Property:Monitoring surveys and results
Jump to navigation
Jump to search
This is a property of type Text.
D
Pre-project data<br>Photographs pre-works<br>Photographs post-works +
R
Pre-removal surveys have been undertaken of the river for habitat, fish & native crayfish and post-removal survey work will be undertaken for comparison.
Fixed point photographs will be used to monitor the visible physical effects on the river of removing the weir. +
Pre-restoration works monitoring have been carried
out. It includes a topographic survey for a hydraulic
analysis of the site. Furthermore, fish rescue by electric
fishing was performed at the opening of the culvert.
Fish stocks were monitored following the culvert
removal on the Redon, six months after the restoration
work. As part of the appraisal of the “Crossborder
river contractforthe southwest part of Lake Geneva”
(2006-2012), fish stocks were monitored in all the
watercourses in the area covered by the SYMASOL.
For this, the fish population was counted in the
Redon at the location of the work site in the summer
of 2011, four years after the restoration work.
An IBGN survey was conducted in 2009 (two years
after the work) by a consultancy.
Lake trout can now swim up the whole length of
the Redon.
Six months after the works, about 230 river trout
were recorded throughout the reopened stretch,
i.e. 3,800 individuals per hectare against only
fifteen or so individuals identified during the fish
rescue operation.
The results of the 2011 electric fishing confirm the
trend noted six months after work was completed.
Thus, 48 trout were counted on the upstream
station, i.e. 3,678 individuals per hectare.
These results are very positive and seem to indicate
that the fish population is stabilising in the part of the
watercourse where the culvert has been removed.
The IBGN analysis suggests that the quality of water
is restrictive in this portion of the Redon. The taxon
indicator (Hydropsychidae) is relatively tolerant to
poor water quality and taxonomic diversity is quite
low (18 taxons identified). However, the absence of
a sampling point before the restoration work does
not allow the observation of a potential gain in
terms of water quality or habitat diversity due to
removal of the culvert.
The outcome in terms of overall assessment is
excellent from the point of view of elected officials,
residents and fishing stakeholders.
Pursuant to the River Contract (2006-2012), a
general policy to review weirs preventing river
continuity was implemented. Rocky boulders or
bypasses were set up to make weirs passable.
L
Pre-works monitoring was carried out in 2009 on the hydromorphological characteristics upstream of the weir (flow patterns, substrate sizes, morphology of the river bed and banks).
These measurements were not pursued following the works, however biological monitoring was set up in 2011 by the Côtes-d’Armor FDAAPPMA in the former impounded reach. Monitoring consisted of electrofishing for salmon and of visual inspections of the spawning habitats and redds for the two other species. This monitoring programme was set up for a period of five years and carried out annually from 2011 to 2015.
The continuity of the Leff River has been restored over a 700-metre section up to the next hydraulic structure. Flows are now more rapid and the fine sediment deposited in the impounded reach was carried off to reveal a more coarse substrate made up of rocks and gravel. The diversity of habitats, flow patterns and new substrates revealed upstream of the former weir is favourable for diadromous migratory species that have found along the 700-metre section new spots suitable for their reproduction (well oxygenated gravel) and to the growth of juveniles (riffles). In 2011, approximately 30 spawning grounds for sea lampreys were observed upstream of the former weir. Prior to the lowering of the weir, the water was too deep and hindered the reproduction of the species. Juvenile salmon use the new riffles created in the former impounded reach during their growth phases. On the other hand, no shad have been observed upstream of the former weir, possibly because the species has not yet colonised the new environment.
In terms of recreational activities, the site is more frequently visited by anglers since the restoration project. It has become a good fishing spot with larger numbers of salmon caught than in the previous years.
The kayakers are happy with the changes made because it is now easier to travel over the weir and the white-water areas are fun to shoot. The improvements to the historical heritage were also one of the strong points of the project. The formerly abandoned mill building was spotlit with signs installed on the existing trail to explain the history of the site.
