An Introduction to River Biodiversity

🌱 What biodiversity is found in rivers and wetlands?

While “covering less than 1% of the global surface area, freshwater ecosystems […] support a disproportionate number of flora and fauna”.[i] Overall, wetlands host 40% of all species.[ii] As rivers connect different wetlands to one another, they are seen as “arteries of the landscape”.[iii] In line with this, river ecosystems are also key hubs for biodiversity — with species living inside and outside of the water.

🌱 What threats are there to river biodiversity?

There are multiple threats that rivers and their vast biodiversity face. The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) outlines five major drivers of biodiversity loss: “(1) changes in land and sea use; (2) direct exploitation of organisms; (3) climate change; (4) pollution and (5) invasive alien species”.[iv] Each of these drivers indirectly affect the reproductive abilities of species and directly affect factors in rivers such as water quantity (flow), quality, and how the river is connected from “source to sea”.[v] This, in turn, affects ecological conditions in the river.

🌱 What role does climate change play?

The listed drivers are exacerbated by climate change. A changing climate alters habitats through increased wildfires, extreme weather conditions, shifts in temperature and water distribution. A concrete example of climate change directly affecting river diversity is that it causes an increased irregularity of the flow of rivers and streams.[vi]

🌱 Why is it important to protect biodiversity?

Biodiversity is crucial to preserve a whole web of intricate interactions between species in ecosystems, which in turn ensure climate regulation,[vii] food production, water purification and flood protection. With biodiversity loss, we can expect huge economic losses. This is best illustrated by the European Central Bank’s research from 2023, which shows that approximately 75% of all euro area corporate loans are strongly dependent on at least one ecosystem service.[viii]

This post has been adapted from a newsletter written by Krisna Baghouzian and Christine Nikander. The newsletter titled “How can businesses protect rivers and their biodiversity?” was originally published in “The Just Transition Newsletter” by Palsa & Pulk.

[i] Anuradha Kumari and Sarika, “Riverine biodiversity and importance: Potential threat and conservational challenges”, Chapter 13 of Ecological Significance of River Ecosystems Challenges and Management Strategies (2022). https://www.sciencedirect.com/science/article/abs/pii/B9780323850452000091 (20.02.2025)

[ii] Wetlands International, Call for an ambitious Global Biodiversity Framework on World Wetlands Day 2020. https://www.wetlands.org/call-for-an-ambitious-global-biodiversity-framework-on-world-wetlands-day-2020/ (20.02.2025)

[iii] Wetlands International, Rivers and Lakes. https://www.wetlands.org/our-work/rivers-and-lakes/ (20.02.2025)

[iv] Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), Media Release: Nature’s Dangerous Decline ‘Unprecedented’; Species Extinction Rates ‘Accelerating’. https://www.ipbes.net/news/Media-Release-Global-Assessment (20.02.2025)

[v] Petersen et al., Incorporating free-flowing rivers into global biodiversity targets: Prioritization and targeted interventions to maintain ecological integrity (2022). https://onlinelibrary.wiley.com/doi/full/10.1002/aqc.3898 (20.02.2025); Harvey et al., How Hydrologic Connectivity Regulates Water Quality in River Corridors (2019). https://onlinelibrary.wiley.com/doi/10.1111/1752-1688.12691 (20.02.2025)

[vi] Gianuca et al., River flow intermittence influence biodiversity-stability relationships across spatial scales: Implications for an uncertain future (2024). https://pubmed.ncbi.nlm.nih.gov/39162046/ (20.02.2025)

[vii] Rockstaröm et al., We need biosphere stewardship that protects carbon sinks and builds resilience (2021). https://www.pnas.org/doi/10.1073/pnas.2115218118 (20.02.2025)

[viii] European Central Bank (ECB), Occasional Paper Series No 333: Living in a world of disappearing nature: physical risk and the implications for financial stability (2023). https://www.ecb.europa.eu/pub/pdf/scpops/ecb.op333~1b97e436be.en.pdf (20.02.2025)