International Conference on Engineering and Ecohydrology for Fish Passage

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https://hdl.handle.net/20.500.14394/393

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Fish ladders at small hydropower plants and potential contribution to downstream passage of eggs and larvae
(2018-12-13) Brambilla, Eduardo
Fish passage can potentially enhance downstream fish passage of larvae and eggs at small hydropower plants (SHP’s). To evaluate this hypothesis, two SHP’s located in the Sapucaí-Mirim River, Southeastern Brazil, both with weir-and-orifice type fish ladders were studied. Eggs and larvae were collected fortnightly between November 2016 and February 2017 (seasonal reproductive period) from set locations upstream of the dams, including the lotic, transition and reservoir. Additional downstream drifting samples were collected from within the fish ladders. Higher densities of eggs and larvae were collected, from all sampling sites, in December, January and early February. Larvae and eggs were only collected from the fish ladders during these periods and only during intense pluviosity events after river flow peaks. The low egg and larval abundance registered with the fish ladders, when compared with lotic, transition and reservoir sites, indicates that few eggs and larvae successfully move downstream through the fishway. They likely travel through turbines and/or the spillway, get eaten by predators or even simply drop out of drift. Increases in river flow has significantly influenced the passage through the fish ladders.
Cost Effective Modelling to Improve the Functionality of the Broken Creek Rice’s Weir and Kennedy’s Weir Vertical Slot Fishways
(2018-12-13) Slarke, Steven; Muller, Jarrah; Stuart, Ivor; O'Connor, Justin; Jones, Matthew; Turner, Mark
Acknowledgement Goulburn-Murray Water Broken Creek in north-central Victoria flows into the River Murray upstream of Barmah. There are 10 low-head (<2 m high) weirs on Broken Creek which all have vertical slot fishways however these have high turbulence (i.e. 75 W/m3) and thus limited functionality for several species of native small and medium sized fish (i.e. <300 mm long). In late 2017, the Victorian government (DELWP) engaged Jacobs and Kingfisher Research to hydraulically model the Rices and Kennedy’s Weir fishways to prepare conceptual designs for retro-fitted ‘key-hole’ slots to reduce pool turbulence and demonstrate potential for improvement in functionality to pass much smaller fish (i.e. >50 mm long). Jacobs applied a Microsoft Excel based fishway model which takes fishway geometry, calibrated slot discharge coefficient data, and headwater/tailwater ranges, and uses these data to predict individual pool turbulence, depth and slot velocity. These hydraulic outputs were combined with fish swimming ability, maximum allowable turbulence, and minimum water depth to graphically demonstrate water level ranges for which each fishway could pass small, medium and large-sized native fish. Conceptual level ‘key-hole’ slot designs were then developed, reducing slot areas and flow rates and enabling passage of all fish sizes. The modelling showed that The theoretical implementation of ‘key-hole’ slots effectively halved the fishway discharge and reduced the pool turbulence to 35 W/m3, the known threshold suitable for passage of small-sized native fish. This project demonstrated the efficiency of Microsoft Excel based modelling to bring together both fishway hydraulics and fish biology, with novel design options rapidly evaluated for a low cost. Graphical fishway operation tables were automatically produced for the full range of site operational conditions without the need for costly post-processing of model results. GBCMA propose to retrofit key-hole slots to Rice’s and Kennedy’s weir fishways to improve their performance during 2018.
Hydraulic Approach for Dimensioning Fish Way Attraction Flow
(2018-12-13) Henning, Martin; Heneka, Patrick; Schuetz, Cornelia
The German Federal Institute of Hydrology (BfG) and the German Federal Waterways Engineering and Research Institute (BAW) are working to restore upstream connectivity for fish on German Federal Waterways by means of fish ways. In order for fish to find the entrance of a fish way, sufficient attraction flow is necessary. However, to this day, there is no generally accepted definition of sufficient attraction flow and how to evaluate it. Furthermore, according to the European Water Framework Directive fish of all species and sizes have to be considered for upstream migration. Thus, requirements for attraction flow are diverse. Theoretically, attraction flow should be designed as large as possible. Practically, space for fish ways is often limited and large supply structures may lead to other restrictions, especially distract fish from their passage. In addition, in terms of operational discharge, fish ways often compete with hydropower and other interests. Thus attraction flow should be designed as large as necessary and as small as possible. It is common to design attraction flow rate as a proportion of competing flow, e.g. mean annual discharge or hydro power plant design discharge. However, these approaches do not consider site specific parameters such as geometric and hydraulic boundary conditions. The framework presented characterizes requirements for attraction flow by a simple set of variables. Hydraulic jet theory is used in order to estimate attraction flow diffusion and to take into account tailrace characteristics. In doing so, site specifics such as water depths, river bed boundaries and influence of competing flow are considered. The straight forward approach aims at applicable dimensioning recommendations for attraction flow rates and fish way entrance design.
