A Deplorable Situation: The Mekong Massive Catfish

The biggest freshwater fish in the world is the Mekong massive catfish (Pangasianodon gigas), which is endemic to Southeast Asia and may be found in the Mekong River. The largest of these fish may potentially reach a length of three meters in length and weigh an astounding 650 pounds (300 kilograms) (3 meters).

Although there are no reliable population estimates available for the fish, it is generally accepted that the number of individuals belonging to this species has dropped by eighty percent over the most recent decades. If there is a sudden surge in the development of hydropower projects along the Mekong, there is a chance that the species will go extinct.

The natural migration paths of catfish are at risk of being disrupted by several dams, some currently being constructed and others still in the planning phases. Some barriers have already been completed, while others are still in the planning stages. The catfish may become extinct as a result of this. The Xayaburi dam, on which construction has already started, is now the source of the most significant risk.

Investigating and monitoring this elusive creature's natural habitat requires methods like radio telemetry and environmental DNA analysis, and these methods are essential. The environmentalists working on the proposed Sambor Dam in Cambodia have set themselves the objective of providing the Cambodian government with assistance in the design of a project that can potentially boost aquatic connectivity significantly.

Fish are mainly unseen to us land-dwelling creatures, so the concept of conserving their species does not seem to excite us very frequently — that is, until, of course, they are ready to be served up on a dinner plate. However, the Mekong enormous catfish need to be placed on the list of almost famous animals in Asia since it is more deserving of this distinction than any other fish (Pangasianodon gigas).

The P. gigas is the biggest freshwater fish in the world, with the most prominent individuals reaching lengths of up to 10 feet (three meters) in length and weighing an incredible 650 pounds. That makes the P. gigas the largest fish in any category (300 kilograms). They can be discovered down the length of the Mekong River in Southeast Asia, and their well-being is inextricably linked to the river's well-being.

The prognosis is not optimistic, which is a very disheartening turn of events. It is thought that there has been a reduction in the population of gigantic catfish by around 80 percent over the previous several decades. Even though the IUCN has classified this species in the Critically Endangered category, it is unknown how many individuals of this species are still extant in the Mekong at the present moment. The expansion of the river shortly does not appear to be in good shape.

The Massive Catfish Moves Along The Mekong River.

The Mekong enormous catfish, one of the world's largest freshwater fish, is considered a symbol of the integrity and health of the Mekong River, according to Zeb Hogan, an ecologist from the University of Nevada in Reno. He has been researching the species for almost 20 years. Hogan has been conducting a study on the species for close to twenty years now. "The biggest fish are typically the first to go extinct in a river like the Mekong. Consequently, the Mekong gigantic catfish population is on the decline, which is an early warning sign of overfishing and other environmental issues ", he elucidates. Additionally, the extinction of the Mekong gigantic catfish is an indicator of other ecological problems.

This river in Southeast Asia is a biodiversity hotspot that matches the famous Amazon River in South America. It is home to more than 1,200 species of fish, making it one of the most diverse waterways on the planet. Even though the Mekong is not nearly as well-known as the Amazon River, which is home to a broader range of animal species, the Mekong is a substantial contributor to the diversity of fish species worldwide.

Dams, overfishing, pollution, and climate change are some of the numerous linked threats currently confronting the Mekong and its aquatic species. On the other hand, these threats aren't the only ones they have to worry about it.

The continually growing human population in Southeast Asia is one of the main issues since it strains the whole Mekong watershed. That is one of the most major underlying issues. The necessity to produce food for a worldwide population that is constantly rising has contributed to an increase in overfishing. Additionally, as living conditions have increased, individuals are eating more, which has further contributed to the deterioration of the situation. The requirement to provide food for an ever-increasing population not only leads to an expansion of agriculture and increased competition for the Mekong's limited water resources but also contributes to an increase in the amount of pollution caused by the use of pesticides, fertilizers and animal waste. 

That is the case because agriculture contributes to the rise in pollution caused by pesticides, fertilizers, and animal waste.

There Are Too Many Fishers And Not Enough Fish.

