Riverine Megafauna as “Freshwater Pandas”

A NextGen Blog post by Becca Jordan, University of Nottingham.

All Photos © Alison M. Jones.

This is the latest post to our NWNL NEXTGEN BLOG series. Since 2007, NWNL has supported watershed education with college internships and blogging opportunities. Our NWNL NEXTGEN BLOG series posts only student essays; sponsors a forum for its student contributors; and invites student proposals to write on watershed values, threats and solutions.

Becca Jordan is pursuing a master’s degree in Environmental Leadership and Management at the University of Nottingham in the U.K. This blog, illustrating her keen interest in wildlife conservation, investigates protection of critical freshwater species through public engagement solutions.


The term “megafauna” is commonly defined by the scientific community as an animal with an adult body mass greater than 66 pounds [30kg]. The freshwater megafauna category contains animals that meet this size threshold and are reliant upon freshwater habitats for the completion of their life cycle.1Carrizo, S., et al. However, freshwater megafauna – and indeed freshwater species in general – often receive far less research funding, conservation funding and public attention than their terrestrial counterparts such as elephants, giraffes and big cats.2He, F. and Jähnig, S.

Terrestrial megafaunal species have been used to represent and draw attention to the degradation of terrestrial ecosystems. Many freshwater researchers now suggest that freshwater megafauna could be used to do the same thing for our freshwater ecosystems.

Aerial view of hippo pod on Kenya’s Mara River

Why Megafauna?

Freshwater megafauna possess inherent values as unique living creatures that deserve to thrive in their freshwater ecosystems, and also play an important role in river morphology, topography and habitat creation. Studies have shown that they also may be an excellent biodiversity regulator, as they co-occur with more than 93% of known freshwater biodiversity.3Carrizo, S., et al. Although it is sometimes difficult to clearly establish the roles of different species and their relationships with each other, it is clear that where megafauna can thrive, high biodiversity can too.

In the 1960’s, the World Wildlife Fund unveiled the giant panda as their emblem as a visual representation of their campaign goals. This worked well for them; and their panda logo became ubiquitous, inspiring millions of people throughout the years to get into research, funding and campaigning for terrestrial animals – and subsequently, their ecosystems. Based on successes like this, it stands to reason that maybe what freshwater ecosystems need is a “freshwater panda” as its mascot.4Kalinkat, G.. et al.

Proposed Flagship Umbrella Species

Freshwater megafauna populations have declined by 88% between 1970 and 2012.5Albert, J., et al. This is clearly a huge issue in terms of the subsequent threat to freshwater ecosystems as a whole, and also due to the intrinsic value held by these fascinating and large freshwater creatures.

In this article, I propose four species as appropriate flagship umbrella species that campaigns could use to represent freshwater megafauna and ecosystems. Each represents a global water system, for which there is still hope.

  • The American Alligator is lucky enough to be “of least concern” when it comes to conservation of threatened and endangered species. Commonly found in southeastern states of the USA, this alligator is a familiar face and one of the go-to species when you think of freshwater animals in states such as Florida or Mississippi. Being so easily identifiable, they could be a perfect contender for being a flagship umbrella species for freshwater ecosystems in the US, as long as its snappy reputation does not get in the way.
Alligator in the Lower Mississippi River Basin
  • The Amazon River Dolphin is currently listed on the IUCN Red List as “endangered.” Its home, as you would expect, is the Amazon River Basin of South America, where its population numbers are steadily decreasing. The IUCN website lists numerous factors that are causing its rapid decline, primarily due to various forms of pollution from industry, agriculture and energy production. Dolphins are often the subject of folklore and children’s stories, and their almost mysterious yet playful nature endears them to many people around the world. In my view, they have high potential for becoming a flagship umbrella species – provided that they survive long enough to be established as such.
  • The African Hippopotamus is classified on the Red List as “vulnerable;” although, encouragingly, their population is currently deemed stable. The Mara River Basin, in Kenya’s Maasai Mara National Reserve, is currently habitat for over 4,000 hippos. Fulfilling the megafauna definition mentioned earlier, they positively impact their riverine landscape, and are often listed as one of the big attractions in tourist safari activities. To an even greater extent than the American alligator, hippos are generally well-known throughout the world, which perhaps makes them the perfect starting point for a keystone umbrella species campaign. However their record of killing people wandering along a river could prove to be a negative. 
Hippopotamus in Mara River
  • The Atlantic sturgeon is very large freshwater fish living in wetlands around coastal Europe. It is listed as ‘critically endangered;’ although it is important to note its population has not been assessed by the IUCN since October 2009. There are approximately 20 to 750 of them left in the wild, and they receive little attention. Seemingly due to the unglamorous nature of fish in comparison to other megafauna, the Atlantic sturgeon is quietly slipping out of existence as a result of over-fishing, pollution and unfavourable river management practices.

