Issue link: https://maltatoday.uberflip.com/i/706995
maltatoday, SUNDAY, 24 JULY 2016 17 News x aquarium fish wreaking havoc on ecosystems pointed out that it is only species that make it into the Mediter- ranean through the man-made Suez Canal that are considered "alien". "Given that the other open- ings, like the Strait of Gibraltar are not man-made, fish originat- ing from the Atlantic Ocean and then establishing themselves in the Mediterranean are consid- ered as merely extending their habitat," he said. Asked whether any of the latter species were harmful or invasive species, Deidun said that most of these species weren't harmful, except for the much-maligned jellyfish known the Portuguese man o'war. Deidun explained that around 12 or 13 of the alien species in the Mediterranean had made it to Maltese waters in the last sev- en years, and he explained that a public campaign to notify swim- mers of the alien species to look out for was planned for August. "The campaign will work like the Spot the Jellyfish campaign, to raise awareness about the dif- ferent species and which ones are safe to eat or touch," he ex- plained. The professor added that be- sides the aquarium trade, the biggest culprit for spreading al- ien species was the shipping in- dustry. "Organisms can get stuck in the ballast water in ships and then be released into the sea, or they can attach to the sides of the vessels and then proliferate in other waters if the conditions are right," he said. Deidun explained that the situ- ation in the Suez Canal was fur- ther complicated due to the fact that there are no salinity barri- ers in the canal, which essen- tially means that they can travel freely into the Mediterranean sea, without experiencing a dra- matic change in conditions like salinity or temperature. Although not much can be done to control the species that have already made it into the Mediterranean, Deidun points out that the creation of salin- ity barriers, or even installing equipment that creates bubble walls in the Suez Canal, could ultimately prevent certain spe- cies spreading into the Mediter- ranean. "Malta's geographical position offers it a host of advantages, particularly that we can learn from other countries' experienc- es," he said, stressing that rais- ing awareness amongst fisher- men and the public was arguably the best thing to do at this point. Blue Cornet Fish Lionfish Blue swimmer crab Squirrel Fish Silver-cheeked toadfish Nomadic Jellyfish Arabian Angelfish Sergeant Major Portuguese man o'war Origin: Indo-Pacific Ocean Type: Invasive; spreading and moving fast Danger: Competes with damsel fish (cawl) for resources Most common alien species in Malta. It is edible and can also be sold in the aquarium trade. Origin: Indo-Pacific Ocean Type: Invasive but slow moving Danger: Covered in venomous spikes University's Conservation Biology Research Group recently confirmed it is found in Maltese waters. The fish is edible and it is also a popular aquarium species. Caulerpa taxifolia Seaweed Origin: Indian Ocean Type: Highly invasive Danger: None Origin: Indo-Pacific Ocean Type: Invasive Danger: None The species is commercially fished and sold as a delicacy in some areas Origin: Indo-Pacific and Atlantic Oceans Type: Non-Invasive Danger: None Edible and popular in the aquarium trade Origin: Indo-Pacific Ocean Type: Non-Invasive Danger: Toxic if eaten; can cause paralysis of organs and potentially fatal Spotted in local waters in 2015 Origin: Indo-Pacific Oceans Type: Invasive Danger: Painful stings, large blooms known to cause blockages Origin: Red Sea and Persian Gulf Type: Non-invasive, timid species Danger: None Origin: Atlantic Ocean Type: Invasive Danger: None Populations bloomed recently. Popular aquarium fish Origin: Atlantic Ocean Type: Invasive (comes in groups – colonies) Danger: Tentacles deliver painful and potentially fatal sting Not seen every year. There have been no sightings yet this year. Dusky Spine Foot Origin: Western Indian Ocean and Red Sea Type: Invasive Danger: Venom in dorsal and anal fin, not life-threatening