Nothing fascinates Monica Biondo more than the animals often referred to as the ocean’s “living jewels” — the vividly colored little fishes who dance around in its waters.
Biondo, a Swiss marine biologist, became enamored with ocean life as a child after spending many summers snorkeling along the Italian coastline. Nowadays you’re more likely to find her deep-diving into trade records than marine waters. As the head of research and conservation at Fondation Franz Weber, she has spent the past decade searching through data on the marine ornamental fish trade.
These are the colorful fish you see in home aquariums or for sale at pet stores; Biondo wants to know where they came from, how they got there, and what happened to them along the way.
Compared to the clear waters around the coral reefs she’s explored, the records on these fish are frustratingly murky. Wading through them has though provided her with clarity on her calling: shining a light on the aquarium trade’s vast exploitation of these glamorous ocean dwellers.
Searching in the Dark
Her entry into the fray came in the form of a Banggai cardinalfish, a striking little fish endemic to an archipelago in Indonesia that first became known to science in the 1930s. A scientist redescribed the species in 1994, kickstarting a tragic surge in the fish’s popularity for aquariums. Within less than a decade, 90% of the population had disappeared, Biondo says.
After witnessing that rapid decline, along with the failure of countries to subsequently regulate global trade in the species, Biondo was hooked. “That really pushed me into looking into this trade,” she says.
In her search for information she has pored over paperwork in the Swiss Federal Food Safety and Veterinary Office’s records warehouse. She and her colleagues at Pro Coral Fish have also spent years rifling through a European Union-wide electronic database called the Trade Control and Expert System (TRACES), which collects information on animal imports.
Although the datasets varied, the questions have remained the same. How many marine ornamental fish are being imported? What species are they? Where did they originate?
These straightforward questions are hard to answer to because the trade — despite being worth billions annually — has no mandatory data-collection requirements. As a result, information gathered about trade in these fishes tends to be opaque and haphazard compared to information on live organisms like farmed food animals.
Biondo reckons this is because the fishes are perceived as “just ornamentals.” Everyone is used to seeing them in aquariums, so few people recognize they may be in trouble in the wild.
Illuminating Findings
In a 2022 report for the Convention on International Trade in Endangered Species (CITES), the UN Environment Programme’s World Conservation Monitoring Centre criticized the data on ornamental fish collected and reported by the major exporting regions and some importing countries. Revealingly, WCMC was unable to even estimate the number of marine fishes traded globally each year with the data at its disposal.
CITES is the global wildlife trade treaty body that regulates and monitors international trade in over 40,000 threatened animal and plant species.
In this landscape Biondo’s scrutiny of European imports offers key insights into the trade. She’s revealing where gaps exist in the data collection that does occur and, crucially, how they can be plugged.
For one thing, the origin of marine ornamental fishes in trade is often unclear. Biondo highlights an example: TRACES data points to Singapore as a key exporter to the European Union, but she says the country is a hub for exports rather than a source, meaning many of the fishes were originally caught elsewhere.
Biondo has also found that EU records often fail to identify the species in trade. Her latest research paper highlighted that the bloc imported around 26 million marine fishes from more than 60 countries between 2014 and 2021. But only two-thirds of the fishes — 17.5 million — were identified to species level.
Conservation biologist Alice Hughes says records can be even less specific in other places, with many datasets listing marine fishes simply as “tropical fish.” The Law Enforcement Management Information System, the U.S. wildlife trade database, is a case in point. Data collected in LEMIS and submitted to CITES shows the United States imports 5-9 million marine ornamental fishes annually, but most of that trade is reported generically as “tropical fish.”
The United States has long been the largest importer of ornamental fishes, both marine and freshwater, although Biondo’s research shows that the EU now leads in terms of import value for marine fishes. Overall, she says, existing evidence indicates the global aquarium trade involves at least 3,000 marine fish species — but the actual number is potentially even higher.
All 4,000 known coral reef fishes could be in trade, Biondo says. Without better data, it’s impossible to know for sure.
Strengthening Systems
To improve the situation, Biondo and others have called on the EU and United States to modify TRACES and LEMIS, respectively.
Biondo says both systems should be tweaked to ensure traders always provide species information. She also says they should collect data on whether fishes are sourced from farms or the wild, along with the place of capture of wild-sourced fishes.
