This week an article was published presenting the results of a study carried out by an international (five nationalities) and inter-university team, led by Dr. Efrat Gabish-Regev from the National Nature Collections, the Hebrew University of Jerusalem, and Prof. Yael Lubin from Ben-Gurion University of the Negev.
The article describes a new species of spider, known so far only from the Arava Valley - in Israel and Jordan:
Sahastata aravaensis sp. November Ganem, Magalhaes, Zonstein and Gavish-Regev
Although it is not a large spider, it is the largest of the Filistatidae family species in Israel, among which it also stands out with its velvety black color. The life span of the spider is several years (a lot in spider terms), which it spends in a vertical burrow, lined with silk. The discovery of the spider happened by chance during monitoring carried out by the research team following the oil spill disaster in the Evrona Reserve, in the south of the Arava (by Efrat Gabish-Regev, Yael Lubin, Nitzan Segev, Igor Ermiach Steinpers, Ibrahim Salman and Maria Mayer). Being a soil-dwelling species, the idea arose that this new species is sensitive to the quality of the soil, and therefore could be used as a bio-indicator of pollution.
At the end of five years of monitoring, in which many students and volunteers participated, it was found that the number of spider burrows in areas that were polluted with oil in 2014 and 1975 is significantly lower compared to the number in nearby areas, which remained clean. In addition, the researchers found that the size of the spider burrows in the areas of the 1975 spill was significantly smaller than the size of the spider burrows in the control areas (the comparison of the burrow size was made by Assaf Ozan, Ibrahim Salman and Efrat Gabish-Regev on a sample in the field). The paucity of spider burrows in the areas of the 1975 spill, which occurred almost half a century ago, compared to the control areas, suggests the continued damage of the oil to spiders, and by extension, to the desert ecosystem.
Additional support for the effect of oil on the spiders came from laboratory experiments, conducted by Yavin Bayan and Efrat Gabish-Regev, in which spiders of the new species were placed in containers divided between contaminated and clean soil. Here too, the majority of the spiders settled on the clean ground, already at the end of the first day of the experiment.
These findings emphasize the fact that many of the secrets of the Israeli desert have not yet been revealed to us, but also bring alarming data about the fragility of the desert ecology in the face of man-made hazards.
The monitoring was commissioned and financed by the Nature and Parks Authority and the Marg - the national program for assessing the state of nature in Israel.
Written by: Igor Ermiach Steinpers and Efrat Gabish-Regev
Link to the scientific article describing the new spider: https://www.mdpi.com/2075-4450/13/1/101