Helping Fish Move Freely: Study On Target Species And Swimming Ability, And How Fishways Can Help

Dams have expanded rapidly in the world. People focus on issues ranging from irrigation, hydroelectric power, water resource allocation, and ecological restoration and believe it will facilitate future operations.

Although dams carry out enormous economic benefits and promote the development of society, they also influence the hydrological regime, water chemistry, and biological habitats, especially when it comes to river connectivity, often resulting in fragmentation.

Dams obstruct fish from freely moving in rivers. Many fish species have migratory behavior. For examples, many adult salmon and sturgeon migrate for long distance to spawn. Their offspring juvenile fish migrate to find food. Besides, before winter comes, some fish migrate to warmer areas. Dams might obstruct gene exchange between fish populations. Therefore, people try to design and build fishways to help fish go upstream or downstream safely and quickly. Depending on the design, fishways are classified as technical structures, nature-like structures, and special-purpose structures (such as fish lifts).

China is planning to build the Huangdeng Dam on the Mekong River. The dam will obstruct fish moving with freedom in this area. Therefore, we investigated fish information near the dam and tested their swimming ability. Then fish lift design suggestions were provided.

We made inquiries among local fishermen and reviewed the available literature. There were 20 fish species near the dam site. Then we investigated their migration habit, upstream habitat suitability, protection class, economic value, and fish resource status (five criteria). Five carps, Schizothorax lantsangensis, S. griseus, S. yunnanensis, S. lissolabiatus, and Percocypris retrodorslis, were selected as target species based on the above five criteria. Since the rest of the non-target species belong to the families Cobitidae and Sisoridae, we decided to also test two of the more common non-target species Paracobitis anguillioides (Cobitidae) and Pareuchiloglanis myzostoma (Sisoridae). Seven test fish (n=10 each species, body mass 2.7 – 588.3 g, standard length 0.063 – 0.342 m) were of a size commonly found in the river.

Fish swimming tests were carried out in a swimming respirometer (Figure 1). We assessed swimming ability including induced flow velocity (Uind), critical swimming speed (Ucrit), and burst speed (Uburst). The relationship of swimming ability to body length was also analyzed.

Figure 1: Work photo. Image courtesy Lu Cai

This research led to three primary findings: (I) The Uind and Ucrit (m/s) were positively correlated with fish length, but the relationship between the absolute Uburst (m/s) and fish length were inconsistent. (II) To help more fish migrate successfully, the flow that was 90% effective in reaching the desired endpoint (EF90) was used to set fish lift design criteria for flow velocity. The EF90 value for Uind was 0.17 m/s and the values for Ucrit and Uburst, were 0.62 m/s and 0.87 m/s. (III) Recommended velocity criteria for the fish lift are as follows: entrance velocity, 0.37 – 0.87 m/s (0.6 Ucrit-EF90Uburst-EF90); passageway velocity, 0.17 – 0.50 m/s (Uind-EF90 – 0.8 Ucrit-EF90); holding chamber velocity, 0.17 – 0.37 m/s (Uind-EF90 – 0.6 Ucrit-EF90). The approach developed in this case study has potential as a general method for determining target species and setting flow velocity criteria for fishway design.

This research is described in the article entitled Case study: Targeting species and applying swimming performance data to fish lift design for the Huangdeng Dam on the upper Mekong River, recently published in the journal Ecological Engineering. This work was conducted by L Cai and P Zhao from the Institute of Hydroecology, Ministry of Water Resources and the Chinese Academy of Sciences, C Katopodis from Katopodis Ecohydraulics Ltd, D Johnson from Ferrum College, and P Zhang from Wuhan University.

About The Author

LC
Lu Cai

Lu is a research assistant at the Institute of Hydroecology, Ministry of Water Resources and Chinese Academy of Sciences, China.

Speak Your Mind!

READ THIS NEXT

Powerful Dehalogenation Tool: A Simple Route To Graft Carbon Materials With Well-Defined Open Pores

Porous carbon materials (PCMs) hold great scientific and technological importance due to their ability to allow gases and liquids to penetrate their entire bulk.(1) They have been long regarded as key components for building up sustainable and clean energy technologies such as fuel cells, rechargeable batteries, supercapacitors, etc.(2) Especially, PCMs with open pores (including mesopores, […]

Cursive Capital Letters: From A To Z

Are you interested in learning to write all the capital cursive letters, from A to Z? This article will show you how to write all the capital cursive letters as well as discuss some interesting facts about cursive. The list of capital cursive letters below will help you get acquainted with uppercase cursive letters. You’ll […]

Michael Bloomberg, Former New York Mayor And Billionaire, Pledges $4.5 Million Towards Paris Deal After Trump’s Withdrawal

Michael Bloomberg has pledged $4.5 million towards the Paris Deal that the United States withdrew from the deal that aims to prevent, or at the very least slowdown, the effects of climate change due to human activity. The former New York Mayor believes that it is part of his responsibility to help this deal succeed […]

What Is A Sand Dollar?

The term¬†sand dollar refers to several species of flattened burrowing sea urchins that belong to the order Clypeasteroida. Sand dollars, also sometimes called sea biscuits or sea cookies, are closely related to urchins, sea cucumbers, and starfish. They are found in temperate¬†zones virtually all over the world, beneath¬†the mud and sand in bodies of water.¬†Sand […]

Organ System: Definition And Examples

In biology, an¬†organ system¬†refers to a group of one or more organs arranged in a particular way that work together to perform some physiological function. The term “organ” refers to specialized collections of biological tissue that perform similar functions. Thus, an organ system can be considered any interacting network of specialized tissues that work together […]

On-Demand Release Of Persulfides As Antioxidants

Cellular redox balance is critical for maintaining normal function and preventing damage to DNA and proteins, which may lead to accelerated aging, and, more nefariously, the development of Alzheimer‚Äôs disease, heart failure, depression, and others. Generation and sale of antioxidant supplements is a multi-billion dollar industry, despite apparent discrepancies in efficacy, mode of action, and […]

New Rare Earth Elements Found In Amazon Estuary?

Nowadays, the industry is more and more demanding of many metals. Among these many metals are rare earth elements, and some of these elements (e.g., neodymium, Nd) are used in particular to produce powerful permanent magnets that are used in wind turbines, electric motors, etc. (Figure 1). Others, such as europium, are used as luminophores. […]