Fish Passage Remediation through the NSW Recreational Fishing Trust Habitat Action Grants
(2018-12-13) Nichols, Scott
The NSW Recreational Fishing Licence was introduced on 23rd March 2001. The funds generated by the licence are held in a Trust and used to improve recreational fishing in the state via a number of targeted programs including fish habitat restoration. One of the success stories of the NSW Recreational Fishing Trust has been the Habitat Action Grant (HAG) Program that directs funds to onground works via a devolved grant process. Since the HAG Program began in 2003, over $850,000 has been used to leverage 40 road crossing and weir fish passage remediation projects valued at $7.1M. Importantly, native fish access was improved to over 2,000 km of waterway. Despite the success of the program, Trust funding for individual HAG projects is capped at $40,000 per year and is primarily directed towards smaller projects involving on-ground works. Such funding is often not enough to tackle larger, more complex projects. Recently, the Trust approved a larger scale version of the HAGs called the Flagship Fish Habitat Rehabilitation Grant for which projects are able to apply for up to $400,000. The Flagship program has allowed for higher priority fish passage programs to be discussed and initiated that otherwise would have been delayed indefinitely. The Flagship program also value-adds to the existing HAG program, achieving a more holistic outcome for fish passage as will be discussed in one northern NSW catchment. This talk will detail the outcomes achieved by the HAG program and lessons learned along the way. The NSW Recreational Fishing Trust’s Habitat Action Grant Program and Flagship Fish Habitat Rehabilitation Grants are an excellent example of the NSW licence fee being directed back into the fishery to provide long term, permanent improvements to the waterways of NSW.
Optimisation of Fishway Entrance and Exit Conditions Using Physical Modelling: SARFIIP Pike Floodplain Regulator and Fishway Designs
(2018-12-13) Slarke, Steven; Stuart, Ivor; Pezanitti, David
As part of SARFIIP, Jacobs and Kingfisher Research prepared designs for two integrated regulator and fishway structures at the Pike floodplain for SA Water, DEW and the MDBA. These structures will enable the future managed inundation watering of Pike during regulated river flows to restore floodplain health and fish passage connectivity through the floodplain. A successful floodplain flow regulator and fishway design requires that fish are able to readily locate and enter the downstream entrance. The entrance must be located at the ‘limit of fish migration’, represented by either a wall or a line of turbulence below the regulator gate that fish cannot pass. The upstream fishway exit must be located where fish are not drawn back downstream over the gates. To confirm the optimal fishway entrance and exit arrangements, a 1:15 scale physical model was constructed and tested at the UniSA AFMG facilities. The model was designed to enable the performance of critical elements to be identified and if necessary, quickly adjusted. The sheet-metal model incorporated six lay-flat regulator gates and an adjustable downstream fishway entrance. The model was tested for variable scaled passing flows up to 3,000 ML/d. The modelling revealed the existence of complex hydraulics and the need to maintain the integrity of attraction flows to the fishway entrance. A ‘flow straightening wall’ was incorporated to ensure positive velocity vectors downstream of the entrance. A nib wall was provided across the regulator below the overshot gates to form the ‘limit of fish migration’, aligning with the fishway entrance. The location of the fishway upstream exit was also confirmed and the optimised arrangements demonstrated to the client. In summary, low-cost physical modelling was undertaken to optimise the fishway designs and provide certainty to the biological functionality of the structures and this helped maximise ecological value for investment.
