Pufferfish and Other Invasive Species: Has the Time Finally Come to Have a Serious Discussion About the Issue?

June 27, 2026

“Effective protection of fish reproduction is a prerequisite for the recovery of fish populations and the restoration of healthy marine ecosystems, which have the natural ability to self-regulate and limit population surges of alien species, jellyfish, and other marine organisms.”

Amid the unwarranted fearmongering that has prevailed in recent weeks in the media and on social media regarding pufferfish, which only serves to sow panic among the public, it is now time to have a serious discussion about the problems we have caused in our seas and the solutions we must implement.

As far as swimmers are concerned, it should now be clear that pufferfish are not aggressive toward humans and are only poisonous if consumed. This is confirmed by numerous observations by divers and swimmers throughout the country, who have come into close proximity with pufferfish without any adverse interactions being reported. Reported biting incidents are usually linked to human activity that has altered the behavior of individual fish, such as deliberate feeding by people or the dispersal of food and fishing bait (often enriched chemical attractants) in shallow waters.

The real problem caused by the increase in pufferfish populations primarily affects fisheries and marine ecosystems. Although the compensation programs announced by the government will provide some necessary support to affected fishermen, these cannot be considered a long-term or substantive solution, as they do not address the root causes of the problem. Similarly, the competitions and “hunts” for pufferfish – which have recently been gaining increasing publicity – are not a solution either.

“The real danger is that we will rely on such measures, believing that we are solving the problem, and once again avoid dealing with the root causes.”

In a country with more than 16,000 km of coastline and one of the largest maritime areas in the Mediterranean, it is naive to assume that even targeted fishing of the pufferfish could substantially reduce the population of a species that produces hundreds of thousands to over one million eggs per individual. The rapid growth of pufferfish populations, as with other invasive species, can only be effectively limited in healthy, biodiversity-rich marine ecosystems where there are sufficient populations of species that act as natural predators.

The example of Cyprus is telling: after five years of implementing the program and nearly half a million euros in compensation, approximately 100 metric tons of pufferfish were removed. However, the pufferfish populations were not reduced, as no substantive management measures were implemented. As the Cypriot authorities also note, this program was designed as a measure to mitigate the impact on coastal fishermen and not as a means of eradicating the species.

In Greece today, beyond any compensation programs, instead of the government scrambling to respond to media-driven panic, has the time finally come – albeit years late – to address the root of the problem, which is none other than chronic overfishing and destructive fishing practices? Practices that decimate fish stocks, especially during the spawning season, undermine the ability of marine ecosystems to self-regulate and resist the spread of invasive species.

The mahi-mahi is one of the natural predators of the pufferfish, along with the garfish and other fish species. They feed on pufferfish mainly during the early stages of their lives, which is the most critical phase for controlling their populations. It is noteworthy that between 50 and 180 juvenile pufferfish have been found in the stomachs of mahi-mahi.

The Real Causes of the Problem

🔵 For decades, we have been depleting our seas, while the government has consistently failed to take even the most basic measures to protect fish stocks. It is telling that both commercial and recreational fishermen intensify their fishing activities every spring- precisely the season when most species gather in coastal waters to reproduce, making them particularly vulnerable to overfishing.

🔵 Equally telling is that, from the 1990s to the present, the same individuals in the relevant fisheries departments of the Ministry of Rural Development have been allowed by successive political administrations to improvise in fisheries management, with politicians remaining essentially absent, neither aware of nor seeking to understand the problems of a sector, many of which could have been resolved years ago.

🔵 Without effective management and protection measures, overfishing is getting worse year after year. As our seas are depleted of fish, they are gradually becoming ecologically barren, creating gaps that are often filled by alien and invasive species. It is no coincidence, after all, that the largest outbreaks of pufferfish and other non-native species have been recorded in Crete and Evia, two of the most overfished regions in the country.

🔵 Climate change certainly contributes to this process, as it favors the establishment and spread of new species. However, climate change cannot continue to serve as an alibi for inaction or as a convenient excuse that fosters fatalism, rather than prompting the implementation of the necessary protection and management measures.

As the Archipelagos Institute for Marine Conservation, we do not act as a protest group, but rather seek to contribute with evidence-based and immediately implementable solutions. After many months of preparation, next week we will submit a proposed draft law to the Ministry of Rural Development, based on experience and best practices from Mediterranean and Balkan countries, which will aim to protect the reproduction of key fish species.

No matter how many measures are announced, the natural self-regulating mechanisms of marine ecosystems will not be restored unless we effectively protect fish reproduction along the entire Greek coastline- and not just in isolated marine parks – while allowing fish populations to recover.

A healthy, fish-abundant ecosystem has the natural ability to self-regulate and largely limit population surges and imbalances, whether these involve invasive species, such as the pufferfish, or jellyfish and other marine species.