Property:Monitoring surveys and results
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A
A monitoring programme funded in the first three years via this project, examining the physical and biological development of the newly created habitat at Alkborough Flats, began in summer 2007. Although the project had an existing programme of monitoring in place, this was primarily targeted towards the delivery of extreme water level reductions and the establishment of the basic habitat types. This project has meant that we have been able to develop the most comprehensive monitoring programme across the widest range of parameters of any managed realignment site in Europe.
The design work for the monitoring programme was agreed by a team made up of key stakeholders and partner organisations. Work on agreeing the programme started in November 2006 with a workshop meeting and was agreed in early 2007. This includes a topographic and sedimentological survey, fish and benthic community analysis and analysis of spatial patterns in the distribution of feeding and roosting birds. The monitoring report attached as Appendix B1.5 details the findings of the second survey, conducted in 2008/2009. +
L
A new riverscape was created on an area of 150 hectares in the mouth section of the Traisen at the Danube power plant near Altenwörth. It is now continuously connected with its floodplain’s waterbodies.
LIFE+ Traisen is one of the most comprehensive restoration projects in Central Europe. Together, the project partners made an important contribution to the nature conservation objectives of the European Union.
The riverbed was successfully completed in 2016. Over an area of 150 hectares, a regionally typical new biosphere was created that will provide an expanded habitat for a multitude of domestic animal species. In order to do this, 800,000 m3 of clay and sand and 1.9 million m3 of gravel were relocated within the floodplain area to create standing water bodies and shallow water areas. Within the construction process the river was extended by 7.6 kilometres and the estuary of the Traisen River was relocated. The LIFE+ Traisen project resulted in a unique riverscape with a mosaic of existing and new habitats. Many animal and plant species have already settled in –including numerous endangered species. +
B
A newly formed relationship with the University of Worcester has created mutual benefits for both parties. A Sonde collects data and the university use this within their courses and final year projects, which we receive a copy of. +
L
A number of environmental and amenity enhancements were delivered by this project. These included improved habitat for wildlife (including provision of Biodiversity Action Plan (BAP) habitats), improved access to waterside areas, new seating/viewing areas, retreated and renewed flood defences and increased flood storage capacity.
This is an area of London where development has historically lead to the degradation of habitats along the River Roding and its tidal confluence with the Thames. It is therefore important that BAP habitat such as saltmarsh and mudflat is restored to the Creek.
''MSC thesis reults'': Small size restored intertidal habitat within heavy urbanised estuaries can function as relic marsh and provide a successful nursery and feeding grounds for juvenile fish. These fragmented habitats also help establish an intertidal migratory corridor through rivers, safeguarding fry from the high flows found in the central channel. This emphasises the importance of intertidal estuarine habitat in achieving ‘good ecological status/potential’ under WFD, and the added value they could bring if included within the network of Marine Protected Areas (MPA) planned for around in the UK coast. +
C
A phase 2 habitat survey was carried out prior to works in 2016. Areas of low quality MG4 meadow were identified and protected from earthworks. The remainder of the site was seeded in an appropriate wetland mix in April 2016. In July 2017 a bioblitz was carried out on the site and over 614 species were recorded. The meadow is improving but further enhancement of yellow rattle might be advantageous to control the grasses on the site that was originally protected from works. Seeds donated from a floodplain meadow area within Kingsbury Water Park will be used to enhance the flora further.
The Wetland works even better than anticipated filling from Mitchell's pool in the north through the ditches and flooding over the meadow and from the impoundment of the leys brook which fills the pond and dry reedbed area and then flooding over the meadow. +
Creation of flood channels and restoration of exchanges between the flood plain and the low-flow channel on the Vezouze +
A pre-restoration monitoring was carried out by a
consultancy in 2000 and again in 2003, 2004 and
2005 on the hydraulic component. Investigations
were required to study the hydrography,
hydrology, topography and geology of the land.
A bibliographic study was used to describe the
biological component of the aquatic environment.
Post-restoration ecological monitoring (habitats,
species) began in 2010 and will continue until 2014.
This monitoring consists of describing the natural
environment and assessing the impacts (positive
and / or negative) of operations on animal and plant
life, specifically targeting the restored flood plain
and side channels created. The hydromorphology
and biological communities living in the lowflow
channel (fish, aquatic invertebrates, etc.) are
however not investigated in this work.
The first results of 2010 and 2011 highlight
several outstanding species for Lorraine, including
insect and plant species. It will therefore be very
interesting to monitor the evolution of these
species on the site. Particular attention will be
paid to plants receiving protected status, as these
species were most likely to have been introduced
during the restoration work.
