Pterois miles, a species of lionfish called the common lionfish (as opposed to Pterois volitans, the red lionfish that is found in the Atlantic), first appeared in the eastern Mediterannean sea in 2012 and quickly spread across almost the entire Sea. By 2018, groups of up to 70 lionfish were found on rocky grounds and artificial reefs of depths ranging between 0 to 50 meters. Adults can spawn all year long in that region, and are most active during summer when the sea surface temperatures reach 28 °C, a highly permissive temperature for spawning. Lionfish are generalist predators in that region and can consume fish and crustacean prey, significantly impacting the region’s economy.
Given all the indicators, it appears that the lionfish are thriving and already well established in the region. It is only a matter of time before they become the ecological and medical threat that they have become in the Gulf of Mexico, Caribbean and Atlantic coast of the United States.
How did they arrive? A study by Bariche et al. in the peer-reviewed science journal Scientific Reports actually did DNA analysis from P. miles found in the Red Sea (where they are a non-invasive species) and from P. miles invaders found in the Mediterannean to see if they had the same genetic background. If they did, that would mean that lionfish invaded the Mediterannean Sea from the Red Sea by some passage (suspect #1 was the Suez Canal in Egypt). Other invasion hypotheses included a spread from the Atlantic (which would be an especially long voyage for the notoriously lazy swimming lionfish), or an accidental introduction because of humans.
As it turns out, there was a genetic match between the P. miles in the Mediterannean and Red Seas, and the most likely explanation for that travel was that the invasive lionfish actually travelled up the Suez Canal into the Mediterannean. This wouldn’t be the first time an invasive species entered the Mediterannean from the Red Sea by this path, the Matuta crab species are thought to have invaded the Med in the same way. The successive enlargements made to the Suez Canal over time (Katsanevakis et al., 2013) have reduced the natural salinity barrier of the Bitter Lakes and increased the influx of non-indigenous species, some of which are venomous or poisonous and a direct threat to human health (Galil et al., 2015). These invaders can also cause profound changes in the coastal ecosystem (Galil et al., 2015, 2018).
Historically in the Mediterranean Sea, the first lionfish was seen in 1991 off the coast of Israel (Golani and Sonin, 1992). It remained essentially absent for nearly two decades, until new sightings were made off the coast of Lebanon in 2012 (Bariche et al., 2013). It is thought to have rapidly spread after that through the entire eastern Mediterranean basin, including Cyprus (Jimenez et al., 2016; Kleitou et al., 2016), Lebanon (Dailianis et al., 2016), Syria (Ali et al.,2016), Turkey (Özbek et al., 2017), and Greece (Giovos et al., 2018), reaching Tunisia in 2015 (Dailianis et al., 2016) and Italy in 2016 (Azzurro et al., 2017). It is therefore only a matter of time before the Mediterranean region starts seeing the ecological impacts of the invasion.
Now that Pterois miles has invaded the Mediterannean, the next steps should be implementing the same kinds of community-based and government-based efforts to help control lionfish populations. These can be anything including teaching locals how to safely hunt lionfish (with a Zookeeper and StingMaster in tow of course), how to filet and cook lionfish, funding research into understanding the current spread of the lionfish as well as funding research that can help predict future spreads. Research is essential in understanding the spread of the lionfish, and it will be the “way out” for us by allowing communities and governments to help plan and optimize control measures so that the spread of this incredibly invasive lionfish can be stopped once and for all.
References:
Ali, M., Alkusairy, H., Saad, A., Reynaud, C., & Capapé, C. (2016). First record of Pterois miles (Osteichthyes:Scorpaenidae) in Syrian marine waters: confirmation of its accordance in the eastern Mediterranean. Tishreen University Journal for Research and Scientific Studies ‐ Biological Sciences Series, 38, 307–313. doi:10.19233/ASHN.2017.19
Azzurro, E., Stancanelli, B., Di Martino, V., & Bariche, M. (2017). Range expansion of the common lionfish Pterois miles (Bennett, 1828) in the Mediterranean Sea: an unwanted new guest for Italian waters. BioInvasions Records, 6, 95–98.
