For almost a century and a half, carp have flourished and spread throughout the freshwater rivers and lakes in much of the world. The US and Australia have been particularly hard hit by the invasion of these fish from Eurasia, but Africa and South America have not been spared the spread either.
Deliberately introduced to many places to supplement the natural fish stocks for food and for recreational fishing, huge sectors of industry have grown up around these fish, and billions of dollars around the world are made annually of the backs of these industries, thousands are employed.
Yet in Australia there is a plan to get rid of these fish from the landscape. Not a good plan, in fact an absolutely terrible plan, but a plan nonetheless. This plan revolves around releasing yet another organism into the natural environment and hoping it does the work. This virus is a herpes strain, the Cyprinoherpes Virus III, a strain so virulent it is projected to wipe out up to 90% of carp stocks in the first releases. Sounds pretty good, hehe, if you want to clean out a species. The issue arises when you consider the sheer numbers. Carp make up the bulk of the bioload in the system; between 65-80% of the bioload is made up of these fish. The virus will kill 90% of that species, say 60% of the bioload on average. Higher in many places. That is a lot of dead fish to try and clean up, which is where we come to the major problem. How do you clean up thousands of kilometers of waterways of dead and rotting carp?
This is a major stumbling block. The virus is active between 20 and 28 degrees Celsius. This corresponds with our slack flow period. however, the grand plan is to have prioritised, targeted clean up points. The hope is that the corpses will collect at certain points and can be targeted for clearance. This is never going to happen. Carp are big, heavy fish. They sink when killed, until the gasses of the breaking down innards bloat and expand and float the already decomposing corpse. These gasses are also being released into the water, along with all the other things that come with decay. The water is not flowing and these gasses build up to pollute the slack flow, with each passing pool adding to the aggregate pollution in the flow. This toxic soup begins to kill off other species, not only fish, but turtles, frogs, insects and larvae, shrimp and yabbies and other inverts and so on all dis as the water becomes too toxic and too low in oxygen to maintain life. Plants die in the water and in the riparian zone as the toxins build up to kill them. Mammals, birds and reptiles cannot utilise the water for drinking. Platypus, water rats etc are in trouble. And in the end, there is nothing, and a black water situation has become an extinction event. The water is useless for urban or rural purposes, which are in fact the core of the problem.
Australia is to become a continental, open air testing ground for pathogens and their spread . Am I being dramatic and conspiratorial here? Not according to this paper from the US institute of Health and science.
What is worse is that there are many factors beyond carp which are to be held responsible for the reprehensible state of our waterways. Most of these are man made in their origin, and the removal of carp will not restore the natural, pristine waterways it is promised to.
The topmost of these reasons, but not restricted to, are:-
1/ Removal of logs, rocks and other habitat for channel clearance and flood damage mitigation. - To prevent damage to hydroelectric turbines, dam walls and flow ways, irrigation channels, bridges, jetties, weirs, pumping stations and other infrastructure, river channels are regularly cleared of the debris which naturally accumulated in these channels from deadfall riverside trees, undercut banks and flood events. This all was the natural habitat of many of our natural fish species from the Maquaria perches to the Suliriid catfish, to the Macullochella cod species, all rely heavily on cover to make their home. Cod often spawn in hollow logs or on the underside of large boulders, the very things targeted for removal. A large tree with roots and branches might provide the habitat for a large number of golden perch or cod, and they are removed regularly.
2/ Dredging channels destroying buffered flow and creating lineal flow, scouring the river bed and banks and causing erosion. - Australian waterway are long, flat and slow moving for the most part. This changes during flooding rains, when the plains become lakes, but generally speaking, lazy would be the best way to describe most of our rivers, the largest of which, the Murray, would not even be considered a decent waterway in most countries. Due to this, they tend to silt up heavily, and dredging is required to keep channels open for the limited shipping that utilises these waters. This removes the natural obstacles which buffered the flow of the water and allows the water to flow straight down a cleared channel. This lead to stress on the fish in the system having to constantly fight the flow, and to increased erosion and scouring of the river bed. This removes substrate for plant root establishment and nutrients for growth which are then in suspension and available to algae for their growth, giving green stagnant water.
3/ Tree removal, especially the wholesale removal of the willows, causing river bank erosion and loss of habitat for fish and their prey, insects and crustaceans. - The loss of riparian trees and undergrowth for rural land use purposes leads to serious erosion problems as there is no tree roots to hold the soil together. It has also led the flow becoming lineal, again, as the tree roots that would grow into the rivers and the streamside transition plants and reedbeds would spread and slow the water, holding it in the system, helping reduce flash flooding down the system and allowing natural absorption and seepage to spread excess flow into the surrounding ground. Now that water just rushes down the system and is not restrained until the next manmade obstacle and flow management device. This might help mitigate flooding, but does nothing for the river or the surrounding land. In addition to this, fish, insects and their larvae, crayfish of all types, snails and a host of other organisms including filtering bacteria utilised the trees and their roots for habitat and protection, food source and shelter from the extreme elements. The river temperatures were buffered by the surrounding vegetation. Now they are open to sun, wind, freeze and evaporation. The major blow came a few years ago when war was declared on the willow tree and they were systematically removed from rivers and streams all over NSW and ACT. The rivers became manky and the trout and silver perch disappeared from many regions. As if this is not enough, there is also no buffering of the water flowing into the river after rain, so it does not get a chance to soak into the soil naturally, and it carries all sorts of pollutants and nutrients with it which would normally be filtered out by the trees.
