Researchers are First in the World to Track Detailed Movements of
European Sea Bass
Galway-led study finds that localised residency and inter-annual
fidelity to coastal foraging areas may place sea bass at risk of
collaboration between Irish researchers from NUI Galway, UCC and
Cork Harbour Angling Hub, have become the first in the world to
track the detailed movements of individual sea bass in Europe. The
authors have found that sea bass in Cork Harbour were highly resident,
remaining within one to three kilometres of where they were originally
caught and tagged, a behaviour not known before this study. They
also found that these localised fish returned to the same areas
after their winter migration.
study, published this week in Scientific Reports, was led and co-authored
by Dr Tom Doyle from the Ryan Institute and MaREI Centre at NUI
Galway, in close collaboration with researchers Mr Damien Haberlin,
Mr Ashley Bennison and Dr Mark Jessopp from UCCs MaREI Centre
and expert angler, Jim Clohessy from Cork Harbour Angling Hub.
bass is a large fish species only found in Irish and UK waters and
south into the Mediterranean and along North Africa. It is a commercially
important species as it fetches a high price on the markets compared
to other fish species. Sea bass is also an important fish for recreational
anglers and is worth up to €70 million to the Irish economy.
very robust conservation measures in place in Ireland, sea bass
populations in northern European waters have been declining since
2010, so much so that the EU has introduced a series of emergency
measures to try and halt this decline. These include catch restrictions
on various bass fisheries, a large closed area around Ireland and
Celtic seas, and a limit to the amount of sea bass that recreational
anglers can retain in a day (one fish). The International Council
for the Exploration of our Seas (ICES) advised the EU Commission
that there should be no catch of sea bass in 2017.
study presents the first telemetry tracking movements of sea bass.
Telemetry is the remote tracking of an animal using an electronic
device (transmitter) and a series of listening posts (acoustic receivers),
which were strategically placed all around Cork Harbour. The team
used acoustic telemetry to track 30 individual fish for up to one
year during 2013 to 2015 in the harbour. As the tagged fish swam
around the harbour their movements were detected if they swam within
500 metres of a listening post.
about the research, Dr Tom Doyle from the Ryan Institute at NUI
Galway, said: Knowing that sea bass return to the same little
patch of coastal water each year is absolutely fascinating and asks
so many questions about how they navigate and recognise when they
are home, but it also has important implications for
the conservation of this species.
left the harbour in October and November and returned in May and
June, accurately describing the timing of departure and return migrations.
Remarkably, 93% of fish returned to Cork Harbour after their winter
migration and 86% returned to the exact area they resided in before
their migration, displaying high fidelity to these local areas.
Given their longevity (fish can live up to 25 years) and the combination
of inter-annual fidelity to localised foraging areas, sea bass may
be very susceptible to local depletion.
of the study, Mr Jim Clohessy from Cork Harbour Angling Hub, said:
The marriage between science and angling in this study is
fascinating. The results and some of the information coming out
of this research has the potential to save the state a lot of money
in terms of targeting their fisheries protection.
Damien Haberlin from UCCs MaREI Centre, added: It is
really amazing that for many of our familiar marine fish we know
very little about their movements beyond some very broad generalisations
that they are found inshore during the summer months and during
the winter they move offshore to reproduce. So in this context,
our findings are very exciting. Its really nice to have some
detailed movement data on one of our most important marine fish
research was funded by ESB and Science Foundation Ireland (under
MaREI Centre), with strong support from the local angling community
in Cork Harbour, and in particular Richie Ryan and Andy Davies,
who helped catch the fish to carry out the research.
read the full paper in Scientific Reports visit: www.nature.com/articles/srep45841