Issue link: https://maltatoday.uberflip.com/i/1248303
10 maltatoday | SUNDAY • 17 MAY 2020 NEWS JAMES DEBONO IN a confirmation of the impact of global warming on Maltese waters, the number of non-indige- nous species in Maltese waters is approaching the 100 mark, an increase that includes predatory fish with the ability to put greater pressure on local ecosystems. The latest addition to Malta's marine biodiver- sity was documented by the 'Spot the Alien Fish' citizen-science campaign in which divers and fish- ermen are encouraged to report alien species for documentation. The newcomer, a fish species, belongs to the ten-pounder Elops ge- nus, for which a single individual was caught off Delimara in Oc- tober 2019. The s p e c i m e n consisted of a long, slen- der, silvery s p e c i m e n estimated to have a total length of 55-60cm. The fish had elongat- ed and pointed fins, including a deep- ly-forked caudal fin. According to Dr Alan Deidun, from the Depart- ment of Geosciences, and coordinator of the Spot the Alien Fish citizen science campaign, this latest discovery was con- sistent with the progres- sive warming trend of the Mediterranean, given that Elops species are native to tropical and sub-tropi- cal regions of the global ocean. The fact that the fish was first recorded in the Mediterranean basin in Maltese waters is consid- ered "anomalous", espe- cially since the genus is not used in the aquarium or pet industry, therefore ruling out any deliber- ate release of the species within Maltese waters. One possibility is that the spread of the fish may have been brought about through ballast wa- ter-mediated transport, when the fish was in lar- val form. "However, given the relatively large dimen- sions of the specimen, a passive range-expansion mode of introduction is more likely." While the capture of a single Elops in the M e d i t e r r a n e a n might represent a vagrant adult, its occurrence suggests it could po- t e n t i a l l y survive in t h e s e waters. Further surveys with fishermen are necessary to monitor the species. Only one photograph of the fish was submitted, which makes it hard to identify it given that there are seven Elops species that are morphologically very similar to each other. According to one study, over 90% of the stomach contents of sampled El- ops individuals consisted of fish, which indicates the kind of pressure it could exert on local eco- systems. Alien fish's first Med appearance in Malta While the capture of a single Elops in the Mediterranean might represent a vagrant adult, its occurrence suggests it could potentially survive in these waters Biologist Alan Deidun runs the Spot The Jellyfish and Spot The Alien Fish campaigns BIRDS are masters of the skies – they fly great distances to find food, shelter, mates, and migrate to es- cape seasonally adverse weather. But when they hatch they are un- able to do so and rely on their par- ents for food and protection, gaining flying ability only in the first weeks or months of life. So how do birds go from grounded, dependent young to confident flyers? That is what Maltese PhD researcher Marie Claire Gatt set out to dis- cover with colleagues from the prestigious Max Planck Institute of Animal Behaviour (MPIAB) in Germany, with whom she recently published the results of their study on young Greylag Geese. The results are among the first of their kind in the field of ornitholo- gy, helping understand the ecology of bird species that depend on ex- tensive flight early in their lifetime. She joined the MPIAB in the sum- mer of 2015 as a research intern under the supervision of Prof. Dr Martin Wikelski, with the aim of understanding how Greylag Geese expend energy as they start learn- ing to fly. Using small, cutting-edge da- ta-loggers that were worn by the geese on a ribbon backpack, they measured the birds' body move- ments as they flew. But to get these devices into the air, they needed willing partici- pants. So Michael Quetting, tech- nical assistant at the MPIAB and aircraft pilot, hatched and hand- raised a group of seven goslings: Gloria, Frieder, Maddin, Nemo, Nils, Paula… and Calimero! "Michael was the first thing the goslings saw when they emerged from their egg so they considered him their 'papa goose' – a process called 'imprinting' – and for the next months they would follow him everywhere," Gatt told MaltaToday – Michael has since published best- selling book Papa Goose about this unique experience. "I joined this special goose family a few weeks later, and together we Marie Claire Gatt set out to study the way geese conserve energy when f lying, shedding light on how birds manage long distances when they migrate south Maltese boffin takes a gander at geese in flight DPA Marie Claire Gatt holds Paula – the most affectionate of the seven geese – in her arms. Photo: K.H. Metzger