English Summary
A new MyPond survey has launched in 2026!
Check out our video of the first preliminary results:
Ponds account for 30-50% of the Earth's standing water. They can be found in every biogeographical region, from deserts to tundra.
They are extremely important habitats for both aquatic and terrestrial flora and fauna.
They play a significant role in mitigating climate change and adapting to it.
They are excellent recreational locations, as scientific findings confirm the calming and health-improving effects of ponds!
In some regions of Europe, 50-90% of ponds disappeared during the 20th century.
They are easy to create and, with a little care, can become natural habitats.
Ponds account for 30-50% of the Earth's standing water. They can be found in every biogeographical region, from deserts to tundra.
They are extremely important habitats for both aquatic and terrestrial flora and fauna.
They play a significant role in mitigating climate change and adapting to it.
They are excellent recreational locations, as scientific findings confirm the calming and health-improving effects of ponds!
In some regions of Europe, 50-90% of ponds disappeared during the 20th century.
They are easy to create and, with a little care, can become natural habitats.
Ponds with great importance!
Ponds are freshwater or occasionally saltwater bodies of water that are less than 10 hectares in size. They can be found in gardens, cities, villages, farmland, floodplains, plains, forests, grasslands, and marshes. Their wildlife is extremely abundant and diverse, therefore they play an important role in maintaining biodiversity.
OUR GOALS
- Creation of an urban and garden pond database and assessment of their biodiversity
- assessment of the number, water quality and biodiversity of ponds in Hungary
- DNA based methods
- citizen science
- Education, environmental education
- Preparation of scientific publications
Publications
Garden ponds hide unseen biodiversity, but fish decide who thrives
As cities grow, artificial water bodies are slowly replacing natural ones. Among the most numerous but least studied are the garden ponds, which can be found by the millions in private gardens. A new study from researchers at the HUN-REN Centre for Ecological Research provides the first systematic look at zooplankton communities living in these garden ponds and finds that even the smallest of them contribute to urban freshwater biodiversity, adding to what the larger public urban ponds already provide.
Zooplankton (rotifers, cladocerans, and copepods that drift in the water column) are “ecological workhorses” and play a key link in the aquatic food web. Yet while public urban ponds have drawn growing scientific attention, the life inside privately managed garden ponds has remained poorly studied. To close that gap, the team sampled 90 ponds in and around Budapest, including 38 private garden ponds and 52 public urban ponds during spring 2022, through the MyPond citizen science project.
Across all 90 ponds, the team recorded 95 zooplankton species, including two rotifers new to Hungary (Lecane tudicola and Monommata arndti), found in both garden and urban ponds, and three non-native species found only in urban ponds.
Fish were the strongest driver of community composition in both pond types, with their effect being stronger in garden ponds, whose small size offers zooplankton fewer places to hide from predators.
A key novelty is that this is the first systematic study of zooplankton in private garden ponds, a habitat so understudied, with two rotifer species never before recorded in Hungary. Additionally, their communities are less affected by urbanisation. That makes garden ponds valuable for urban biodiversity despite their small size.
Urban Ponds and the Emerging Role of Garden Ponds: Ecosystem Services and Disservices, Multifunctionality, and Trade-Offs
A new comprehensive study led by researchers at the HUN-REN Centre for Ecological Research provides the most comprehensive assessment to date of urban ponds and their ecological significance. It also highlights that even the smallest, often overlooked backyard ponds can play a surprisingly significant role in maintaining urban biodiversity and ecosystem services, while also contributing to certain negative ecological impacts.
An article published in one of the highest-ranked journals in the field, evaluates the findings of more than 200 scientific publications. It is the first to distinguish between the ecological roles of urban ponds located in public spaces (such as ornamental ponds in parks or stormwater retention ponds) and garden ponds in privately owned yards.
Although garden ponds are often only a few square meters in size, together they can form a complex network of aquatic habitats in cities. Furthermore, in certain areas, they may represent the only accessible freshwater habitat for numerous species. The research also highlights that urban ponds are ecosystems with two sides: they provide ecological services—such as supporting pollinators, regulating the microclimate, and offering recreation—while at the same time they can cause ecological problems if not properly managed. These include, for example, facilitating the spread of invasive species, the proliferation of mosquitoes, and the risk of adverse effects associated with eutrophication, including increased production of greenhouse gases.
