Alien species in all habitats have started to colonise native habitats due to Malta’s lack of control when it comes to importation.
Native species of animals and plants alike in Malta could be in danger of being overrun, or even completely extinguished, by alien species in all habitats as they have started to colonise most native habitats across the islands and is likely due to Malta's lack of control and enforcement when it comes to importation.
Jeffrey Sciberras, botanist and Flora Conservation Officer of Nature Trust Malta, finds it concerning that in spite of all the knowledge regarding alien species and their devastating effects, Maltese authorities still allow exotic species to enter.
"Local authorities still allow exotic species to enter our country with the least enforcement and control once they have been introduced. The Red Fountain Grass is the latest example of lack of responsibility from the authorities," Sciberras explains.
This point is also reiterated by environmentalist Alfred E. Baldacchino who says that his greatest concern is that importation of such species is being done without observance to the national and international legal obligations, including the European Union's.
"Furthermore, some of these alien invasive species are being imported and used and financed by public funds and approval by Government," he explains.
The environmentalist says the immediate measures would be to honour the legal obligations Malta has, particularly with towards the EU Environment Acquis.
"This responsibility mainly belongs to the Malta Environment and Planning Authority which is the competent authority in this field. It is of no consolation to publish colour documents such as the National Environment Policy and the Guidelines for the control of Invasive Species if these are not strictly and immediately enforced, or ignored by other Ministries. Once an invasive species gets established, it is next to impossible to eliminate it," Baldacchino says.
Alfred E. Baldacchino says the threat from invasive alien species is widespread and will become more specific as they settle in Maltese ecosystems.
"A few examples include the Palm Tree, Mulberry Tree and Fig Tree, as well as the possibility of wild indigenous geranium species," Baldacchino says.
Besides flora species, several fauna species have been introduced over the last five years or so have also caused evident and damaging effects.
These include the Red Palm Weevil which has killed a large number of Palm trees, the Geranium Bronze Butterfly, the Mulberry Long-horned beetle which has devastated nearly all old Mulberry trees in Malta and a number of land snails found primarily around garden centres.
"This is far from an extensive list of invasive alien introduced fauna. This unfortunately reveals the failure of the Ministry concerned regarding the importation of exotic species and controlling the phytosanitary [fumigation] certificates declaring that imported species are free from disease and other dangerous species, according to national and international obligations," Baldacchino says.
Alien species can be introduced as ornamental plants, as pets or by accident, through imported soil and other trees or plants.
Red Fountain Grass is well known around the world for its invasiveness from many scientific journal and articles and yet it was allowed to be imported to Malta and introduced as an ornamental plant on road strips and roundabouts.
"After a couple of years of its introduction, it escaped rapidly into the wild, and is on the increase, and nothing is being done to control it," Jeffrey Sciberras says.
The term Ruderal Habitat is usually used for those habitats being colonised solely by alien species, especially those that have a majority of annual species.
"Genetic pollution is another great concern. Some species which are native to Malta, such as rosemary, olive-leaved Germander and the Great Sage were also recently introduced from abroad, which are of different genetics from our wild native populations," Sciberras says.
Through pollination by insects, Sciberras says these plants from different gene pools can easily interbreed, possibly creating hybrid generations, reducing the purity of wild indigenous populations.
Pest species of insects may also be introduced by foreign plants and devastate local populations.
"The rosemary beetle has devastated local populations of rosemary in inland valleys," Sciberras says.
Education and enforcement could be the answer to limiting alien species from being introduced and spreading.
"Educating the locals about native species and their habitats could help to build preference within the public over alien ornamentals. Enforcement on laws about alien species should be strengthened and strongly implemented. There should be more focus on native species to be used for ornamental purposes," Sciberras believes.
The conservation officer believes existing alien species should be removed manually both from completely devastated sites, and from ecologically important sites.
"Not allowing alien species to colonise ecologically important sites will keep those sites pristine, while for other sites, it may give chance for native species to re-colonise, or for new afforestation projects to be held.
"Introducing participation of the public, both adults and children, for forestation projects with native species of shrubs and trees, and hands on education about our local environments could help reduce the risk of completely wiping out indigenous species," Sciberras explains.
Professor Patrick Schembri, a University lecturer and marine biologist, says his main concerns involve alien species in the marine environment.
"The invasion of native species by non-indigenous species could represent a threat to the economy and human health as well as the integrity of biotic communities. This is a threat recognised worldwide," Schembri says.
He says it is difficult to predict what the impact of an alien species can be beforehand or which native species are likely to be impacted.
"Experience has shown that aliens may interact with native species in unexpected ways. The concern is more about the effect of aliens on local ecosystems than on individual species. If an alien changes the structure of a local ecosystem, multiple species will be affected as a result."
When it comes to the introduction of exotic species in the marine environment, Schembri explains that this usually occurs through shipping transportation, either as hull-fouling or in ballast water.
It can also take place via aquaculture and by the release from captivity such as the disposal of marine aquaria into the sea.
"However, there has been a very interesting phenomenon associated with rising seawater temperatures, attributed to global warming. With the opening of the Suez Canal in 1869, a large number of species from the Red Sea entered the Mediterranean and established themselves in the easternmost part of the sea, the Levantine Sea, where they have remained until recently," Schembri explains.
However, many of these species started to expand their distribution westwards over the last couple of decades because waters, previously too cold, have become warmer and hospitable to these species.
"Maltese waters now have a number of these westward-moving alien species. For example, the small Red Sea Mussel which entered via the Suez Canal, which was previously rather rare locally, has recently greatly increased its populations on Birzebbugia's rocky shore," Schembri says.
The Red Sea Mussel now forms dense beds covering the rock of this particular shore and is affecting the organisms occurring there.
What about reducing the risk of completely wiping out indigenous species?
Schembri says that the obvious thing would be to prevent entry in the first place because once a marine alien species has established itself, it is practically impossible to remote or even control it.
"For species that are introduced directly by human activities, like shipping, aquaculture or the aquarium trade, some precautions can be taken. However when it comes to the range expansion of aliens already established in other parts of the Mediterranean, there is nothing much that can be done," Schembri says.
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