Data gathered from the fisheries of the Mekong exhibit all of the telltale signs of a catastrophe that is only getting worse with time. Overfishing is a severe issue throughout the interior rivers of the world. For example, the number of people fishing on Tonle Sap Lake, an ecologically important section of the Mekong Basin, has skyrocketed from 360,000 individuals in 1940 to an astounding 1.3 million in 1995. That represents a significant increase from the previous number of people who fished on the lake. This growth took place over time, between the years 1940 and 1995 specifically.

During that period, there was a fifty percent reduction in the total number of fish an individual could catch. The kind of fish that were caught changed as well; in the past, people saw a preponderance of enormous fish, but tiny fish now make up the bulk of the catch in the Tonle Sap, which shows that mature adult fish have been wiped from the population in great numbers.

According to Erin Loury, a Fisheries Biologist at FISHBIO and a member of the Mekong Fish Network, "Freshwater ecosystems are critical to the health and wellbeing of both people and wildlife, but they are also among the most threatened ecosystems in the world." "Freshwater ecosystems are vital to the health and wellbeing of both people and wildlife," "The health and wellbeing of both people and other forms of life, including animals, are inextricably linked to the condition of freshwater environments."

A reduction in the amount of rainfall and a rise in water temperature are two examples of the effects already being attributed to climate change in the area. The most recent El Nio event caused a severe drought in Vietnam in 2015 and early 2016, which led to the Mekong Delta reaching its lowest recorded level in the past one hundred years. El Nio caused this drought. This specific record hadn't been surpassed in the previous century, making this occasion the first time who had ever done it. As a result of significant heat waves and water shortages experienced in neighboring Cambodia and Thailand, China has been forced to open the gates of its Mekong dams to deliver additional water to countries that are further downstream in the Mekong Basin. That is being done to help countries located downstream in the Mekong Basin.

These issues pose a danger not just to the Mekong large catfish but also to the millions of people throughout Southeast Asia who depend on the river for their lives and livelihoods. The Mekong giant catfish are not the only ones at risk; so are these people. According to Hogan, the Mekong River is the most productive river on the earth, providing food and water to more than seventy million people. Not just their destiny but also that of the Mekong enormous catfish will be determined by how we manage the extension of the Mekong River.

The Stampede To Dam The Mekong

The building of dams is possibly the single biggest threat to the ecosystem of the Mekong River and the migratory giant catfish that lives there. The people and governments of Southern Asia are expressing a rising interest in switching from the polluting fossil fuels that are now being utilized to supply their energy needs to hydropower, considered an attractive and viable alternative. This transition is expected to take place within the next few decades.

The government of the Lao People's Democratic Republic (PDR) has said that one of its aims is to become the "battery of Southeast Asia," and it is without a doubt the case that the Mekong River holds sufficient "battery power" to make that ambition a reality. It is estimated that the total hydropower potential of the Mekong Basin amounts to 53,000 Megawatts (MW), which is more than a third of the energy requirements that are expected to be met by 2025 for all of Cambodia, the Lao People's Democratic Republic, Thailand, and Vietnam combined. In other words, the Mekong Basin can supply more than a third of the energy needs of these four countries.

Six dams have now been built on the Upper Mekong in China. Collectively, these dams can harness around 11,000 MW of the energy that is carried by the river. There are at least 27 more dams scheduled to be built along the main stem of the Mekong River, most of which will be situated in Laos and China. These dams are expected to be made to control flooding along the river. At this time, two further dams are being constructed further downstream in Laos, in addition to the fact that another two barriers are now in the building stages.

Xayaburi As An Example

The several dam projects in Southeast Asia that are now under consideration have the potential to deliver renewable energy sources to the region's growing human population. However, the construction of these dams will also significantly impact aquatic ecosystems, most notably fish populations. That will be the case since fish are a vital component of marine ecosystems.

The governments of Laos and Thailand commenced construction on the Xayaburi mega-dam in 2010, hoping to produce 1,285 megawatts of energy once it is completed. However, estimates suggest that Thailand does not require that great of an amount of energy to satisfy its national demand, even though EGAT, the power company of Thailand, has vowed to buy 95 percent of that electricity. That indicates that part of the energy may be exported rather than used domestically, as would otherwise be the case.
Cambodia and Vietnam, located downstream of the project, and local and international environmental groups, have also voiced their fierce opposition to the idea. Cambodia and Vietnam are both located downstream of the project.