Weir going to build a wall
(2018-12-13) Pearce, Luke K
Whilst improving fish passage is valuable and often essential tool to rehabilitating native fish populations, there can also be the unintended consequence of facilitating the passage and spread of undesirable alien fish that are known to have devastating impacts on certain threatened fish species. Similarly the blockage of fish passage to limit or stop the spread of alien fish into new habitats can be a useful tool in the protection of remnant populations of vulnerable threatened native fish species. We provide three separate case studies of where barriers, both constructed and natural have been used to protect remnant populations of two threatened fish species in NSW, from recent invasions of alien fish species, a fourth case study will be included, where we have designed and propose to construct a significant fish passage barrier, then remove alien fish upstream of that barrier with the aim of reinstating and expanding a population of threatened native fish.
Sea to hume fish passage task force
(2018-12-13) Barrett, Jim M.
In 2001, the Murray-Darling Basin Commission (MDBC) initiated a program to improve fish passage along 2225km of the River Murray, from the sea to Hume Dam, including the construction of 15 new fishways. The three disciplines of biology, hydraulics and engineering are inherently linked in fishway design. As such, a Fish Passage Taskforce (FPTF) was established to recommend fishway design criteria and comprised a team of scientists, engineers, managers and river operators. In order to complement the FPTF, a team of freshwater fish scientists from three states of the Basin (NSW, Victoria, South Australia) was also created to quantitatively assess fishway performance and any associated longer-term benefits from improved fish passage. The rigour instilled in the design process by the integration of the three disciplines was crucial to the overall success of the program. The FPTF has provided a good model for interdisciplinary cooperation and integration of ideas in relation to the conceptual design, construction and monitoring of fishways, setting objectives according to the characteristics of native fish species. An adaptive management approach to fishway design was taken, thus leading to constant design improvements, optimisation, and improved cost-effectiveness as the construction program progressed. The program had a strategic, holistic view and a strong ecological basis, recognising that fish migration can occur over hundreds, and occasionally thousands, of kilometres.
Use of built barriers in New Zealand streams as a conservation management tool
(2018-12-13) Bowie, Sjaan; Jack, Daniel; Nelson, Dean
New Zealand has 77 species of freshwater fish. Fifty-seven of them are native, most are endemic and 72% are threatened with, at risk of extinction or extinct; a higher proportion than almost any other country in the world. While providing fish passage is advantageous for most fish, some of New Zealand’s native freshwater fish, other instream species and habitats cannot cope and/or compete with some invasive species. In these situations, physical barriers, which impede or prevent upstream and/or downstream movement of unwanted fish species, can help protect key locations by keeping invasive species out and providing safe refuge areas. Prior to retaining or installing a new fish passage barrier, consideration should be given to what species and habitats are present, their distribution and extent, their conservation status, habitat preferences, timing of migration and spawning, life history and possible impacts of providing or impeding fish passage. Natural waterfalls do protect a few of these key native locations, however under changing climates and flows these key native fish hotspots are also being compromised and invasive species are impacting on a number of these populations. Fish removal and barrier installation has been successfully undertaken in a number of key locations in New Zealand to remove invasive species and prevent reinvasion and has resulted in good recovery of native fish species. An overview of the use of physical built barriers in small streams as a conservation management tool; focusing on lessons learnt from invasive species removal, important design criteria for structures to exclude invasive species, and monitoring and maintenance considerations will be presented.
Control of globally invasive common carp: a 10 year commercial trial of the Williams' carp separation cage in a Murray River fishway
(2018-12-13) Conallin, Anthony J.; Stuart, Ivor G.
Common carp Cyprinus carpio, are a highly migratory pest fish in Australia, North America, New Zealand and parts of Europe. Fishways built to facilitate native fish passage also benefit invasive carp. The Williams’ cage was developed to separate carp from native fish as they pass through fishways by exploiting their unique jumping behaviour. We report on a 10-year commercial application in a fishway on the lower Murray River (SE Australia) where a high biomass of carp resides. Between November 2007 and April 2017, the automated Williams’ cage was installed and operated at Lock 1 by a collaborative team of river managers, weir keepers, commercial fishers and researchers. To date, over 700 tonnes of adult carp, (approx. 350,000 fish) have been removed at a maximum rate of 5 tonnes per day. The income generated from the sale of the fish has far exceeded set up costs. Catches and separation efficiencies were highest in spring (Austral) when fish were migrating to spawn. During the cage design phase, refinements helped reduce bycatch of non-target native fish to practically zero (0.03%) and informed future designs, application and operation. The Williams’ cage has now successfully moved from an experimental idea to full commercial viability and could play a key role in controlling the dispersal and abundance of carp where high abundances preside and collaborative management alliances can be formed.
