LI Wei-Wei ， BAO Jiang-Hui ， ZHANG Chao-Shuo ， WANG Li-Wei， LI Hong-Tao，WEN Jing-Ya and DUAN Ming

(1. Freshwater Ecology and Biotechnology， Institute of Hydrobiology， Chinese Academy of Sciences， Wuhan 430072， China;2. Hebei Environmental Monitoring Center， Shijiazhuang 050037， China; 3. SINOECO， Wuhan 430063， China;4. Appraisal Center for Environment & Engineering， Ministry of Environmental Protection， Beijing 100012， China; 5. University of Chinese Academy of Sciences， Beijing 100049， China)

Abstract: Many efforts have been devoted to developing， constructing and refining fishways or fish passage facilities to facilitate the target fish species to pass barriers in fluvial systems. Once dominated by an engineering-focused approach， fishways science nowadays involves a wide range of disciplines from fish behaviour to socioeconomics， and to complex modeling of passage prioritization options in river networks.Designing efficient fishways， with minimal passage delay and post-passage impacts， requires adaptive management and continued innovations. After the completion of fishways construction， corresponding management systems usually need to be improved as well. In the current study， we first reviewed international fishways adaptive management systems (e.g.， aspects of development， construction， and management) from 1991 to 2017 reporting on “fishway”， “fish passage”， “fish” and “dam”. The functions of fishways gradually transferred from conservation of economic stocks to overall biodiversity conservation， from facilitating upwards to both upwards and downwards passages， from developing a single project to considering the entire river basin，from fish passing function to habitats restorations as well， and from pure engineering construction to considering adaptive management. Finally， we discussed adaptive management systems and management prospects of fishways for China.

Key words: Dams; Fish passage; Fishways; River connectivity restoration; Management systems

Connectivity of watersheds is typically important to fishes and other aquatic organisms[1]. Most of the world’s rivers have been or are currently being dammed[2]. According to the statistics of the International Commission on Large Dams， as of 2017， there have been 58519 dams with a height of 15 m or greater from the lowest foundation to crest or a dam between 5 m and 15 m impounding more than 3 million m3of water[3]. While the construction of dams has brought great economic benefits and form of entertainment to human， more and more deleterious effects on fishes are also stressed[1]. It significantly undermines the original appearance of rivers and changes the hydrological regime， resulting in the fragmentation of habitats， the local extinction， the loss of aquatic biodiversity and genetic diversity[4—7]. According to Nilsson， the construction of dam have negatively effect on over half of the world’s largest river system[8]. Fish passage (e.g.， Fish ladder， Fish lift，F(xiàn)ish lock， Trap and truck， Denil fishway and the nature-like fishway) gradually have been developed as a mitigation facility[9—15]. From 1900s to 2000s， the interest in fishways increased gradually. To data，there are 400 fishways estimated in England， 57 fishways in South Africa， 44 fishways in Australia， and 40 fishways in China[16，17]. During the course of a lifespan， fish may have feeding migration， refuge migration， and/or reproduction migration[18]. The most direct ecological impact of dams is the blocking of the migratory route of migratory fishes in rivers， resulting in the inability of these fishes to complete their entire lifespan， seriously affecting fish population suitability， community structure and biodiversity[19—21].For example， the reason of the drastic decline (–75%)of the European eel (Anguilla anguilla) during the past few decades is that the death of adult eels passing through hydropower turbines during their migration between freshwater feeding grounds and oceanic spawning grounds[22]. Moreover， there are countless instances that dramatic changes in the upstream fish community and extinction of some species as the result of anadromous fish migrations have been blocked entirely by dams that lack upstream fish passage[18].

For the past half-century， biologists and engineers alike have been working towards improving the efficiency of fish pass so that the physical structure is rendered “transparent” (The fishes can pass dams without delay， stress， injury or some other effect factors)[1，23]. Depending on the designs， fishways can be classified as: (1) technical structures (e.g.， pooltype， vertical slot and Denil fishways， surface bypasses)， (2) nature-like structures (e.g.， nature-like bypass channels) and (3) special-purpose structures(e.g.， fish ladders， fish locks and fish lifts)[24]. The rate of construction of fishways has increased in recent decades[25，26]. However， the performance of fish passing through these structures remains low in many regions[17]. The lack of management of fishways at design， construction and later stages of operation may be one of the main reasons[27，28]. Since 21 century，there are 40 fishways under construction or has been completed in China[17，28]， whose designs of fish passage by engineers was lack adequate understanding of the purpose in the fishway construction and the hydraulic characteristics. Thus， it is an urgent need for adaptive management systems to learn and implement[29].

