Scottish Marine and Freshwater Science Vol 6 No 5
The introduction of hatchery-reared Atlantic salmon smolts to rivers in support of local salmon fisheries (termed ranching) is a controversial subject with little information available to fishery managers on the value of the method in a Scottish context. Here we present recapture data from monitored smolt releases on four Scottish rivers and compare return rates of hatchery and wild-reared salmon smolts originating from a common stock on two of these rivers. Rod recapture rates from stocked hatchery smolts ranged from 0-0.23%. In comparative tests return rates for wild-reared fish were on average ten times greater than those for stocked fish (range 6 to 13-fold where at least one reared fish returned). Given the relatively poor returns and associated production costs any benefit to fisheries of stocking with hatchery-reared smolts is unlikely to be sustainable in the Scottish context. Furthermore, risks of adverse genetic effects should be considered.
Data and Resources
Dataset InfoThese fields are compatible with DCAT, an RDF vocabulary designed to facilitate interoperability between data catalogs published on the Web.
|Spatial / Geographical Coverage Location|
UK Open Government Licence (OGL)
To investigate the effectiveness of smolt ranching as a tool to enhance local salmon fisheries, we examine first, the range of recapture rates from monitored smolt releases in Scottish rivers and second, we compare returns from hatchery and wild-reared smolts originating from the same stocks released concurrently at the same river sites. We then consider a range of practical issues associated with operating a smolt ranching scheme on a Scottish river, both for conservation and fishery enhancement purposes, and then, using best available information, assess the likely financial implications.
Marine Scotland Science
|Public Access Level|