ISBN:978-84-453-4986-1 9 788445 349861 Razor clams: Biology, Aquaculture and Fisheries Published by: Xunta de Galicia, Consellería do Mar Edited by: Alejandro Guerra Díaz, César Lodeiros Seijo, Miguel Baptista Gaspar and Fiz da Costa González Cover photographs: Impronta Grá[ ca, S.L. Layout and processing: Rosa Mª Martín García Printed by: Copy Nino Dep. Legal:!"!#$$%&%'## ISBN: 978-84-453-4986-1 Dep. Legal (CD):!"!#$$(&%'## ISBN (CD): 978-84-453-4987-8 All Rights Reserved. No part of the material protected by this copyright notice may be reproduced or utilized in any form or by any means, without written permission from the authors of each chapter. English reviewer: Dr. Alan Floyd This is an updated and extended edition of the book “Navajas y longueirones: biología, pesquerías y cultivo”. 2008. ISBN: 978-84-453-4546-7. Razor clams: Biology, Aquaculture and Fisheries Edited by: Alejandro Guerra Diaz Centro de Investigacións Mariñas (CIMA). Xunta de Galicia. España César Lodeiros Seijo Instituto Oceanográ[ co de Venezuela, Universidad de Oriente.Venezuela Miguel Baptista Gaspar Instituto Nacional de Recursos Biológicos, I.P. / IPIMAR. Portugal Fiz da Costa González Centro de Investigacións Mariñas (CIMA). Xunta de Galicia. España Consellería do Mar, Xunta de Galicía. 2011 This English edition of the [ rst issue, entitled “Razor shells and razor clams: biology, [ shery and culture”, published in 2008 by the Autonomous Government of Galicia, has been extended and modi[ ed. It has been published due to the interest displayed in these species in a large number of countries, and also due to the social recognition and protection provided for artisanal and small-scale [ shing, carried out by traditional methods and systems, which are highly selective and environmentally friendly. Numerous international organisations, among them the UN Food and Agriculture Organization (FAO), byway of its Code of Conduct for Responsible Fisheries (CCRF), have stressed the importance of paying special attention to these [ shing sectors, favouring the protection and rights of [ shers and other workers, and providing preferential access, where warranted, to those [ shing resources traditionally exploited in the territorial waters of [ shing workers inhabiting coastal areas. The management and exploitation of razor shells and razor clams in Galicia are a clear example of all of this. Galicia is the place where this book initially found its inspiration and is the subject of a large part of its contents. Later on, for this new edition, several other countries and research groups were incorporated, all of which have provided information on their particular situation as to [ sheries and their management. In Section 3, this situation is re\ ected for a wide range of countries where these [ shing resources are relevant: Spain, the UK, Ireland, Portugal, Italy, Greece, the USA, Peru, Chile, Argentina and Thailand. The information contained in this book will undoubtedly contribute to providing the best possible conditions to guarantee the sustainable management of [ sheries and food safety requirements (with regard to quantity, access, use and supply), which is essential for the responsible management and governance of the same. Rosa Mª Quintana Carballo Conselleira do Mar, Xunta de Galicia PREFACE Several reasons have driven us to publish a second edition of “Razor clams: biology, aquaculture and [ sheries” published in Spanish in 2008. In the [ rst place, we felt the need to incorporate newly-acquired knowledge about razor clam species (Pharidae and Solenidae families), together with information contributed from countries with [ sheries for these species, and secondly, we felt it was necessary to publish in English. The result is a more mature and more universal work than the [ rst. We must stress the composite nature of this book, with contributions based on scienti[ c publications, doctoral theses and the reports of public and private agencies; the latter are mainly from administrative organisations and researchers from several countries involved in this subject, where razor clams are relevant or have commercial interest. Several experts on the subjects discussed in this book have reviewed the information provided here. We believe that this last decision, with the editors endorsing the information given, is a valid strategy, more than a limiting factor, in order to continue investigation into this group of bivalves, which so far have not received the attention they deserve, given their ecological and commercial importance. Commercially exploited species of razor clams represent a substantial food resource, especially in several countries of Europe and South America; in the former, they are distributed along the coasts of the Atlantic Ocean and