20/05/2010 02:56

Monday conference warns it can take 20 years for an invasive species to overcome local competition, yet have devastating effects when it does.

It could start with something as innocuous as getting a goldfish or a turtle as a present and then letting it loose in the wild, or bringing in a new type of insect or plant for agricultural purposes.

Such actions could devastate local ecosystems, experts warned on Monday at the Society for the Protection of Nature in Israel’s annual conference at the International Conference Center (Binyanei Ha’uma) in the capital.

The process isn’t always fast – it can take 20 years for an invasive species to overcome local competition, Nature and Parks Authority scientist Dr. Noam Lider warned. Yet slowly but surely, a turtle released into the Yarkon can eat up all of the plant life in the stream. A plant brought from elsewhere can spread over vast areas, choking life from the land. The Asian tiger mosquito brings with it from Southeast Asia dangerous viruses and fevers like West Nile virus, Yellow Fever and Dengue Fever.

Invasive species don’t have natural competition when they arrive in the new habitat and so are able to grow unchecked, Lider explained.

In the US, invasive species cause $136 billion of damage annually, according to Lider.

While the strategy for keeping out or containing and eradicating invasive species is well defined, it has not been implemented well in Israel, the panel of experts concluded.

Right now, the strategy for dealing with these plants and animals includes several steps, Lider said. The best is preventing them from reaching Israel in the first place. If they do arrive, they should be eradicated forthwith. If this proves impossible, they should be contained, and if that doesn’t work, then nothing is left but to surrender to the inevitable and try to figure out how to accommodate the new species.

Dr. Jean-Marc Dufour-Dror, an environmental consultant, proposed a national action plan for dealing with invasive species.

“We’ve garnered a lot of knowledge in the last 15 years about invasive species and the plan is drawn from that knowledge base,” he said.

Dufour-Dror proposed three cornerstone principles to guide the policy.

Invasive species grow in two phases: the lag phase and the exponential phase. The lag phase is where they grow slowly, which could last for years. The exponential phase is where they proliferate at a tremendous rate. Therefore, the species need to be monitored and eradicated in the lag phase, before they reach the exponential phase.

Second, the attempt to eradicate large populations is misdirected. Large populations are too big and grow back too quickly, so any elimination efforts “are like running in place.” Instead, small populations should be targeted and eradicated as there’s a better chance for success.

Finally, Israel should create a plant and animal blacklist, to prevent species that could become invasive from being imported altogether.

Ronit Justo-Hanani, a lawyer and scientist, said such a list wasn’t possible now because there were too many loopholes in the law. She said a comprehensive legislative overhaul or a core legislation was needed to effectively deal with invasive species. For example, the Plant Protection Law of 1956 should theoretically enable protection, but it only applies to agricultural products. The National Parks Law of 1998, she continued, doesn’t allow for blacklisting plants and animals.

While a new body to deal with the issue and consolidate authority in one place would be ideal, according to Justo-Hanani, it was more realistic to work for a legislative overhaul.