BAC2023 – Best biotope aquariums in 2023

By Natasha Khardina

Presenting the top winners of the 4th edition of the Biotope Aquarium Contest (BAC2023), organized by the BIOTOPE AQUARIUM Project (BAP), an independent educational project that aims at motivating aquarists to study the surrounding aquatic environments by applying their knowledge in the recreation of biotope aquariums.

Tuesday, July 4, 2023 – two weeks before the end of registration for the BIOTOPE AQUARIUM Contest 2024 – was the hottest day ever recorded on Earth. The average surface temperature of our planet reached 17.18°C, surpassing the record set just one day earlier: 17.01°C. The data was recorded by scientists from Climate Reanalyzer, a project developed by the Climate Change Institute of the University of Maine, in the United States, which is based on observations conducted from 1979 to today. The two previous records dated back to August 14, 2016 and July 24, 2022, when the Earth reached a temperature of 16.92°C.

The estimates from the University of Maine confirm what the scientific community has been saying for some time now: the effects of the climate crisis and global warming are already before our eyes. At the beginning of the year 2023, Copernicus – the European program for monitoring climate change – had estimated that the last eight years have been the warmest on record, with Europe confirming itself as the fastest warming continent. In 2023, several parts of the world were experiencing temperatures above the seasonal average. In some provinces of China the thermometer reached 35°C, while in North Africa it exceeded 50°C. Even Antarctica during winter has documented anomalous record temperatures, which in some cases have reached 8.7°C.

How does global warming affect the aquatic environments and its inhabitants? And what consequences does climate change have on aquatic, in particular on freshwater fish fauna, which is already rather badly treated?

In December 2023, the International Union for Conservation of Nature and Natural Resources (IUCN) presented the update of the Red List at the UNFCCC COP 28 in Dubai, which also includes the first global assessment of freshwater fish.

Now the IUCN Red List includes 157.190 species, of which 44.016 are at risk of extinction. Presenting the update, IUCN Director General Grethel Aguilar underlined that “Climate change is threatening the diversity of life that is home to our planet and highlights the strong links between the climate and biodiversity crises, which must be addressed jointly. The decline of species is an example of the havoc wreaked by climate change.”

The new update completes the first comprehensive assessment of the world’s freshwater fish species, revealing that 25% (3.086 of 14.898 species assessed) are at risk of extinction. Kathy Hughes, co-chair of the IUCN SSC Freshwater Fish Specialist Group, highlights that “Freshwater fish make up more than half of the world’s known fish species, an incomprehensible diversity given that freshwater ecosystems include only the 1% of aquatic habitat. These different species are an integral part of the ecosystem and vital to its resilience. This is essential for the billions of people who depend on freshwater ecosystems and the millions of people who depend on their fisheries. Ensuring that freshwater ecosystems are well managed, continue to flow freely with sufficient water and good water quality is essential to halt species decline and maintain food security, livelihoods and economies in a resilient world to climate change.”

At least 17% of threatened freshwater fish species are affected by climate change, including falling water levels, rising sea levels causing seawater to rise up rivers and change of seasons. Added to this are the threats deriving from pollution, which affects 57% of freshwater fish species at risk of extinction, from dams and water extraction, which affect 45%, from overfishing, which threatens 25%, and from invasive species and diseases, which damage 33%.

For Barney Long, senior director of conservation strategies at Re:wild, “It is shocking that a quarter of all freshwater fish are now at risk of extinction and that climate change is now recognized as a contributing factor in significantly to their risk of extinction, which has recently also been reported as a serious emerging threat to amphibians. It is critical that we better safeguard our freshwater systems as they not only host precious and irreplaceable wildlife, but also provide humans with many services that only the natural world can provide.”

Jon Paul Rodríguez, president of the IUCN Species Survival Commission (SSC) concluded: “The climate crisis and the biodiversity crisis are two sides of the same coin. On the one hand, climate change is one of the determining factors of the documented decline of animals, but on the other, the resilience of nature through the recovery and regeneration of species and ecosystems is our ally through proactive conservation action.”