1 The define and prospects of fishways adaptive management systems

The management of fish passage systems would consider not only as an integral part of design process， but it also have challenge about the component and the operation of the hydroelectric project to aid fish[30]. Fishways adaptive management systems is a method to determine the best design schemes after constructing of fishways. Professionals must timely detect some problems (e.g. the construction and investment of fishways， the efficiency of fish pass)through long-term monitoring， to realize the longitudinal connectivity of channel and promote the harmonious development of the social economy and the ecological environment[1]. A number of operating scenarios examined flow manipulations across the river to optimize fish guidance upstream movements and attraction for downstream migrants. A minoring process is involved to passage performance and provide information on actual fish migrations in the river， and assist with implementing operating scenarios that optimize fish passage efficiency[30].

There are many laws (e.g. The Water of The People’s Republic of China and The Environmental Impact Assessment Law of The People’s Republic of China) about the water conservancy and hydropower in China since 1980[1－3]. These legislation only require that the construct of fishways but few requirements on the technology， management and monitor of fish passage. Although the fishways adaptive management has been proposed， it haven’t been defined until now[17， 27， 28].

2 Fishways construction conditions

2.1 Cooperation among international, national and government to achieve coherent policies is necessary

The international levelRelated forums for promoting coherent intersectoral policies include United Nations (UN) conventions， European Union(EU) level negotiations and various bilateral negotiations.

The national levelAll related ministries(e.g.， ministries of the environment， agriculture and forestry， employment and economy) should be in cooperation.

The local levelGovernments should encourage formal and informal discussions between the stakeholders to explore joint solutions for the achievement of a common goal: ensure larvae eventually reach the sea[2].

2.2 Defining the target level of migratory fish and derive river environmental standards

The global principles of the coherent management of migratory fishes should be translated to accurate spatial scales. The first， to a regional， sea scale，the second to a national level and the last， to the level of individual river basins. Migratory fish values (hu-man consumption， recreation， tourism， aquatic food webs， ecosystem function， present and future existence value) must be accounted for targets. These target population levels， which based on the potential reproductive habitat are reflecting the regeneration capacity. The main method is to make the minimum bounds as the annual juvenile production[2].

2.3 Select the type of fish passage according to the cost of fish passage construction and the type of target fish

The construction of an effective passage facility may be required whenever a dam or barrier is constructed. But， the cost in the construction， monitor，management and evaluation of fishways is expensive(e.g. Pool and weir， Vertical slot， Denil fishway， Fish lock， Fish lift， Natural bypass costs about 7100—￡150000 m–3， ￡77000—154000 m–3， ￡89000 m–3，￡15000—75000 m–3， ￡1700000 m–3and￡32000—45000 m–3respectively.). So it should be considered currently that the fish pass efficiency， target species of fishways， the use of the fishway types and the cost of fishways construction. Different types of fishways construction costs are different， which range from 10000 EUR to 1700000 million EUR[2](Tab. 1).

2.3.1 Technical fishways

Pool and weir passPool and weir passes were constructed as a series of small pools in steps[31].Generally， pool and weir passes appear to work well for salmonids and other strong-swimming species， but they may not allow some species， which have a large variety of differently behaving， to ascend[31，32]. From Noonan， pool and weir fishways， which is the more expensive， had higher passage efficiency than Denil fishways and fish locks/elevators[31]. According to some estimates， the construction cost of a pool and weir pass ranges from 7100 to 150000 EUR per vertical meter[26].

Vertical slot fishwaysVertical slot fishways have been installed mainly on water control structures and natural barriers that allowed fish to swim through dividers between pools[19].The construction costs of different types of vertical slot fishways， which are sometimes combined with other forms of fishways， range from 34000 to 91000 EUR per vertical meter[26].

Denil fishwaysDenil fishways have been used for anadromous and potamodromous species in the northern hemisphere and used for the small nonsalmonid fishes in southern hemisphere[9]. Denil fishways include a steep flume with vanes. The construction costs of Denil passes are estimated at 89000 EUR per vertical meter[32].