I think that it  would be important and beneficial to have a fish like the Atlantic Sturgeon as one of the spearheads of a flagship umbrella species campaign. Often species that are less aesthetically exciting and less charismatic get overlooked, despite their inherent importance and value to the freshwater ecosystem.

Freshwater Megafauna Threats

There are a variety of threats facing our global freshwater megafaunal populations. An overwhelming 84% of the distribution zones of these species exist outside of areas protected by legislation. This leaves them vulnerable to a whole range of menaces.

Despite their protected status under CITES (Convention on International Trade in Endangered Species), freshwater megafauna species are still commonly poached for their skin, meat and eggs.6He, F. and Jähnig, S. 2 Exacerbating this is the growing issue of man-made river obstruction and infrastructure. Damming and over-abstraction of water can change crucial river regimes relating to temperature, sediment and flow of any river. This can lead to the fragmentation of rivers, drainage of wetlands and major disruption of migratory pathways, as well as destruction of freshwater nurseries.7Carrizo, S., et al. In the future, these impacts are expected to be particularly significant and increase in South America and Asia, where the introduction of more hydropower dams lacking fish passage mitigation will further obstruct rivers and decrease these threatened species.8Zarfl, C., et al.

In addition, ongoing pollution from agricultural land and urban areas, plus inhospitable warming and alteration of watersheds due to climate change, suggest a precarious future for freshwater megafauna.

Grand Coulee Dam and its reservoir, Lake Roosevelt in the Columbia River Basin

Freshwater Futures

While most freshwater megafauna are assessed on the IUCN Red List, 60% of the assessments of these species are “insufficient” or “outdated.”9He, F. and Jähnig, S. It is more crucial than ever that we give these species – and in turn, freshwater ecosystems – the attention they need. By exciting, interesting and investing people in freshwater megafauna, just as we’ve done with terrestrial megafauna, we could reverse today’s decline of freshwater populations and ecosystems. By doing this, we could protect and conserve freshwater ecosystems – benefitting all species that live within them, and also those that rely upon them, including ourselves.

By no means are flagship umbrella species a singular solution to freshwater degradation and megafaunal extinction, but it they are certainly a large step in the right direction. If we begin this process now, the “freshwater pandas” approach may help save our freshwater megafauna from extinction, and in turn bring attention, research and conservation to freshwater ecosystems all over the globe.

Sunset over Lake Martin, Louisiana

Sources:

Albert, J., et al. “Scientists’ warning to humanity on the freshwater biodiversity crisis.” Ambio, 2019

Carrizo, S., et al. “Freshwater Megafauna: Flagships for Freshwater Biodiversity under Threat.” BioScience 67(10), pp.919-927

Greshko, M., “Reported Sighting Of Extinct River Dolphin Is Unlikely.” National Geographic, 2016. Accessed October 15, 2020 by BJ. https://www.nationalgeographic.com/news/2016/10/baiji-extinct-river-dolphin-china-sighting-conservation/#:~:text=The%20last%20confirmed%20baiji%20sighting,off%20the%20Caribbean%20monk%20seal  

He, F. and Jähnig, S. “Put freshwater megafauna on the table before they are eaten to extinction.” Conservation Letters, 12(5).

Naiman, R. and Rogers, K., “Large Animals and System-Level Characteristics in River Corridors.” BioScience 1997, 47(8), pp.521-529.

Kalinkat, G., et al. “Flagship umbrella species needed for the conservation of overlooked aquatic biodiversity.” Conservation Biology, 31(2), pp.481-485.

Zarfl, C., et al. “Future large hydropower dams impact global freshwater megafauna.” Scientific Reports 2019, 9(1).

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