The ecological evolution of the site is very
satisfactory. The results of monitoring attest to the
positive effects of the work on biodiversity with the
presence of wildlife characteristic of wetlands and
the presence of outstanding species in terms of flora
and insect life. The evolution and diversification of
the side channels, which have a dense vegetation
of helophyte-type plants, are also very conducive
to pike reproduction (even though there is no
monitoring of this aspect, side channels here show
strong potential).
Hydraulically, the results are equally satisfactory.
Upstream to the restored area, height and surfaces
of areas flooded in Lunéville have significantly
diminished.
As the primary objective of this restoration is flood
defence, the explanation to elected representatives
of the benefits of preserving the flood storage
area and diversifying habitats in the flood plain has
led to the setting up of a project that reconciles
hydraulic and ecological objectives. Cross-cutting
objectives particularly motivated elected representatives
who were thus able to meet the expectations
of the local population in terms of safety and
landscaping issues. These developments make
it possible to combine flood management and
improvement of the ecological status of the river.
In addition, a pedestrian path has been created in
the area and its regular use reflects the renewed
interest of local people for the site. Previously, they
tended to avoid this unattractive, unsightly sector.
The work thus helped to enhance “nature” in a
peri-urban area.
R
A pre-works survey showing the hydro-geomorphological
functioning of the Adour was carried out. It
was based on expert opinion and observations of the
river’s morphological characteristics (flow pattern,
erosion zones, disconnected secondary channels) and
any changes over time. Since the end of the works,
no specific monitoring has been carried out, with the
exception of regular observations in the field.
The restoration works diversified the flow pattern
and habitats, making possible salmonid reproduction.
An immediate effect of reconnecting the side
channels was an increase in the mobility space of the
river and a decrease in flooding risks (greater dissipation
of energy, a reduction in vertical and lateral
erosion processes, stabilisation of banks, etc.).
The awareness on the part of the elected officials of
the need to protect biodiversity and the creation of a
comprehensive, integrated and pragmatic approach
to river management, in close contact with the local
population, guarantee the success of the project.
The guiding principles behind the restoration and
maintenance works have now been adopted by the
towns downstream.
The intermunicipal association has also made significant
financial savings thanks to the halt of the previous
large-scale and expensive work programmes. +
N
A range of monitoring studies were undertaken to describe ecological development of site (i.e. surveys of overwintering waterbirds, benthic invertebrates, vegetation and sedimentation/erosion patterns) as well as impacts to saltmarsh habitats and benthic invertebrate communities outside the breached area.
A PhD study investigating sediment characteristics and invertebrate colonisation reported the following results from monitoring the site during the first three winters post implementation (with the caveat that the realignment sampling points were higher in the tidal frame than those on the reference intertidal flats) (Crowther, 2007):
(1) The '''particle size''' of the '''sediments''' in Nigg Bay realignment site was significantly smaller than that of the (fronting) reference intertidal flats (mostly silts compared to mostly fine sands) – this was attributed to the sheltered environment and limited wave exposure within the site.
(2) The '''organic matter''' content of the '''sediments''' on the reference intertidal flats was less than 1%, whereas within the site, it was 46.6% in the first winter, and 27.2% in the second. The author highlighted that ‘organic matter is usually associated with fine grained sediments (…), so the sediments in [the site] are likely to have provided a large surface area for colonisation by
micro-algae’. Furthermore, the higher organic content during the first winter was described as ‘not surprising given the large quantity of vegetation that had been killed following the re-establishment of tidal conditions’. A significant positive relationship with elevation in the tidal frame was found for the percentage organic matter in the sediments during the second winter. The author theorised that such high organic matter content of the sediments ‘may have caused hypoxic conditions due to the increased biological oxygen demand of the sediments’, however oxygen content was not measured (and the presence of hypoxia hence not determined).
(3) The following four '''invertebrate species''' were found to be most abundant within the site three years after the re-establishment of tidal conditions: ''Corophium volutator'', ''Hediste diversicolor'', ''Hydrobia ulvae'' and ''Macoma balthica''. All of these were also noted as colonists in the first year, and also found to be the most abundant species on the adjacent reference marshes. The presence of M. balthica during the 1st winter was considered unusual, as it is usually considered to be relatively immobile. It was theorised that this could have resulted, at least in part, from wind or wave-driven immigration. The presence of ''C. volutator'' and ''H. diversicolor'' was (amongst others) attributed to the high organic content of the sediments. Intertidal invertebrate densities within the site were generally lower than the reference intertidal flats; which was mostly related to the higher elevations of the realignment site.s well as impacts to saltmarsh habitats and benthic invertebrate communities outside the breached area.