Fish lock/Fish liftFish lock/lift systems collected fishes in an enclosed lock before raising the water level to the top of the dam[32]. The construction costs of fish lock are estimated at approximately 1.7 million EUR， with annual maintenance expenses of 5% of the capital cost[31].

The average costs of fish lifts are estimated to range from 15000 to 75000 EUR per vertical meter and 50000 and 125000 EUR per vertical meter[32].

2.3.2 Natural fishways

Tab. 1 Construction costs， target， function with different fish passage technologies partly in the world

Natural fishwayThe main goals of the natural fishway are， (1) to provide a long-term free passage for site-specific species， and (2) to provide habitat for the community (e.g.， reside in a local tributary or side-channel)[11]. Construction costs have ranged from 14800 to 45000 EUR per vertical meter， with an annual maintenance cost of approximately 5% of the construction cost[2].

Trap and TruckAfter including in trap and truck installations in some attraction system， the transportation of collected fish upstream facility appropriate vehicles[31，33]. The costs have been estimated at 15—200 EUR per fish depending on whether the service is purchased or involves volunteer labor[2].

Stocking and Habitat restorationOn-site stocking costs have been estimated at 1—2.5 EUR per individual[2].And the aim of habitat restoration is that rehabilitation of the fish species affected by the formation of Dams. Habitat restoration is an expensive method， and the costs have been estimated at approximately 20000 EUR/km in a stream[2].

Dam relocationThe costs of dam removal in the USA range from 2100 to 135000 EUR per vertical meter for smaller dams (The dam height is lower 30 meters) and from 3700 to 280000 EUR per vertical meter for higher dams (The dam height is over 70 meters)， excluding the costs of permits， easements，designs and monitoring[16]

3 The requirements of fishways construction

With the increasing number of fishways， the related requirements have also gradually increased. The optimization and improvement of each fishways construction could not be separated from the laws and regulations.

3.1 Laws and regulations (incomplete statistics)

Effective law and policy is an important guarantee for the protection and restoration of fishways. The development about the hydropower of the European Union， the United States， the Japan and other developed countries have a long time history. Countries are very focus on perfecting the legal system and policies to ensure the orderly development of hydropower and water ecosystem restoration and reconstruction. In this paper， three levels of laws and regulations have been introduced.

3.1.1 The EU level

In 2000， the Canadian Species at Risk Act and the EU Water Framework Directive emphasized that required to improve fish passage at diversions and dams in Canada and the European continent[30]. River managers and scientists turn their attention to the health problems of river ecosystems. The goal of river protection and restoration not only met the water quality indicators but aim at restoring the structure and function of river ecosystems (European Commission 2000).

3.1.2 The country level

(1) The U.S. Business Institute of Pennsylvania(BIOP) has put a reasonable and prudential alternatives designed to improve the functioning of the federal government’s power and configuration of systems to meet the non-hazardous requirements of the Endangered Species Act (ESA) and to fulfill the United States’ fishing rights to protect tribal treaties.

(2) In 1935， the Federal Power Act as modify prescribed fishways as needed at all hydropower plants in the United States[30].

(3) In 1842， the Fisheries Act added legal strength for requiring weirs to have fishways in Ireland， which passed salmon effectively， in spite of the fact that no specifications for fishways were provided[30].

(4) In 1965， the Anadromous Fish Conservation Act that focus on the fish on the east coast of the U.S.[30].

(5) In 1973， the U.S. Endangered Species Act efforts to provide effective fish passage structures at dams. As the implementing agency for the development of the Columbia River hydroelectricity， steps must be taken to ensure that its development activities do not jeopardize the long-term viability of these fishes and will not destroy the key habitats for these fishes[30].

(6) In 1990， Japan issued the Circular on the Construction of a Multi-Natural River， and in 1997，Japan amended the River Law and added the contents of river management for the preparation and protection of the river environment. Since then， fishways have been considered not only to be fishways， but also to become channels through which fish can survive.

(7) The Resource Development Act of 2000(Public Law 106—541) authorizes the U.S. Army Corps of Engineers (US ACE) to conduct research and implement the necessary ecosystem restoration projects to protect， monitor and restore habitats for fish and wildlife downstream of the Columbia River.

