Mare Nostrum, Mare Quod Invaditur—The History of Bioinvasions in the Mediterranean Sea

Abstract

Intentional and unintentional introductions of marine species into the Mediterranean date back to the 15th century, when maritime shipping expanded with geographical discoveries and new mercantile horizons. Hull fouling on ships was recognized as a vector in the late 19th century, yet early introductions were overlooked because they had occurred centuries before the onset of biogeographical studies. The opening of the Suez Canal in 1869 drew scientific attention to the introduction of marine species and records of shipping and mariculture-introduced species kept appearing in the scientific literature, yet their number and impact were considered inconsequential. Concerns were raised only in the 1980s following conspicuous outbreaks with dire environmental and economic impacts in the Mediterranean and the neighboring Black Sea. The natural and cultural history of marine bioinvasions in the Mediterranean Sea is outlined, as framed by scientists and legislators, whereby perceptions of unintentionally introduced species evolved from ignorance and indifference to ‘biological pollution’ impairing potentially exploitable marine resources and harming indigenous species and habitats. The anthropogenic vectors at the root of the introductions into the Mediterranean Sea are summarized, and cases of environmental transformation, ecological damage, economic impact and human health issues are highlighted. The development of the legislative response, reflecting cultural attitudes to introductions and economic priorities, is briefly documented.