R
Pre-works monitoring was carried out on several compartments of the hydrosystem. The characteristics of the morphological compartment (long and cross profiles, substrate measurements, flow patterns) were identified prior to the works. The fish and riparian-vegetation compartments were also assessed by the FDPPMA 69 and the SMRPCA respectively. Finally, pre-works monitoring of the spawning redds was done by the Rhône local office of Onema. Post-works monitoring was done on the same compartments in 2011.
The removal of the Brosses weir opened 2.5 km of river and potential spawning redds for brown trout. The free movement of fish species and sediment was restored between this section of the Soanan and the Azergues River.
On the site of the former weir, the Onema local office noted, post works, more diversified flow patterns and a shift from lentic to lotic facies. These changes in facies would seem to have stimulated the populations of bullheads and juvenile brown trout, whose respective densities were multiplied by factors of ten and three one year after the works.
In 2017, following numerous floods including a particularly morphogeneous flood in 2016, it was decided to pursue monitoring on the Soanan. The flood in question reduced some of the irregularities in the long and cross profiles of the river. The slope is now similar to the steady slope observed in the rest of the river. However, regressive erosion upstream of the former weir has been observed.
Analysis of the monitoring data revealed reactivation of sediment over a distance of 120 metres upstream of the former weir and, downstream, sediment progression to the confluence with the Azergues River. The fine sediment (sand and silt) disappeared from the upstream zone, revealing gravel beds. In just one year, the natural sediment dynamics were restored in this section of the river.
Prior to the removal of the weir in 2009, no spawning activity by brown trout had been observed over a distance of 200 metres below the weir. Two spawning redds were subsequently observed in 2010, i.e. during the winter immediately following the removal, and twelve spawning redds were observed in December 2011. On the basis of the monitoring results for fish, the species commonly found in calm waters and ponds/lakes had disappeared following the removal of the weir. The number of brook lampreys fell virtually to zero due to the disappearance of the sand and silt substrates. The studied river section had returned to its initial fish-population context comprising essentially salmonids. In 2017, the trout population had returned to a certain equilibrium in that all age classes were represented. However, juveniles were under-represented due to two very hot and dry summers the previous two years.
An action programme for flood prevention (PAPI) and a river-basin contract are currently in effect in the Azergues basin. These two instruments aim to enhance the coordination of management work to control floods and restore aquatic environments by developing contacts and project development in the area.
Preliminary data from 88 tagged trout show that fish can find and navigate the pass. We will review the data in spring 2014 to assess fish behviour in the channel.
The channel has colonised well with the hard work of Rodley Nature Reserve volunteers who have hand pulled Himalayan balsam to allow more native plants to flourish. The visitors and volunteers of the reserver report frequent sightings of dippers and grey wagtais and a male otter has moved into the site and is using the channel as a hunting station - indeed some of our tagged fish may have been dinner. +
T
Prior to the weir removal fish surveys were conducted by the Environment Agency with the next surveys due in 2016. We continue to liaise with the angling clubs who have kept catch records at this site for a number of years. Currently we are seeing the expected dip in overall biomass of fish through this section as the resident Carp disperse away from the now flowing river and the overall species composition changes. We expect to see more natural, sustainable populations of river species develop over the coming years. The backwater habitats were immediately effective with over 300 fry counted in a single refuge within days of completion and larger individuals recorded during over-winter peak flows resting in the still waters these refuge areas have created.
In addition to the changes in fish species composition we have also recorded two kingfishers on site, the first time they have been observed here for over a decade. Through a separate project OART have been supporting the landowner in a programme of mink trapping which has not only captured 26 mink in its first year (in 2km of river) but has also recorded Polecat (known to have re-colonised Sussex approximately 8 years ago) and seen the number of wading and river birds rapidly increase.
We continue with our regime of fixed point photography to monitor change in bank profiles and the rate of vegetation establishment. +
V
Project
The aim of this project was to test out the effectiveness of carrying out more detailed environmental planning on one waterbody and understand if this would drive action and improvements.
