Ponds, as small freshwater ecosystems, are particularly vulnerable due to their limited size. Yet they are often overlooked in research, possibly because they are considered less important (Biggs et al., 2017). Shallow water bodies support higher biodiversity than larger aquatic ecosystems. Peri-urban areas, characterized by a blend of agricultural and urban land uses, are dynamic and constantly evolving landscapes with diverse activities and stakeholders (Zoomers et al., 2017); as such, they are referred to as "restless landscapes" or zones of continual transformation (Zoomers et al., 2017). They often harbor neglected ecosystems, and despite their ecological importance, ponds and wetlands in peri-urban areas remain relatively underexplored (Wanek et al., 2021). Furthermore, these areas may experience increased contaminant inputs, which are regarded as one of the 12 major threats to freshwater biodiversity (Reid et al., 2019).

In this context, Hulot et al. (2025) monitored 12 peri-urban ponds in the Île-de-France region (near Paris, France) to investigate the relationships between land use, pollutant concentrations in water and sediment, and macroinvertebrate distribution. The originality of this work lies in its multidisciplinary and integrated approach, combining ecological and chemical analyses. While assessing agricultural, urban, grassland, and forest landscapes surrounding each pond, this study aimed to understand how contaminants constrain macroinvertebrate communities. The authors hypothesized that i) ponds in grassland and forest environments support higher local diversity than those in agricultural or urban areas, ii) rare and pollution-sensitive species significantly contribute to regional diversity, and iii) contaminants in water and sediment influence the distribution of macroinvertebrate morphotaxa.

This study provides numerous novel results. Specifically, it demonstrates that fluctuations in morphotaxa composition are predominantly driven by species replacement rather than by disparities in species richness. This pattern was largely attributed to the high prevalence of pollutant-tolerant species in certain ponds. In addition, community compositions appeared to be influenced by sediment levels of pharmaceuticals, water conductivity, and ammonium concentrations. In summary, ponds located in peri-urban areas are subject to a range of human-induced disturbances, and these results suggest that these disturbances lead to chronic and varied contamination, which in turn affects the composition of morphotaxa communities.

These findings establish a clear connection between local pollution and ecological composition, a crucial aspect for effective conservation and restoration efforts on peri-urban ponds.

References

Biggs, J., S. von Fumetti, Kelly-Quinn M. (2017). The importance of small waterbodies for biodiversity and ecosystem services: implications for policy makers. Hydrobiologia 793(1): 3-39 625. https://doi.org/10.1007/s10750-016-3007-0

Hulot, F.D., Hanot, C., Nélieu, S., Lamy, I., Karolak, S., Delarue, G., Baudry E., (2024) Do macroinvertebrate abundance and community structure depend on the quality of ponds located in peri-urban areas? ver.3 peer-reviewed and recommended by PCI Ecotoxicology and Environmental Chemistry. https://hal.science/hal-04850220v1

Reid, A. J., A. K. Carlson, I. F. Creed, E. J. Eliason, P. A. Gell, P. T. J. Johnson, 712 K. A. Kidd, T. J. MacCormack, J. D. Olden, S. J. Ormerod, J. P. Smol, W. W. Taylor, K. Tockner, J. C. Vermaire, D. Dudgeon, Cooke, S. J. 2019. Emerging threats and persistent conservation challenges for freshwater biodiversity. Biological Reviews 94(3):849-873. https://doi.org/10.1111/brv.12480

Wanek, A., C. L. M. Hargiss, J. Norland, Ellingson, N. 2021. Assessment of water quality in ponds across the rural, peri-urban, and urban gradient. Environmental Monitoring and Assessment 193: 694. https://doi.org/10.1007/s10661-021-09471-7

Zoomers, A., F. van Noorloos, K. Otsuki, G. Steel, van Westen, G. 2017. The Rush for Land in anUrbanizing World: From Land Grabbing Toward Developing Safe, Resilient, and Sustainable Cities and Landscapes. World Dev 92:242-252. https://doi.org/10.1016/j.worlddev.2016.11.016