Hence the fundamental part of conservation presents environmental education and Citizen Science, in which the participants of the BIOTOPE AQUARIUM Contest make their important contribution to society by promotion of the natural biotopes – since they call attention to high-risk environments in the wild, introduce to the often unknown remote regions and endangered species.

So here we are, presenting the winners of the 4th Edition of the BIOTOPE AQUARIM Contest (BAC2023) and their aquariums reproducing the aquatic environments from in 8 different geographical regions.

And as always, our THANK YOU goes to the aquatic experts and sponsors who continue supporting this unique educational event.

For those aquarists who wish to participate in the BIOTOPE AQUARIUM Contest next year (BAC2024) we invite you to safe the date – on 20st April 2024 the professional biotope challenge continues.

North America – sponsored by AQUAEL

Approved by: Fritz Rohde (NANFA) and Lawrence Kent (NANFA)

BAM: Niangua River, Ozarks region, Missouri, USA, by Anikó Csanadi (Hungary):

Niangua River, Ozarks region, Missouri, USA. @BAP, photo by Anikó Csanadi

I’ve always been a big fan of North American biotopes, so most of my home aquariums are based on this region. I chose the Niangua River because it is located in an area with a unique biodiversity on the Ozark Plateau. The landscape, with its abundance of forests, rivers and streams, is a wonderful experience for nature lovers.

I have tried to show a coastal section where the leaves, branches and roots of trees form a beautiful ensemble. There are many species of darter in the river, my choice was the Orangethroat darter. I managed to breed them this year, so I can show you a population of fish that born here. There are no other fish species in the tank, so everything is based on their needs. The rocks and tree branches provide great hiding places, and the open space at the front gives them the opportunity to swim and play freely.

Central America & Caribbean – sponsored by AQUARIUM MÜNSTER

Approved by: Juan Miguel Artigas Azas (Cichlid Room Companion), Jairo Arroyave (UNAM) and Michael Köck (Goodeid Project)

BAM: Río San José, Horquetas, Sarapiquí, Costa Rica, by Andrés Cordero Porras (USA):

Río San José, Horquetas, Sarapiquí, Costa Rica. ©BAP, photo Andrés Cordero Porras

This 200L aquarium represents the high water flow in the San Jose River, where fish move across algae-covered rocks in crystal clear water. The fish are divided between those that inhabit the open waters and those that find their territory between the crevices of the stones.

Central America & Caribbean – sponsored by AQUARIUM MÜNSTER

Approved by: Juan Miguel Artigas Azas (Cichlid Room Companion), Jairo Arroyave (UNAM) and Michael Köck (Goodeid Project)

BAM: Riverbank of Rio Tamasopo in the dry season, David Nørholm (Denmark):

Rio Tamasopo, San Luis Potosi, Mexico. ©BAP, photo David Nørholm

I love Central American biotopes, and Mexican setups in particular. And I really like livebeares as well. So in this aquarium I wanted to create a natural looking setup, dedicated to livebearers. I wanted this setup to have the beatiful Xiphophorus montezumae as the main character, and not just as a supporting role.

Along with this I also wanted to create a biotope based on the great work by Rune Evjebjerg and Kai Qvist, and to pay a tribute to their amazing book “A Selection of Freshwater Fish Biotopes in Mexico”.

According to composition, my main focus is on the hardscape and attempt to recreate the look of a natural riverbank. This both affects the use of driftwood, branches, stones, dirt and even DIY hobby concrete.

South America – sponsored by FLUVAL

Approved by: Roberto E. Reis (PUCRS), Flávio Lima (MDBio) and Pablo C. Lehmann (PUCRS)

BAM: Rio Nanay, Loreto, Peru, by Emil Visan (Romania):

Rio Nanay, Loreto, Peru. @BAP, photo by Emil Visan

The aquarium wants to represent a coastal area in a river meander with secondary forest, specific to the Nanay River, with partially flooded ceticos, cataguas and chontas trees, and some branches that were broken by the water found their place on the sandy bottom and white water where together with the leaves and roots of trees and plants provide shelter and even a source of food for fish.

The tannin released by the fallen branches and leaves creates, through the low pH, a favorable place for the spawning and reproduction of many species of fish. From place to place an Echinodorus appears forming a green spot on the red-brown surface of the water.