While freshwater species are often farmed, relatively few marine fishes have been successfully bred in captivity in commercial numbers. This means that marine species are overwhelmingly wild caught, taken mainly from coral reefs.
These adaptations to the EU and U.S. systems would improve the data landscape dramatically. In turn, better data would help to ensure that the trade is sustainably managed. Hughes says that in the absence of robust information, sustainable management is presently “entirely dependent on good will of suppliers, and often a degree of guess work given the lack of population data for many species.”
Safeguarding Fishes and Ecosystems
Considering that most marine fishes are taken from the wild, sustainable management is necessary to ensure that trade does not threaten species’ survival. This is particularly true at this juncture as coral reefs currently face a litany of threats, including marine heatwaves, ocean acidification, storm damage, pollution, and diseases. Biondo argues that “all coral fishes are endangered because their habitat is endangered.” That means it’s vital to ensure coral fish populations are not put at risk by additional pressures, such as trade.
Safeguarding fishes is crucial for coral ecosystems, too, because these environments originally flourished due to the interrelations and reciprocities between organisms that live in them. This is why marine fishes don’t breed well in captivity, says Biondo, as only natural coral ecosystems can offer what they need to thrive — and vice versa.
For instance, bluestreak cleaner wrasses are among the species who remove parasites from other fishes. Studies show that the cleaner wrasse’s services can benefit recipient fishes’ growth and size, as well as the abundance and diversity of fishes on reefs. Their services even improve the cognitive function of damselfishes who, in turn, consume algae on reefs, alongside parrotfishes and surgeonfishes. These fishes ensure that algae, which is also vital to reef ecosystems, does not become so abundant that it suffocates corals.
All these types of fishes are exploited in the aquarium trade to greater or lesser extents. But without adequate data and monitoring, whether their exploitation poses a threat to crisis-stricken reefs is anyone’s guess.
Running Against the Clock
If robust information existed, species potentially at risk could be identified and considered for inclusion in CITES, ideally before they became endangered. The trade in aquarium fishes has largely flown under the treaty body’s radar to date, with few ornamental fishes listed in CITES. The treaty body regulates international trade in seahorses, some sharks and rays that are exploited for larger aquaria, the clarion angelfish, and the humphead wrasse. But the thousands of small, colorful reef species found in aquariums are not covered.
However, thanks to Biondo’s doggedness, CITES has begun to review the marine ornamental fish trade in recent years.
In May the treaty body held a four-day workshop on the issue. Among other things, attendees discussed strategies for identifying potentially at-risk species.
Unsurprisingly, Biondo has some ideas on this. In her research, she has created “watchlists” that she says could be used to pinpoint species traded within the EU that would benefit from CITES listings. The watchlists, which were published in her latest paper this June in the journal Animals, spotlight species that warrant close monitoring due to various factors, such as trade levels and trends, vulnerability to fishing, and conservation status.
Biondo’s research — including her watchlists — fed into the outcomes of the May meeting, as did the work of other researchers and relevant parties. These outcomes, which included the creation of a “catalogue” of species in trade and various vulnerability analyses for some of those species, are now being considered by CITES’ Animals Committee.
Some common marine aquarium fishes feature in the watchlists. Indeed, the blue-green damselfish sits at the top of one of them — perhaps the most heavily traded marine ornamental fish of all. The fish’s watchlist position is due high levels of trade and an inexplicable 70% drop in imports to the EU between 2014 and 2021, which could indicate population declines.
The United Kingdom’s Ornamental Aquatic Trade Association says this “abundant” fish is safeguarded from overexploitation because extraction is spread out over “dozens of collection points.” Many millions of blue green damselfish have been taken from the ocean over the years, yet the International Union for Conservation of Nature Red List only assessed the species’ conservation status in 2021. The IUCN categorized the fish as Least Concern but stressed that “quantified data” on populations is limited across most of its range. Overall, the IUCN found the species to be declining globally and strongly recommended monitoring of populations and trade, alongside improved regulation of exploitation.
Nonetheless, Biondo says fishes like the blue-green damselfish illustrate a persistent mentality that because the fish are abundant, they can’t be fished out.
She doesn’t agree.
“We’re running against the clock,” she warns, to safeguard coral reefs and the living jewels that call them home.
