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Large die off of crayfish found in the River Barrow in Ireland

Large numbers of dead freshwater crayfish were reported in the River Barrow in the stretch from Carlow to Graiguemanagh.
 
It has been confirmed using DNA analysis that the cause of death was Crayfish Plague.
 
This is the fifth outbreak of the disease to be found in Ireland in the last two years.
 
It is feared that if the disease spreads further, then it will threaten the survival of the entire Irish population of this endangered species.
 
This worrying situation is being investigated by the National Parks and Wildlife Service (NPWS) of the Department of Culture, Heritage and the Gaeltacht, Inland Fisheries Ireland (IFI) and the Marine Institute.
 
The kill only impacts White-clawed Crayfish; other freshwater animals and people are not affected.
 
Experience of the disease elsewhere is that it causes 100% mortality. It is of grave concern that if the disease takes a firm hold millions of crayfish could vanish from Irish rivers and lakes in a short period of time.
 
All the agencies involved in managing and protecting the rivers in Ireland are concerned that another outbreak has been detected and are reiterating their advice and guidance to all users of the river to implement routine cleaning and drying of their equipment once they leave the river and before using it again.
Courtesy of leinsterexpress.ie

Thousands of dead crayfish found floating down a river in Putaruru, New Zealand

A man has witnessed "thousands" of dead and dying koura floating down a stream in Putaruru.
Photo By Waikato Times
A man out for a leisurely fish this afternoon was “shocked” after seeing thousands of dead koura floating past him.
 
Erin Hampson-Tindale headed down to Oraka Stream in Putaruru for a bit of fishing only to find what he described as “thousands” of freshwater crayfish of all sizes and ages floating past him.
 
“I have spent over an hour here now and there has been a constant flow of them. It’s shocking, there are literally thousands and thousands stumbling past,” he said.
 
“They are semi-alive but obviously a whole colony has been wiped out by something because there are even really tiny ones.”
 
He said he had no idea what was causing the koura to slowly die as there were no obvious signs of contamination.
 
“The water is not as clear as it can be but it could just be from the rain we had yesterday, other than that it really looks fine,” he said.
 
“It’s hard to say what has caused this but I know koura are sensitive when it comes to contamination.”
 
He said he had contacted the Department of Conservation (DOC), the Waikato Regional Council, and had taken samples so they could be tested.
 
“It is a very depressing situation because not many streams would have this amount of koura. This is not something we can wake up tomorrow and forget about, it needs to be monitored,” he said.
 
“They are also the main food source for trout and they are going to gorge on them. There are no trout floating by yet but I would not be surprised if they start to.”
 
Waikato Regional Council senior communications advisor Stephen Ward said the council had been made aware of the situation and was investigating.
 
“They have got couple of guys checking it out at the moment and they will be taking water samples but that is all the information we have at this stage,” he said.
 
Courtesy of stuff.co.nz

600 Crayfish dead in due to disease in a river in County Cavan, Ireland

US crayfish species are resistant to the plague but can act as a carrier, and can also out-compete Ireland's smaller native crayfish
US crayfish species are resistant to the plague but can act as a carrier, and can also out-compete Ireland’s smaller native crayfish
Investigations are under way after 600 crayfish were killed by crayfish plague in a Co Cavan river.
 
Preliminary results indicate the cause of deaths in the River Bruskey, near Ballinagh, to be the incurable, waterborne, fungus type disease.
 
If this plague becomes established, there is a high probability that white-clawed crayfish, Ireland’s only freshwater crayfish species, will be eliminated from much of the island.
 
The disease may have been accidentally introduced from contaminated equipment that was previously used in affected waters in another country.
 
However, if the disease was caused by the introduction of non-native crayfish, then it is likely to become established with a severe and probably irreversible ecological impact.
 
Many US crayfish species are resistant to the plague but can act as a carrier of the disease, and can also out-compete Ireland’s smaller native crayfish.
 
The introduction of non-native species is illegal and the white-clawed crayfish has already been completely eliminated from much of its European range.
 
Until now, Ireland has been free of crayfish plague and is the only European country without any established non-native crayfish species.
 
The only means of protecting native crayfish stocks is to prevent the introduction and spread of the disease, and this is possible if the disease was accidentally introduced from contaminated equipment.
 
The disease has no direct threat to human, fish or other animal life.
 
Non-native crayfish can also destabilise canal and river banks by burrowing, and have a severe impact on other freshwater species such as salmon and trout.
 
While non-native crayfish may be a potential cause, there is no evidence to date that they have been introduced to Ireland.
 
Members of the public are asked to alert the authorities to any reports of mass mortalities of crayfish as well as sightings of unusual crayfish, and in particular to disinfect boots or angling equipment before moving from one body of water to another.
Courtesy of rte.ie

Mass die off of crayfish, shrimp and shellfish in Chachoengsao Province, Thailand

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Mass die off of crayfish, shrimp and shellfish in Chachoengsao Province, Thailand