3.1.3 The local level

Oregon’s Water Law proposed to increase the salmon fish egg hatching project enjoy the right to immunity. In addition， water used for fish grills， fish tracks and bypass structures also enjoy immunity.

What’s more， in 1709， the Plymouth Colony，which is the State of Massachusetts in the United States， had a law illustrates that forbade construction of weirs that would limit fish passing during the spring[33].

3.2 Relicense requirements

In addition to government management， NGO(Non-Governmental Organization) are also playing an auxiliary role in the environmental management of hydropower projects during their operations. Low-impact hydropower certification by the low impact hydropower research is representative. Such as the construction of fishways solutions must have dam-building licences in Scotland， the USA and China[1，17].

Projects undergoing relicensing make up the majority of the proposals being evaluated by the hydropower licensing staff of the Office of Energy Projects.The commission has three licensing processes (US Army Corps of Engineers， 2017; http://www.usace.army.mil/).

3.2.1 Integrated Licensing Process (ILP)

The Integrated Licensing Process is intended to streamline the Commission’s licensing process by providing a predictable， efficient， and timely licensing process that continues to ensure adequate resource protections. The efficiencies expected to be achieved through the ILP are founded in three fundamental principles:

(1) Early issue identification and resolution of studies needed to fill information gaps， avoiding studies post-filing;

(2) Integration of other stakeholder permitting process needs;

(3) Established time frames to complete process steps for all stakeholders， including the Commission.

3.2.2 Traditional Licensing Process (TLP)

(1) Applicant issues notice of intent， preliminary application document， request to use TLP， and newspaper notice; Commission approves use of TLP; Applicant conducts joint agency/public meeting and sitevisit; Resource agencies and tribes provide written comments; and Agencies， tribes， or applicant request dispute resolution on studies with the Commission.

(2) Applicant completes reasonable and necessary studies of Applicant provides draft application and study results to resource agencies and tribes; Resource agencies and tribes comment on draft application; and Applicant conducts meeting if substantive disagreements exist.

(3) Applicant files final application with Commission and sends copies to agencies and tribes.

3.2.3 Alternative Licensing Process (ALP)

(1) Tailor the pre-filing consultation process to the circumstances of each case;

(2) Combine into a single process the pre-filing consultation process and environmental review processes under the National Environmental Policy Act and other statutes;

(3) Allow for preparation of a preliminary draft environmental assessment by an applicant or an environmental impact statement by a contractor chosen by the Commission and funded by the applicant[34].

4 Organization of fishways construction

Typical Practice: North American Columbia River Fishways Management Organization

The Columbia River， the largest river in the Pacific Northwest region of North America， which has a total length of 1953 km and a catchment area of 671000 km2. The 370 hydroelectric power stations in the basin provide many services (hydropower， flood control， irrigation and navigation)[35]. The Columbia River Fish Facilities Management Program is mainly composed of legislation， government intervention， the involvement of Army Corps of Engineers， post-monitoring of fish ecologists， signing of agreements， and recreational facilities. These six ways complement each other to form the North American Columbia River Fish Facilities Management System.

4.1 Legislation

The Federal Opinion on the Conservation of Power Systems in the Columbia River was enacted in 1973 for fish that migrated along the Pacific and the Columbia rivers. The Columbia River Power System is the executive body of the Bio-capacity Action and needs to develop a concrete plan of implementation and carry out implementation， monitoring， analysis and reporting.

The Columbia River and its tributaries Snake River is an important habitat area for salmon. In order to protect the salmon reproduction and migration habitat area of the middle and lower reaches of rivers in hydropower development， the federal government passed the Pacific Northwest Electricity Planning and Conservation Act in 1980， The height of the dams constructed must not exceed 30 m and fishways should be constructed to meet the migration needs of salmon and other fish.

The Bonneville Powers Act prioritizes public and cooperatively owned distribution systems， while the new agency adopts a comprehensive tax policy throughout the transmission system.

4.2 Government intervention

The Commission works with national， federal，and non-governmental partners to jointly address the fish-crossing effects and hydro-power needs[36]. In the Federal Opinion on the Conservation of Power Systems in the Columbia River， National Oceanic and Atmospheric Administration (NOAA) requests for protection of fish in the Columbia River from six aspects of adaptive management， hydropower project operations， habitat， hatching， predation management and research， monitoring and evaluation. Primarily funded by the federal government， it is allocated to the United States Army Corps of Engineers and then to the next level by the United States Army Corps of Engineers (or NOAA) agency[37].