Peasants from eight different provinces in Thailand filed a lawsuit in 2012 against five government entities, including EGAT, for their participation in constructing the Xayaburi dam. The peasants' complaint centered on the government's failure to adequately compensate them for their losses. The people were concerned about the project's effect on their means of subsistence. In the complaint, they stated that the government authorities had failed to perform an appropriate review of the project's health and environmental ramifications before it was approved and construction began. That was an allegation that was made concerning the lawsuit.

This contentious issue brought to the attention of the general public the environmental impact of hydropower on the Mekong, even though the court's final judgment determined that the state agencies had complied with Thai law. Despite this fact, this contentious issue brought the issue to the general public's attention. The Xayaburi dam and other proposed dams on the Mekong are causing significant concern among the local population. According to this population, these dams will worsen seasonal floods and disrupt fish spawning, ultimately driving farmers and fisher folk off their lands and out of their means of subsistence. 

These concerns stem from the fact that seasonal floods are already a significant problem in the area.

Migratory Fish And Dams Don't Mix

Dam-building establishes a physical barrier, preventing fish from moving up and down rivers and spawning. That is one of the potential adverse effects of dam construction. Between October and December, Mekong giant catfish begin their yearly migration from the lakes in the lower Mekong area of Vietnam. This migration is for spawning, which takes place farther upstream in Cambodia, Laos, and Thailand.

Hogan claims that catfish are "extremely migratory," meaning they travel quite a from place to place. The use of radio telemetry has made it possible for him to track and monitor the annual movements of adult catfish throughout the river system. Because the travels of adult catfish across the watershed are, for the most part, undiscovered, this is something that has to be done. During the dry season, he says, "animals move out of the Tonle Sap Lake and into the main channel of the Mekong River." It is known that young catfish go downstream as larvae, following the floodwaters, and finally find their way to Cambodia between July and August. However, very little information is available on the adult return migration.

A new study published this year proved that the Mekong giant catfish is a significant league traveler. To perpetuate the species' lifecycle, the Mekong giant catfish utilizes the entire length of the river and its environment. Researchers from the University of Hong Kong undertook the work necessary to complete the inquiry. Eva Bellemain and her coworkers at SpyGen were able to track the movement of the catfish throughout the watershed by using ambient DNA. That allowed them to determine how the fish got there.

According to the explanation that Bellemain offered, "Environmental DNA (eDNA) is DNA that has been released into the environment by an organism via feces, hair, urine, skin, gametes, and other methods." [citation needed] "This DNA can be extracted from environmental samples such as soil and water" and sequenced to detect that a particular species is present in a specific location without ever having to see or catch the animal in question that is being investigated. "WHO can sequence this DNA to detect that a particular species is present at a particular location." That can be performed by collecting "environmental samples," including water and soil.

"At one location on the Mekong mainstream, near the line between northern Thailand and the Lao People's Democratic Republic," continues Bellemain, "we identified the DNA from the huge catfish." On the main channel of the Mekong river is where scientists believe the species maintains its breeding grounds. Researchers have determined that catfish once inhabited the location in issue based on the discovery of catfish DNA at the site, indicating that the fish settled in the area not too long ago.

"Unfortunately, this region is upstream of the first major dam being developed on the lower Mekong in Xayaburi," she explains who may find this location upstream of the first mainline dam now being built on the lower Mekong close to Xayaburi. It is currently uncertain whether or not the Mekong giant catfish will be able to complete its voyage and breed after the construction of the Xayaburi dam is ultimately done.

The Xayaburi dam will be the first one built downstream of catfish breeding areas, and as a result, it will prevent catfish from following their typical yearly migratory route. According to Bellemain, "when the dam has been constructed, further eDNA investigations will allow us to determine if the known spawning area upstream of the [blocking] infrastructure is still populated." This assessment will be possible once the dam has been completed. Assessing whether or not they can move around the dam will provide a clue as to whether or not the catfish can migrate around it in some way.

