Further Mediterranean expansion of the non-indigenous bryozoan &lt;em&gt;Celleporaria brunnea&lt;/em&gt;: multiple records along the Italian coasts

Jasmine Ferrario,Anna Occhipinti-Ambrogi,Alice Lodola

doi:10.3989/scimar.04174.31a

Abstract

In the framework of a wider systematic survey aimed at studying non-indigenous species in Italian harbours and marinas, the ascophoran bryozoan Celleporaria brunnea was detected for the first time in the western Mediterranean Sea. The species is presumably native to the Pacific coasts of North America and is distributed from British Columbia to the Galapagos Islands (Ecuador). In the Mediterranean Sea, C. brunnea was first recorded in 2004 in the inner part of Izmir Bay near Alsancak harbour (Turkey) and later reported along the Lebanese coasts. The species was recently detected in Cascais marina in Portugal and in the Arcachon Basin (France), documenting the first records in the eastern Atlantic. The finding in the Italian harbours of La Spezia (Liguria), Olbia (Sardinia) and Lampedusa (off Sicily) marks its western and northernmost occurrence within the Mediterranean basin. Pathways of introduction into the western Mediterranean Sea are discussed, concluding that hull fouling is the most likely vector. The species may be expected to appear soon in other harbours of the Mediterranean basin.

Highlights

In recent years, many marine organisms have been introduced into new habitats by human-mediated transport, mostly by fouling of the hulls of ships or other submerged surfaces and through transfer in ballast waters (Carlton 1985, Carlton and Geller 1993, Gollasch et al 2000)
La Spezia and Olbia are two large harbours, both characterized by international trade shipping, recreational boating and aquaculture activities
La Spezia is located on the eastern coast of the Ligurian Sea, between Genoa and Leghorn, while Olbia is situated on the northeast coast of Sardinia and faces the western-central Tyrrhenian Sea

Summary

Introduction

Many marine organisms have been introduced into new habitats by human-mediated transport, mostly by fouling of the hulls of ships or other submerged surfaces (e.g. anchors, buoys and nets; Carlton and Hodder 1995, Gollasch 2002, Floerl et al 2009) and through transfer in ballast waters (Carlton 1985, Carlton and Geller 1993, Gollasch et al 2000). The most significant factor contributing to the current patterns of biogeographic distribution of many marine organisms worldwide (Carlton 1985, 1987). Many different taxa, such as algae, sponges, molluscs, polychaetes, crustaceans, bryozoans, ascidians and fish, have spread as part of the fouling community or as passengers in ballast water tanks due to their ability to survive for several weeks during transoceanic journeys (Gollasch et al 2000). Some of them possess a planktotrophic larva that may have a potential planktonic life of up to several weeks, so their transport by ballast waters is considered (Carlton 1985, Carlton and Geller 1993, Watts et al 1998)

Methods

Results

Discussion

Conclusion