The secrets of aquariology, a science serving the conservation of seas and oceans

A booming discipline, aquariology – not to be confused with aquariophily – allows the study of aquatic organisms under controlled conditions. A valuable experimental approach for the conservation of species, which must also meet requirements for respecting animal welfare.

Numerous scientific tools and techniques help us today to characterize and better understand the functioning of the seas and oceans: oceanographic campaigns, molecular biology, scientific diving, mathematical and computer modeling, acoustics… So many methods which provide elements of answers to very diverse scientific questions in the fields of species biology, the resilience of ecosystems or the impact of climate change on marine environments.

Among these approaches, aquariology is booming. It is defined as the science of aquatic life in aquariums and is based on biological, physicochemical, ecological and ethical principles. It aims to promote the maintenance of marine and freshwater organisms in aquariums and the development of the reproduction of these species under controlled conditions.

Aquariology therefore constitutes an “in vitro” (and ex-situ) tool which provides complementary elements to scientific studies carried out “in situ”, during oceanographic campaigns, for example.

A booming science

The beginnings of aquariology date from the 19th century^e century. It was work carried out on a species of cephalopod mollusk, the Argonaute, which laid the foundations of this discipline. For the first time, the scientist who led them, Jeanne Willepreux-Powerwas able to study the characteristics of this species by observing living individuals. Until now, work on this animal could only be carried out on samples preserved, for the most part, in alcohol or formalin.

By settling by the sea to carry out her research, the scientist laid the foundations for maintaining this species in captivity. Subsequently, other scientists followed suit, such as Henri de Lacaze-Duthiers, a specialist at the end of the 19th century.^e century of the study of red coral in aquariums.

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Since then, aquariology has continued to evolve thanks to the progression of techniques and methods inspired by aquaculture, veterinary medicine, water treatment, nutrition, electronics, etc. Aquarium keeping, a booming hobby since the mid-20th century^e century, also contributed greatly to its development.

Because the key to aquariology is the possibility of maintaining marine and freshwater organisms in aquariums, the evolution of techniques guaranteeing excellent lighting conditions, food or water quality for example, is crucial to the success of this discipline. These technologies are constantly evolving and thus broaden the horizons of experimentation each year.

Today, the progress made helps answer a very wide range of scientific questions in the fields of research, marine ecology and biology and conservation. Let’s look at some concrete examples.

Measuring the impact of sunscreen on corals

Coral reefs, which harbor exceptional biodiversity, are subject to multiple human pressures. They are particularly affected by the effects of climate change.

In certain very touristy areas, corals are sometimes exposed to significant concentrations of molecules called solar filters. These constitute the active ingredient in sun creams that we apply to protect ourselves from the extremely harmful effects of exposure to the sun.

In order to determine the impact of these molecules on natural marine environments, and specifically on corals, research is being carried out today in aquariums, to test the effect of the different molecules currently used as solar filters. on these particularly sensitive animals.

Let us cite some of the tests that can be carried out in an aquarium to evaluate their possible impact on the physiology of corals: exposure to gradual concentrations of solar filters, simulation of stress caused jointly by solar filters and by temperatures abnormally high…

The results of this work should allow manufacturers and legislators, in the short term, to select molecules that are less harmful to the marine environment.

Studying an invasive blue crab

Now let’s take another example. For around ten years, the Mediterranean coasts have been subject to the population explosion of a species of crab native to North America, the American blue crab.

This predatory species, most likely arriving in Mediterranean waters in the larval stage via the ballast water of cargo ships, has taken up residence in numerous European lagoons and estuaries and is causing considerable damage to the fauna and flora that usually reside in these areas. .

How to estimate these impacts? What are the potential weaknesses of an invasive alien species in the marine environment? Aquariology provides, once again, elements of understanding to this type of question.

In fact, the studies carried out in aquariums make it possible to analyze the physiological response of the blue crab to controlled variations in environmental parameters in the aquarium, to evaluate its diet and its behavior towards its prey and possible predators. Enough to complement the monitoring carried out in the natural environment and give marine space managers decisive elements to protect the natural environments invaded by this species.

Preserving a giant heritage shell

There is a giant shell in the Mediterranean, a sort of large mussel planted vertically in sandy bottoms or Posidonia meadows (a marine plant that forms meadows), which bears the name of large mother-of-pearl.

This species, one of the largest known shells, can reach one meter in height. It is endemic in the Mediterranean, where it is a protected species. Since 2016, populations of large pearl shells have been victims of an attack by a parasite whose origin is currently not clearly identified.

This microscopic parasite has thus led to the virtual disappearance of large mother-of-pearl stocks across the entire Mediterranean in just a few years. Only a few populations of this species survive in coastal lagoons such as the Etang de Thau or the Etang de Salses-Leucate.

Maintaining a population of large mother-of-pearl in an aquarium in the form of a conservatory, safe from the parasite, successfully reproducing this heritage species in captivity, testing possible treatments… These are the challenges of aquariology today about this fascinating animal. The challenge, difficult to meet, mobilizes many specialists in this species at European level.

Respect the animal and inform the general public

These various aquarium studies, some of which involve animal experimentation, must therefore take animal welfare into account. Today, this is a mandatory and unavoidable issue: it involves ensuring that the scientific work carried out, particularly within the framework of conservation projects, affects at a minimum the organisms housed in aquariums.

This dimension is at the heart of scientists’ concerns. Regulation governs all of these activities – it is a major and crucial aspect in the development of the many studies based on the use of animals in the laboratory.

Aquariology is also developing well beyond research laboratories. The discipline is also deployed within public aquariums and certain scientific culture centers dedicated to the sea and oceans. The objective is then to present to as many people as possible (tourists, schools, etc.), the riches of our rivers, our seas and our oceans and to provide information on the threats weighing on these ecosystems.

Participating in conservation programs is also at the heart of the activity of these establishments. Thus, in France, for example, public aquariums and research institutes are now joining forces as part of an initiative led by the Ocean Institute of the Sorbonne-University Alliance to make aquariology a even more efficient tool, which responds to current research challenges in marine biology and ecology.

This article is published as part of the Science Festival (which takes place from October 4 to 14, 2024), and of which The Conversation France is a partner. This new edition focuses on the theme “ocean of knowledge”. Find all the events in your region on the site Fetedelascience.fr.