Coastal and Estuarine Risk Assessment - Chapter 12

Incremental Chemical Risks and Damages in Urban Estuaries: Spatial and Historical Ecosystem Analysis - Cửa sông đô thị hóa có thể là môi trường bị lạm dụng nhất trên trái đất. Sau nhiều thế kỷ phát triển bờ biển, đất ngập nước "khai hoang," đầu nguồn thay đổi, rối loạn thể chất từ các hoạt động như nạo vét, vận chuyển, kiểm soát muỗi, và xử lý rác thải, cộng đồng sinh học đã phải chịu đựng sự mất mát đáng kể môi trường sống và. | 12 Incremental Chemical Risks and Damages in Urban Estuaries Spatial and Historical Ecosystem Analysis Dave F. Ludwig and Timothy J. lannuzzi CONTENTS Introduction 3Z2 Risk and Damage Assessment Foundations for Urban Ecosystems The Problem Unique Conditions in Urban Estuary Envứonments Ecosystem Conditions Organisms and Habitats Chemic s Where and When The Solution Ecological Coincidence Analysis ECA in Practice Application Examples Bứds in an Urban Estuary Habitat Analysis in a Wisconsin Lacustuary Newark Bay Estuary Historical Baseline Conclusions References INTRODUCTION Urbanized estuaries may be the most abused environments on Earth. After centuries ofshoreline development wetland reclamation watershed alteration physical disturbances from such activities as dredging shipping mosquito control and garbage disposal biotic communities have endured substantial habitat loss and degradation. For more than 150 years urban waterways have been subjected to vrrying degrees of chemical pollution from industrial and municipal sources. Over 2002 CRC Press LLC time the habitats that support estuarine-dependent organisms in urban areas have decreased in size and become spatially fragmented. Water and sediment quality is so degraded at least seasonally in some urban systems that many organisms areexcluded from portions of the estuary. Consequently despite their adaptive flexibility many estuarine-dependent organisms have been constrained to patchy use of the urban environment. Our ability to evaluate incremental risks and damages from various chemical groups in urban waterways depends on many interrelated factors bridging a number of rcientihc disciplines. These include the ecology of the system the form mode ofrction and toxicity of the chemicals and the physiology of the organisms that mar be sensitive to the effects of exposure . at risk . Effective chemical risk assessment should be accurate .