Carrying the Torch: BAC 2025 and theLiving Legacy of Heiko Bleher

By Natasha Khardina

Estimated read time: 5-6 minutes

The Biotope Aquarium Contest 2025 (BAC2025) has once again carried forward a quiet revolution in the aquarium world: transforming precise field research of natural habitats into public education. Instead of rewarding artistic layouts alone, BAC demands scientific documentation - photographs of the original location, species lists, substrate analysis and systematic notes - and celebrates those who faithfully translate wild habitats into living aquariums. This year's edition, supported by global industry partners, reaffirmed the contest's dual mission: to inspire aquarists and to raise awareness about fragile aquatic ecosystems. In fact, BAC2025 reached a milestone with a record number of entries, reflecting the contest's growing influence and the rising interest in authentic biotope recreation worldwide.

Carrying Forward a Legacy

The passing of Heiko Bleher in August 2025 was a turning point for the global aquarium community. For many, it felt as if the last great explorer of ornamental ichthyology had left the stage. Yet his influence continues tangibly through the Biotope Aquarium Project (BAP), an initiative he helped shape by contributing archives, photographs and field data. Today, BAP and BAC work hand in hand: one as a repository of scientific and visual documentation, the other as a platform engaging aquarists, educators and sponsors in carrying the legacy forward.

From Field Research to Public Education

Beyond trophies and social media posts, the contest generates materials that teachers and museums can use. When a winning entry documents an endangered waterway or a rare species composition, that story can be amplified in classrooms, museum exhibits and outreach programs supported by sponsors. Companies that back BAC are not just providing prizes; they are helping to transform niche hobbyist interest into broader public awareness of conservation. As one participant observed, “The contest builds a reproducible corpus of biotope knowledge — exactly the kind of legacy Heiko would have wanted.” The contest is also a reminder of unfinished work: preserving archives, protecting intellectual heritage and ensuring that field data remain accessible.

BAC2025 Results

With this perspective in mind, the contest presented its BAC2025 results, featuring carefully documented and faithfully recreated habitats that highlight the educational and scientific goals at the heart of the contest.

1. North America - Sponsored by FLUVAL

The North American entry recreates the shallow littoral wetland zone of the Pigeon River headwaters in Kawartha Lakes, Ontario, Canada. Inspired by field observations made during spring, the setup mimics the slow spring-fed water movement observed in nature, aiming to reflect the subdued, biodiverse and functionally complex nature of this coldwater wetland habitat.

2. Central America & Caribbean - Sponsored by AQUAEL

This biotope recreates a shallow backwater pool in Rio San José, Horquetas, Costa Rica. The setup highlights the role of Zygia longifoliolata in shaping habitat complexity, along with a 420L aquarium where filtered lighting mimics sunlight through the forest canopy.

3. South America - Sponsored by Ocean Nutrition

The South American biotope recreates the banks and waters of Caño El Pozo, Orinoco basin, Venezuela. The setup uses natural materials including branches, leaf litter, seeds, bark and submerged plants. The bottom contains remains of Mauritia flexuosa and its seeds, while roots, trunks and leaves create a natural structure.

4. Europe - Sponsored by BIOTOPE AQUARIUM Project

The European entry recreates rocky canals in Padule del Capitano, Puglia, Italy. The aquarium is a replica of a section of an aquatic site, with a portion of the vertical limestone wall and a submerged channel connecting the pool to the sea. Fine white sand, limestone rocks, driftwoods and semi-aquatic plants form part of the landscape, alongside invertebrates and a population of Aphanius almiriensis living among the rocks and aquatic roots.

5. Africa - Sponsored by BIOTOPE AQUARIUM Project

The African biotope recreates the shoreline of the Moliwe River in Cameroon. The aquarium incorporates riverside vegetation extending into the water, creating shelter and current breaks. The substrate is free of sediment, while a strong current - produced by two circulation pumps and an external filter - prevents plant growth. The setup focuses on authentically recreating the dynamic, clean and species-rich habitat of the Moliwe River.

6. Eastern Asia - Sponsored by San Francisco Bay Brand

The Eastern Asian entry recreates a stream-slice from the southern foothills of the Shiwandashan Mountains, Guangxi, China. Exposed boulders, ferns and submerged branches create a refuge for species such as Aphocypris sp. and Araiocypris batodes. The aquarium reflects a stream section with harsh water conditions, strong currents and abundant aquatic life, standing as an ecological memorial to a lost ecosystem.

7. Southern, Central & Western Asia - Sponsored by JBL

This 135L aquarium recreates a small replica of the Lake of the Societies, Kolkata, India. The motivation behind the project came from the lack of available data on Brachygobius nunus in its natural habitat. The setup replicates as much as possible the original biotope using collected proper aquatic plants and floaters, with Nymphaea pods and water hyacinth roots providing shade and security for the fish.

8. Southeastern Asia & Oceania - Sponsored by JBL

The final featured biotope recreates a Suo Cai stream in Quang Dien district, Vietnam. The 300L blackwater aquarium provides an environment for Tanichthys micagemmae and Oryzias pectoralis, along with Trichopsis vittata. The scene is built around fallen branches and exposed roots, creating a highly natural and visually captivating setting.

Reproducibility at the Heart of BAC2025

This year's contest placed strong emphasis on reproducibility. Participants submitted BIN (Biotope In Nature) evidence and were evaluated by an international jury of scientists, editors and explorers. Sponsors contributed prizes and publicity, but the true value remained educational: a growing, shared repository of biotope reconstructions that can inform future research, museum displays and teaching programs. In each BAC entry, the distributed method of preserving field knowledge becomes part of the biotope itself.

A Living Classroom for Conservation

BAC2025 demonstrates how an aquarium can become more than an artistic display. The contest connects photographs, field observations, species lists, habitat descriptions and recreated aquatic environments into a format that can be shared beyond the hobby. From shallow wetlands and backwaters to rocky streams, limestone habitats and blackwater systems, each biotope becomes a small window into a real ecosystem. The larger message is that aquariums can serve as living classrooms and ambassadors for conservation.

Read the full story

The complete feature explores BAC2025, the legacy of Heiko Bleher, and the documented biotopes recreated from habitats across North America, Central America & Caribbean, South America, Europe, Africa, Eastern Asia, Southern/Central/Western Asia, and Southeastern Asia & Oceania.

Read the complete story in the October 2025 issue of The Weekend Aquarist.

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