Guidelines for fish safety tests of turbines ATKB, Author: Ir. F.T. Vriese

Transcription

1 Guidelines for fish safety tests of turbines ATKB, Author: Ir. F.T. Vriese Pro-Tide supervisors: Dr. ir. J. van Berkel, dr. ir. B. Van Esch and ir. A. Breukelaar Report version

2 Guidelines for fish safety tests of turbines Report number: /rap01 Status: Final Date: Author: Project leader: Supervisor: F.T. Vriese F.T. Vriese J. Hop Commissioned by: Province of Zeeland Mr. Drs. S.J. de Groot Postbus LA Middelburg Dit rapport is digitaal gegenereerd en derhalve niet voorzien van een handtekening. De inhoud van de rapportage is aantoonbaar gecontroleerd en vrijgegeven.

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4 TABLE OF CONTENTS 1 INTRODUCTION LEGISLATION Dutch guideline fish mortality hydro power installations Legislation on the protection of animals used for scientific purposes TEST FISH Relevant fish species Relevant size classes of fish EXECUTION OF EXPERIMENTS Setting up a test installation Numbers of test fish to be used in experiments Acquiring the test fish Transport of test fish Storage of test fish Control group Survival testing of fish Delayed mortality Autopsy of dead fish After the experiment, humane endpoints REFERENCES... 13

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6 1 INTRODUCTION With a growing demand for green energy, the interest for hydro power installations has increased worldwide. As recently fish safety has become an important issue (the Dutch government issued a guideline permitting a maximum mortality rate of 0,1% per passage), manufacturers strive to produce fish friendly innovative turbine solutions. Strike models and Computational Fluid Dynamics are used to predict the degree of fish friendliness of these new installations. Also, testing with live fish is done to ascertain fish mortality rates of new concepts under different conditions. It has become apparent that these tests are not in any way standardised, leading to results that are not comparable and difficult to interpret. Within the Interreg NWE project Pro-Tide it became necessary to remedy this and to formulate guidelines for live fish testing of turbines. The project Pro-Tide is aiming on the development, testing and promoting of tidal energy in coastal en estuarine areas. The project is led by the province of Zeeland, together with sub partners province of Zuid-Holland and the Dutch Ministry of Infrastructure and the Environment (RWS). Other partners are: The Isle of Wight Council, Dover Harbour board (English partners), ULCO Université du Littoral Côte d Ópale (French partner) and Waterwegen en Zeekanalen N.V (Belgian partner). Within the project a further development of hydrokinetic turbines and low head tidal turbines will take place. Themes for the project are technology, ecology, economy and public-private partnership. The Dutch project within Pro-Tide, Pro-Tide NL, is trying to identify Best Available Technology (BAT) for the conditions that are present at the Grevelingen and the Brouwersdam tidal power plant: extreme low head (~ 1 m average) and large discharges (2,500 m 3 /s average). As similar conditions can be present in river deltas, hydrokinetic turbines are also taken into account. With the purpose to identify BAT, the first step was to make an overview of available technologies that might be suitable. By using a Multi Criteria Analysis, the R&D advise board has made a prioritization of available technologies. Based on this study it was advised to conduct further research on the following topics: 1. To perform fish safety test with a modified bulb turbine; 2. To do a performance test and also a fish safety test with a hydrokinetic turbine; 3. To perform a desk study on the costs of the VETT technology. However, before any testing is done, the issue of formulating valid guidelines for fish safety tests is addressed in this report. Figure 1. Life cycle of long distance migrants Project number: , final, Blz. 1 van 13

