Two further outbreaks of Crayfish Plague, one on the River Lorrha in North Tipperary and a major outbreak on the River Barrow has highlighted the need for continued vigilance. National Parks and Wildlife Service (NPWS), who are the lead agency in charge of the management of our native white clawed crayfish have conducted a review with the Marine Institute and recommend that the Voluntary Ban on movement between catchments, which is in place on the River Suir be extended for another three months. This effectively extends the Ban until the New Year. River users are requested to follow biosecurity protocols and not to move equipment such as fishing gear, kayaks or boats from the River Suir to other catchments and avoid bringing in equipment from other infected rivers (plague now confirmed on the River Loorha, Deel (Rathkeale), Bruskey and the Barrow below Carlow town). It is also important that people do not move between the infected zone (from Knocklofty Bridge downstream to Carrick on Suir and Lower River Anner) and the remainder of the Suir, which appears to still be free from plague.
It is now five months since the Crayfish Plague outbreak, a disease that decimates our native crayfish populations on contact, was first noticed on the River Suir. The plague, which is a mould is not native to this country, attacks our native crayfish causing a 100% mortality. Ireland has Europe’s most important crayfish populations and the River Suir is extremely important for a variety of reasons. During the first week of the outbreak, all crayfish from Clonmel to Carrick-on-Suir were wiped out. It is estimated that in excess of 400,000 crayfish perished. Subsequent investigations found that crayfish were also killed in the lower reaches of the River Anner which is a tributary of the River Suir, downstream of the N24 crossing, and also along the main River Suir at Sandybanks.
A Voluntary Ban has been in place on the River Suir for the last few months and has been working quite well within the river catchment with good co-operation locally. People have been asked to voluntary restrict their movements within the river catchment and confine their activities to where they normally operate. The co-operation of the public has been exceptional, with people adhering to the recommended biosecurity protocols. These are to check, clean (disinfect) and thoroughly dry their equipment and gear. Dr. Fran Igoe of the Local Authority Waters and Communities Office was very complimentary of the public support. “We have had loads of enquiries from the public and organisers of events to find out what is the best way to prevent the spread of the disease. People are reading the signage along the River catchment which has information on the plague and what people can do, and recent events have prioritised the crayfish plague in their planning. For example, the Clancy Festival, Carrick-on-Suir, took the outbreak into account in planning their Family Funday last June and the excellent “Drive for Hope” event organised by the Travelling Community in Cahir took steps to ensure that proper biosecurity steps were taken. Tipperary County Council staff were on hand to assist together with the organisers, again showing that it is only through community participation and everybody working together that we can deal with this emergency situation. We know that individual anglers, kayakers, and rowing clubs etc are also being responsible and doing what is necessary and this should be acknowledged”.
Regrettably some large events planned for the river have had to be postponed, but this has been necessary considering the circumstances and the risk to not just the rest of the River Suir but also to other river catchments. To date it would appear that the Crayfish plague has been confined to the area in the Suir, where the outbreak originally occurred. Dr. Igoe said “We carried out a recent crayfish survey in the River Suir in Golden and found that the crayfish were alive and well there and information coming from Cahir and Ardfinnan suggest that they are ok there too. So the voluntary ban seems to be working on the Suir which is great news”.
The reason provided by National Parks and Wildlife Service for the extension of the Voluntary Ban is that the Crayfish Plague is still active within the Suir Catchment and there have been two recent outbreaks in nearby river catchments. A spokesperson for the NPWS says they are monitoring the outbreaks on all five locations. Investigation of the strains involved in each outbreak is underway and until the results of this are known, a precautionary principal should be adopted and all water users should therefore be asked to continue to respect the voluntary ban.
Dr. Igoe from LAWCO stated that “this extension is a major inconvenience for people dependent on the river for their livelihood or enjoyment and this needs to be acknowledged. Hopefully the situation will be contained and the ban can be lifted as soon as possible and again we would like to thank everybody for their ongoing cooperation”.
We are appealing to people to continue to be careful and follow the recommended biosecurity protocols. More detailed information is available on the National Biodiversity Data Centre website (http://www.biodiversityireland.ie/crayfish-plaque-2017/) and this gives good advice on biosecurity measures that people can take.