When viewing a world map, the vivid blue of the vast oceans and seas is hard to miss. After all, around 97% of the earth’s water is in the ocean. However, freshwater ecosystems tend to be neglected due to the visibility of larger saltwater ecosystems. While freshwater only makes up 3% of our planet’s water supply, it can be found almost anywhere. In the United States alone there are over 250,000 rivers, not to mention other types of freshwater ecosystems in other parts of the country.
“Freshwater ecosystems provide a lot to a lot of people and pretty much every living thing in the world,” said Natalie Shahbol, a senior program officer at the World Wildlife Fund, in an interview that I conducted with her. Freshwater ecosystems provide over 2 billion people with drinking water, allow for the production of a ¼ of the world’s food source, and support more than 125,000 species.
These habitats are inextricably linked to freshwater fish, who maintain healthy rivers, lakes, and wetlands.
“Fish often are involved in the food chain in different ways; they might be the food that other fish or animals eat, they eat other animals, they eat bacteria, and they help sustain the natural freshwater ecosystem,” adds Shahbol. This issue also affects terrestrial animals such as bears that eat salmon – without an abundance of fish, the population of their predators would decline. You can have a collapse of other species that depend on the fish when fish populations decline.
Freshwater fish also have a direct impact on humans. This is mostly due to the large number of freshwater fish – they make up 51% of the entire fish population with over 18,000 different species. Due to the prominence of freshwater fish many people around the world depend on them for food and their livelihoods. Over 200 million people worldwide depend on freshwater fish as a major source of protein.
Additionally, freshwater fish have a great economic impact. Over 60 million people depend on these fish for a living. In the United States, fisheries and recreational fishing make 38 billion dollars and 100 billion dollars annually, respectively.
Despite their importance, not enough has been done to help freshwater fish, as their populations have been declining at rapid and continuous rates. The most recently published IUCN Red List of Threatened Species found that around 25 % of the 14,898 tested freshwater fish species are at risk of extinction. The IUCN (International Union for Conservation of Nature) red list also declared 80 species to be extinct with 16 of these species just from 2020.
Many notable freshwater fish species are included in this count. For instance, Atlantic salmon populations dropped 23% from 2006-2020, migratory freshwater fish populations have fallen 76% since 1970, and large fish that weigh over 30 kilograms have gone almost extinct in river habitats.
This decline has followed the development of technology over the years as more factors impact the livelihood of freshwater fish species. For example, around 33% of freshwater fish species in risk of extinction are endangered by invasive species, 57% are endangered by pollution, 45% are endangered by dam water extractions, 25% are endangered by overfishing, and 17% of all freshwater fish species are impacted by climate change. The combination of all these factors has led to a decline in freshwater fish populations as they have long-standing impacts on the habitats, food sources and reproduction rates of freshwater fish.
While saltwater fish populations have also declined in recent years, the impact on freshwater fish is especially evident. The decline of freshwater species is happening at twice the rate compared to that of marine and terrestrial habitats.
“Freshwater fish are in a more accessible place to humans than our ocean fish. There are more management laws around ocean conservation like marine protected areas and ocean zoning. It is harder to do so for freshwater as there is life all around it,” said Shahbol. Additionally, compared to marine fish, freshwater fish conservation efforts are often underfunded. In fact, the European Foundation Centre’s analysis found that freshwater systems only get 3.2% of the environmental funding from European foundations. All of this has made freshwater fish more susceptible to extinction.
While many freshwater fish species are in risk of extinction, progress is still being made in favor of their conservation. Many international organizations and local governments that have been making efforts to help freshwater fish. A new report entitled ‘The Worlds Forgotten Fishes’ is the result of a collaborative effort of 16 global conservation organizations. It details a six part plan on how freshwater fish can be protected. This plan includes points such as: allowing rivers to flow more naturally, improving water quality, protecting critical habitats, controlling invasive species from entering freshwater habitats, protecting free-flowing rivers, removing obsolete dams, and stopping unsustainable sand mining and overfishing.
