Menachem GOREN, GALIL B.S.
Steinhardt Museum of Natural History and Israel National Center for Biodiversity
Studies, and School of Zoology, Tel Aviv University, Israel.
E-mail: gorenm@tauex.tau.ac.il
INADEQUATE: ISRAELI MONITORING SURVEYS’ FAILURE TO
ASSESS ALIEN BIOTA
Abstract
The shelf ecosystem along the Mediterranean coast of Israel is impacted by mainly Erythraean
introductions through the Suez Canal, in addition to regional and local stressors, - causing
significant changes in the biodiversity locally and across the Mediterranean Sea. The present
study evaluates the current National Monitoring Program of Israel's Mediterranean waters.
Key-words: Alien species, Survey, Management
Introduction
“About 1000 marine alien species have been reported in the Mediterranean Sea"
(SPA/RAC 2017), more than 400 of them reported from the Israeli coast (Galil et al.
2021). The flood of the alien species is an ongoing process that heavily affects
biodiversity throughout the Mediterranean as well as the economy and public health. An
analysis of a comparative study of two habitats along the Israeli coast revealed the
inadequacy of the current National Monitoring Program, highlighting an urgent need for
a comprehensive sampling program that would faithfully assess actual status of alien
populations.
Materials and methods
Diurnal and nocturnal surveys, using an otter trawl at about 30m depth, were conducted
in June and November-December, 2012, at sites (Haifa, Nitzanim) about 160 km apart,
18 tows at each site in total. Fish were identified to species (with few exceptions),
counted and weighed. Analysis of Data carried out using Primer 7 statistical package.
Results
A total of 142,805 fish were identified to 105 species, of which 93,708 fish (66%) were
identified to 36 non-indigenous species (NIS) (34%). At the northern site (Haifa), NIS
fish abundance comprised 23% of the haul in June and 77% in November-December,
whereas in the southern site (Nitzanim), NIS comprised 37% in June and 92% in
November-December.
A similarity analysis of the sites and seasons revealed that the similarity between
autumn and spring samples was ca. 50%, similarities between autumn and spring
samples in the sites were ca. 65% in autumn and ca. 55% in spring.
A comparison of the number, proportion and abundance of NIS revealed considerable
differences in spatial, seasonal and diurnal samples (Fig. 1, Nitzanim ver. Haifa; spring
ver. autumn; day ver. night).
The differences were also expressed at the specific level. For example, 8,378
individuals of the native Axillary seabream Pagellus acarne were collected in daytime
2nd Mediterranean Symposium on the Non-Indigenous Species (Genoa, Italy, 22-23 September 2022)
97
Steinhardt Museum of Natural History and Israel National Center for Biodiversity
Studies, and School of Zoology, Tel Aviv University, Israel.
E-mail: gorenm@tauex.tau.ac.il
INADEQUATE: ISRAELI MONITORING SURVEYS’ FAILURE TO
ASSESS ALIEN BIOTA
Abstract
The shelf ecosystem along the Mediterranean coast of Israel is impacted by mainly Erythraean
introductions through the Suez Canal, in addition to regional and local stressors, - causing
significant changes in the biodiversity locally and across the Mediterranean Sea. The present
study evaluates the current National Monitoring Program of Israel's Mediterranean waters.
Key-words: Alien species, Survey, Management
Introduction
“About 1000 marine alien species have been reported in the Mediterranean Sea"
(SPA/RAC 2017), more than 400 of them reported from the Israeli coast (Galil et al.
2021). The flood of the alien species is an ongoing process that heavily affects
biodiversity throughout the Mediterranean as well as the economy and public health. An
analysis of a comparative study of two habitats along the Israeli coast revealed the
inadequacy of the current National Monitoring Program, highlighting an urgent need for
a comprehensive sampling program that would faithfully assess actual status of alien
populations.
Materials and methods
Diurnal and nocturnal surveys, using an otter trawl at about 30m depth, were conducted
in June and November-December, 2012, at sites (Haifa, Nitzanim) about 160 km apart,
18 tows at each site in total. Fish were identified to species (with few exceptions),
counted and weighed. Analysis of Data carried out using Primer 7 statistical package.
Results
A total of 142,805 fish were identified to 105 species, of which 93,708 fish (66%) were
identified to 36 non-indigenous species (NIS) (34%). At the northern site (Haifa), NIS
fish abundance comprised 23% of the haul in June and 77% in November-December,
whereas in the southern site (Nitzanim), NIS comprised 37% in June and 92% in
November-December.
A similarity analysis of the sites and seasons revealed that the similarity between
autumn and spring samples was ca. 50%, similarities between autumn and spring
samples in the sites were ca. 65% in autumn and ca. 55% in spring.
A comparison of the number, proportion and abundance of NIS revealed considerable
differences in spatial, seasonal and diurnal samples (Fig. 1, Nitzanim ver. Haifa; spring
ver. autumn; day ver. night).
The differences were also expressed at the specific level. For example, 8,378
individuals of the native Axillary seabream Pagellus acarne were collected in daytime
2nd Mediterranean Symposium on the Non-Indigenous Species (Genoa, Italy, 22-23 September 2022)
97