Download River Welland :- a plan for Fish

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River Welland - A suggested Partner Action Plan for Fish David Moore - March 2012
This DRAFT PLAN has been suggested as a way forward for improvement of WFD Status of fish
on the Welland.
David Moore is an Environment Agency Committee Chairman & member of the Board of the
Angling Trust, working with the Welland Valley Partnership Steering Group & Habitats & Fish
Group.
The river Welland and its tributaries support most of the freshwater fish species found in England.
This reflects its varying physical and chemical characteristics and its temporary post-ice-age
connection to northern European rivers.
The species it supports have mostly populated the river through natural migration although a few have
been introduced by human intervention in the past 50 years.
The rivers fish have been variously managed and monitored since the Welland Fishery and District &
Fishery Board was established in 1923 through to current responsibility of the Environment Agency.
During this time the river has undergone significant changes which have affected the fish populations.
Status of fish stocks
Data provided by the Environment Agency showsVery poor fish stocks above Market Harborough
A decline in fish stocks downstream to Stamford where most sites fail to reach good status. There are
some brown trout in this stretch but some un-quantified dependence upon artificial stocking
Better but declining fish populations are recorded at some sites from Stamford downstream to the
Deepings.
Barbel were introduced in the Deepings area in 1955-6.
Data from the ‘wide river’ downstream of Deeping St James is difficult to provide because of the
physical characteristics and excessive plant growth for most of the year.
Although common relative to the adjacent River Nene, eels have declined rapidly over the past 30
years reflecting the national and European trend.
Sea trout are occasionally reported upstream as far as Stamford
Dace have declined in the river above Stamford where they were previously very common or dominant
and were recently re-stocked in the upper reaches by the Environment Agency.
The main tributary above Stamford is the River Chater whose fish populations are classified as poor in
the River Basin Management Plan.
The River Gwash downstream of Rutland Water and the main Welland between Harringworth and
Duddington are managed and stocked as brown trout fisheries.
Angling competition records for the lower river are available in Welland & Nene River Authority
annual reports back to 1967 when it was fished by over 20,000 anglers each year with the top ten
weights in each competition averaging 1.0 to 1.5 Kg per angler.
More analysis of fish population data is required to identify constraints and measures.
Pressures on fish stocks
Straightening and widening the channel to protect Market Harborough from flooding between 1967 -70
reduced depth and encouraged silt accumulation in the upper and middle reaches. This reduces the
holding capacity especially for larger and mature fish and restricts breeding success and recruitment for
most species native to these reaches. Fish in these conditions are also more vulnerable to predation.
Bank-side vegetation has been reduced by this management and the lack of overhanging bushes and
trees exposes fish to predation and also increases water temperatures beyond optimum. When flows are
low this leads to a combination of high temperatures and low dissolved oxygen which stresses and kills
fish,
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A high proportion of the dry weather flow in the Welland is dependant upon sewage treatment works.
The historic pollutions and fish mortalities from inadequate treatment and increasing population growth
over the past 40 years have been overcome through many improvements especially to the two largest
STW which serve Market Harborough and Stamford.
In the middle and lower reaches downstream of Stamford flows are limited by the combination of
abstraction for Rutland Water at Tinwell and the reservoir’s impoundment of the River Gwash which
joins above Uffington.
The Gwash has a similar catchment area to the Chater but only around half its dry weather flow. The
fish stocks of the Gwash may be affected by the reservoir compensation flow, which is set at the
average summer flow prior to the impoundment and accumulations of silt affect depth and breeding
success and lack of depth may restrict fish holding capacity.
An artificial flood channel Maxey Cut by-passes the villages downstream of Uffington. This cuts
through gravel strata giving an unstable bed and a vulnerability to drying out. Several weirs have been
built to address this since its construction over the past 50 years and fish passes are being installed.
Downstream of the Deepings the river is an artificial wide channel resembling a very slow-flowing
fenland drain. Here the fish stocks are dominated by bream, roach and pike. Extensive macrophyte
and algal growth covers most of the surface for the summer and autumn in most years and has resulted
in the loss of fishing which attracted 20,000 anglers annually until 30 years ago. Assessing the fish
populations is difficult because of the weed growth. The excessive aquatic vegetation is presumed to
be a reflection of diffuse and point source phosphorus from the whole river catchment upstream.
The original river channel through Spalding is heavily modified but supports good fish populations and
navigation. The Flood relief Coronation Channel is an artificial water body which resembles the
Welland upstream of Spalding and holds similar fish populations.
The fish in the tidal river are not very well researched but sea trout migrate from the Wash into the nontidal river as far as Stamford and work is in progress to enhance these migrations through fish passes at
the many barriers.
Management Actions
Measures to improve fish stocks in the Welland include1. Habitat restoration in the channel of the upper reaches down to Stamford to improve holding
capacity and breeding and recruitment potential
2. Habitat restoration on the bank-side of the Upper and middle reaches to provide shade and
protection
3. Completion of fish passes from the tidal river to above Stamford and into the Gwash
4. Control of agricultural pesticides to restore invertebrate food for fish in the upper and middle
reaches
5. Phosphorus reduction to reduce aquatic vegetation in the lower reaches
6. Assessment of stocking strategies to test interactions with native stocks and how stocking can
be optimised
7. Engaging and coordinating fisheries and angling interests to collect information and to develop,
agree, implement and monitor actions