7 2 LEGISLATION 2.1 Dutch guideline fish mortality hydro power installations Recently a Dutch governmental guideline regarding the Water permit licencing of hydro power installations in governmental waters (Staatscourant nr , December 2th 2014) has become operational. Figure 2. Published guideline This policy is based on the authority to give a permit within the Water act, together with the authority to judge the request for a permit within the objectives of the Water act in mind, and to attach specific requirements to the permit. The Water act aims to protect and to enhance, among others, the ecological quality of water bodies. Fish mortality emphatically is a component of the ecological quality of water bodies. The request for a permit has to be judged in the light of the potential amount of fish damage a hydro power installation inflicts on the fish stock. Within the Dutch guideline, the following sections are important. Sections 4 A Water permit for a hydro power installation can only be granted, when the installation meets the requirements regarding maximum protection of fish and downstream fish migration and compensates for possible negative effects on the efficiency of upstream fish migration. Section 5 1. Notwithstanding the requirements in section 4, a Water permit for a hydro power installation in a relevant area can only be issued if the operation of the hydro power installation does not lead to a cumulative fish mortality of more than 10 percent for salmon(smolts) and silver eel in the relevant area. In this assessment, irrefutable decisions leading to less fish mortality can be taken into account; 2. In exception of section 5.1, a Water permit for a hydro power installation in a relevant area can be issued if the cumulative fish mortality is 10 percent or more, when the fish mortality caused by this hydro power installation does not exceed 0.1% and when not already 5 permits are issued using section 5.2; 3. Notwithstanding the requirements in section 4, a Water permit for a hydro power installation outside the relevant areas can only be issued if the hydro power installation causes fish mortality not exceeding 0.1% for salmon(smolts) and silver eel in the concerning water body and if not already a Water permit for a hydro power installation in the concerning water body has been issued. Although not explicitly mentioned in the Dutch guideline (only in the background documents), per hydro power installation a maximum fish mortality of 10% is allowed for other prioritized fish species larger than 30 cm. Species that belong to this group are sea lamprey, river lamprey, flounder, smelt, Blz. 2 van 17 Project number , final,

8 common nase, barbel, ide, chub, dace, burbot and bleak. The maximum allowable percentage of fish mortality is very important for the requirements regarding the fish safety tests. Figure 3. Cross section Linne hydro power station 2.2 Legislation on the protection of animals used for scientific purposes When evaluating fish mortality associated with pumps and turbines using live fish, the law on animal testing applies (in Dutch: Wet op de Dierproeven). Directive 2010/63/EU revising Directive 86/609/EEC on the protection of animals used for scientific purposes was adopted on 22 September 2010 by the European parliament. This directive was adopted in Dutch legislation only recently on 18 th December 2014 and as a result, there are several changes in the procedure to obtain permits to conduct experiments with animals involved. Not only that, the general concept of what constitutes an animal experiment has changed and there is still a lot of uncertainty, especially with regard to experiments with wild animals. Nevertheless, it is evident that an organisation can only conduct experiments with animals when it is in possession of a general licence of the Ministry of Economic Affairs. With that, the organisation is licence holder and has a special identification number for the Netherlands Food and Consumer Product Safety Authority that is supervising animal experiments. The organisation has to apply for a project licence for any specific type of animal experiment (e.g. passing live fish through a pump or turbine), that is issued by the Central Committee for Animal Experiments (in Dutch: CCD, Centrale Commissie Dierproeven). Other documents that are necessary to apply for such project licence are the Non-Technical Summary (which gives a description of the experiment in layman s terms), a project proposal (main features of the project) and an attachment that gives a detailed description of the animal experiment. Within the organisation there should be a an animal welfare body (several persons, including a veterinarian) (in Dutch: IvD, Instantie voor Dierenwelzijn), which is responsible for the welfare and the housing conditions of the animals. With regard to the necessary expertise and competence to perform experiments, the requirements are the same as in the former legislation. Within the organisation it should be verifiable and controllable how Project number: , final, Blz. 3 van 13

9 the requirements of the new legislation are met. Expertise and competence of involved officials should be registered in a straightforward way. Regarding live fish testing specific conditions apply to the transport and housing of the fish. Also, humane endpoints need to be formulated, stating what to do with the fish after the experiments. In the next sections of this report, these issues will be addressed where necessary. Figure 4. Barbel, one of the species of importance Blz. 4 van 17 Project number , final,