A lot of small caracids play among the roots of the trees and plants on the river bank. Also among the roots and branches appear the angel fish specific to this water course, with their majestic swimming and proud posture, true princes of the waters. Corydoras tirelessly run close to the sandy soil, seeming to play in the multitude of leaves.

Europe – sponsored by SICCE

Approved by: Alexey Malyshev and Francesco Denitto

BAM: Tisza Lake, Great Hungarian Plain, Hungary, by Klementina Keresztes-André (Hungary):

Tisza Lake, Great Hungarian Plain, Hungary. ©BAP, photo Klementina Keresztes-André

In the past I was lucky enough to visit the Ecocentre of Tisza Lake, where I could see the largest freshwater aquarium in Hungary, then I took part in a boat tour on the lake and its floodplain. The experience was really decisive for me, so I decided to make an aquarium that was a piece of the lake.

The Lake provides a very diverse habitat with open water, canals and floodplains. I chose a part near the coast, where the water is quite shallow, the bed is covered with silt, branches, and terrestrial plant parts, but also have an “open water” area with Ceratophyllum demersum, which plant is the most dominant in the lake.

This habitat provides an ideal place for one of our most colorful fish, the Bitterling (Rhodeus sericeus) which mainly prefers shallower water that are rich in hiding places.

Africa – sponsored by BIOTOPE AQUARIUM Project

Approved by: Ad Konings (CichlidPress) and Anton Lamboj (UniWien)

BAM: Lake Barombi Mbo, Cameroon, by Nico Luchoro (Spain):

Lake Barombi Mbo, Cameroon. @BAP, photo by Nico Luchoro

It is a 160L aquarium inspired by a video by Adrian Indermaur from Lake Barombi Mbo where we see Stomatepia pindu under a crosswood and leaf filled bed. Every detail has been created to recreate the natural habitat of the fish.

Eastern Asia – sponsored by BIOTOPE AQUARIUM Project

Approved by: Fan Li and Zhou Hang

BAM: Jungmuncheon Stream, Jeju-do, South Korea, David Nørholm (Denmark):

Jungmuncheon Stream, Jeju-do, South Korea. ©BAP, photo David Nørholm

South Korea, Self-governing province of Jeju-Do, Jeju Special Autonomous Province.

This 98L aquarium is based on the hillstream of Jungmuncheon, which is a riverstream flowing through the beautiful landscape of the Island of Jeju-Do, South Korea.

This habitat is a rather classic hillstream, with fast running water, and no aquatic vegetation. I chose to replicate this beautiful habitat because I was fascinated by the stoney look and the interesting behavior of Rhinogobius giurinus, which inhabits the place. I wanted to recreate a fast flowing habitat for a while, and this seemed to fit perfect into my newly gained obsession with Rhinogobius.

Southern, Central & Western Asia – sponsored by BIOTOPE AQUARIUM Project

Approved by: Friedrich Bitter (Amazonas Magazine), Sven Kullander (NRM) and Sujoy Banerjee

BAM: Periyar River Basin, Kerala, Western Ghats, India, by Devagya Uikey (India):

Periyar River Basin, Kerala, Western Ghats. ©BAP, photo Devagya Uikey

This aquarium represents a mild blackwater part of the Periyar River, very close to Periyar National Park and Wildlife Sanctuary, with pure water and high levels of trace minerals and nutrients. Forests along the side are growing on white sand and soil. The bottom of the river is covered with a fine layer of algae-covered river basin sands and Eleocharis acicularis, along with some green and dried coconut leaves fallen from the tall trees.

This aquarium shows a very common natural habitat, but one of the most favorite aquarium fish: Horadandia brittani, known as the grass carplet. They prefer this kind of habitat, where there is minimal water flow and big coconut leaves for them to hide and spawn.

Southeastern Asia & Oceania – sponsored by BIOTOPE AQUARIUM Project

Approved by: Greg Martin (ANGFA) and Heok Hee Ng (NUS)

BAM: Indawgyi Lake, Kachin State, Myanmar, by Klementina Keresztes-André (Hungary):

Inle Lake, Shan State, Myanmar. ©BAP, photo Klementina Keresztes-André

Small-sized fish have always been close to me, especially the rarer, lesser-known species and for this reason, I chose Indostomus paradoxus and Dario hysginon for my aquarium. Both species are endemic in Myanmar and can be found at the shallower coastal section of the Indawgyi Lake.

