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Beauty and
the Beast - A Tale of two fishes
Sea lamprey and salmon have been
living in a symbiotic relationship since the last Ice Age in a most
peculiar manner, here in Ireland. This tail of beauty and the beast,
where the attractive salmon plays the part of beauty and the rather
grotesque yet fascinating lamprey plays the role of beast, hopefully
will continue and have a happy ending on the Mulkear River, Co.
Limerick.
The Shannon Regional Fisheries
Board together with a number of partners is working towards the
conservation of lamprey and salmon on the Mulkear River. This river
is one of the most important salmon tributaries of the River Shannon
and has been the focus of a fisheries catchment management programme.
Indeed the Mulkear River probably gets a greater run of wild salmon
than the main Shannon River upstream of Castleconnell.
The Sea lamprey is a primitive
eel like fish, which lack true bone and jaws. Adults are heavily
blotched dark green, grey or black on sides, yellowish-white
ventrally. Instead of jaws, they have a large sucker for a mouth,
and instead of gills they have holes which they breath through.
These fascinating creatures spend the first few years of their lives
in burrows in silty areas in rivers filtering organic material. They
then metamorphose and migrate to sea and parasitise on fish such as
salmon or herring, by sucking onto their host and digesting their
juices. This mode of behaviour has given them a bad name. Though
justly earned in the USA, where they have decimated many fisheries
in the American great lakes such as Ontario and Superior where they
were given access relatively recently; on this side of the Atlantic
they have evolved in balance with their hosts over thousands of
years and rather than being a problem they themselves face
extinction in many places. Habitat destruction, construction of man
made weirs and pollution being the main problem. Lamprey are not as
good a swimmer as salmon and are therefore are more vulnerable in
many ways.
Although the benefit of salmon to
lamprey is obvious, a recriprocal benefit has been known to many
local Limerick people for generations. Known locally as the “lamper
eel”, the sea lamprey enter the river to spawn usually about May and
dig the same gravels used by salmon to spawn later in the year.
Essentially cleaning and preparing the beds for use by the salmon
later on in Autumn. This truism was recently shown to be scientific
fact by Eamon Meskell of Duchas, who recently studied the spawning
behaviour or lamprey and salmon in Castleconnell.
The EU have listed the lamprey
and salmon as species requiring special protection under the
Habitats Directive and Ireland is obliged to designate Special Areas
of Conservation to protect them. One such area is the Annacotty
stretch on the Mulkear River, soon to be extended to cover most of
the river, and it is hoped that EU funding under the LIFE Nature
Programme can be procured to help advance their conservation
throughout the river.
Fran Igoe
says : The project intends to extend the range of lamprey in the
Mulkear catchment, which is limited by man made weirs.
To improve water quality and
restore degraded habitat to lamprey and salmon. This will be done
with the cooperation of the farming community, angling bodies, state
agencies including the fishery owner the ESB, and other interested
parties in the catchment. In fact there are three lamprey in
Ireland, the Sea lamprey, Petramyzon marinus, River lamprey
Lampetra fluviatilus and the brook lamprey Lampetra
lampetra and all three occur in the Mulkear and will benefit
from the project. The Annacotty stretch is perhaps the most famous
stretch for sea lamprey in Ireland, as they can be seen readily from
Annacotty bridge, building their redds or nests with stones form May
until early August in most years. They will often lift larges
stones, twice the size of a fist to build their nests and great care
is taken not to disturb adjacent nests already built by other
lamprey pairs.
Already we have had a good
response from the local community to the project proposal, including
farmers and anglers who recognize the uniqueness of the area
for these wonderful species.
Mr. Andrew Long
of River Monitoring Technology Ltd is one of the most
technologically advanced fishery projects to be proposed in Ireland
todate. He states that the most modern, state of the art technology
will be used develop appropriate management protocols and results
will be posted in real time on the internet. Radiotracking of
lamprey will be carried out by use of special fish friendly tags to
monitor their progress. Other novel techniques, including some
customized designs will be used in tandem with more traditional
methods to ensure maximum information is generated. Lamprey in
particular are difficult to monitor, and for this reason, ironically
with the exception of the Mulkear there is virtually no quantitative
data out there on lamprey stocks in Ireland to date.
Dr. Fran Igoe
of Shannon Regional Fisheries Board states that this year we carried
out a study of the adult spawning lamprey by snorkeling below
Annacotty weir in association with River Monitoring Technology, and
estimated that on one day there were in excess of 420 adults
spawning immediately below the weir. We carried out exhaustive
surveys upstream of the weir at targeted locations and found no sea
lamprey and showed conclusively that no sea lamprey spawning
activity had occurred. Additionally lamprey were recorded trying to
surmount the weir unsuccessfully. This information has already been
forwarded on to Duchas for management purposes.
Dr. Fran Igoe
states that this project will not only radically improve the Special
Area of Conservation for Lamprey and salmon, and other Annex II
species in the river such as kingfisher, crayfish and otters,
increase our knowledge of lamprey population dynamics but will also
allow local people learn and benefit form the educational value from
the project. Additionally, there are real tangible benefits to
farmers from nutrient management perspectives, but also the
potential to the community as a whole from ecotourism is limitless
if managed properly.
Dr. Fran Igoe
says that we have been in discussions with representatives of the
IFA and the ICMSA to ensure that the farming community is kept
abreast of the project.
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