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Quần thể rùa biển đã được giảm đáng kể kể từ khi tương tác giữa con người và rùa biển bắt đầu. Mặc dù quần thể rùa biển Caribbean nói chung có được coi là nguyên sơ khi Columbus đến năm 1492, khảo cổ nghiên cứu hiện nay tiết lộ rằng một số con rùa biển làm tổ tập hợp tại vùng biển Caribbean extirpated hoặc giảm đáng kể bởi Amerindians (Carlson, năm 1999; O'Day, 2001). | 10 Roles of Sea Turtles in Marine Ecosystems Reconstructing the Past Karen A. Bjorndal and Jeremy B.C. Jackson CONTENTS 10.1 Introduction .259 10.2 Ecological Roles of Sea Turtles .261 10.3 Case Study Caribbean Green Turtle.262 10.4 Case Study Caribbean Hawksbill .265 10.5 Conclusions .269 Acknowledgments .269 References .270 10.1 INTRODUCTION Populations of sea turtles have been drastically reduced since interactions between humans and sea turtles began. Although Caribbean sea turtle populations generally have been considered to be pristine when Columbus arrived in 1492 archeological research is now revealing that some sea turtle nesting aggregations in the Caribbean were extirpated or significantly reduced by Amerindians Carlson 1999 O Day 2001 . Therefore the roles that sea turtles played in the functioning of ecosystems in the Caribbean may have been substantially affected before European contact. Initially a result of directed harvest population declines have more recently been driven by factors in addition to direct harvest such as incidental capture in commercial fisheries habitat degradation introduction of feral predators on nesting beaches and marine pollution Eckert 1995 Lutcavage et al. 1997 Witherington in press . These population declines have produced a corresponding decline in the extent to which sea turtles fulfill their roles in maintaining the structure and function of marine ecosystems. Because the massive proportions of the declines occurred so long ago sea turtles are now viewed by many as charming anachronisms or quaint archaic relics. Their past roles as major marine consumers in many marine ecosystems from 259 2003 CRC Press LLC 260 The Biology of Sea Turtles Vol. II tropical to subarctic waters have been forgotten. Thus sea turtles are victims of the shifting baseline syndrome Pauly 1995 Sheppard 1995 . This pervasive syndrome is the use of inappropriate baselines to assess population change or stability. Referring to fisheries management