4/ Removal of water for domestic and other urban usage. - Huge volumes of flow reduction are suffered as water is pumped out for urban usage and much id not returned, or if it is, it may be many miles from the source or may contain contaminants and pollutants. A good example of this is the Canberra region. 3 major rivers flow through the region. The Queanbeyan, the Molongolo which loins with the Qbn just below the border of the town of Qbn and Canberra and the Murrimbidgee which the Molongolo flows into just below Uriarra, outside Canberra. Water is removed from the system at Googong Dam and not returned until just before the juncture with the 'Bidgee. This is many miles that there is greatly reduced flow in the lower Qbn and lower Molongolo rivers. It is evident below the outflow this has a major impact as the river runs clear for the first time in many kilometres. Above the out flow it is sluggish and green.
5/ Removal of water for irrigation and other rural usage - flow in water is laden with herbicides, pesticides and fertilisers, all of which have a huge negative impact on the water ways. - Especially in the regions of the Murrumbidgee Irrigation Zone and the Cotton Growing region up the Darling River system, this is one of the greatest impacts on our rivers. Water is removed in vast volumes from the riverways and the return flow is heavily laden with all the wonderful chemicals that are the modern farmers friend, and the environment's worst nightmare. Fertilisers feed algal blooms, pesticides kill off all sorts of aquatic life, not only insects, and herbicides poison higher order aquatic plans and animals. This toxic soup concentrates as you get further down the systems.
6/ Lack of flooding into inhabited flood plains. - Flooding used to bring all sorts of benefits to the rivers and the areas that surrounded them. The initial flood would carry sediment and nutrients that had built up during times of slack flow and deposit them on to the surrounding plains, the water would sit in large, warm, shallow lakes, with abundant plant growth for the laying of eggs, terrestrial insects and reptiles trapped for food and all sorts of benefits for spawning fish. This is where the fish traditionally fed up to spawn, spawned and the fry hid and fed on rotting vegetation as the water receded, getting up to size before life in the rivers. The water would be absorbed into the ground over a period of time over a wide spread of land, bringing with it plant growth and bird life. Dykes, dams and weirs and other flood mitigation practices have led to this being a thing of the past.
7/ Commercial over fishing up until the 1960s - carp were introduced originally in 1854ish and did not do well until the Boolara Strain was hybridised in Victoria and released to supplement native fish stock which had dwindled, and in some places collapsed entirely. That is how they and redfin got the opportunity to spread so widely in such great numbers. Now that commercial fishing is ended and recreational fishing heavily regulated in regard to native species, their numbers are recovering, alone and with human assistance, but they are recovering.
8/ As the native stocks begin to recover, in many places the carp numbers are stabilising and dropping and natives are being more represented in catches. This is due, in part, to populations of cod that are well enough established to predate effectively upon the carp and these cod are getting to a size they can eat all but the largest carp.
9/ The removal of large carp reduces the population pressure and competition for available space and food and allows the young ones to establish. Large carp eat the eggs and young fish of their own species as well as others.
10/ introduction of diseases and parasites. - Many Australian natives suffered from various disease they had no immunity that were introduced with exotics through aqurium, fish farming and stocking progams. These disease have devastated certain species. In addition, and related to this, the native Australian disease infected their new hosts which then became carriers, if not succeptable themselves. Thus the red fin out breaks of Epizootic Haematopoietic Necrosis Virus (EHNV), a hemorrhagic virus endemic to Australia, had huge consequences for the silver perch and other native species as the perch spread and shared their environments in great numbers. They carried with them the disease and their population presence was such that natives suffered outbreaks also. Silver perch and river black fin are all but absent from waters containing red fin due to this reason. Now they want to introduce yet another pathogen
And that leads to another issue, resistance. It does not take a genius to ascertain that the fish that are resistant will pass that resistance on to their offspring.
And that leads to another issue, resistance. It does not take a genius to ascertain that the fish that are resistant will pass that resistance on to their offspring. As these grow out and pass the resistance on, subsequent outbreaks will not have the virulent impact that the initial release will have. It does not take a genius, and indeed the idiots proposing this also figured it out. The solution? To release more virulent strains in the future.
It is interesting to note that the proposal for future control agents is linked closely to imperfect vaccines, almost like there is a plan in mind...
And for my fellow conspiritards out there, it might interest you to note that the disease arose in fish farms in Israel, jumped somehow to England and the patent is owned by a university in Brussels. Hmmmm. Agenda 21 coming to your continent soon.
It will not solve any of the problems and just create massive new ones. And some of those could be potentially disastrous.
#Fishing #nature #science #Australia