10.7489/1459-1
Malcolm I A
Review of migratory routes and behaviour of Atlantic salmon, sea trout and European eel in Scotland’s coastal environment: implications for the development of marine renewables
Scottish Marine and Freshwater Science Vol 1 No 14
Marine Scotland Science
2014
Fish behaviour
Rasmussen, Jens
Malcolm, Iain
2014-00-02
2014-41-02
eng
The Scottish Government has ambitious targets for renewable energy production, to
which offshore renewables could make a substantial contribution. However, the new
marine energy industries must develop on a sustainable basis, ensuring that
environmental impacts are assessed, and if necessary, minimised through
appropriate mitigation. The likelihood of any impacts on Atlantic salmon, sea trout or
European eels will depend on interactions between (1) migratory routes and
behaviour (2) the distribution of offshore developments (3) the technologies deployed
and (4) the dynamics of the relevant fish populations. This report summarises
available information on the migratory routes and behaviour of salmon, sea trout and
eels in a Scottish context.
Broad scale patterns of migration are identified for adult Atlantic salmon, although the
resolution of available data is unlikely to be sufficient to inform site specific risk
assessment. Less extensive information is available on juvenile migratory routes and
no information is available on juvenile migration from important east coast rivers.
The limited information available on sea trout migration suggests predominantly
inshore and local use of the marine environment, although wider ranging migrations
have been observed from some rivers. No specific migratory routes can be
discerned for either juvenile or adult sea trout. European eels in Scotland are part of
a single European population for which there is considerable uncertainty regarding
migratory routes. The limited evidence which is available suggests that eels from a
number of European countries may migrate through Scottish waters. For all the
species considered, there is only very limited information on behaviour and
swimming depths. Most of this information has been generated outwith Scotland and
it is uncertain whether it can be reliably transferred to the Scottish context given
differences in the life stages observed and local geography.
Significant knowledge gaps remain for all three species considered in this review.
These knowledge gaps should be considered as part of an overall assessment of
research needs in relation to offshore renewable developments and diadromous fish.
This report is a literature review.