I
A regular monitoring as foreseen for the WFD was not yet implemented. Existing results of former studies are mainly related to river discharge and random samplings for water quality controls. Further monitoring results are collected by several departments of the Ministry of Ecology and Natural Resources of Ukraine. The sampling stations are however further downriver of the subbasin border. +
S
A small group of people organised by Land Life and Livelihoods were able to obtain information through questionnaire and interview from 66% of the households with septic tank sewerage systems in the area. In general there was a low degree of awareness of how tanks worked, but people in the locality seem to have readily addressed problems when they have arisen. 52% of tanks are over 30 years old and 37% of soakaway systems being within 25m of a watercourse. The majority of householders (54%) have their tanks desludged frequently (<3 yrs) but a significant proportion (16%) wait 10 yrs or longer. A risk assessment was carried out using the information collected and a ranking list drawn up. Only 3 (2%) systems showed obvious signs of failure and need attention, although the condition of tanks was not physically inspected. Some systems are in high-risk locations but without obvious signs of malfunction and in the absence of supporting water quality data it is difficult to determine whether they are working effectively. Recommendations are made for improvements to the 3 sites and further investigation of the remaining higher-risk sites.
The investigation of the flux of silt and sediment from hillsides and road verges via the road system suggested that roads were major carriers of sediment and that as well as some road drains, overflows from accumulated water and ditches alongside roads also needed to be considered. However, road drains are mostly located in the valley bottoms and so dealing with them is akin to treating the symptom rather than the root causes. The report suggests that a whole catchment analysis of the erosion and sediment transport issues is needed of which managing road drains should play a part. +
C
A ten-year monitoring programme is being is being undertaken to describe both changes to sites fronting the realignment (in relation to bathymetry, invertebrates and waterfowl), and to the realignment site itself (in relation to topography, saltmarsh composition, changes to intertidal invertebrates and bird and wildfowl usage).
Over 12 ha of mudflat were created. During 2006/2007, a total of 13 waterbird species were found to be using the newly created intertidal area. All target species established for the site were observed with one exception. Although the grassland and hedgerow are relatively new habitats six bird species were observed using the grassland of the newly created embankment during 2007, four of which held breeding territories. Again, all target species were observed with one exception. Welwick: The site covers a total area of 54 ha to the edge of the current saltmarsh in front of the seawall. Landward of the current defences the site area covers approximately 48ha, whilst the current sea defence accounts for 3 ha and saltmarsh in front of this covers 3 ha. A total of 29 waterbird species have been recorded with the realignment site having developed as a major roosting site for a number of wading birds at high water. With one exception, all target species established for the site have been observed.
In total, 66 ha. of farmland have been converted into new inter-tidal habitat to compensate for the 22 ha. of land lost due to the new port developments.
At a very early stage, an integrated plan, considering flood protection, nature protection and maritime transport including mitigation measures, was developed. When the plans were first put forward, there was strong resistance because of the habitat loss. Through extensive consultation and close co-operation with a number of environmental organisations, an outcome was reached that was acceptable to all parties. The process ensured that the environmental impact of the project was clearly identified and mitigation and compensation actions taken. This led to a legally binding agreement – the first of its kind in the UK – that meant that ABP had to carry out the agreed set of offsetting measures but that they would not have to face a lengthy and costly public enquiry.
W
A ten-year monitoring programme is being undertaken to describe both changes to sites fronting the realignment (in relation to bathymetry, saltmarsh evolution, invertebrates and waterfowl), and to the realignment site itself (in relation to topography, saltmarsh composition, changes to intertidal invertebrates and bird and wildfowl usage).
'''Invertebrates''': The monitoring has shown that invertebrates have colonised this new sediment. In 2009, between 667 and 7,286 organisms were found per m² (belonging to between 5 and 13 species). The abundance, diversity and biomass of species in the mudflat have been increasing since the realignment has been implemented, although these are still typically lower compared to fronting, pre-existing, mudflat sites. This is unsurprising given that the community has still not had much time to establish and develop.
'''Birds''': Shorebirds are making good use of the site; overall, numbers observed exceed original predictions. For example, a total of 31 different waterbird species were recorded using the realignment site between September 2008 and March 2009. The site has developed as a major roosting site for wading birds at high water, including red knot, dunlin, curlew and bar-tailed godwit. Birds such as black-tailed godwit and curlew have been using the site with increasing frequency.