10 3 TEST FISH 3.1 Relevant fish species Based on the Dutch guideline, the species eel and salmon are most important for installations at specific parts of the rivers Meuse and Rhine (where installations are already present, cumulative norm of maximum 10% fish mortality). For these species it is necessary to ascertain beforehand (during the licencing process) the mortality they are likely to experience (%) due to the new hydro power installation. Only when fish mortality is sufficiently low, a permit may be issued. Damage to eel and salmon and other prioritized species must be evaluated after implementation of the installation by way of an extensive monitoring program. Eligible turbine types must be tested beforehand with the species eel and salmon. When the level of protection (fish friendliness) is high enough for these species, it is assumed that passing the turbine is also safe for other fish species. Figure 5. Salmon of the river Meuse When testing fish friendliness of low head tidal turbines, more species need to be considered. Next to salmon smolts and silver eel also one round fish species and one flatfish species need te be tested. Bass and flounder are considered to be appropriate species. Both species are present in rather large numbers in the transition zone between the rivers and the sea and are representative of a large group of sea fishes. Species that are also abundantly present in these areas are juvenile herring and sprat, and several goby species (sand goby, common goby, transparent goby and black goby). The decision has been made not to use these species for fish safety test. The goby species are robust and small in size so little damage is to be expected (also no swim bladder, less sensitive to barotrauma). On the other hand, juvenile herring and sprat are not included because of their susceptibility to handling. When touching or netting these species their scales are very easily lost, causing superficial damage and mortality, leaving them unsuitable as test fishes. Nevertheless, it is expected that juvenile herring and sprat have little to fear when passing tidal turbines. Due to their size, the chance of collision (the most important cause of mortality) with turbine parts is relatively low. Also the conditions within the turbines are relatively mild, there is no cavitation, hardly any shear or turbulence, nor are large pressure differences apparent. 3.2 Relevant size classes of fish In full scale installations the amount of mortality of salmon smolts and silver eel is most important. As fish testing is mostly conducted with turbine models that have a smaller scale, the relevant size classes of fish should be determined by the same scaling rules. When testing a turbine scale model of 1:20, size classes of fish should also be scaled down by a factor 20. This, of course, has its limitations. A younger fish might be more susceptible to injury than an older fish. The vulnerability is more or less dependent on the life stage of the species. A glass eel is much more sensitive than a yellow eel or a silver eel. Differences between yellow eel and silver eel are not so clear. A silver eel is less flexible than a yellow eel and might have a higher injury risk when colliding with turbine blades or guide vanes. Project number: , final, Blz. 5 van 13

11 A silver eel however has a much firmer skin and might be less vulnerable to superficial damage. Growth of fish is allometric, changes in body shape occur during growth, resulting in different vulnerability to damaging factors. The application of scaling laws to fish therefore should be a compromise, taking into account that size reduction is possible to such a level that other factors (life stage, swimming capacity, sensitivity to handling etc.) are determining fish mortality. As the current knowledge on this subject is limited, a proposal on the minimal length of test fish is done based on expert judgement. In the current experiments (scale model turbine 1:20) fish of the following length will be used: Yellow eel (Anguilla anguilla) of 20 cm length; Flounder (Platichthys flesus) of 10 cm length; Salmon (pre)smolts (Salmo salar) (or small rainbow trout (Oncorhynchus mykiss) of 12 cm length; Bass (Dicentrarchus labrax) (or pike perch (Sander lucioperca)) of 16 cm length. It should be clear that these lengths are average values. In a batch of test fish there will always be a certain variation in lengths. A separate report will be written on scaling laws with regard to turbine testing. For other aspects of importance, readers are referred to that report. Figure 6. Fish species and lengths of test fish Blz. 6 van 17 Project number , final,

