Historical ecology of semi-enclosed coastal embayments: tools and techniques for discovering ecological events of the recent past

Abstract

The sheltered environments of coastal embayments have played a vital role for humans for millennia and their resources have underpinned modern industrial development globally. Their effective management and restoration remains an enormous challenge, owing, in part, to lack of recognition of the threshold changes that occurred in many bays prior to scientific study (i.e. >50 years ago). Advances in marine extraction technologies and increased clearing of catchments for agriculture and urbanisation in recent history (∼400 years) have resulted in profound physical, chemical and biological changes to these ecosystems. More recently, the integration of ecology, history, archaeology, economics and fisheries science have contributed to the emerging field of ‘marine historical ecology’ (MHE). The synthesis of information from these different disciplines can markedly improve knowledge of past ecosystem condition, thereby assisting managers to set realistic goals for environmental restoration to improve biodiversity and ecosystem function. This paper reviews historical knowledge of long-term environmental degradation processes in coastal embayments, summarising the wide range of methods and techniques used as evidence and providing examples from around the world, thereby illustrating the need for longer time-frames of reference for contemporary restoration ecology.