For example， the U.S. federal government will give about 5 trillion U.S. dollars to the U.S. Army Corps of Engineers in its 2018 budget. This budget supports core mission areas for coastal and inland navigation， reducing flood risk in rivers and coastal areas and restoring aquatic ecosystems. Nearly 400 million U.S. dollars are spent on aquatic ecosystems.The Bonneville Dam has signed a three-year contract with Bonneville Power Administration (BPA， about 2.5 million EUP). Projects on the Corps Continuing Authorities must compete on a country-by-country basis with relatively limited resources (25 million EUP)[37].

4.3 The involvement of Army Corps of Engineers

So far， a total of eight water control projects (including dams， locks and power plants) have been constructed in the lower reaches of the Columbia River and its tributary snake river， with a total of 16 fish tracks[38]. The number of fishways built at each water control station is generally above two， basically consisting of vertical slot and pool and weir fishways.Among them， the Bonneville Water Conservancy Project， as the most downstream level， has a wide reach and a total of four fishways， but also by the Army Corps of Engineers to establish conservation projects in the lower reaches of Colombia River， the main measures include: (1) fish ladder; (2) juvenile descending bypass system; (3) spillway discharge，collected and transported by special ship truck Fish;(4) increase the flow of migratory season river and so on. Effective maintenance of the migration channel.Army Corps of Engineers and the National Marine Fisheries Administration jointly manage juvenile transport projects. A team of fishery experts was established to develop a plan to migrate migratory fish downstream. Typically， Center for Excellence arranges project biologists to be stationed daily to inspect the dam. Established in 1948， Hydroelectric Design Center (HDC) is the administrative department of the National Engineering Corps， which provides professional knowledge for water conservancy and hydropower construction and engineering services[39].

4.4 Fishways monitoring

The construction and operation of the downstream of the Columbia River and its tributaries Snake River， based on the continuous monitoring data for the management of the fishways， the ecological operation has been actively carried out through the analysis， evaluation and functional adjustment， and have achieved remarkable results. (1) In cooperation with fish and ecological experts， the corresponding rules of operation were worked out; (2) The flow conditions suitable for the dam crossing are provided during the period of fish migration， including the flood control，power generation and shipping scheduling and coordination of the water control hub; Spring and summer discharge flow scheduling rules， signed by the agreement in the operation of scheduling to be implemented.

4.5 Building a public website and public culture

The Bonneville Dam was built from 1933 to 1938 over a five-year period. In 1937， The U.S. Congress formed the Bonneville Power Administration to promote the electricity production of Bonneville Dam. The establishment of the Colombian Telecommunications Network (CBT)， which exists electronically on the site， is permitted on all parties， whether public or private， to download and print this document. When the report is revised， the revised report will be identified. The public website is the central agency that links the construction departments， management departments， discipline experts， engineers and hobby staffs of the fishways to ensure effective communication， and to provide convenient management for the pre-construction and post-management of the fishways (e.g.， Fish Passage Center[36]， U.S.Army Corps of Engineers[37]).

In 1941， BPA hired folk singer Woody Guthrie to create songs to help the public understand the benefits of Bonneville and other Columbia River utilities[37].

4.6 Cooperating agencies

Public Utility District No.1 of Douglas County，Public Utility District No. 2 of Grant County， etc.

The monitoring assessments of the Bonneville Power Administration and the Corps provides the information of factors， such as the use and impact of salmon on the lower Columbia river environment(Tab. 2)[38，39].

4.7 Recreational facilities construction

After 1986， Bonneville became a historic site that offers travel， boating， fishing， etc. Some visitor centers also provide information on fish migration and power station operations. The power planning team is involved in the development of regional plans，conducting regular model studies， assessing the hydraulic effects of specific operations as defined by the biological point of view， and restoring the ecological environment of endangered species such as salmon[37].More than 10 sites for public viewing have been es-tablished at Bonneville Fishways[40].

Tab. 2 Columbia River Management System[38， 39]

5 Development and direction of international fishways

At present， international fishways management are gradually transferred from conservation of economic stocks to overall biodiversity conservation，from constructing fishways to facilitate upwards to downwards passages， from developing a single project to considering the entire river basin， from a single fish passing function to considering habitats restorations， and from pure engineering construction to considering adaptive management.

