Media release

From: The University of Sydney

New research has revealed that about 90 percent of marine aquarium fish sold by online retailers in the United States are sourced directly from wild populations, mostly in the western Pacific and Indian Ocean. With the US accounting for around two-thirds of all global aquarium fish imports, researchers warn that this reliance on wild capture threatens the sustainability of coral reef ecosystems and puts endangered and threatened species at greater risk of extinction.

The research, led by postdoctoral research associate Dr Bing Lin from the University of Sydney’s Thriving Oceans Research Hub in the School of Geosciences, analysed data from four major US-based online aquarium retailers. The results were striking: out of 734 fish species available for sale, a staggering 655 species were sourced solely from the wild, while just 21 species were available exclusively through aquaculture.

The researchers believe the true proportion of wild-caught fish is almost certainly higher, given the study’s conservative methodology.

The study, which formed part of Dr Lin’s research for his doctorate at Princeton University, is published today in Conservation Biology.

Dr Lin, who completed his PhD at the Center for Policy Research on Energy and the Environment in the Princeton School of Public and International Affairs, warned that the often unregulated nature of supply chains for wild-caught fish means there is a substantial risk to conservation efforts.

“We urgently need stronger traceability and regulatory oversight to ensure that aquarium fish are sourced responsibly,” Dr Lin said. “Consumers have no reliable way of knowing whether the fish they buy were sustainably harvested.”

While it didn’t form part of this study, Dr Lin also said that the Australian aquarium fish market faced similar problems.

“Australia is among the world’s top 20 importers of live ornamental fish. That’s not necessarily a bad thing, but when the global trade is so opaque, we’re left guessing where each fish came from and how it was caught.”

Dr Lin’s research also highlights that many commonly traded species – including wrasses (Labridae), clownfish and other damselfish (Pomacentridae), and gobies (Gobiidae) – are collected from tropical reefs, often in the Indo-Pacific, and can be an important source of income for the communities where they are sourced.

These regions have long been hotspots for the ornamental marine trade, where unsustainable fishing practices, including cyanide use, have been documented. Concurrently, they are also home to sustainable fisheries that serve as exemplars for a responsible marine aquarium trade.

Alarmingly, 45 species identified in the study were noted as being of conservation concern, including 20 listed as threatened and 25 with declining population trends, according to the International Union for Conservation of Nature (IUCN). Of these 45 species, 38 were sourced solely from the wild.

The study also uncovered what should be a significant market driver: aquarium fish raised in aquaculture environments were on average 28.1 percent cheaper than their wild-caught counterparts. However, the vast majority of fish in the US market remain wild caught, underscoring the need for sustainable strategies and improved conservation.

“The fact that aquacultured fish are often cheaper than wild-caught ones suggests that sustainable alternatives are not only possible, but profitable,” Dr Lin said. “But consumer preferences, technical and biological barriers to breeding, and murky supply chains continue to fuel demand for wild-caught fish.”

Dr Lin said that investing in aquaculture, supporting well-managed wild fisheries, implementing credible eco-certification schemes, and reducing demand for unsustainably caught fish could help shift the industry toward a more sustainable path.

“Public awareness about the ecological impacts of the aquarium trade is also critical to driving better consumer choices and meaningful policy reform,” he said.

Dr Lin emphasised the importance of a balanced approach that protects biodiversity and reef ecosystems while sustaining the livelihoods of coastal communities in source regions.

“We hope our findings motivate policymakers, industry stakeholders and consumers to work together to safeguard vulnerable reef species, foster sustainable trade practices and support the coastal communities whose livelihoods rely on this industry,” Dr Lin said.

Download photos of clownfish and other images by Dr Bing Lin at this link.

Research

Lin, B. et al ‘Extent of threats to marine fish from the online aquarium trade in the United States’ (Conservation Biology 2025) DOI: 10.1111/cobi.70155

Declaration

The authors declare no competing interests. Funding was received from Princeton University and the High Meadows Foundation.