12 4 EXECUTION OF EXPERIMENTS 4.1 Setting up a test installation Test installations can be situated in a laboratory or outside, on or near a relevant water body. In the first case testing will be done in a closed loop (water in the testing installation is circulated). In the second case there will be an open loop (on one side, surface water is pumped into the test installation, on the other side the water flows back into the water body). In both situations it makes sense to test the turbine in a steady state, under maximum conditions with regard to head or flow velocity. Fish mortality will be worst case under these circumstances. Test installations in a laboratory has the advantage that environmental conditions are more constant (controllable). However, when testing takes a long time, water quality should be monitored. Also, storage of fish in large quantities in a laboratory setting is difficult. Care should be taken that the water quality in the testing facility is the same as in the storage facility. Long term pumping may lead to a rise in water temperature. When test fish are caught in the wild, acclimatization to indoor conditions is an important issue. In testing facilities outside, surface water can be used in the test installation and also for storage of fish in enclosures or in large tanks. Although environmental conditions may vary, they are the same in the test installation and in the storage facility. As the system is once through, there is no warming of the water due to pumping. It is important that the test installation nor the storage facility is accessible for unauthorized persons. Whether storage of fish is outside or inside, it has to comply to the requirements of the law on animal testing. A fish welfare journal has to be kept, water quality measurements have to be taken on a regular (daily) basis, unusual (welfare) events have to be recorded. As storage of fish is mostly short term, feeding of fish is not an issue. When sea fish have to be tested, it can be useful to have a test installation that can be transported in an easy way, so tests can be conducted in fresh water and in sea water (sea side locations). Species like bass and flounder have a large tolerance for water with low salinity. Acclimatization to fresh water is probably possible. When flounder is caught in fresh water, there is no need for acclimatization. Also, bass as a species can be replaced by pike perch, so testing could be performed in fresh water only. It has to be taken into account, that using different species or testing under different circumstances, might influence the validity of the results. It is therefore important to involve the stakeholders in an early stage so there is agreement on the way the tests are performed. 4.2 Numbers of test fish to be used in experiments As stated in the previous chapter four fish species will be used to test the fish safety of the turbines. The number of fish used in the test (N) determines the accuracy of the proportion of fish mortality that is established. Testing fish is a binomial experiment. For each fish there is a probability (p) of success (or in this case the probability of dying). A 95% confidence interval around the proportion of dead fish can be calculated, dependant on the amount of fish passed through the turbine as can be seen in table 1. When fish safety demands are very high (as in the Dutch guideline) and the expected mortality is very low (<0,1%), a very large number of fish should be tested (5000 fish with no damage or fatalities, see table 1, lower limit confidence interval 0,00% - upper limit confidence interval 0,07%, being less than 0,1% mortality). As this is not achievable in any practical way, a different approach has been chosen. Instead of the mortality proportion being lower than the upper limit, the lower limit should exceed the mortality proportion, indicating that the amount of damage done by the turbine is definitely larger (95% chance) than the demand of 0,1%, using 100 test fish. Of these 100 test fish 0 or 1 can be damaged or dead, in which case the lower confidence limit is still less than 0,1% and theoretically the demand of <0,1% could be met by the installation. In fact, in this way the installation is given the benefit of the doubt. It should however be realized that de amount of damage could also be 5%. Project number: , final, Blz. 7 van 13