Building a fish passage assessment protocol for New Zealand: implementation of Bayesian network models for estimating fish passage success
(2018-12-13) Franklin, Paul A.; Wilkes, Martin; Baker, Cindy; Brown, Callum; Ammon, Sam
Migratory fish species are dependent on connected habitats to complete their life cycles. Instream structures such as culverts, weirs and dams can impede the movement of migratory species. Disruptions to migratory pathways impact ecosystem health by reducing the abundance and diversity of species present. A number of metrics are available for quantifying habitat fragmentation within river networks, but they are dependent on sufficient information being available on the location and severity of migration barriers. Characterising the likelihood of fish passage success at instream structures requires information on the characteristics of the structure and the capabilities of fishes. Biotelemetry and mark-recapture studies are the most effective approaches for quantifying passage success, but are impractical for broad-scale evaluation of multiple instream structures. Bayesian networks offer a flexible approach for deriving probabilistic models suitable for broad-scale rapid assessment of instream structures for barrier severity. We present a Bayesian network derived for evaluating the probability of fish passage success at culverts in New Zealand. A formal expert elicitation process was utilised to populate the prior probability distributions in the model. We present the results from over 350 culverts where the model has been applied. By taking advantage of expert knowledge, the model offers a practical and objective approach for rapidly quantifying the likelihood of fish passage success at multiple instream structures without the need for resource intensive tagging studies. The results are also consistent with requirements for developing environmental reporting metrics for stream connectivity and the model has been used in a new fish passage assessment protocol for New Zealand.
Re-defining upstream fish passage
(2018-12-13) Shearer, Tom
In efforts to re-establish populations of migratory fish in areas previously blocked by man-made barriers, upstream migration of adults needs to be facilitated past those barriers. Passage solutions need to meet the standards of being safe, timely, efficient and effective. While traditional upstream adult passage solutions may meet these agency standards, the upfront planning and implementation costs associated with these solutions severely impacts the timing and financial viability of these programs. In an environment of increasing pressures on fish populations caused by climate change and habitat degradation, solutions that are cheaper and quicker to deploy are needed. In this talk we describe a pilot adult volitional passage system that took less than 3 months to install in 2017 at a high head dam in Washington State, USA, and the results from that system. This pilot was made possible by collaboration of private industry, tribal interests and the federal government. We will look at the technology used and additional testing that has been performed to make sure that the solution meets the acceptable standards. Biologists and engineers may be able to use this project as an example to accelerate other passage implementations with industry and government participation.
Proof of concept for an innovative pump fishway design to move fish upstream over dams
(2018-12-13) Harris, John H.; Peirson, William L.; Mefford, Brent; Kingsford, Richard T.; Felder, Stefan
Reversing worldwide declines in freshwater fish while making sustainable use of water resources will require effective and economical fishways to restore fish migrations. Mitigation of barrier effects at dams and weirs is too often impeded by poor fishway performance and high costs, so that many fish migrations continue to be obstructed. Improved and less-costly designs are urgently needed. Our innovative pump fishway concept combines fish-behaviour insights, proved fishways techniques and aquaculture’s pumping methods for safe upstream transport of living fish. We ran a series of experimental trials using several scale-model fishway designs with young, hatchery-bred fish. Our horizontal-cylinder design successfully combined volitional-passage functions of existing fishways with non-volitional transport in a conduit carrying pumped water. Several key principles of fish behaviour in fishways led to design improvements: disturbed fish often seek refuge at depth; fishes’ escape reactions strongly motivate swimming into flows; and curved structures aid passage by reducing delays. Replicated trials finally produced an average of 98% successful passage, within brief cycling periods. The pump fishway concept offers potential for effective upstream fish passage at new and existing sites >~2m high, with low construction and maintenance costs and highly adaptable operation in variable flow regimes. Development beyond the concept-trial phase is now a priority.