This involved three stages of work:
Stage 1 - Intelligence report
Stage 2 - Detailed environmental planning
Stage 3 - Production of the plan
Stage 1: Intelligence report
The intelligence report brings all of the information e know about the brook into one place. This allowed us to identify the significant issues on the brook whilst maintaining an overview.
Two main issues were identified for Valley Brook:
* Restoring a more natural flow and function to the river (mitigation measures)
* Reducing the input of phosphate from upstream catchments +
S
Project is very recent so just establishing. We have baseline data for fish and river habitat survey as well as detailed drone topo. Post monitoring work will commence from 24 on wards.
River condition assessment pre and post delivery has taken place. +
R
Project progress has been monitored in a number of ways:
Through fixed point photography (FPP);
Aerial drone footage;
MoRPh surveys;
Macroinvertebrate (RMI);
Wildlife surveys to assess the reinstatement of native species.
As most of the major restoration works were completed by Thames21 in the spring of 2023, BEPREP research at ‘time zero’ in a rewilded wetland started (report attached as supporting file). Sampling began in April 2023, with a second session in August of the same year; sampling will continue with two sessions in 2024.
In addition, Thames21 are measuring the impact of the project on the local community by the number of participants in volunteering and other nature-related activities (e.g. nature walks, discussions, nature/art workshops). The aim is to achieve meaningful points of direct contact with at least 600 people including those from underrepresented communities (ethnic minorities and low-income groups).
The effort to restore natural processes on the Rom is demonstrated by several indicators that are tracked and evaluated via surveys, anecdotal evidence, and media coverage.
The Horizon funded BEPREP project, researches the effects of rewilding on improving health resilience. At the project site, biological indicators were measured both immediately after excavation and for five years post- restoration. The first few data points demonstrate that, especially the new wetland scrapes, have shown improved biological outcomes and shown which flora and fauna are settling at the site.
Specific indicators include microbiota (bacteria and fungi) changes in the water (e.g. amphibians), on the land (e.g. soil, arthropods, vegetation, micromammals, canids) and in the air (e.g. bats, birds). This research will provide crucial information on which flora, fauna and microorganisms colonise and interact in newly excavated urban wetlands and is fundamental for the sustainable management of aquatic urban environments, and for understanding their importance to human health. The first few data points demonstrate that, especially the new wetland scrapes, have shown improved biological outcomes and shown which flora and fauna are settling at the site.
We are using data from citizen science and observational monitoring, as well as advanced molecular analysis techniques (using environmental DNA) to measure the changes in macro and micro biodiversity of the restored wetlands and nearby forests (Report provided in the ‘Supporting Documentation’ section F1). Preliminary results already show arthropods, amphibians and reptiles colonising the new wetlands. Particularly noteworthy discoveries include molecular identification of faecal pellets from water voles, a nationally rare species.
Records from Fixed Point Photography (FPP) provide a visual record of the changes that are taking place; comparison photos from before and after the restoration work effectively show how the Rom and its floodplain have changed. These images provide a good view of the project impacts through increased river-land interface connectivity and the instigation of natural processes.
To ensure that large wood structures are performing their intended purpose, periodic assessments took place. The maintenance assessment included the characterisation of the structures in terms of stability and an assessment of material integrity and deterioration. After the large wood installation period, in December 2021, we carried out monthly visits for the first 6 months, and then bimonthly visits for the remainder of the first years. After this, we assessed the large wood every six months.
Anecdotal feedback from local communities and stakeholders further reinforces the success of our restoration project. Through our regular volunteering events we gathered valuable insights from the community, from appreciation of improvements to habitat quality to new recreational opportunities, such as the use of the new bridge for bird watching. In addition, the dissemination of information about our project through news articles, videos, and interviews emphasised the beneficial effects of our restoration efforts on the RBI catchment area.
W
Quality of habitats
An environment must provide idyllic conditions for the persistence of vegetation and wildlife. The restoration has delivered clearer water, with better oxygenation, and improved flow preventing silt build-ups and stagnation. There is more riparian space, allowing habitats to expand and communities to mature. Due to the partnership with the EA through their fish passage project, all impoundments to fish and eel movements have been removed, allowing free passage and mixing of populations for the entire project reach.