Bariche, M., Torres, M., Azzurro, E. (2013). The presence of the invasive lionfish Pterois miles in the Mediterranean Sea. Mediterranean Marine Science, 14, 292-294.
Bariche M, Torres M, Smith C, Sayar N, Baker R, Bernardi G. Red Sea fishes in the Mediterranean Sea: A preliminary investigation of a biological invasion using DNA barcoding. (2015). Journal of Biogeography. 42 doi:10.1111/jbi.12595
Bariche, M., Kleitou, P., Kalogirou, S. et al. Genetics reveal the identity and origin of the lionfish invasion in the Mediterranean Sea. Sci Rep 7, 6782 (2017). https://doi.org/10.1038/s41598-017-07326-1
Dailianis, T., Akyol, O., Babali, N., Bariche, M., Crocetta, F., Gerovasileiou, V., et al. (2016). New Mediterranean biodiversity records (July 2016). Mediterranean Marine Science, 17, 608–626.
Galil, B., Boero, F., Fraschetti, S., Piraino, S., Campbell, M., Hewitt, C., Carlton, J., Cook, E., Jelmert, A., Macpherson, E., Marchini, A., Occhipinti‐Ambrogi, A., Mckenzie, C., Minchin, D., Ojaveer, H., Olenin, S. and Ruiz, G. (2015), The Enlargement of the Suez Canal and Introduction of Non‐Indigenous Species to the Mediterranean Sea. Limnology and Oceanography Bulletin, 24: 43-45. https://doi.org/10.1002/lob.10036
Galil, B., Marchini, A., & Occhipinti‐Ambrogi, A. (2018). Mare nostrum, mare quod invaditur—The history of bioinvasions in the Mediterranean Sea. In A. I. Queiroz & S. Pooley (Eds.), Histories of bioinvasions in the Mediterranean (pp. 21–49). Cham: Springer.
Giovos, I., Kleitou, P., Paravas, V., & Marmara, D. (2018). Citizen scientists monitoring the establishment and expansion of Pterois miles (Bennett, 1828) in the Aegean Sea, Greece. Cahiers de Biologie Marine, 59, 359–365.
Golani, D., & Sonin, O. (1992). New records of the Red Sea fishes, Pterois miles (Scorpaenidae) and Pteragogus pelycus (Labridae) from the eastern Mediterranean Sea. Japanese Journal of Icthyology, 39, 38–40.
Jimenez, C., Petrou, A., Andreou, V., Hadjioannou, L., Wolf, W., Koutsoloukas, N., & Alhaija, R. A. (2016). Veni, Vidi, vici: the successful establishment of the lionfish Pterois miles in Cyprus (Levantine Sea). Rapid Communications International Mer Méditerranee, 41, 417.
Katsanevakis, S., Zenetos, A., Belchior, C., & Cardoso, A. C. (2013). Invading European seas: assessing pathways of introduction of marine aliens. Ocean and Coastal Management, 76, 64–74.
Kleitou, P., Savva, I., Kletou, D., Hall‐Spencer, J. M., Antoniou, C., Christodoulides, Y., … Rees, S. (2019). Invasive lionfish in the Mediterranean: low public awareness yet high stakeholder concerns. Marine Policy, 104, 66–74.
Özbek, E. Ö., Mavruk, S., Saygu, İ., & Öztürk, B. (2017). Lionfish distribution in the eastern Mediterranean coast of Turkey. Journal of Black Sea/Mediterranean Environment, 23, 1–16.
Savva, I, Chartosia, N, Antoniou, C, et al. They are here to stay: the biology and ecology of lionfish (Pterois miles) in the Mediterranean Sea. (2020) J Fish Biol. 97: 148– 162. https://doi.org/10.1111/jfb.14340
