Gyrodactylus salaris
Name: Gyrodactylus salaris (Gs)
Habitat: Parasite that lives on salmon in fresh water
Problem: Once it is present in a river system this parasite quickly devastates the salmon population and extreme methods have to be used to kill everything in the river network, leading to a complete close down of all activities in the river system.
Risk: Anyone returning from overseas countries where Gs is present could import the parasite on damp and untreated equipment.
British canoeists travelling to Europe should be aware of a serious fish disease that could have severe consequences if it was brought back into the UK. The Scottish Canoe Association is issuing this advice to reduce the likelihood of canoeists unwittingly importing the parasite, Gyrodactylus salaris (Gs) that causes the disease into this country.
Whilst the current concern is connected with Gs, there are other diseases that could have equally devastating effects, so the advice we are issuing represents a range of sensible precautions that should prevent the import of any disease into this country.
Our advice is divided into two strands:
• Precautions to take before travelling back to the UK after canoeing in Europe;
• Action to take if you are going to use your boat or other equipment within a week of leaving the foreign country.
After canoeing in Europe
After leaving the water for the last time and before travelling back to the UK it is advisable to wash your boat then disinfect it with a chemical disinfectant such as Virkon S or a saline solution. Sachets of Virkon S can be bought from some canoe shops, or a bag of salt can be taken on holiday to easily make a saline solution for disinfecting your boat and other equipment.
Within a week of leaving the Continent
If you are going to use your boat and/or other equipment within a week of leaving a foreign country it is advisable to dry equipment thoroughly, and where this is not possible to use hot water, disinfectant or salt to kill the parasite. Freezing also kills the parasite.
Items of equipment such as buoyancy aids, spraydecks, throwlines, towlines and sponges should all be considered as potential means of carrying this parasite and be treated in at least one of the above ways.
The area of highest risk is Scandinavia, so paddlers travelling to Norway and Sweden should take particular care. The disease is regarded as a serious threat within Scandinavia and disinfection facilities are available for paddlers and anglers as they move from one river system to another.
For advice from the Norwegian Canoe Association (in English) on infected rivers and disinfection stations, click on the following links:
http://www.padling.no/files/{5472FEBB-A1E0-4BD7-BF1E-D43D7510B526}.doc
http://www.padling.no/files/{1F75789A-2324-4E25-ADAD-559EDEACF94D}.pdf
This page on the River Tweed Commission website contains a very useful video about Gyrodactylus salaris: http://rtc.org.uk/Management/Gyrodactylus_salaris/gyrodactylus_salaris.html.
Some pictures of the parasite - pictures courtesy of Dr. Tor Atle Mo, National Veterinary Institute, Oslo.
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Group of Gs
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Closer view
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Gs on a fin
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North American Signal Crayfish
Name Pacifastacus leniusculus
Habitat Rivers, burns, lochs and ponds
Problem Digs into banks, making them unstable; eats native species
Risk Transfer of eggs and larvae in water, soil or plant material
Picture credit - GBNNS
Links
Zebra mussels
Name Dreissena polymorpha
Habitat Rivers and lochs
Problem Out compete native species for space and food, and can deplete food supply for fish.
Risk Transfer of larvae in water
Photo credit GBNNS
Link
Name Crassula helmsii. Also known as Australian Swamp Stonecrop.
Habitat Mainly still or slow moving waters e.g. ponds and canals.
Problem Grows from very small fragments so can take over from native species, growing rapidly into thick mats which can choke the watercourse, prevent access on to the water and increase flood risk.
Risk Transfer of plant fragments
Photo credit GBNSS
Link
Marine Wireweed
Name Sargassum muticum. Sometimes called Japweed.
Habitat Coastal waters, mainly sheltered areas. Can be attached to rocks, floating in clumps or washed up on the shore.
Problem Takes over from native species. In shallow waters and harbours the floating masses can become a hazard for paddlers.
Risk Paddling through wireweed encourages it to break off and spread
Photo credit SNH
Link
Chinese mitten crab
Name Eriocheir sinensis
Habitat Adults live in freshwater, but move to estuaries and coasts to breed. Some larval stages live in open water at sea.
Problem Dig deep burrows in estuary banks, making them unstable. Voracious predators that eat native species.
Risk Transfer of eggs and larvae in water
Photo credit FERA
Link
Name Crepidula fornicata
Habitat Coastal waters
Problem Competes with native species for space and food
Risk Transfer of larvae in water
Photo credit - GBNSS
Link
Didemnum – Carpet Sea Squirt
Name Didemnum vexillum. Also known as carpet sea squirt.
Habitat Coastal waters
Problem Smothers native species and grows over structures such as fish farm cages, pontoons and boat hulls.
Risk Didemnum has been found in Largs Yacht Haven (October 2009), which is the first time it has been identified in Scotland. See the SNH news release. The greatest risk is from boats that stay in the water long enough for the sea squirt to attach, so kayaks are not considered to be a likely means of dispersal. Nevertheless, paddlers should be aware of the risk of picking it up on items of equipment, particularly in yacht marinas, and transporting it to other places. It is worth bearing in mind that sea squirt could be attached to a piece of seaweed. For the time being the area of greatest risk in Scotland is likely to be the Firth of Clyde and the south west coast around Ayrshire and Dumfries & Galloway.
Photo credit - Rohan Holt, Harry Goudge - CCW
Link
Himalayan balsam
Name Impatiens glandulifera
Habitat On the banks of rivers, burns and lochs, and on coastal areas
Problem Takes over from native species and forms thick growth that can make it difficult to access the water. Dies back in winter making soil unstable and more likely to erode, especially on river banks.
