Ibbotson, A.T.

Ladle, M

Welton, J.S.

NERC Open Research Archive

Impact of Stocked Rainbow Tmut on Resident Salmonid Populations,Phase 1, Scoping StudyR&D Progress Report October 1995Institute of Freshwater EcologyOctober 1995R&D Progress Repot D02(95)4/1 NRANational Rivers Authoritysz)aImpact of Stocked Rainbow Tmut on Resident Salmonid Populations,Phase 1, Scoping StudyR&D Pmgress Report October 1995Institute of Freshwater EcologyOctober 1995R&D Progress Repot D02(95)4/1R&D Project D02(95)4Impact of Stocked Rainbow Trout on Resident Salmonid Populations,Phase 1, Scoping StudyJ S Welton PhD, CBtol MIBiolA T Ibbotson, PhDM Ladle, PhDR&D Progress Report October 1995Dissemination StatusInternal: RestrictedExternal RestrictedResearth ContractonInstitute of Freshwater EcologyRiver LaboratoryEast StokeWarehamDorsetBH20 6BBTel: 01929 462314Fax: 01929 462180NRA Pmject LeaderDr A G Owen - NRA Southern RegionIntmductionThis report deals with progress from the start of the project to the end of October.Litemture ReviewLiterature searches of ASFA databases for the period 1979-present and of the FBA/IFE currentawareness databases have been completed. This raised >500 references concerned withrainbow trout. Titles and abstract of these have been read and from these 87 papers wereconsidered to be relevant. These papers have been obtained and their references searched forfurther relevant information (mostly pre- 1979). These papers have also been acquired andtheir bibliographies searched. To date 131 relevant publications have been collected. Severalother relevant documents have been identified, mostly available from the USA. These will takea further 2-3 weeks to arrive. It is hoped that this literature, which is considered to be critical,will arrive in time to be incorporated into the review to meet the 30 November deadline.NRA Stocking PolicyA letter (Append x 1) was sent to each Regional FRCN Manager requesting details of stockingpolicy. To date, six replies have been received either by letter or telephone. Replies vary indetail. Information asked for on existing practices is usually brief but managers do offer todiscuss the matter further if necessary. This would require further time either on the telephoneor for visits. Some supplementary information on policy and practices is being received fromArea Managers as part of their response to the letter sent (Appendix 2).NRA DataA letter requesting data from the regions was sent out to all Area FRCN managers in eachregion. Copies were sent to Regional FRCN Managers to keep them informed of the project.A copy of the letter sent is presented in Appendix 2.Eighteen replies from the 26 managers have been received. The eight missing replies are fromthe three regions of Anglian (although a letter has been received from The Regional FisheriesManager), and from one area each of North West, Severn Trent, Southwestern, Thames andWelsh.No data on the impact of rainbow trout on existing fish stocks was received from any arearegion other than Southwestern where a report was written in the Devon area. The Southwestern region of Welsh sent a report on escapees. Most area managers (or their deputies),said they did not have any information on impacts. However, it is likely that they do have datafrom fishery survey programmes which may provide information on the impacts of rainbowtrout, particularly in areas where there are known to be self-sustaining populations. The datahave probably not been investigated for impacts and it would require extra effort to, forexample, correlate densities of rainbow trout with native salmonids, or compare growth ratesin the absence or presence of rainbow trout.Stocking practicesInformation in this category was varied in detail. Some sent raw data from Section 30s, mostlyfor the previous year but some sent data for longer (maximum four years) . Others said theyhad information but no-one to extract or collate it. Information was stored in different waysin different regions eg on paper forms or on Microfiche.Histotical dataVery little data has been sent on this topic mainly because Section 30 forms are a recentintroduction. Information may exist within NRA offices but may be time consuming to collate.General information may exist in the literature and will be collated during the review. Someangling club records may provide a better historical picture if they can be identified, but again,extra work to collate this will be required and identification of these clubs will only be possiblewith the co-operation of the NRA.Self sustaining populationsMost judged this to mean evidence of successful spawning ie the existence of juveniles. Manyonly have anecdotal evidence (anglers catches) but no hard data. Data is not usually sitespecific but refers to rivers or tributaries in general. Maps showing these rivers