by Prof. Pua Bar (Kutiel)
Dr. Kutiel works in the Department of Geography and Environmental Development at the Ben-Gurion University of the Negev. Dr. Kutiel is a member of a steering committee recently established by the Israel Nature and Parks Authority to address invasive species in Israel and internationally.
Invasive species are alien species which have been directly or indirectly introduced by man to a new habitat where they become established and spread to additional new habitats. These species spread at the expense of indigenous species, a process that is accompanied by a decrease in biodiversity, that is to say a decrease in species diversity, a decrease in habitat diversity (homogenization of the landscape) and a disruption of ecological and environmental processes with significant economic impacts (damage to aquifers, introduction of pests and disease agents in agriculture, etc.).
In Israel, invasive alien species, both plants and animals, are found in all terrestrial and aquatic habitats. Unfortunately, methodological long-term research studies have not been carried out to investigate the causes, patterns and impacts of the problem or the tools to minimize it, and consequently there are no tools or a comprehensive policy to address such aspects as prevention, management and enforcement. What’s more, Israel does not participate in global and European projects on the subject.
Yet, there are initial signs of progress. A master’s student in Tel Aviv University has developed an updated inventory of invasive fauna in terrestrial and fresh water habitats. This inventory reveals the following: 18 invasive bird species of tropical origin are mainly found along the coastal plain or the Syrian-African Rift. Among these, starlings have a high representation. There are 20 invasive species of fresh water fish in the Jordan River system, coastal rivers and Sea of Galilee, of which 10 reproduce in nature. The invasive species in the Sea of Galilee, one of Israel’s drinking water reservoirs, compete with local species (including endemic species) for littoral habitats and nesting sites and impair water quality over time. The invasion of species from the Red Sea (Lessepsian immigration) to the Mediterranean Sea is one of the best-known phenomena in biological invasion on a global scale, which began with the opening of the Suez Canal in 1869. More than 300 flora and fauna species of Red Sea origin have invaded the Mediterranean Sea, of which 60 were documented which constitute about 15% of the fish fauna in the Middle East. These species can be used as a model for other species, which have not yet been described or documented. Currently, one invasive fish is discovered every year. Other known or suspected invasive species include 200 invasive insects, most of which are considered pests, 28 alien ant species, 10 terrestrial and 26 fresh water mollusk species, and mussels from the Red Sea that infiltrated to the Mediterranean.
There are 164 alien vascular plant species in Israel, of which 53 are considered invasive (24 are known as weeds in agriculture). Unfortunately, there are nearly no systematic research studies on the ecological-environmental-economic significance of invasive plants in Israel. One comprehensive research study is currently being compiled at Ben-Gurion University with the participation of researchers from the Hebrew University and the Volcani Institute. It focuses on management tools for suppressing the spread of invasive species through a combination of methods, with an emphasis on the suppression of the seed bank. Invasive plant species, such as the Acacia saligna (a legume tree), on the one hand, and Heteroteca subexilaris (an herbaceous composite), on the other, produce over 400,000 seeds per individual per year and their seed bank, in the case of the acacia, reaches 40,000 seeds per square meter. The research also concentrates on invasion strategies of plants and their impacts on habitat diversity.
In recognition of the severity of the problem, the Nature and Parks Authority has set out to deal with all aspects of invasive species by establishing a steering committee to address invasive species in Israel and internationally. We hope that this will be a strong beginning to an Israeli response to this critical environmental issue.
1. Citation: Israel Environmental Bulletin, January 2005, Israel Ministry of the Environment, reprinted with permission of the author.
2. Professor Pua Kutiel, Dept. of Geography and Environmental Development, Ben Gurion University of the Negev-Beer Sheva, Israel
Originally posted in “On Eagles’ Wings” April 5th 2006