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The Maigue
Case Study
A Clean Up
The Maigue
Catchment:
The River Maigue drains an area of 96,000 hectares
in the heart of the Golden Vale, an intensive agricultural area, in
Co. Limerick. Rising in Castletown Conyers flowing northwest, through
well known picturesque angling sites such as Bruree, Croom and Adare,
the River Maigue enters the Shannon Estuary at Carrigclogher point.
Once renowned for its stock of migratory Atlantic
salmon and native brown trout, it provides for the best of angling
opportunities of over 115 km of river.
Over the past number of years a noticeable decline
in salmonid stocks in the Maigue and its tributaries has occurred,
resulting in poor rod returns, and draft net activities discontinued.
The demise of this fishery gave rise to grave concern and warranted
immediate attention.
Pollution Control The Shannon Regional Fisheries Board is currently
undertaking a new and realistic approach to dealing with aquatic
pollution by means of the River Maigue Catchment Project. This programme
has highlighted agricultural 'point
source pollution ', as the main cause for the deterioration in water
quality and the damage to salmonid populations within the catchment.
Consequently over the three years duration of this programme, to date,
over 150 kms of channel has been assessed and remedial action taken to
eliminate ‘point source’ pollution.
Other sources contributing to the pollution
problem are from industrial activity, inadequate sewage treatment
facilities and forestry activities. As this river Catchment is located
in the Golden Vale and a prime agricultural area, there are a large
number of farms dispersed widely and uniformly throughout the system.
Poor waste management practices and inadequate effluent collection
systems within a large farming community proved the main issue that
needed to be addressed.
Findings have indicated that individual discharges
from farm point sources were in some cases small but the overall and
collective impact on water quality was significant and detrimental to
fisheries as illustrated. Consequently a co-operative approach to
pollution control was decided upon as the best course of action and this
involved collaborating with a
number of agencies. A
meeting was convened with the farming bodies, I.F.A. and I.C.M.S.A.,
Limerick County Council, and Teagasc who met with Shannon Regional
Fisheries Board staff. Collaboration with these bodies was met with 100%
support and has since led to immediate improvements in waste management
practices within the farming community. It has also led to the provision
of farm effluent storage
facilities.
Damaged Fishery Habitat A
monitoring programme was set up through out the catchment and results
highlighted our concern. Spawning and nursery streams were yielding
phosphate levels up to seven times greater than the acceptable level for
salmonid waters with phosphates giving rise to excessive plant growth
and Eutrophication. Analysis of invertebrate fauna (fish food) showed
many tributaries to be devoid of pollution sensitive species such as
Mayfly and Stonefly and therefore unsatisfactory as a game fishery.
These were the main environmental factors identified for the decline of
salmonid life within the Maigue catchment.
Supporting our findings, the E.P.A. confirmed the
Maigue and its tributaries have been continuously under threat. Results
show a steady deterioration of the water quality in the River Maigue,
with 50% of the channel categorized as class B or slightly polluted in
1994 to 100% of the channel now in class C or moderately polluted since
1997.
The
Problems
Left
Frame - Point Source Pollution – Farm effluent
Right
Frame - Euthrophication - a
choked channel – unsuitable habitat (nursery stream) Mahore River
Action
Plan
In order to clean up the River Maigue,
remedial action taken was focused, selecting initially the most
threatened spawning tributaries and progressing systematically down the
system, identifying all pollution sources. Farm visitation followed and
remedial measures were instigated
Significant
Improvements
A
reduction in phosphate levels in the disciplined nursery streams was
been achieved. Diversification in invertebrate species
has increased, with the more oxygen sensitive species now present which
indicate a recovering ecosystem. With this improvement evident, a
restocking programme of the tributaries has been undertaken since 1999
in association with the E.S.B., to re-establish extinct salmon and trout
stocks
The
Future:
As the ecosystem continues to recover, we look
forward to a new future for game fisheries in the Maigue and its
tributaries. With significantly less phosphates now entering the water
course and the restoration of the nursery streams, fish stocks will
naturally increase and be self replenishing in the future
The Shannon Regional Fisheries Board is satisfied
that this new approach to pollution monitoring and control will set a
precedent as a model of best practice in other catchments in the region
with similar problems, into the Millennium.
Awareness
and Education is the Key
The Board has prioritized the need for education
and fishery awareness and is currently involved in developing and
running environmental
& Fisheries
awareness and education programmes for schools,
the farming community and angling groups.
Our slogan is ‘You are the solution to our water
pollution’ Please play your part to help keep our waterways clean.
Please report all pollution incidents to the Board
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