13 Table 1. Confidence interval around proportion of dead fish (x) in relation to the numbers (N) passed. N dead fish N passed Confidence interval around proportion x N 95% BinomLow BinomHigh Proportion % Lower limit % Upper limit % ,025 0,0000 0,0362 0,0000 0,0 0,00 3, ,025 0,0003 0,0545 0,0100 1,0 0,03 5, ,025 0,0024 0,0704 0,0200 2,0 0,24 7, ,025 0,0000 0,0243 0,0000 0,0 0,00 2, ,025 0,0002 0,0366 0,0067 0,7 0,02 3, ,025 0,0016 0,0473 0,0133 1,3 0,16 4, ,025 0,0000 0,0183 0,0000 0,0 0,00 1, ,025 0,0001 0,0275 0,0050 0,5 0,01 2, ,025 0,0012 0,0357 0,0100 1,0 0,12 3, ,025 0,0000 0,0122 0,0000 0,0 0,00 1, ,025 0,0001 0,0184 0,0033 0,3 0,01 1, ,025 0,0008 0,0239 0,0067 0,7 0,08 2, ,025 0,0000 0,0092 0,0000 0,0 0,00 0, ,025 0,0001 0,0138 0,0025 0,3 0,01 1, ,025 0,0006 0,0179 0,0050 0,5 0,06 1, ,025 0,0000 0,0074 0,0000 0,0 0,00 0, ,025 0,0001 0,0111 0,0020 0,2 0,01 1, ,025 0,0005 0,0144 0,0040 0,4 0,05 1, ,025 0,0000 0,0037 0,0000 0,0 0,00 0, ,025 0,0000 0,0056 0,0010 0,1 0,00 0, ,025 0,0002 0,0072 0,0020 0,2 0,02 0, ,025 0,0000 0,0018 0,0000 0,0 0,00 0, ,025 0,0000 0,0028 0,0005 0,1 0,00 0, ,025 0,0001 0,0036 0,0010 0,1 0,01 0, ,025 0,0000 0,0007 0,0000 0,0 0,00 0, ,025 0,0000 0,0011 0,0002 0,0 0,00 0, ,025 0,0000 0,0014 0,0004 0,0 0,00 0, Acquiring the test fish The law on animal testing states that no wild animals can be used for testing, unless it can be substantiated scientifically that without the use of these wild animals the goal of the experiment cannot be achieved. Of the chosen species, yellow eel, salmon(pre)smolts and pike perch can be obtained from fish farms. In the Netherlands several eel farms are present. Pike perch of the right size is difficult to obtain, as there is a shortage within pike perch breeding stations. Salmon smolts can be obtained from hatcheries in Germany or France. Bass and flounder are not present in farming systems in the Netherlands. In the Mediterranean, bass are cultured in sea cages in coastal lagoons and tidal reservoirs. Transporting this species to the Netherlands is not an option, due to the distance and costs involved. In the project license it should be made clear to the Central Committee for Animal Experiments that the only way to test tidal turbines is to incorporate these wild species bass (or if possible, pike perch) and flounder in the experiments. Local coastal fishermen can deliver these fish as they are caught during their normal fishery activities. 4.4 Transport of test fish Transportation of live fish requires oxygen for respiration and removal of the toxic gases and byproducts that accumulate, such as CO2 and ammonia. Most fish are transported alive in water saturated with oxygen and kept at a temperature low enough to reduce their metabolism. Fish is often starved (also called conditioned) before transportation to reduce its metabolism and hence the production of excrements. When transporting live fish within or out of the EU, veterinary inspection is necessary and TRACES (Trade Control and Expert System) documents are mandatory. 4.5 Storage of test fish Fish holding facilities can be simple or complex, depending on the duration the fish have to be kept. When keeping fish for a long time (weeks or more) necessary facilities are the same as in fish farms (re-circulating units, bio-filters, water treatment installations, heating/chilling facilities etc.). It is Blz. 8 van 17 Project number , final,

14 assumed that the actual testing of fish will not take a long time so holding facilities can be simple. After transportation to the test site fish will be stored for 24 hours to adapt to local conditions. Fish storage can take place in large circular holding tanks (1,800 l) or in large keepnets situated in the water near the test site. When using tanks, a pumping facility is necessary to supply the tanks with a continuous flow of fresh water (15-30 l/min). Tanks should be covered with a lid to ensure a calm, dark environment. Keepnets should be covered with netting to prevent fish from jumping out and to prevent predation by birds. After testing (1 batch of fish per day) damaged and dead fish are removed and inspected (see survival testing of fish). Remaining healthy fish are transferred again into the holding facility for another 48 hours. After this period fish are inspected again for delayed mortality. Figure 7. Fish holding tanks 4.6 Control group Of each species a control group of 100 individuals will be used. These fish will be exposed to exactly the same conditions as the test fish with the exclusion of passing through the turbine. Mortality in the control group will be used to correct mortality in the experimental group, according to EPRI (2011). Survival (immediate (1-hr) and total (1-hr + 48 hr)) will be calculated as follows. The input parameters for survival estimates include the following: N C = total number of control fish recovered (alive and dead); c = number of control fish recovered alive; N T = total number of treatment fish recovered (alive and dead); and t = number of treatment fish (i.e., turbine passed) recovered alive. Immediate (1-hr) and total (1-hr + 48-hr) control survival (S C) and turbine survival (S T) were calculated as: Project number: , final, Blz. 9 van 13