With my 63L aquarium, I tried to provide a suitable living space for these tiny fish. Since both species are near the shore, I used reed stems as decoration with driftwood and smaller branches. The dirt layer covering the soil was made of decomposed leaves and peat. I used Vallisneria spiralis and Salvinia cucullata which are among the most common plants in the Lake. The lighting is not too strong, the filter flow is calm and equable.

We invite you to take part in the upcoming BIOTOPE AQUARIUM Contest!

The BIOTOPE AQUARIUM Contest is the best way to bring together aquarists and scientists in an effort to document and monitor the conditions of aquatic habitats and their inhabitants, water quality and possible introduction of alien invasive species that cause damage to native ecosystems and even to people. Public awareness and active involvement of the aquarists play an important role in contributing to the successful implementation of the biotope mapping worldwide with its main instrument, BAP-Map.

The participation in the contest consists of 2 applications:

1. BIOTOPE IN NATURE (BIN) – the personal biotope exploration done in situ or through extensive online research with the involvement and contribution of other aquarists and scientists. This kind of cooperation allows to create a network of people interested in the conservation of aquatic environments and leads to concrete projects. The bibliography/sitography of the BIN might play a decisive role – being a demonstration of profound research, it can be helpful for other biotope fellows to understand that precise ecosystem.

2. BIOTOPE AQUARIUM MODEL (BAM) – the reproduction of the original aquatic biotope as a closed micro-ecosystem in the aquarium. This is more creative and fun part of the application, as the aquarists are required to show their practical skills and biotope knowledge by putting together the right components, such as water chemistry, substrate, light, filtering system, décor, in combination with the correct aquatic inhabitants in correct proportions – fishes, plants, crustaceans, mollusks – to give fish and plants species a home with appropriate niches for hiding and breeding. The most important thing here is to describe in detail one’s own practical experience with the biotope tank – to share their knowledge with aquarist colleagues.

BIOTOPE AQUARIUM Contest is divided into 8 categories, each one judged by the experts who did aquatic research in that particular region – ichthyologists, biologists, professional aquarists with a deep knowledge of local ecosystems and a vast fieldwork experience. The experts define the final ranking and advise all participants on how to improve their setups to make them as close as possible to the natural biotopes.

BAP Expert Fritz Rohde
BAP Expert Lawrence Kent
BAP Expert Juan Miguel Artigas Azas
BAP Expert Jairo Arroyave
BAP Expert Roberto E. Reis
BAP Expert Flávio César Thadeo de Lima
BAP Expert Pablo Lehmann Albornoz
BAP Expert Alexey Malyshev
BAP Expert Francesco Denitto
BAP Expert Ad Konings
BAP Expert Anton Lamboj
BAP Expert Fan Li
BAP Expert Zhou Hang
BAP Expert Friedrich Bitter
BAP Expert Sven O. Kullander
BAP Expert Sujoy Banerjee
BAP Expert Michael Köck
BAP Expert Heok Hee Ng
BAP Expert Greg Martin
Jury members in 8 categories (geographical regions) at BIOTOPE AQUARIUM Contest 2022.

The international aquatic companies like Aquael, Fluval, Sicce, Aquarium Münster, Oase, Newa and Dohse Aquaristik understand the importance of transformation in the aquatic hobby and support BAC2022. These companies look forward to a positive change and embrace the biotope concept as inevitable and necessary development of the aquarium hobby.

AQUAEL, Sponsor of the BIOTOPE AQUARIUM Contest
FLUVAL, Sponsor of the BIOTOPE AQUARIUM Contest
Project Piaba logo
SICCE, Sponsor of the BIOTOPE AQUARIUM Contest

BAP is gearing up for BAC2023 with a pre-registration announcement on April 20st, 2023, and opening the registration on May 20st, 2023. We invite you and all hobbyists that take great pride in creating natural-looking environments in their aquariums to take part at the BIOTOPE AQUARIUM Contest (BAC2023)!