansion & creation of companies like Charlie Carp and K&C Global ( Keith Bell) Fisheries could utilize more of the Carp biomass & at the same time reduce the amount of Chemical fertilizers used on farms & in homes, which vastly affect the health of our waterways when run offs occur after rain.
If the Koi Herpes Virus is released then it is very possible that this will no longer be an option.
Keith Bell, the fisherman who is responsible for almost all the Carp exported from the country in the last two decades, states that once the Carp begins rotting, it can’t be used for either pet food or fertiliser. He says that even if the fish could be collected in time (a matter of hours after dying), the volume would probably overwhelm processing facilities. Carp isn’t being used for pet food at the moment and the fertiliser industry only processes a couple of hundred tonnes per year, according to Keith.
Now if we are to utilize Carp for Fertilizer on a larger scale this will also increase the need for Commercial Fishing Operators to catch them.
This leads me to my next point – Commercial Fishing & Export. Currently there appears to be no export of Carp. That does not mean the demand is not there for it. Keith Bell was exporting thousands of tonnes of Carp every year until 2015 when he sold up & moved overseas. This was because the drought reduced his catch numbers to become unviable
Keith, who was exporting a couple of thousand tonnes of Carp per year from Australia from the late 90’s until 2016, when he sold up & moved to Mississippi. In the article “Weaponising Herpes – What could possibly go wrong with Carpageddon?” he was further quoted in saying “It’s a wasted resource” & said that restrictions placed on what equipment he could use to catch the fish & restrictions to minimise the bycatch of native fish, made fishing Carp too expensive. By relaxing some of these restrictions on commercial fishing, it could possibly boost the export of Carp.
identify the spike point.
Also known as:
Carp
Oriental Carp
Common Carp
River Rabbit
Koi
Common Group Name:
Carps
Family Name:
Cyprinidae
Genus Name:
Cyprinus
Species Name:
Cyprinus carpio
Dispatch Method:
Carp can be very tolerant of air exposure and can live for prolonged periods in ice slurrys. To maximise their eating qualities they should be killed humanely by iki jime, or a firm knock to the head before being placed in an ice slurry after bleeding.
Fish Description:
- European Carp have small eyes, thick lips with two barbels at each corner of the mouth, large scales and strongly serrated spines in the dorsal and anal fins.
- The colour is variable depending on water conditions, but is commonly olive green to grey dorsally, fading to silvery yellow on the belly.
Fish Distribution:
- Carp are actually native to Asia, but ancient traders are thought to have spread the fish west into Europe.
- From there carp have been introduced into Australia on several different occasions. European carp have been introduced into the Murray-Darling system as well as many other water bodies and rivers in south eastern Australia.
- Small populations also occur in Tasmania and Western Australia.
- They also have been translocated into many other countries and are now one of the most widely distributed freshwater fishes in the world.
Fish Size Common Length:
40-50 cm, maximum size exceeds 120 cm and 60 kg.
For assistance with identifying fishes, see fishesofaustralia.net.au. For information on size and bag limits, check out the website of your State Fisheries Department.
We thank fishesofaustralia.net.au and Australia’s various Fisheries Departments for some of the thumbnail images used to assist with fish identification on this website and its applications, as licensed for use under Creative Commons Attribution 3.0 Australia. Thanks also to Michigan State University and Georgia Aquarium for generous donation of xrays of some US fish species.
What Is Ike Jime?
Ever wonder why yellowtail or bluefin sashimi tastes better at a truly authentic sushi bar? You’ve probably brought fish home from a trip and created your own sashimi platter only to discover it didn’t quite taste the same and the texture wasn’t as nice as what you’re accustomed to ordering at your favorite Japanese restaurant. You just harvested the fish yesterday – it doesn’t get any fresher, so what gives? The way a fish is handled once it comes aboard is what truly makes the difference in terms of taste and quality. Welcome to Ike Jime. Follow this simple four-part process and you will enjoy an elevated caliber of fish at home or on the back of your boat.
The finest quality seafood is often associated with sashimi, sushi, and other Japanese raw fish preparations. Ike jime is a traditional Japanese slaughter technique that involves instantaneously euthanizing a fish by inserting a spike into its brain cavity. The fish is then thoroughly bled and undergoes spinal cord destruction (shinkei jime) before getting iced down.
Why Is Ike Jime Important?
Ike jime produces a biochemically superior grade seafood product as the process helps to eliminate stress and the natural consequences of death. When a fish experiences stress, its brain goes to work by flooding the muscles with lactic acid, cortisol, and adrenaline. Core body temperature also rises. The combination of hormones and elevated temperature turns muscle tissue to mush and negatively impacts taste. When performed correctly, ike jime prevents this from occurring.
The following four steps will yield tremendous results. When performed correctly, you will notice not only a better tasting fish but a fish that will last longer. The term “fresh” is commonly used by grocery stores to convince you to buy their imported fish. A properly processed fish will stay “fresh” significantly longer. Harvested with the ike jime method, fish can be refrigerated for weeks when safely stored in a vacuum sealed bag or airtight container. This process not only makes the fish taste better – it also lasts longer, has zero smell, and reduces waste as it won’t spoil nearly as fast, allowing you to respect the fish and the fishery to the maximum ability.
After rejecting outright asphyxiation for being cruel, and clubbing the fish by hand for being inefficient and easy to mess up, the institute (the Institute of acquelculture in Shepherdstown West Virginia landed on automated stunners from Seafood Inovations in Australia, which they’ve been using ever since.
There’s plenty of evidence that killing fish with a blow to the head results in better food. But Tsui wanted to see if using the full ike jime process, including spinal cord destruction, made a significant difference. There were slight differences immediately after death, but a few days after slaughter, the color, texture, and pH levels were about the same, suggesting that a quick, calm death is the most important route to high-grade fish.
Fish for eating we have people to eat them all cooks are there to make fish palatable you should not be a cook unless you can. Soak them in vinegar 50 50 with water overnight removes the unpleasant taste.
European Carp a no different.
the fish have to go. Eat them as roe . Even the mail gonads make a dish if that’s what you wish.
CargelligoWetlands 