the Mediterranean Sea, in the latter, along the Atlantic and Paci[ c coasts of America, and they are also present in Asia. They settle in very different habitats, from sheltered estuaries to coasts highly exposed to the sea. Depending on the species, these gonochoric bivalve molluscs, most of them with K strategy, are distributed from intertidal to subtidal areas, reaching depths of 70 m. They live buried in benthonic substrate, burrowing to a depth of 50-70 cm as soon as they receive some signal that disturbs their environment. This behaviour makes it more dif[ cult to research and record biological parameters in their habitat. Different harvesting techniques are used for catching razor clams, ranging from extraction by hand and the use of rudimentary tools derived from agricultural activities, mainly at intertidal areas, to apnea diving, or its counterpart with autonomous diving suits, and the use of mechanical and hydraulic dredgers in subtidal areas. In general, each method represents 9 the need for [ shermen or gatherers to harvest this natural resource in shallow sandy areas or a greater depth, respectively, in a rational way. The book is divided into 3 main sections. The [ rst describes various aspects of the biology of the species in the following chapters: taxonomy and distribution, anatomy, physiology, reproduction, genetics and pathology, with preferential information about the three species that appear on the Spanish coasts and particularly in Galicia (sword razor shell, Ensis arcuatus; pod razor shell, Ensis siliqua; and grooved razor shell, Solen marginatus). The second section of the book focuses on the [ shing practices in different habitats and countries and the impact they have on the environment, as well as the latest advances made in the aquaculture of these species. The third section gathers together information concerning the current status of the resource worldwide, mainly from European countries (Spain, Portugal, Italy, Ireland, United Kingdom and Greece), but without forgetting others where razor clam [ shing has been and still is important (Chile, Peru, Argentina, Canada, USA, Thailand, Tunisia, etc.). Contributions in the [ rst section come mainly from research theses and projects carried out during recent years, and from scienti[ c publications arising from them. In this investigation, which has been carried out from the 1990’s on, Spanish research centres have been involved, individually or in a coordinated way, especially from Galicia, the “Centro de Investigacións Mariñas” (CIMA) funded by the Fisheries Department of the “Xunta de Galicia” (regional authority) and the Genetics Laboratory of the Cellular and Molecular Department of the University of A Coruña. Part of the money for [ nancing these projects was obtained from funds for marine investigation from the Xunta de Galicia, and especially from National Plan of Aquaculture (JACUMAR) and from two Interreg IIIB European projects: “Sustainable Harvesting of Ensis” (SHARE-90) and “Towards Integrated Management of Ensis Stocks” (TIMES). The results of these research projects, developed by groups from the above-mentioned institutions, form the backbone of this book and will undoubtedly be useful as a point of reference for future studies on the topic of bivalve molluscs. The second section, regarding [ shing practices and their impact on the environment, comprises original collections and information gathered together for the [ rst time in this publication, since there are no references available regarding the effects produced by different [ shing practices. The most frequently-used practices, their role and the environmental impact 10 of the different techniques on the habitat exploited are here described. Analyses based on multiple criteria are also carried out, in order to suggest the most suitable techniques, depending on the performance and sustainability of the resource in [ shing management. The other parts of this section are made up of contributions regarding the acquisition of seed in hatcheries. Although the bulk of the information is based on Europe, mainly on Spain with regard to traditional species (Ensis arcuatus, Ensis siliqua and Solen marginatus), advances made in Chile with Ensis macha are also described. These investigations show that they are organisms with different larval stages, which are sensitive to the effects of manipulation, parasite infections and other kinds of stress related to ongrowing in beds, just like all aquatic organisms in aquaculture activities. Nevertheless, the greatest obstacles identi[ ed in farming are the stabling and maintenance of juveniles before transfer for on-growing outside. In the third section, the situation of the resource in countries where razor clams are commercially important