A trap-and-haul fishway for multi-species upstream fish passage at a challenging site
(2018-12-13) O'Brien, Steve; Harris, John; Mefford, Brent; Roberts, David
Australia’s first trap-and-haul fishway was built on the Nerang River in southeast Queensland during enlargement of the Hinze Dam. In gaining government approval for the project, the constructing alliance (HDA) concluded that providing upstream fish passage would have significant environmental benefits by conserving upstream native fish communities and encouraging recruitment into the reservoir’s recreational fishery. But downstream passage, other than modifications to protect fish emigrating during spill events, could not be justified. Severely constrained outflows from the dam and the impacts of downstream urban development contrast starkly with upstream habitat conditions. North American design approaches were adapted to suit the river’s fishes and streamflows. Challenges for fish passage at the site included the marked restriction of downstream river flows and the location of the flow-release point 300m from the spillway. A barrier weir was built to prevent upstream migrants bypassing the fishway entrance during spillway flows. HDA developed a trap-and-haul system to collect migrating fish at the weir and transport them by tanker to multiple upstream release areas. This system provides flexibility to accommodate varying fish biomass; ability to operate over a range of flows up to 20-year ARI events; facilities for sorting, data collection and removal of pest species; and capacity to limit predation mortalities. Fishway performance studies led to redesign of the entrance vee-trap and other modifications. To 2017, 55,590 fish from 27 large and small-bodied species used the fishway, together with 8 turtles. Fish of three pest species were identified in the sorting facility and removed to prevent their entry to the reservoir. This paper covers the project life cycle for Australia’s first trap-and-haul fishway including the basis for selecting the fishway type, design and construction. Fishway performance studies and results from ongoing operation, including the lessons learned and the improvements made, are also discussed.
Fish on the run: facilitating fish passage from drying floodplains
(2018-12-13) Stuart, Ivor; Sharpe, Clayton
In the Murray-Darling Basin, river managers are implementing site-scale managed floodplain inundations for vegetation outcomes but there is a risk of native fish stranding during floodplain recession due to the absence of natural cues. In 2014, at the 5,000 ha Gunbower floodplain, central Murray River, we devised a fish exit strategy which included: (i) a fish ‘exit hydrograph’, a designed recession to cue fish to leave the floodplain, (ii) evaluation of a new fishlock to facilitate fish passage from the floodplain to the permanent Gunbower Creek. During our evaluation of the exit strategy we collected 113,099 fish exiting the fishlock at up to 20,000 fish/hr, with juvenile non-native carp, native Australian smelt and native carp gudgeons dominating the catch. Fish were 15-500 mm long. Native fish exited the floodplain during the initial drop where carp exited during the later half of the recession. In addition, 30 golden perch were acoustic tagged to identify their floodplain exit pathways. The implications of our results are discussed in the context of maximizing safe exit of fish from other temporary floodplain habitats.
Connecting fish, flows and habitats on lowland river floodplains
(2018-12-13) Brown, Paul; Wood, David; Ellis, Iain; Greenfield, Andrew; Gillespie, Warwick; Healy, Sascha
Connectivity between river and floodplain habitats is important to many lowland river fishes enabling them to complete their life cycle, maximise growth potential and minimise early life-history mortality. There is increasing recognition of this need and in regulated systems, increasing sophistication of management processes and infrastructure around environmental water allocations to facilitate this connectivity. Providing connecting flows with limited water resources often means prioritising watering one area over another; so comparative evaluation of fish movement, growth and productivity can be important to demonstrate success. In the Great Darling Anabranch, we used directional-netting, measures of whole stream productivity and fish otolith growth and body condition analysis to investigate benefits of connecting flows in 500km of restored ephemeral river channel alongside the same factors in an alternative flow-path, the Darling River. The Hattah Lakes, a complex of regulated, lowland-river floodplain lakes can be filled using large, purpose built environmental pumps; transferring water and fish recruits from the Murray River to productive floodplain habitats. We investigated the lateral movement of resident fish during filling and draw-down of the lakes, using acoustic tags in a native fish species, Golden perch (Macquaria ambigua) and an invasive fish, Carp (Cyprinus carpio). We generated regular movement-trajectories for tagged fish using interpolation, then tested observations against null models to evaluate individual and group movements against a one-dimensional behavioural hypothesis; “do fish move towards or away from the river in response to draw-down or filling?” Results are assisting natural resource managers develop designs for environmental watering hydrographs for connecting flows in large anabranch channels and floodplain lakes.