In addition, shallower riffled areas have become ideal for fish spawning; total number of areas suitable for spawning has increased from 12 to 52. 40 of these have been observed as actively used for spawning by Sticklebacks, Minnow, Chub and Dace.
Ongoing sampling will determine how much of an ecological recovery the river has made towards a more natural state. The objective of ‘Improving the habitats’ is considered fulfilled, however this will be an ongoing improvement as the restoration works mature.
Biodiversity
Both marginal and emergent plants have thrived. Varieties are more diverse and abundant along the water’s edge. Surveys show the previously 2 dominant species have been reduced, and now there are 10 prevailing species. Several species have naturally returned indicating the environment is now more favourable to support diverse aquatic life.
There has been an increase in the diversity of fish species; however decreases in total catch numbers and decrease in body size. With the barrier removal, the fish are no longer restricted and so have spread into the newly opened areas. Fish (and eels) have been seen further upstream than before, and in large numbers. Trout are freely able to connect with upstream wild populations. However, during surveys of the restored reach, fewer numbers are caught – this is thought to be due to 2 factors; 1) space - weirs before created a ‘catching fish in a barrel’ scenario, 2) predators – Otters have been frequently using the restored river to fish, and are thought to have a holt nearby.
There has been an increase in species richness of aquatic macroinvertebrates. Particular improvement is seen in the riffle habitat where diversity, abundance and biomass have increased for aquatic macroinvertebrates.
There is now a much wider variety of habitats. The original 4 dominant habitats types have been reduced or replaced with other key varieties, giving a total of 13 types. Homogenous stretches where 1 or 2 habitats dominated have been replaced with multiple types of habitat, distributed more evenly between types. In addition, there has been a decrease in the less beneficial habitats (for metabolic rate processing) of cobble, emergent and boulder, with an increase in valuable marginal, submerged, algae and woody material habitats.
There has been an average increase of 1.6mg/l/s-1 of oxygen within the restored reach. This is due to an increase in photosynthesis and a decrease in the sediment oxygen demand.
The objective of ‘Increasing the biodiversity of the river Welland through Market Harborough’ is considered part achieved, but study is ongoing for a 5-year period to thoroughly assess the impact.
Flow diversity
The flow seen across the whole project reach has diversified. The removal of weirs and insertion of riffle-pool habitat has led to a replacement of stagnated monotonous flow with fast paced riffles and slow gentle pools.
Water clarity has improved due to a reduction in the stagnation effect. Stagnation before the works had led to suspended sediment dropping out behind weirs, and encouraging weed growth across the channel. The works creating a continuous flow has removed this issue, and reduced monoculture weed choking the channel.
Similarly, measures taken to reduce erosion risk (coir matting, gravel topping, planting and woody lattice deflectors) have led to a reduction in sediment lost in the reach, resulting in clearer water. The objective of ‘reducing the stagnation and sluggish flow of the river’ is considered fulfilled but study is ongoing to assess the geomorphological response.
Visual aesthetics
Before works the river was deep-sided, stagnant, muddy watered ditch. Now the river is clear, diversely flowing channel with shallowed margins abundant with variety of flowering and non-flowering aquatic plants.
Birds have become more conspicuous users of the river. Common birds are seen bathing and hunting insects from the surface. Birds such as Grey Wagtail have increased in abundance, including the number of breeding pairs. Kingfishers have been sighted frequently, nesting in some of the uncovered banks, and hunting in the now clear shallow waters. Otters have also been frequent users of the river, enjoying the improved fishing, and easy access into and out of the river.
All these aspects have led to positive and complimentary feedback from individuals and community groups concerning the visual transformation of the river.
