Food and AgricultureFood and Agriculture General FisheriesGeneral CommissionGeneral Fisheries Fisheries Commission Commission for the Mediterraneanforfor the the Mediterranean Mediterranean Organization ofOrganization the of the Commission généraleCommissionCommission des pêches générale générale des des pêches pêches United Nations United Nations pour la Méditerranéepourpour la la Méditerranée Méditerranée STUDIES AND REVIEWS 87 ISSN 1020-9549 NON-INDIGENOUS SPECIES IN THE MEDITERRANEAN AND THE BLACK SEA Carbonara, P., Follesa, M.C. eds. 2018. Handbook on fish age determination: a Mediterranean experience. Studies and Reviews n. 98. General Fisheries Commission for the Mediterranean. Rome. pp. xxx. Cover illustration: Alberto Gennari GENERAL FISHERIES COMMISSION FOR THE MEDITERRANEAN STUDIES AND REVIEWS 87 NON-INDIGENOUS SPECIES IN THE MEDITERRANEAN AND THE BLACK SEA Bayram Öztürk FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS Rome, 2021 Required citation: Öztürk, B. 2021. Non-indigenous species in the Mediterranean and the Black Sea. Studies and Reviews No. 87 (General Fisheries Commission for the Mediterranean). Rome, FAO. https://doi.org/10.4060/cb5949en The designations employed and the presentation of material in this information product do not imply the expression of any opinion whatsoever on the part of the Food and Agriculture Organization of the United Nations (FAO) concerning the legal or development status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. Dashed lines on maps represent approximate border lines for which there may not yet be full agreement. The mention of specific companies or products of manufacturers, whether or not these have been patented, does not imply that these have been endorsed or recommended by FAO in preference to others of a similar nature that are not mentioned. 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Users wishing to reuse material from this work that is attributed to a third party, such as tables, figures or images, are responsible for determining whether permission is needed for that reuse and for obtaining permission from the copyright holder. The risk of claims resulting from infringement of any third-party-owned component in the work rests solely with the user. Sales, rights and licensing. FAO information products are available on the FAO website (www.fao.org/publications) and can be purchased through [email protected]. Requests for commercial use should be submitted via: www.fao.org/contact-us/licence-request. Queries regarding rights and licensing should be submitted to: [email protected]. Preparation of this document eliable scientific data relating to changes in the distribution and abundance of non-indigenous Rspecies in the Mediterranean and the Black Sea over time are essential for understanding their ecological and economic impacts, including on human health. While the production of this monograph has taken some time in gathering the best available information and reviewing it extensively, it now provides the foundation for future comparative studies. Besides the usefulness of the images and descriptions of the various non-indigenous species, some of which are increasing in economic importance, others of which are detrimental to local ecosystems, tourism or human health, this document presents a unique historical and regional perspective of the impacts of these species. This document was prepared by Bayram Öztürk, Professor at the Faculty of Aquatic Sciences, Istanbul University, and Head of the Turkish Marine Research Foundation, Istanbul, Turkey. iii Abstract he biota of the Mediterranean and the Black Sea has started to change significantly over the Tlast few decades, due to the introduction of non-indigenous species as a result of Lessepsian migration, ship ballast water, range expansion of Atlantic species, intentional or unintentional introduction and climate change. The Black Sea has suffered from the non-indigenous invasive comb jelly Mnemiopsis leidyi since the late 1980s, which has led to biodiversity loss and a decrease in fish catch, mainly driven by a sudden collapse of small pelagic species, in particular of the European anchovy. The trend of Mediterranization has also contributed to changes in Black Sea biota, as many species that used to be restricted to the Mediterranean have infiltrated the Black Sea, presumably due to climate change. Rapa whelk (Rapana venosa), a sea snail, is the most harvested non-indigenous invasive species by Black Sea countries and has also been commercially exploited in the Marmara Sea. The Marmara Sea, situated between the Black Sea and the Aegean Sea, plays a crucial role in the range shifts of invasive species due to its exchange of water mass and marine biota. Like the Black Sea, the Marmara Sea has also been negatively impacted by the comb jelly M. leidyi, showing a recovery of small pelagic fish species only in recent years. Lessepsian fishes and invertebrates are increasingly found in the Marmara Sea, but overall impacts are not yet known. Numerous Lessepsian species have invaded the eastern Mediterranean Sea entering through the Suez Canal, while others have expanded through the central and western sectors of the basin. A number of fish and invertebrate species originating in the Atlantic have also reached the eastern part of the Mediterranean Sea. In total, over 900 non-indigenous species have been reported in the Mediterranean Sea, and almost 300 non-indigenous species in the Black Sea. Over half have established permanent populations and are geographically expanding. Many Lessepsian fishes have become abundant and commercially relevant, gaining influence in local markets, mostly in the eastern Mediterranean region. Indeed, the new market for non- indigenous species is growing. Due to the lack of overall statistics, the total catch in the entire basin is neither known nor predictable. While non-indigenous species are targeted through various fishing techniques, many others are simply discarded due to a lack of value and there are even some, such as lionfishes, pufferfishes and several jellyfish species, that present immediate dangers to human health. Additionally, important impacts on biodiversity have already been reported, due to habitat displacement and competition with native species. The creation of marine protected areas and the protection of native species may represent effective measures for mitigating the negative impacts of non-indigenous species. Disseminating information and raising public awareness, in particular on harmful species, are also important tools at the regional level. For the purposes of monitoring and protecting marine biodiversity, regional cooperation on the enforcement of legal measures is essential in order to minimize and reduce the impacts of non-indigenous species both in the Mediterranean and the Black Sea. iv Contents Preparation of this document iii Abstract iv Contents v Tables, figures, plates vii Abbreviations and acronyms viii Acknowledgements ix Executive summary x INTRODUCTION 1 1. NON-INDIGENOUS SPECIES IN THE BLACK SEA 3 1.1 Main characteristics of the Black Sea 3 1.2 Vectors for non-indigenous species in the Black Sea 4 1.2.1 Shipping activities 4 1.2.2 Intentional or unintentional introduction by humans 5 1.2.3 Mediterranization effects 5 1.3 Occurrence and impacts of non-indigenous species in the Black Sea 6 1.3.1 Non-indigenous invertebrates in the Black Sea and their impacts on biodiversity 7 1.3.2 Other non-indigenous species and their impacts on biodiversity 12 1.3.3 Impacts of non-indigenous species on pelagic fisheries in the Black Sea 13 1.3.4 Non-indigenous fish species and their impacts 15 1.3.5 Lessons learnt for the Black Sea 16 2. NON-INDIGENOUS SPECIES IN THE TURKISH STRAITS 19 2.1 Introduction of non-indigenous species in the Marmara Sea