Risk Transfer of seeds
Photo credit CCW, GBNSS
Link
Japanese knotweed
Name Fallopia japonica
Habitat On the banks of rivers, burns and lochs, and on coastal areas
Problem Takes over from native species forming thick growth that is difficult to access the water. Dies back in winter making soil unstable and more likely to erode, especially on river banks. Can grow through concrete!
Risk High risk as transfer of even a tiny fragment of stem or root will allow it to spread.
Photo credit - GBNNSS
Link
Giant Hogweed
Name Heracleum mantegazzianum
Habitat On the banks of rivers, burns and lochs, and on coastal areas
Problem Takes over from native species forming thick growth that is difficult to access the water. Makes access dangerous as produces sap which if in contact with skin causes blisters especially if exposed to sunlight. Dies back in winter making soil unstable and more likely to erode, especially on river banks.
Risk Transfer of seeds
Photo credit - RPS Group plc
Important notice. It is not advisable to touch a Giant Hogweed as the sap from the plant can cause blisters. The man in this photograph is wearing gloves.
Link
Avian Influenza (Bird Flu)
The SCA is aware that an outbreak of Avian Influenza, or Bird Flu, could have an impact on our activity by affecting some of the places where we paddle. It goes without saying that this could happen at any time.
We have taken the decision, therefore, to have a dedicated Bird Flu information page on our website containing general advice about the issue and links to other useful sites; then if and when there is a confirmed outbreak we will post more specific information on here.
The exact message in the event of an outbreak will come from the Scottish Executive and will include details of the various control response measures they put in place in implementing their contingency plan.
In the meantime the general advice from the Scottish Executive is worth being familiar with.
The Executive’s advice with regards to the current situation can be found at: http://www.scotland.gov.uk/Topics/Agriculture/animal-welfare/Diseases/SpecificDisease/AvianInfluenza/AIIntroduction
Their more specific advice in relation outdoor access can be found at: http://www.scotland.gov.uk/Publications/2006/09/19105107/16
This outdoor access page is well worth reading.
The important points to come out of that page are:
- The only people who risk spreading Avian Influenza (low or high pathogenic) or Newcastle Disease are those who have contact with poultry or their manure/litter, and those who unintentionally carry the disease on their footwear/clothes/hands/transport. Risks of disease being spread by those seeking recreational access to the countryside are generally very small. These risks can be reduced to negligible by avoiding direct contact between people, vehicles and other modes of transport - and flocks, including those birds within free range farms and those wild birds congregating in a particular area, e.g. loch side. Provided these circumstances prevail, there is no requirement to restrict public outdoor access even in the Protection Zone.
- Any specific closure of land or restriction of access rights may only be declared by Scottish Ministers within a part, or whole, of the Protection Zone. Any such restriction will be based on veterinary risk assessment carried out under the auspices of the State Veterinary Service. Official signage must be followed at all times. With regard to access signs, members of the public should only take account of those signs provided formally by the Scottish Executive, the State Veterinary Service or by the local authority. It is an offence under section 73 of the Animal Health Act 1981 as amended, punishable in accordance with section 75 of that Act, to erect unofficial signs preventing or deterring access rights.
- Part 1 of the Land Reform (Scotland) Act 2003 establishes rights of responsible access to land and inland water for recreation, passage and other purposes. Local authorities have the duty to assert, protect and keep open and free from obstruction any route or means by which access rights are exercised. In the event of an outbreak of a disease such as Avian Influenza/Newcastle Disease, these rights may be restricted within the Protection Zone. Local authorities, in conjunction with local access forums as appropriate, will continue to have a role in resolving local issues with veterinary advice from the SVS being provided when necessary.
A useful piece of general advice is that you should avoid any direct contact with ill or dead birds and bird faeces, and follow normal hygiene procedures when visiting the outdoors.
Further guidance can be found on the Outdoor Access Scotland website by going to: http://www.outdooraccess-scotland.com/default.asp?nPageID=377&nSubContentID=0
Leptospirosis (Weil's disease)
In February 2003, a paddler contracted Weil's disease, a potentially fatal disease carried in rats urine. The disease is caught by swallowing water or through cuts. The burn flowing into Pease Bay or the Whiteadder are the most likely sources of this particular infection, but potentially any river could contain the bacterium which causes the disease. Those where there are likely to be rat populations e.g near habitation carry the greatest risk. It is important to be aware of the symptoms of Weil's disease as it develops quickly and needs prompt treatment.
Early symptoms are fever, chills, muscular aches and pains, loss of appetite, and nausea when lying down. These can easily be mistaken for influenza, menengitis or the classic physician's excuse, 'FUO' or Fever of Unknown Origin.
Later symptoms include bruising of the skin, anaemia, sore eyes, nose bleeds and jaundice. The fever lasts for approximately five days, then a significant deterioration follows. Detailed information is available from the Weil's Disease Information Centre.
If you develop these symptoms within a few days of paddling, it is important to see a doctor. A blood test should be taken to confirm the disease. As a GP would only expect to see a case of Weil's disease once in 50 years, they may be reluctant to diagnose it, so make sure that they know that you are a paddler and therefore in a group at high risk.
The following links may also be of interest for finding more information about non-native species, parasites and diseases.
If you still need to be convinced about how invasive some non-native species can be then check out these video clips of Didemnum vexillum (carpet sea squirt):
http://woodshole.er.usgs.gov/project-pages/stellwagen/didemnum/htm/video.htm