Community use and interaction
Community involvement during the design stages and a subsequent sense of community ownership was seen as a key goal for project success. Multiple evening discussion and group meetings drew gatherings between 50-150 people. Physical activities were also popular, attracting between 8-40 people, and a Bioblitz drew hundreds of visitors over 24 hours. Wildlife watching groups have formed for the local Kingfishers, Otters and general wildlife with Facebook pages to post images and updates.
The river is now widely regarded as an amenity to preserve, evidenced by maintenance promises offered by community groups, including regular river litter picks. Landowners for every section of the river also agreed by contract to maintain the upkeep of the restored river as required.
Nine primary schools have been involved in pond dipping and river lessons; also a secondary school has been involved through assembly demonstrations and presentations. Two Scouting groups have taken part in wildlife walks, bird box building and painting. The use of the river for educational purposes will continue - with easier and safer access to the river installed throughout the Town. Groups and individuals are able to access the river without difficulty, demonstrated by more children using the river to play post restoration works.
G
Recording the length of riparian habitat not accessed by stock - on farm surveys and mapping were undertaken to create a baseline of the area prior to improvement works being delivered. An additional layer of final improvement works has subsequently been mapped.
Monitoring the increase of ground cover and abundance and diversity of plant and tree species in newly created buffer strips - fixed point photographs were taken before improvement works were delivered, and photographs were taken again very shortly after works were been completed. As we expect an ecological lag time to detect the benefits of the improvement works delivered, these fixed point photographs will be repeated again at key sites in three years time to assess long term change.
Monitoring newly planted trees and ensuring tree stakes and guards are upright and secure - newly planted trees will be monitored over the next five years by each farmer, who will report to the Catchment Partnership Officer if any have died (so that they can be replaced), or if any work is needed such as re-staking after high flow conditions.
Monitoring bank stabilisation: this work will be monitored using fixed-point photographs.
Monitoring water quality, before and after restoration works, and highlighting any pollution incidents - we have baseline data of macro-invertebrate monitoring to family level identification and resulting BMWP scores using standard three minute kick samples at eight sites. These samples were collected in Autumn 2014 and Spring 2015. We undertook some volunteer lead Riverfly Monitoring surveys before restoration works were delivered at two sites on Glaisdale Beck. Following the restoration works Riverfly Monitoring is being undertaken at these two sites each month from May - October 2016 and for future years as we expect an ecological lag time (around three years for invertebrates). Our Riverfly Monitoring volunteers are now also recording phosphate and nitrate levels. We also hope to develop a new monitoring site in Glaisdale Beck to assess phosphate levels.
Following the commencement of the works (May 2016), an ecological lag time is expected before benefits to water quality and the riparian habitat will be evident. Our monitoring planner will enable us to record these benefits in due course.
C
Removal took place relatively recently, and so monitoring has yet to be undertaken. Site visits are planned for early 2017, and in the longer term Galloway Fisheries Trust will carry out electrofishing surveys upstream of the site in order to compare the data with pre-works survey results. +
R
Research actions included in the protocol were:
• characterization of the presently existing composition and structure of the aquatic and riparian vegetation in the Odelouca river and assessment of its integrity and longitudinal continuity;
• characterization of in stream habitats and banks; assessment of quality and degree of human disturbance;
• Characterization of key animal communities of the river banks (birds) and river channel (macroinvertebrates and fish) and their relation with riparian and habitat features and human disturbance;
• development of nursery practices for local woody species and best methodologies for field implanting during rehabilitation,
• The study of the functional role of riparian communities in shaping and structuring in-stream habitats and driving river processes.
o Application of this knowledge to the development of rehabilitation proposals for selected river stretches (next phase).
• Modelling abiotic and biotic changes resulting from river rehabilitation actions. Validation of the model results through biomonitoring.
The next phase of activities carried out following the work described above comprised:
• Development and implementation of a proposal for a programme of requalification and rehabilitation measures for Odelouca riparian galleries and fish habitats for selected river stretches;
• Monitoring of requalification and rehabilitation measures for Odelouca riparian galleries and fish habitats at sites situated along a selected reach of river.
A set of monitoring sites provides data that (i) enable validation of proposals based upon modelling results and in depth data analyses and (ii) to correct deviations from the original line of desirable change.