can bepresented by the deadline assuming data from the missing areas is received quickly. Maps willinclude one of the whole of England and Wales and one for each region where populationsexist.Risks of stockingNo data is available from the regions. Factors such as disease, competition, predation andhybridisation will be considered from data collected from the literature.EscapeesVery little information came from the regions other than anecdotal from anglers catches. Littleinformation is available on numbers of escapees (or estimates) or why or how escapeshappened. No assessments had been made on the effects of escapees or to their eventual fate,with the exception of a report on one event from southwestern area of the Welsh region.Appendix 1 Letter sent to all Area FRCN ManagersRiver LaboratoryEast StokeWAREHAM DorsetBH20 6BB7 September 1995DearThe IFE is reviewing the Impact of Stocked Rainbow Trout on Resident SalmonidPopulations, for the NRA, under R&D Project D02(95)04. The contract requires us:to review existing NRA data on the impact of rainbow trout on resident salmonidpopulations, andto review existing NRA policy including existing practices (i.e. what is stocked Whereand why) and historical introductions.Please will you supply for your area the following information.Any data regarding the impact of rainbow trout on resident salmonid populations.Details of your local NRA policy on stocking.Details of stocking practices within your area covering issues such as numbers, size,location, origin and reason for stocking.Any data on historical intmductions of rainbow tmut.Maps indicating where self sustaining rainbow trout populations are known to existwithin your area.I would also greatly appreciate available information on known or perceived risks of stockingand any instances of escapes of rainbow trout into the wild.There is a tight schedule for the collation of this information, and to comply with this theinformation is required by the end of September 1995 at the latest.Please contact me by phone if you would like to discuss this request.Best WishesAnton Ibbotson (Dr)Appendix 2 Letter sent to all Regional FRCN ManagersRiver LaboratoryEast StokeWAREHAM DorsetBH20 6BBTelephone (01929) 462314International (44929)462 314Facsimile 01929 462180Telex 94070672-WARE GE-MAIL jswe@wpo.nerr.ac.ukDr J. Hilton BSc PhD CChem MRSCAssistant Director25 September 1995DearNRA R&D PROJECT D02(95)4 Impact of Stocked Rainbow Trout on Resident SalmonidPopulations. Phase 1.Recently, you will have received a copy of a letter sent to your Area FRCN Managersrequesting information for the above project. At a recent meeting with Tony Owen, the TopicLeader, he suggested that the Regional FRCN Managers were better placed to supplyinformation on policy, including existing practices.I would be grateful for any information from your region on stocking policy for rainbow trout,either as an official policy document or from papers and minutes of RFAC meetings if theseare available.Yours faithfullyDr J.S.WeltonDISTRIBUTION SHEETTo be completed by all Project Leaders completing commissioned research project reports. Please binda copy of this distribution sheet as the final page in all internal (1FE) copies of the report. Tide: Impact of stocked Rainbow Trout on Resident Salmonid PopulationsPhase 1. Scoping Study. R&D Progress Report October 95. D02(95)4/1Authors: J S Welton, M Ladle & A T IbbotsonReport ref: T11064E4Master copy held by: D M MortonReport access code (assign a suitable code from list below): C DISTRIBUTION LIST [A)-G) standard, H) other] No.copies Date• 3.Contract customer: NRA SouthernDirector IFEAssistant Director (tide page and abstract only)FBA Library, WindermereRiver Laboratory LibraryDiana Morton (title page only + no.pages for adding to publication list)Project leader:Other (list below and indicate no. copies in RH column)J S WeltonM LadleA T lbbotson1111111Oct 95Oct 95Oct 95Oct 95Oct 95Oct 95Oct 95Oct 95Oct 95Total number of copies made 7REPORT ACCESS CODESIn strict confidence - restricted access - Access to named customer(s) - (could be namedrestricted access individuals), IFE Directorate, Project Leader and all authors.In confidence - restricted access - Access to customer, IFE Directorate, Project Leader, allauthors, and IFE staff with permission of Project Leader.'Normal' access - Access to customer and all IFE staff. Access to visitors and general publicwith permission of Project Leader.General access - General access to anyone as required.9

Impact of stocked Rainbow Trout on resident salmonid populations. Phase I, scoping study. R&D Progress Report

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Impact of stocked Rainbow Trout on resident salmonid populations. Phase I, scoping study. R&D Progress Report

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