Aquatic Ecosystems Are In Danger

The meteoric rise in the number of new hydropower projects will have an effect not just on the considerable catfish but also on a diverse array of other animal and plant species. It is believed that many of the fish in the Mekong are migratory, and scientists have projected that the construction of additional dams could potentially obstruct the migration routes of up to one hundred different species of fish, including the Mekong enormous catfish. That would be a problem because the Mekong giant catfish is an endangered species. In addition, the local people rely on these migratory animals as a source of food and a method of making a living, which gives these species an excessive amount of importance. Seventy percent or more of the Mekong's economically significant fish population comprises species that have traveled great distances.

Dams are feasible to significantly impact catches made in other parts of the basin if fish cannot migrate down the main stem of the Mekong River. Dam-building on Brazil's Araguaia-Tocantins River has interrupted long-distance catfish migrations, causing catching losses of up to 70% farther downstream. In the Amazon Basin in Brazil, scientists have documented the occurrence of consequences similar to these in the past.

D dams' disruption of natural flood cycles and the potential for the riverbed to become more story are two additional adverse effects on the ecosystem. Barriers also have other negative effects on the ecosystem. The impounding of rivers is responsible for both of these unintended environmental effects. The sudden outbursts of water caused by dams are responsible for carrying away sediments and silt, which are essential for the survival of aquatic plants, animals, and fish because they provide a habitat and a source of food. Given the significance of silt and sediment to the survival of many species, this is an alarming development. Dams have the additional effect of interrupting the normal flow of deposits throughout river systems, which is necessary to ensure that sediments are distributed appropriately. That results in an accumulation of trash further upstream and limits the transfer of nutrients further downstream. As a direct result of this, there will be an impediment.

Probably, the accumulation of silt behind dams in the Lower Mekong region will have a significant and negative influence on the aquatic ecosystems located there, in addition to the agricultural practices utilized in the area. Suppose the river cannot generate the steady flow of nutrients it regularly produces. In that case, likely, not only the yields of fisheries but also agriculture yields would rapidly decline, which might have a significant impact on the local economy. Already, dams on the Mekong are linked to lower agricultural production and changed seasonal sediment flow cycles in the Mekong Delta. This problem is because the Mekong Delta is home to a large agricultural sector. In this part of the world, this is the situation.

Dams along the Mekong River, such as the Xayaburi Dam, are only one of the many artificial barriers that jeopardize the river's natural habitat and potentially exacerbate its deterioration. Other artificial obstacles along the Mekong River include other dams. As an employee of FISHBIO, Loury asserts that "Connectivity is one of the most critical components of a healthy freshwater ecosystem." Because of the connectivity between different areas, it is now feasible for animals, water, and nutrients to go from one place to another. The degree to which different parts of the freshwater ecosystem are connected is one of the most critical aspects of determining the ecosystem's overall health. On the other hand, in the Mekong River System, "thousands of barriers have been created, which might damage these natural processes, and many more are planned."

Finding Answers And Moving On

According to Hogan, the prognosis for the Mekong giant catfish is "not good," which is an honest evaluation of the existing condition. The current circumstance is as follows: The construction of the Xayaburi dam is nearly finished, and at this point, the most who can hope for enormous catfish is that they will be able to live out their life cycle in a river that has been broken up. That is the best case scenario for who can predict for them now. At this point, this is the best one can wish for in terms of how things will turn out. If they cannot do so, it is unavoidable that they will go extinct in the environment in which they were initially found.

However, it is conceivable for migratory fish to find a way to get around the dams and continue their voyage. That would allow the fish to complete their journey. Some engineers think it is possible to capture the energy of rivers like the Mekong without causing any disruption to the natural nutrient cycles or migration patterns of fish. That is a theory that is held by some of these engineers. The technical community has this perspective, and others own it.