5.1 From economic stocks protection to biodi versity conservation

Fishways have an important role in the distribution and adaptation of anadromous species. However，it is difficult to design fishways which are appropriate for target species and many non-target species cannot ascend the structure[41，42]. Restrictions to the free movement of native fishes (and other biota， including invasive species) influence the entire community and resultant ecological interactions[43]. More and more people are aware that different species have different access needs， which requires the transfer of expectation from a single species to the entire fish community. It is necessary to provide access for aquatic communities， including fish and invertebrates，as they could use the traditional fishways design[44]. In order to make fishways available to all kinds of fish，other countries have conducted extensive research on the swimming performance and behavior of fish and monitored them through PIT (passive integrated transponder) technology. The monitoring results are used to evaluate the influence of different designs and operations to achieve biodiversity conservation[45]. In Canada， the ultimate goal for habitat compensation programmes has been termed No Net Loss (NNL)，where restoration efforts legally must result in no decrease in fish producing capacity. And the fishway would need to not just allow passage of target species，but allow passage of all species without subsequent effects in all life-spans on reproduction success[1].

5.2 From only upstream passage to both upstreams and downstreams passage

Fish life history includes move consideration distances upstream and downstream[46—48]. Long time ago， all original efforts were directed at providing effective passage for fish migrating upstream. Beginning in 1950s， the highlight of the negative effect had been recognized， which is passage through turbines at multiple dams. They would have on survival of salmon stocks led to the development of research to safely pass larvae fish downstream[30]. Gradually， fishways facility shifted from the upstream fishways(grouped into: pool and weir， vertical slot， natural，Denil， fish lift/lock and trap and truck) to the downstream via (including physical screen， angled bar racks and surface bypasses)， which can ensure the species， who have spawning in upstream， won’t be injured when they go back the downstream of the river and stream[17，44，47]. (Tab. 3) (Fisheries Act， 1985[49])

5.3 From single fish crossing function to supplementing habitats

In 2000， the EU formulated the EU Water Framework Directive， river managers and scientists began to turn their attention to the health problems of river ecosystems. Throughout Europe in the last decade there has more nature-like passes (e.g.， natural-like bypass channels)[11]. Some investments made to improve Atlantic salmon， which have been met by general failure， during fishway and hatchery intervention:Rainbow smelt Osmerus mordax may require specialized fishways， which was some specially designed to pass elvers[54]. The goals of river protection and restoration not only met the water quality targets， but to repair of structure and function of river ecosystem[55].Traditionally， the main target of fishways are migratory species (e.g.， salmon， trout and lamprey)[56]， but recently at present the trend of European researches have been shifted from study of a single fish efficiency to non-salmon fish efficiency[57]. And the objective of fishways is being developed towards the supplementing habitats[55].

5.4 From simple engineering to adaptive management systems

In the past， only the designers were involved in the construction of fishways， but no fish scientists，fishermen and the public were united. In recent years，the construction trend has gradually shifted from simple engineering construction to adaptive management， which improve data collection efficiency and meet ecological needs through activities such as scientific management， monitoring and control management[35]. For example， the U.S. Army Corps of Engineers have established a website about the fishways，which involved the data of the evaluation and the efficiency of fish pass annually[37]; the Columbia have set up a Fish Passage Center to provide an access and communication terrace for the researchers of fishways[38].

6 Rationale and criteria for fishway evaluations

Theodore et al. described an ideal fishway must have the following characteristrics: (1) fishway entrance is followed by successful passage， with (2) no temporal or energetic costs and (3) no stress， disease，injury or other fitness-relevant costs associated with passage; (4) any species could move upstream or downstream without experiencing and delay[58].

Information from evaluations is most useful if performance parameters are reported in consistent and biologically relevant terms. The more information provided the better. Thus， documentation of spawning fish upstream， or even window counts， indicate some level of success[58]. The list is not intended to be exhaustive. Instead， it is intended as a framework from which managers can draw and assess how well fishways are being evaluated (Tab. 4).

7 Fishway management prospects for China

7.1 Green certificate and specific legal system are urgently needed

Tab. 3 The types， method and target species of fish passage systems for downstream migrants

From the data， we can know that the cost is main used in construct the fish passage， but few in the moni-toring and management after fish passage have been constructed (approximately 5% of the cost used in the late monitoring and management) (Tab. 1).