Garden ponds: hidden sources of plant invasions?
Small ponds—waterbodies smaller than 5 hectares—are among the most common freshwater habitats worldwide, but they are rapidly disappearing as a result of agricultural activities, urban sprawl, climate change, and other human impacts. At the same time, in Hungary as well, we are creating an increasing number of artificial habitats in the form of garden ponds, which provide refuge for numerous aquatic organisms, including protected amphibians. Furthermore, during dry periods, they can be particularly important for birds, pollinators, and other terrestrial animals.
However, their growing numbers also raise a new problem: the ornamental plant trade offers many aquatic plants that are non-native and may even be invasive. Since these ponds are located on private property, it is difficult to study and monitor the species living in them. Data collection involving the public— citizen science—can be an effective tool for mapping these hidden habitats.
Based on data provided by participants, at least one of the six invasive plant species included in the study was found in nearly half of the 560 garden ponds. A frequently occurring species is the water hyacinth (Eichhornia crassipes), which is considered the most harmful invasive aquatic plant worldwide. In addition, water lettuce (Pistia stratiotes) was frequently found, as were several submerged species, such as waterweed (Elodea), hornwort (Vallisneria), and Brazilian water milfoil (Myriophyllum aquaticum).
Most of these species are of tropical origin but have already established themselves in several European countries. In Hungary, current climatic conditions—such as winter frosts—may still limit their spread; however, they are able to survive winter in thermal waters. Numerous species are already present in our natural waters, and climate change is expected to further favor their spread. Although they have so far entered our natural waters primarily through human activity, waterfowl visiting garden ponds may also play a role in their spread.
Effects of urbanisation, habitat characteristics, and management on garden pond biodiversity: Findings from a large-scale citizen science survey
The rapid expansion of urban areas often leads to degradation, fragmentation, and loss of natural habitats, threatening biodiversity. While urban ponds might contribute substantially to the biodiversity of urban blue-green infrastructure, the role of garden ponds is still largely unknown. We lack a comprehensive understanding of how local habitat features, different forms of management, and urbanisation might impact the biodiversity of these habitats. This study aimed to reveal the importance of garden ponds via a country-wide online citizen science survey in Hungary, Central Europe.
Data from over 800 pond owners revealed the occurrence and local frequency of various native animal taxa (amphibians, odonates, and birds), and introduced animals (e.g., fish). We collected data about pond features and management practices. We tested the effects of pond features, pond management, and landscape-level drivers (urbanisation, surrounding wetland coverage) on the presence of conspicuous animal taxa (adult amphibians and tadpoles, birds, odonates) to identify the potential drivers of the biodiversity of garden ponds.
Patterns and correlates in the distribution, design and management of garden ponds along an urban–rural gradient
Urbanisation results in the loss and alteration of natural wetlands and ponds. However, garden ponds in cities and towns can potentially act as rich reservoirs of aquatic biodiversity and stepping stones for dispersal. Homeowners with a range of different motivations, including biodiversity values, install garden ponds. Here, our main aim was to study whether the design and management choices of garden pond owners depended on the location of ponds (capital city vs. countryside), when ponds were installed (pond age), or whether fish were introduced. We surveyed 834 garden pond owners across Hungary using a citizen science questionnaire, asking questions on pond size, location, construction date and materials, vegetation structure, introduction of fish and management practices.
From 753 validated responses, we found that the introduction of fish into ponds and high urbanisation were strongly associated with local features and management practices, especially large ponds with a water circulation feature, irrespective of pond age. A typical garden pond in Hungary is ~ 20 m2, < 10 years old, made of rubber lining, contains fish, aquatic vegetation and circulating water, and is actively managed. There was a spatial separation of ponds based on local features between ponds in the capital city (Budapest) and elsewhere. These findings suggest that garden pond owners in the city were more likely to make different choices in pond design and management compared to owners in regional areas. Our results also suggest that pond owners may primarily select management practices to improve habitat quality for ornamental fish. Our findings have important implications for maintaining aquatic biodiversity in urban areas, where garden ponds may be the only aquatic habitat available.