In light of this fact, fish ladders have been constructed on several of the most contemporary dams along the Mekong River, such as Xayaburi, to assist migrating fish in overcoming the challenges posed by traveling past a barrier that is 33 meters in height. One dam equipped with a fish ladder is Xayaburi (more than 100 feet). The individuals who favor the construction of the Xayaburi dam say that these "fishways" will make it possible for migratory species to go both upstream and downstream in a manner that is not fraught with danger.

According to several studies, fish ladders are only beneficial for a specific subset of fish species, and they are of no help at all for fish species that move slowly. Fish ladders have been used in North America with a certain degree of success; nevertheless, the findings of these studies show that they are only advantageous for a subset of fish species. Fish ladders have been used in North America with some degree of success. A fish ladder was constructed in Thailand as a component of the Pak Mun Dam to enable the flow of fish and other aquatic life from the Pak Mun reservoir into the Mun River. This movement was made possible by the dam. The fish ladder was a total and finished complete failure. Less than ten years after the dam's construction, effective campaigning convinced the government to permanently open the dam gates to protect the fisheries. Who did this to ensure that who would not damage the fisheries?

According to Tom Wild, a Postdoctoral Fellow in Civil and Environmental Engineering at Cornell University, "it is not conceivable to build a dam that does not have any consequences on ecosystems." [citation needed] "It is impossible to construct a dam that does not have any impacts on ecosystems." This accusation was made by Mr. Wild, who is responsible for his actions. "It is all the more crucial... to locate dams that offer some balance," says Wild, "between expanding energy needs and the requirement for a healthy, functioning ecosystem." "It is all the more crucial. To select dams that give some balance," says Wild. The health of a river basin like the Mekong impacts the people's prosperity, according to Wild, because human well-being is so closely linked to the health and productivity of the river.

Wild is a member of a Natural Heritage Institute team working with the National Government of Cambodia to create "an ecosystem-energy balance for the Sambor Dam." This project is being carried out in collaboration with the National Government of Cambodia. The official name of this project is "an ecosystem-energy balance for the Sambor Dam." We are collaborating with the National Government of Cambodia to bring about the successful completion of this project. The dam constructed on the main stem of the Mekong River will be situated in the tributary that is the furthest downstream as a direct result of the fact that this Cambodian project is now in the planning phases. Because of this, the potential influence it has on the movement of fish, and the flow of silt is of utmost significance for maintaining the river's general health.

Wild states, "Sambor Dam would be sited on top of one of the world's major fish migratory corridors." If it were constructed, it would also be the final dam to be erected upstream of one of the most productive lakes in the world (Tonle Sap) and the Vietnam Delta. In addition, the barrier would be the development that would have the most profound effect on the surrounding ecosystem. In addition, the Sambor Dam would be constructed immediately on top of one of the essential passageways for salmon migration around the whole globe.

Continuing with his explanation, "Our research is focused on identifying potential alternative dam locations, dam designs, and operating rules for the Sambor Dam. We are doing this research in to hope that all of these features will considerably enhance the flows of water, sediment, and fish through and around the dam.

Our study is focused on identifying viable alternative sites, dam designs, and management tactics for the Sambor Dam. All of them have the potential to significantly enhance the flows of water, sediment, and fish, and thus we are doing this research with that goal in mind.

Wild acknowledges that this is "an amazing problem" and that it is essential to take a novel approach to the construction of dams as a result of this. As a result, Wild believes it is required to take a creative method. It is possible to guarantee that fish can pass through a project like a dam if the construction process is broken up into smaller pieces and migratory corridors are incorporated into the blueprints. In addition, the team is looking at using radial gates and turbines, which let sediment flow and potentially cut down on the number of fish killed drastically. Both of these possibilities have the potential to lessen the number of fish that are killed.

Wild argues that "a fundamental rethinking of the way dams are sited, engineered, and operated will be essential to prevent fisheries from suffering damage they cannot repair." These factors must be considered early in the planning process, far before a hydroelectric project's site and design are decided. It would help if you did this as soon as possible once the planning phase has begun.

Wild has very high hopes that the Sambor project will be a resounding success and lead the way for alternative river basin infrastructure that will protect the ecological health of the environment and its capacity for productive activity. Wild has high hopes because the Sambor project has the potential to save the environmental health of the environment as well as its ability for productive activity.

