Pink Salmon Lorraine Hawkins River Dee Trust Last year, record numbers of pink salmon were recorded returning from the N Atlantic and into Scottish rivers and coastlines. Pink salmon are a pacific salmon, so a long way from home Lorraine Hawkins River Dee Trust

Background 1 native species of salmon in Europe – Atlantic salmon, salmo salar. 7 species of Pacific salmon, including pink salmon – Pacifics and Atlantic salmon are very different – as you can tell from these photos! They are also very different genetically as they have been separated on an evolutionary timescale. Joking aside, expect any angler who came across a pink salmon to know it was not native salmon – tail! Their only interaction is because humans introduce them - Atlantic salmon are farmed in North Americas, and Pacifics are farmed in the Atlantic region – both are considered are problem outwith their range.

Straying These non-natives have not – we assume – strayed from the Pacific ocean, but are likely instead to have come from some of the rivers in northern Norway or White Sea in Russia. Pink salmon were introduced to some Russian rivers since the 1950s, and following many more introductions since the 1980s have colonized and slowly spread westwards into some northern Norwegian rivers. However, last year captures were reported throughout Scandinavia and also mainland Europe, including Germany and France for first time, as well as Iceland, Denmark, Ireland and England.

2017 invasion So the appearance of pink salmon in Scotland last year was not a first – the first pink salmon caught in Scotland in 1960 – occasional visitor since then. But 139 Pink salmon were recorded in 2017. 7 captured in the Dee and 2 in the Don by anglers last summer. Last year was unprecedented, not only in UK but also Norway and Finland – Norway had around 3000 last year. Don’t know why they’ve spread – climate conditions in 2017??

Possible consequences So, possibly lots more salmon in Scotland…. Is this a problem? – some anglers wondering if it might be a good thing….. Our biggest concern was the impact they could have on our native salmon, which are declining. Particularly through biosecuitry, also competition. e.g. competition with Atlantic salmon – although they do have a very different life cycle, which I’ll come onto. Unpredicted consequences

Salmon eggs are laid in river beds Salmon eggs are laid in river beds. The development of Atlantic salmon and pink salmon is very different. Atlantic salmon in Scotland spend 1-4 years in the river, then 1-3 years at sea. For pink salmon, the juveniles emerge from the river bed generally in late winter, spend up to 2 months in river as juveniles, then move to estuary/coast for up to 6 months. They then move out into the sea, returning the following summer to breed in August/September. In contrast, pinks have a specific 2 year life cycle. This means that odd-year and even-year fish do not overlap or interbreed. For whatever reason, the odd-year population is stronger in the kola peninsular, and therefore most pink salmon occurrences tend to occur in the UK in odd years. We therefore expect then next year particularly.

Risk Do we have anything to worry about? GB Non Native Species Secretariat (GBNNSS) commissioned a full Risk Assessment for Pink salmon last year. GB risk assessment thinks establishment is very likely with rapid spread. Level of impact is not so clear – predicted to be moderate, but with low confidence Guidance: precautionary approach should be taken and fish removed from the wild wherever possible. Pic shows us netting on the Dee to try and remove adult pink salmon, which was partially successful

Management options So a precautionary approach is advised but in reality, management options are limited once Pink salmon have invaded. Options for management are: Recording the occurrence and spread of pink salmon - FMS and MS are coordinating these efforts 2. Removal of adults – netting, or as they are trying in Norway: harpooning - 1639 fish had been removed in this way last year 3. Attempts have been made to excavate eggs and manually disrupt redds.

Pink Salmon – The Future   First question for the future is, will they survive? Eggs laid in the Dee last summer were excavated and transferred to the Marine Lab at Torry. Eggs hatched approx. 1 month later at a range of different temperatures, indicating survival would be likely around most of Scotland. Hatchlings were grown on before being culled. Eggs also successfully hatched in the River Ness in September 2017. Not clear how well they will survive in the river over winter (less food available) However, even if juveniles don’t survive now, chances are more spawning fish will arrive in our rivers in 2019, as they do not home to the same extent as other salmon. Eventually some strain will be successful. Effort required to remove all adults and eggs from a river is huge, and just not feasible to do this in every Scottish river.