'''Saltmarsh and Grassland''': With regards to the development of other habitats, there was a requirement to also create saltmarsh and grassland on site. By 2009, a proportion of the site had developed into saltmarsh, with the typical pioneer plants such as glasswort colonising within one year. Other plants such as common saltmarsh grass, annual sea blite and common cord-grass have been slowly increasing in number. Thus, recognisable saltmarsh plant communities assembled relatively rapidly at Welwick; which was not unsurprising given the proximity of existing saltmarshes (and thus seed sources). With regards to grassland, this was mostly established on the new flood banks, and it appears to be developing the desired species composition. Breeding farmland birds have been found within this habitat. A total of 25 different species were observed during the latest survey undertaken in May 2009, including reed bunting, skylark and yellow wagtail.
S
A variety of monitoring techniques have been employed to assess the impacts of the works. These include fixed point photography, along with regular visual inspections to monitor the integrity and performance of the in-stream structures. An annual programme of fine sediment and gravel sampling to monitor changes in the bed substrate has been established and native crayfish surveys will be repeated on a 2 years cycle. Annual fish surveys are already undertaken and show that the brown trout stocks are currently healthy. +
R
According to monitoring, juveniles of greyling have been found in the bypass channel and big fish species like pike, carp, barbell and wells catfish have used it. These suggests that the bypass channel is providing a new reproductive area. +
After project management was reduced to a biennial cutting of the banks vegetation and, when needed, removal of waste (plastic, etc…) and of major obstacles to the flow.
A preliminary study was carried out in 1996. After works, no scientific monitoring was planned, but the river banks were vegetated and the diversification of flows and bed depth was ensured. There were no longer stagnant water or siltation. +
After restoration, the raised water level within most of the compartments together with restrictions on the use of fertilisers and pesticides and changed management practices is reducing the leaching of nutrients, ochre and pesticide pollution into the surrounding environment. In addition, conditions have been enhanced for flora and fauna, not only within the project area, but also in Ho Bay and the rest of the Wadden Sea.
The animal and plant populations including fish, mammals, amphibians, birds and invertebrates have increased and obtained a more beneficial conservation status. The same is also true for habitats including the estuary, Atlantic salt marshes, freshwater meadows, and the River Varde Å itself. The Corncrake (''Crex crex'') has improved its conservation status.
However, changes in the conservation status of the area have not been as effective and fast as might have been expected. This is mainly caused by the farmer’s choice of management by traditional grass cutting and mowing instead of cattle grazing. It is being considered establishing grazing associations through the Danish Rural Development Programme to encourage the farmers to introduce grazing in larger parts of the target area. +
O
After the changes to the streambed, several new plant species appeared in the area. Several trees in the wooded area died. However, it is difficult to say which of these changes can be attributed to the experiment and which were caused by a beaver building a dam at the same time. There have also been small changes to the macroinvertebrate community, but no significant changes to the diversity in taxa or to the macroinvertebrates' total abundance. Longer measurements are needed to assess the effect on hydrology and morphology. +
H
After the construction of HPP and fish way in 2009 the monitoring began and is still going on. The method used was electrical hunting and fish nets. In 2011 also telemetry was included in monitoring. Results showed that 32 of 40 fish in Sava river on the area of HPP Blanca was evidenced in the fish way (among them also ''Chrondrostoma nasus''), since the beginning of the monitoring, which is good result.
The base for this project, which was done by IBE d. d., was interest in fish species composition in lower Sava river, the assessment of population size for each species, biological characteristics and ecological needs of species. Recommended guidelines and literature about fish passes were basis for the project scheme. The fish experts from Fisheries Research Institute of Slovenia were included in the project from the beginning, which is very good progress in cooperation between experts and energy producers. Even more progress can be done with founding the permanent monitoring of fish way function and maintenance (http://www.he-ss.si/pdf/he_blanca-primer_dobre_prakse.pdf).
Monitoring of fish in the fish pass. +
R
After works, the natural water line is restored and the vegetation along the Baume river is naturally quickly restored.
At present, an evaluation is not possible due to the limited data availability. However, the initial results are very encouraging. +
G
An ecological monitoring programme was also undertaken to complement the water quality study and
investigate the effects of metal pollution on macrophytes, invertebrates and diatoms. The ecological
surveys were carried out in 3 seasonal sampling events over 2 years. Preliminary results show little
adverse effects on invertebrates and macrophytes, but distortion of diatom valves in some species. +