Build it and they will come. Or will they? Golden Perch in Koondrook Perricoota Forest
(2018-12-13) Robinson, Wayne A.; Duncan, Meaghan; Martin, Kate
The Gunbower and Koondrook-Perricoota Forest (KPF) includes a natural floodplain wetland system that has suffered for many years from a lack of water as a result of water extraction practices in the Murray River. The site was targeted with a combination of environmental water allocations and environmental works programs to manage the distribution and retention of water and ultimately improve its ecological health. A major ecological objective for the Gunbower Koondrook-Perricoota Forest is ‘healthy populations of resident native fish in wetlands’. Golden perch, a large-bodied native species utilise similar habitat on the floodplain proper and floodplain channels between nearby Cobram and Yarrawonga and were documented utilising drying waterholes in the vicinity of the nearby Murrumbidgee River as far back as 1917. We report on an acoustic monitoring survey in 2016 when during a natural flood, none of 14 tagged Golden Perch tagged in the adjacent main river channel entered the forest. Yet at the same time, 34 of 44 tagged Common carp moved into the forest when passage became available from rising waters. Further, seven years of consecutive autumn condition monitoring on the KPF floodplain has failed to sample a single golden perch young-of-year in KPF, and only two adults have been sampled within KPF during that time. In addition, intensive electrofishing and fyke netting of the inlet channel during the first managed event in 2014 failed to collect any golden perch, and none were trapped in the fishways. We suggest that it is important that golden perch and other native large-bodied fish continue to be considered when operating the regulators during future events, including monitoring of fish accumulations at the outlet regulator and fishway trapping.
Hydraulic optimisation of a system for transporting fish in water vertically at near-atmospheric pressure
(2018-12-13) Peirson, William; Kim, Isaac; Pugh, Kieran; Harris, John H.; Felder, Stefan; Kingsford, Richard T.
Reversing worldwide declines in freshwater fish while making sustainable use of water resources will require effective and economical fishways to restore fish migrations. We have developed a proof-of-concept for our innovative pump fishway approach (Harris et al., 2018). This aims to safely lift live fish over vertical distances exceeding 100m without injury. Our horizontal-cylinder design successfully combined the volitional-passage functions of existing fishways with non-volitional transport in a conduit carrying pumped water for young, hatchery-bred, non-salmonid fish. Here, we describe the large-scale transport system designed with minimal moving parts and capable of transporting fish in water vertically over distances exceeding 100 metres. The fish and transported water are contained in a conduit with the transported volume kept at near-atmospheric pressure to minimise barotrauma risks. The system has been optimised to minimise the use of large mechanical pump systems. Under certain conditions, all mechanical pumping is eliminated. The entire system has been demonstrated at a physical model 1 metre vertical scale. A numerical model has been developed, verified against the physical model. Further, the numerical model shows that the system is reliable and can be applied at vertical scales exceeding 100 metres. This contribution will describe the key principles of the system operation and larger scale (4m lift) experiments with summary hydraulic characterisations of the entire system. This will includes hydraulic approaches which retain the key biological constraints required for successful attraction but also minimise the hydraulic losses during the non-volitional transport phase. We also describe a novel method to determine the hydraulic energy losses of conduits to transport fish in water.
Mud Mountain Upstream Migrant Trap & Haul Facility Design
(2018-12-13) Christensen, Peter
Mud Mountain Dam, located on the White River in Washington State USA, is owned and operated by the US Army Corps of Engineers (USACE). The project includes a high-head dam operated for flood control and a small diversion barrier downstream for directing upstream migrating fish into a trap facility designed to transfer fish into transport trucks for release upstream of the dam. Migrating fish species in the White River include Chinook, Coho, and Pink salmon; steelhead and Bull Trout. The presence of Pink Salmon in the river is relatively recent, and populations have increased dramatically in the last few years. The existing trap & haul facility is antiquated and in need of replacement to handle the increasing number of fish in the river, and the complex fish sorting requirements associated with a local fish hatchery and regional fish monitoring programs. A new facility including a new barrier in the river, a short fish ladder, and a sorting facility with a research station has been designed to accommodate an unprecedented number of returning adults. This presentation will focus on the sorting facilities, designed to sort up to 60,000 fish per day by species and tag presence. The sorting facilities include two large holding ponds, two 16-meter-long Archimedes screw lifts, visual sorting flumes, automatic tag detection equipment with fish diversion to a related Chinook Salmon hatchery adjacent to the site, and a fish handling & research station with a water-to-water truck transfer station. Some features of the project are unprecedented in scale and operational arrangement, and the entire facility needed to be fit into a small limited property boundary. The design was completed in 2017 and contractor bidding is underway. The project should be in construction by the time of the conference in December.