Tab. 4 Biology indicators of fish pass success[58—62]

Before the construction of fishways， we should have an implemented “green certificate” permit and a clear legal system. Green certificate or other demonstrable technologies are obtained before the construction of fishways. It can ensure that the migratory fish will pass through the dam smoothly when they go upstream or downstream. The current laws and regulations have no clear attribution for the construction and management of fishways and no clear stipulations on the rights and responsibilities of the construction of fishways. Different departments should set up a clear division of labor.

7.2 Enhance theoretical studies

We have less consideration on the determination of the protection of objects. The stipulation of target species who need to migratory is inaccuracy. The limitations on the protection of a single species is extremely easy to fail. Many fishways were unsuccessful， which have lower fish pass effective or even have been abandoned. China has a wide range of fish species and diversified ecological habits. There are obvious differences in the habitats between the upper and lower reaches of rivers. The design of fishways should take into account the differences between the regional ecology， river hydrology， fish habitats and life history to meet the basic needs of fish behavior and physiology. The original design of fish tracks mainly relied on empirical formulas from abroad. The designed fish tracks did not fully comply with the requirements of the main fish in the domestic river tracks. However， the fish tracks designed with the same design method did not work well and the effects of fishways did not get good result. Therefore，how to study the physiological characteristics of different fish and the design of fishways， and to selectively apply the design data has become a crucial link in fishways design.

China should carry out the study of hydraulic characteristics according to the charateristics of different species of fish， the fish living conditions in the reservoir area， fish behaviour， ecological compensation and the conditions of fish pass the dam. Multidisciplinary cross-cutting， accessing to first-hand information (object of protection， design principles， migratory water level， fishy season， import location， exit location， fish pond design， flow rate， etc.) laid the theoretical foundation for the development of fish management practices.

7.3 Developing multi-sectoral cooperations

When a project is established， different contents are assigned to different departments and the division of labor. However， due to the different free time of different departments， there is little time to work together. There is very little cross-cutting discipline in all fields， and no first-in-class information on the construction and repair of over-fishing facilities can be provided[17]. The design of fishway is not only the patent of the water conservancy department， but also the multi-stakeholder such as electricity， environmental protection， government， mass， fishermen， tourism and investors. In order to ensure the success of the design of fishway， the coordinated development of various departments should be ensured and a relatively sound mechanism should be established. In addition， we should actively communicate with foreign experts to obtain the latest information.

According to the principle of “who undermine，who recover”， water conservancy and hydropower engineering units should be the main responsibility for the operation and management of fishways. However，because the construction units were lack of relevant professional management departments and technical staff， even if the fishways is was built according to the design requirements built， it is also very difficult to reach the effective of fish pass. In addition， because the right of management and operation in the local water conservancy departments rather than the fisheries sector or the ecological department， some of the fishways cannot meet their water requirements during operation. Moreover， during the operation period， some lure fish and fish-collecting facilities adjusted to improve the fish-crossing effect were stopped due to the fund shortage of equipment maintenance and renewal and the management problems.

7.4 Set up observation sites for compensating the costs

The establishment of cultural observation spots around and inside the fishways will not only increase public participation and effectively publicize and promote the protection concept of fishways， but also can improve the people’s awareness of environmental protection and enhance the public support for fishways construction. It is also possible to increase the economic income to compensate for the maintenance costs of fishways.

Water conservancy and hydropower projects play a significant supporting role in the development of social economy. In future， hydropower construction will remain an important basic industry of our national economy. To protect the migration of fish and supplement habitats， more fishways will be built.Simple engineering construction can no longer meet the needs of social development and ecological environment capacity， so it is imperative to run the adaptive management.

7.5 Set up an independent management program for each fishways

Different fishways have different fish targets，climatic conditions and geographical environments，so we should be separate management procedures for each fishways system. There is a database involving a fishways table， an evaluation table and a fish table for fishways information. The first table contains the fish species， the fish life span and the reference source.The second table involves the information on target species passage efficiency of the fishways and the result of fishways monitoring. The third table includes the location， engineering， technical specification and evaluation information for each known fishways. All of those should be shared on a special website， which can be downloaded and referenced by professional[63](Fig. 1).

Fig. 1 The database of fishways adaptive management system