15 (1) (2) 4.7 Survival testing of fish Survival tests will be conducted to estimate blade strike injury and mortality associated with fish passage through the turbine (assuming little or no damage to fish would occur due to other injury mechanisms, such as hydraulic shear and/or pressure changes). The test installation consists of two large tanks (one head tank and a low water tank) connected to each other by a large pipe in which the turbine is installed. However, before performing the survival tests, groups of control fish are inserted into the installation (in the low water tank, turbine running steady state), during the first week of the testing. Control group and test group consists of 100 fish per species. Fish will be taken out of the storage facility using knotless dip nets and are transferred into a mobile holding tank. During this process each fish will be measured (nearest cm) and thoroughly checked for damage. Damaged fish will be excluded from the experiment. Remaining fish are then transferred to the test installation. With the turbine running in steady state, fish are injected by a specially designed insertion system, into the front end of the pipe leading to the turbine, via the head tank. The insertion system itself has a separate supply of water, ensuring a fast transport through the system at the same flow velocity (1,5 m/s) as in the large pipe leading to the turbine. It is assumed that the flow velocity of 1,5 m/s is high enough to prevent fish (of relative small sizes) from swimming away from the turbine, back into the head tank. Individual tests will be terminated after all treatment fish have passed the turbine or approximately five minutes after introduction of the fish. After passing the turbine, fish will end up in the second large tank (low water tank) in which a large knotless cage net is present, with which the fish can be removed from the tank easily. Dead and damaged fish will be separated from the healthy fish. All fish will be inspected thoroughly for injuries and scale loss. Damage will be categorized as follows: 1. Non damaged fish; 2. Slightly damaged fish; 2.1 Red and/or enlarged eyes; 2.2 Red and/or damaged fins; 2.3 Slightly scratched and/or scale loss (<20%); 3. Severely (terminally) damaged fish; 3.1 Severe scale loss (>20%, Main & Sangster, 1990); 3.2 Cuts, lacerations and/or severed body parts; 3.3 Fractures; 3.4 Damaged and/or lost eyes; 3.5 Damaged gills of gill covers; 3.6 Severe bruising/haemorrhaging; 3.7 Abnormal swimming movements; 4. Dead fish. Fish of category 3 will be euthanized directly (humane endpoint) by immersion in a solution of benzocaïne (200 mg/l). Fish of category 3 and 4 will be photographed. The healthy fish (categories 1 and 2) will be transported back to the storage facility to be kept there for another 48 hours. Blz. 10 van 17 Project number , final,

16 4.8 Delayed mortality Control and test fish will be kept in the storage facility for another 48 hours. It is assumed that feeding of fish will not be necessary in this relatively short period. Fish will be monitored on a regular basis and dead fish will be removed after the first 24 hours. After another 24 hours all fish will be removed and inspected for damage. Figure 8. Keep nets to store small fish on a long line under water 4.9 Autopsy of dead fish On fish (control group and test group) that are dead instantly or showed delayed mortality, without having any visible injuries, autopsy will be performed. Attention will focus on possible fractures of the spinal column, internal lacerations and barotrauma (damaged swim bladder, bubbles in eyes, tissue etc.) After the experiment, humane endpoints Fish that are alive and healthy after 48 hours will be released at the site of the experiment, in accordance to Dutch law. All other fish (not viable) will be euthanized by immersion in an solution of benzocaïne (200 mg/l). Project number: , final, Blz. 11 van 13

17 Figure 9. Autopsy of dead fish Blz. 12 van 17 Project number , final,

18 5 REFERENCES EPRI, Evaluation of Fish Injury and Mortality Associated with Hydrokinetic Turbines. EPRI, Palo Alto, CA: Main, J & G.I. Sangster, An assessment of the Scale Damage to and Survival Rates of Young Gadoid Fish Escaping from the Codend of a Demersal Trawl. Department of Agriculture and Fisheries for Scotland. Scottish Fisheries Research Report Number ISSN Project number: , final, Blz. 13 van 13