Characterisation of the Odelouca study site was carried out at a total of 30 sites in 2005 and 2006 covering almost the entire length of the river, except the final downstream tidal section (Fernandes et al., 2007; Hughes et al., 2009; Hughes, Ferreira & Cortes, 2008; Hughes et al., 2010). Sampling programmes comprised detailed phytosociological surveys, habitat quality surveys using the River Habitat Survey methodology (Raven et al., 2009) and sampling of biological quality elements comprising fauna and flora (BQE; benthic macroinvertebrates, fish, birds and macrophytes) and physicochemical parameters following WFD compliant protocols (INAG, 2008b; INAG, 2008c; INAG, 2008).
The character of BQE was assessed in relation to longitudinal changes in habitat quality, including riparian quality (Fernandes et al., 2007; Hughes et al., 2009; Hughes, Ferreira & Cortes, 2008; Hughes et al., 2010). Using the KT method which divides the study area into groups of physically similar units and then assesses the extent of given pressures within each unit, habitat and riparian integrity and types of impact were quantified in the study area (Figure 4) allowing impact specific rehabilitation and mitigation measures to be drawn up (Fernandes et al., 2007; Cortes et al., 2002). The KT method can also be applied to characterise and resolve issues in the NWRM context.
Macroinvertebrate communities were found to respond to key habitat elements particularly depth, flow and flow while fish species showed distinct distribution patterns in relation to large scale impacts related to changes in land use and river regulation. Bird communities associated with woods and associated features (canopy cover) predominated in the midsection but were substituted by aquatic and generalist species in the downstream reaches (Hughes et al., 2010; Hughes, Ferreira & Cortes, 2008a; Hughes et al., 2009b.
Cuttings and seeds from all dominant woody species were collected and tested for survival in greenhouse conditions at ISA. Regional nursery managers have been encouraged to be actively involved in this process to debate and demonstrate greenhouse techniques for growing on local tree species.
The well preserved middle course riparian communities, now cleared and submerged, were used as reference sites for the rehabilitation of the selected degraded river sections earmarked for rehabilitation. Emphasis was given to the river segment immediately upstream of the area to be inundated and to the river segment immediately downstream of the dam where minimal flow requirements for maintaining the aquatic biota are now applied. Habitat modelling (river 2D model) was be used to predict fish habitat preference changes according to suggested rehabilitation proposals (Boavida et al., 2011b).
Biophysical Impacts: description of the impact
Biophysical impacts along the Odelouca River were primarily linked to (i) the process of river regulation such as major earthworks, changes in flow regime and associated biophysical processes (natural patterns of erosion and deposition) and habitat destruction (e.g. clearance of riparian galleries) and (ii) changes in land use due to agricultural activities (Fernandes et al., 2007; Hughes et al., 2009; Hughes, Ferreira & Cortes, 2008; Hughes et al., 2010).
The large scale pressures describe changes in land use related to agriculture (e.g. the presence of monocultures) and associated physical impacts at lower spatial scales (river reach and habitat) to bank side and channel (clearance of native riparian vegetation, reinforcement and embankment of the banks to protect against flooding and maximize space for cultivation).
A subsequent programme of requalification, based mostly on natural engineering techniques, was carried out as part of an INTERREG SUDOE financed project called RICOVER (River Recovery in the SUDOE Region). A reach of over 7km in length, situated downstream of the now completed Odelouca dam, was selected and a total of 6 sites selected for intervention measures and subsequent monitoring. Three sites where no intervention measures were carried out were “set aside” as control sites for comparison with the 6 intervention sites as part of the ongoing monitoring programme.
