Early stages of establishment of the non-indigenous ascidian Herdmania momus (Savigny, 1816) in shallow and deep water environments on natural substrates in the Mediterranean Sea

Mey-Tal Gewing

doi:10.3391/bir.2014.3.2.04

Abstract

The solitary ascidian Herdmania momus (Savigny, 1816) was first recorded in the Eastern basin of the Mediterranean, off the coast of Israel, in 1958. Since then, H. momus established along the shores of Israel, albeit restricted to artificial substrates (e.g., pier pillars, artificial reefs, and shipwrecks) and deeper waters (20–30 m) in comparison to its native range. It has recently spread to natural substrates (i.e. the rocky reef) and shallow water environments (< 1 m). Field surveys, augmented by observations by recreational divers, were conducted along the Israeli Mediterranean coast on natural substrates to assess the present distribution. H. momus was detected on natural substrates at eleven sites, some of them at very shallow depths. This change in the distribution of H. momus that now includes natural substrates in shallow waters along with deep water environments may have negative impacts on the native fauna in the Eastern Mediterranean.

Highlights

The opening of the Suez Canal in November 1869 enabled the movement of vessels between the Red Sea and the Mediterranean Sea, dramatically affecting both marine commerce worldwide and the biodiversity of the Mediterranean
There are at least 343 species that have been introduced from the Red Sea into the Mediterranean Sea through the Suez Canal (Galil and Goren 2014)
H. momus populations have become well established along the Mediterranean coast of Israel, until recently its distribution was restricted to artificial substrates such as cement structures, wharves, and submerged vessels and at greater depths (20–30 m) than those occupied by the native Red Sea population (Shenkar and Loya 2008)

Summary

Introduction

The opening of the Suez Canal in November 1869 enabled the movement of vessels between the Red Sea and the Mediterranean Sea, dramatically affecting both marine commerce worldwide and the biodiversity of the Mediterranean. H. momus populations have become well established along the Mediterranean coast of Israel, until recently its distribution was restricted to artificial substrates such as cement structures, wharves, and submerged vessels and at greater depths (20–30 m) than those occupied by the native Red Sea population (Shenkar and Loya 2008).

Results

Conclusion