According to him, “the lessons from [this project] would be pertinent to other sites within the Mekong and in other basins given the massive and ubiquitous expansion of hydroelectric dams.”

Too Late And Not Enough?

On the other hand, the current efforts to build dams and select suitable locations may not be successful in saving the Mekong giant catfish as quickly as they should be.

The fate of the species is challenging, but conservationists are making a significant amount of effort to alleviate the situation to the greatest extent they can. Several fish conservation zones (FCZs) have been established around the Mekong by the World Wildlife Fund (WWF), the Fish and Wildlife Biodiversity Initiative (FISHBIO), and the International Union for the Conservation of Nature (IUCN), and the Department of Livestock and Fisheries in Laos. Did this to protect the fish populations in these areas and ensure their continued existence? These fish conservation zones are intended to safeguard fish populations and guarantee they will continue. In recent years, the United States has established around one thousand fishing-free zones, abbreviated as FCZs. These are the areas where fishing is not allowed under any circumstances. As a consequence of these limits, it is believed that fish populations will be able to make a full recovery. These restrictions will also protect crucial breeding areas, which is a positive outcome.

Government authorities are becoming more aware of the destruction that the inhabitants of the Mekong River Basin would endure as a result of these events, and the political environment in some regions of Southeast Asia is also starting to change. This understanding is leading to a shift in the political climate in those regions. 

The government of Vietnam announced the Mekong Delta Plan at the beginning of this year. This plan is a practical and long-term strategy designed to assist people dependent on the Mekong delta in adjusting to the unavoidable changes brought about by upstream dams and sea-level rise linked to climate change. Who created the plan to assist these people in adapting to these changes so they can continue living off of the Mekong delta.

According to specialists in the field of conservation, the Mekong giant catfish has the potential to become the Panda of the Mekong River, acting as the poster child for one of the most important ecosystems on the globe. According to Loury's argument, "the [species] depends on a healthy, functional river system to live; as a result, measures to safeguard the Mekong giant catfish would also assist a huge number of other species." "[T]he [species] can only flourish in a river system that is in good condition." The Mekong giant catfish, "like an ambassador, may raise attention to these vital freshwater ecosystems,"

She continues by stating that the enormous catfish also has a great deal of cultural significance for various indigenous cultures."In the past, catching a monster fish this size needed the cooperation of the entire town and forged tighter ties among the neighbors."

The World Wildlife Fund's (WWF) Living Mekong Program is another program that collaborates with the Mekong River Commission and the Asian Development Bank to put policies in place to save freshwater habitats and keep aquatic ecosystems vital to nearby populations. We will enforce these policies to ensure that freshwater habitats and marine ecosystems will continue. These rules are now being put into effect to secure the preservation of freshwater environments.

Monitoring will also be a crucial piece of the puzzle when it comes to the preservation of Mekong enormous catfish. Large-scale monitoring may become more feasible if novel techniques for collecting environmental DNA are developed and implemented. In addition to providing baseline data on the biodiversity of the Mekong River, DNA sampling may be utilized, as stated by Bellemain, to monitor fish conservation zones. May also employ this information. An additional illustration of this concept is the proposition that "eDNA sampling might be used to trace the migratory patterns of the fish." "Such multi-species procedures offer the added ability to find unusual and secretive [aquatic] species," she explains. "These techniques are becoming increasingly popular." "These [aquatic] species are necessary for the ecosystem to function properly."

These conservation efforts may give the impression of being promising, but the plans for constructing infrastructure along the Mekong look to be unstoppable. It is anticipated that these plans will cause significant damage to aquatic ecosystems as well as migratory fish species. Large construction projects, like the Xayaburi dam that is now being constructed, have the potential to entirely block vital migration corridors, which might result in the extinction of the Mekong enormous catfish in the not-too-distant future.

Even though environmentalists are attempting to respond to each new dam plan that is put up, the sheer speed and magnitude of development in the Mekong Basin threaten to wipe out the largest freshwater fish in the world, the Mekong massive Catfish. Even though the Mekong Giant Catfish is the world's largest, that is the case.