Summary of some of the natural/bio- engineering measures
The construction works commenced in 2011 (Fig. 6, 7 and 8). Most of the natural engineering methods were used to rehabilitate highly eroded and degraded river banks as a result of human intervention (see Table 1) and are briefly summarized below:
• Resectioning of river banks and placement of geotextile (in some cases pre-treated with herbicide) to prevent erosion, retain soil moisture, prevent (re)growth of weeds and invasive plants and create favourable conditions for planted native plants;
• Construction of a crib wall and placement of stone filled gabions to stabilise river banks;
• Planting of rehabilitated banks with native plant species, collected from cuttings and seeds in the area and grown on in local nurseries (e.g. Tamarix, Oleander, buckthorn and ash);
• Construction of artificial islands in the river channel to augment habitat heterogeneity;
• Clearance of invasive riparian plant species (Arundo donax and Acacia sp).~
The rehabilitated sites were monitored in 2011 and 2012 as part of the RICOVER project (benthic macroinvertebrate and fish fauna; physicochemical quality) and in 2013 – 2014 as part of a contract with Águas do Algarve, SA (River Habitat Survey – to assess habitat quality, sampling of benthic macroinvertebrate and fish fauna; physicochemical quality and phytosociological surveys of the river banks). Water Framework Directive compliant protocols are followed in the field, with the exception of the phytosociological surveys.
• Total cost of the initial sub programme of compensation measure (avifauna, fish fauna, riparian galleries and monitoring studies) 5,430,664 €
• Project RICOVER – Rehabilitation of the riparian galleries 267,636 €.
• Ecological Monitoring of the Odelouca River is carried out by UTAD under contract to Águas do Algarve, SA. and is ongoing.
Results show overall ecological status as “Excellent” and “Good”, despite the fact that the Monchique site continues to be heavily organically polluted. This anomalous result may be due to the innate “hardiness” of the Mediterranean BQE, which are adapted to the extreme environmental conditions of drought and flow and therefore may be more resistant (and therefore less responsive) to some types of impact.
N
Research undertaken by the wildlife trusts concluded that 147 species of river invertebrates are closely associated with woody debris. These features directly provide habitat for such species. Furthermore, woody debris flow deflectors improve river morphology, creating differential areas of fast and slow flowing water. Energetic, faster flowing water improves sediment transfer, helping to keep gravels clean. It is also important for the formation of features such as riffles and pools as well as meanders. Slower flowing water provides a refuge for fish and invertebrates from high flows, and allows silt to settle out, eventually forming berms which will improve diversity of flow and plant communities. +
R
Results electrofishing October 2020 (before reopening of the stream):
Station 1 (downstreams closure): 141 trout / 100 m2.
Station 2 (upstreams closure): 1 trout / 100m2.
Station 3 (200 m ustreams closuse): 57 trout / 100m2.
Fish from upstream stations (2 and 3) is stationary trout introduced by local people from other locations. +
P
Riparian enhancement - 30,365 tress planted along the riparian zone of the river.
In stream restoration - The work was completed in August 2015. Monitoring work is now underway and being implemented by the Esk District Salmon Fishery Board. Following large floods in December 2015 initial observations are showing a wider channel, improved composition of river substrates, availability of new salmonid spawning habitat, channel has become more sinuous.
Reduce nutrient and sediment input from diffuse pollution - 22 land managers were engaged, awareness raising workshop was held, and >20km of water margin fencing was facilitated across the target area. +
R
Riparian trees provide shade, which not only keeps the water cooler, but also helps control excessive weed and algal growth.
Cooler water not only contains more oxygen, but many fish and invertebrates are sensitive to increasing temperature. This is likely to be exacerbated as temperatures increase due to climate change. In the future the tree roots and woody debris from fallen branches and tree trunks will provide important in-channel habitat and flow diversity, providing refuge for fish and invertebrates from both predators and high flows. Trees also help stabilise the banks, reducing erosion as well as improving infiltration and intercepting pollution and sediment. Reduced sediment transfer prevents the smothering of important gravel habitat, and can reduce pesticide and nutrient run off. Tree planting therefore not only provides important habitat but improves water quality and can reduce the need for expensive river maintenance. +
N
River Corridor Survey. +
R
River morphology recovering well. No negative impacts from subsequent major flood events including 'Storm Desmond' December 2015 +