Floodplain reconnection and habitat variability act as mitigation measures for sensitive rheophilic fish species in the lower rhine river, the Netherlands
(2018-12-13) Stoffers, Twan T
Aquaculture and Fisheries, Wageningen University and Research, Wageningen, The Netherlands Freshwater Ecology and Water Quality, Deltares, Utrecht, The Netherlands Water Quality and Nature Management, Rijkswaterstaat, Lelystad, The Netherlands Ecology and Landscape, Bureau Waardenburg, Culemborg, The Netherlands Consultancy for Water, Soil and Ecology, ATKB, Waardenburg, The Netherlands The extensive modifications in the River Rhine resulted in the severe decline or even loss of migratory fish species, typical for European lowland river systems, such as Atlantic salmon (Salmo salar) and European sturgeon (Acipenser sturio). In addition, the numbers of other potamodromous, rheophilic species, such as European barbel (Barbus barbus) and Nase (Chondrostoma nasus) have significantly reduced. Since the 1990s, authorities in the Netherlands have reconstructed numerous floodplains to improve the ecological quality of the river systems. This resulted in positive changes to water quality and habitat variability, but not to the expected recovery of rheophilic fish species, an indicator for good ecological quality. We expect that the slow recovery of rheophilic fish populations is mainly caused by insufficient presence and accessibility of those floodplain habitats that function as nursery areas for young fish. To assess the relation between the quantity and quality of these floodplain nursery areas with rheophilic fish recruitment, a large-scale, 4-year (2017-2020) comparative study was initiated. In 2017 450 juvenile fish communities in 59 floodplain water systems along four main branches of the Rhine, covering 351 river km were sampled in a wide-range of floodplain and river habitats. In addition, 39 abiotic and biotic environmental variables were measured. In the first year of this study we caught ca. 135,0000 fish, belonging to 37 species. The eurytopic species Perca fluviatilis, Rutilus rutilus and Abramis brama were most common, accounting for 56% of the total catch. Rheophilic species Leucistus idus, Aspius aspius, Alburnoides bipunctatus and Chondrostoma nasus made up only 29% of the catch. Our main preliminary conclusion is that water conductivity, river-floodplain connectivity and especially habitat variability were the main positive drivers of juvenile rheophilic fish abundance in the floodplains, suggesting that in future floodplain reconstructions specific attention should be paid to these aspects.
Barrier Tracker - Using citizen science to build the most comprehensive atlas of barriers in Europe
(2018-12-13) Kilbey, David J; Berkhuysen, Arjan; Olivo del Amo, Rosa; Wanningen, Herman
There is already a substantial amount of data in existence on the barriers within European rivers. However, even for the most comprehensively audited countries, data is patchy and often of poor quality. Proper assessment and prioritisation of remedial action cannot be undertaken until the full picture is known. Barrier Tracker, part of the Adaptive Management of Barriers in European Rivers (AMBER) project, seeks to address this issue by using a smartphone app to crowd-source data from across Europe. Initially available in 9 languages the app allows anyone to record the barriers they encounter. The app has been designed to allow a low-level of minimum information to be provided in order to reduce complexity for inexperienced recorders. However, a certain sub-set of data is always required to ensure the data is still useful. The app also features an interactive map which displays both the app generated data and all of the currently known barrier data from Europe. This means that a recorder can easily check their local area to see if the barriers they encounter have already been recorded. It also provides motivation for recorders to tackle under-recorded areas. A specially designed citizen science web portal has also been designed to work alongside the app. Owing the fact that many thousands of records are anticipated, the portal contains a section to allow members of the public to classify the barrier data. Classification ultimately leads to verification and/or re-determination of records. Each record has to be classified a minimum number of times and with a set percentage of agreement before verification occurs. Citizen scientists can, therefore, assist with the entire life-cycle of the data. Having only just gone live at the time of writing, in its first two weeks the app generated over 600 records of barriers from across Europe.

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