A lot of the work on freshwater fish protection have been done by conservation groups like the WWF and IUCN. To get more insight into the conservation of freshwater fish, I also interviewed Mr. Brian Zimmerman, who serves as one of the co-chairs of the IUCN’s Freshwater Fish specialist group and also a EAZA Freshwater Teleost TAG Chair.
“The freshwater fish specialist group which I’m a co chair of basically has multiple roles. It oversees the global view on freshwater fish conservation. I would say it’s roughly divided into work that is done in the field as well as work done in zoos and aquariums which is my kind of main background. We have over 200 members and those members work across a range of areas, fields, and disciplines,” said Zimmerman.
He and his colleagues, consisting of taxonomists, environmental consultants, and researchers, use their professional knowledge to identify the issues plaguing freshwater fish in various areas and attempt to solve them.
“For each situation in which you have a conservation dilemma, it’s really important that it’s understood what those challenges are, and in many cases, it’s more than one cause of the decline or an issue for a particular ecosystem. So that when it is really important that it’s clearly understood what the challenges are so you can develop a conservation strategy that can adjust them,” said Zimmerman.
Zimmerman and other conservationists still face many issues in their efforts to aid freshwater fish species with one their obstacles being politics. Certain places that might need conservation might be dangerous to enter due to conflict and war. When conservationists get into the country, they still have to navigate local laws and political channels.
“If it’s a fisheries-based thing, then it’s multinational. If you look at Lake Victoria, there are several countries that share the coastline. The strategies very much have to be political in nature in many cases because you need to get agreement from everybody there. There is no point in Kenya saying that it’s going to save Lake Victoria if Uganda isn’t going to do the same thing because they are interconnected,” Zimmerman said.
In addition to political issues, conservationists also encounter conflicts of interest in their work. Conservation efforts of fish in certain areas might clash with big businesses or other environmental efforts.
An example of this is hydropower, which has grown in popularity as the world is trying to shift away from fossil fuels to more renewable energy sources. The use of hydropower often involves building of dams which can be detrimental to freshwater ecosystems.
“Not only do they [dams] block migration of the fishes that live there but they also lead to eutrophication of the water that is trapped behind the dams. It can lead to sedimentation, which hinders the reproduction [of fish populations]. Of course, when you’ve got governments and big businesses that are in the business of building huge hydropower dams and it’s in direct conflict with freshwater fish conservation. That is a serious issue for us and our ability to make a difference in those areas.” said Zimmerman.
Despite the difficulties that are present in freshwater fish conservation there has also been improvement over the recent years with more media coverage on freshwater fish. “ Everybody, when they think of conservation, they think of tigers, they think of polar bears, but not many people think of freshwater fish. I think that it’s changing, and more people are becoming aware of freshwater fish and their importance, beauty value, and to me that’s the best bit of hope we’ve got now, that there’s more awareness,” said Zimmerman.
With rising awareness, there can be action and steps taken. This action doesn’t involve just the expertise of conservationists and researchers but everyday people like ourselves. By making small changes in our everyday habits – such as not buying harmful cleaning products that end up in rivers – we can help protect the ecosystem of hundreds of fish. As inhabitants of our planet, we have to be more aware of how we treat the environment around us, and how it will look for future generations.
An avid fish lover, Jaime Yu ’25 said, “Many species have already gone extinct, and saving freshwater fish is one step forward in the grand project of preserving the wildlife on the planet that we live on.” Together with combined efforts of experts and the general public the preservation of these exotic species is not an impossibility.
Despite the difficulties that are present in freshwater fish conservation there has also been improvement over the recent years with more media coverage on freshwater fish. “ Everybody, when they think of conservation, they think of tigers, they think of polar bears, but not many people think of freshwater fish. I think that it’s changing, and more people are becoming aware of freshwater fish and their importance, beauty value, and to me that’s the best bit of hope we’ve got now, that there’s more awareness,” said Brian Zimmerman, one of the co-chairs of the IUCN’s Freshwater Fish specialist group.