ABSTRACT
Introduction ........................................................................................................ 220 Ecological Tools for Assessing Impacts in Marine Systems......................... 221
Univariate Indices .................................................................................... 221 Multimetric Indices .................................................................................. 222 Multivariate and Modelling Approaches .............................................. 223
Approaches Using Indicator Species in Assessing Ecological Quality ....................................................................................................... 224
Examples of Detecting Environmental Impact Gradients in Marine Systems ....................................................................................................... 226 Case 1: Detecting Spatial and Temporal Changes in an Estuarine
System ........................................................................................... 227 Introduction ................................................................................. 227 Methodology ................................................................................ 227 Results ........................................................................................... 229 Discussion..................................................................................... 231
Case 2: Detecting Spatial and Temporal Gradients in Relation to a Submarine Outfall .................................................................... 233 Introduction ................................................................................. 233 Methodology ................................................................................ 233 Results ........................................................................................... 234 Discussion..................................................................................... 237
Case 3: Detecting Spatial Gradients in Oilfield Exploitation ............. 238 Introduction ................................................................................. 238 Results ........................................................................................... 238 Discussion..................................................................................... 240
General Discussion ............................................................................................ 241 Conclusions ......................................................................................................... 243 References ............................................................................................................ 243
Marine environmental investigations have different goals ranging from assessing the ecological quality status of the ecosystems to investigating the response of such ecosystems to global change or any other source of disturbance; these include impacts from hazardous substances or human activities upon biological communities and ecosystems. Recently, significant efforts have been directed also towards resolving various legal disputes over environmental matters related mainly to hazardous substance releases, oil spills, etc. In these particular cases, the ability to obtain clear and defensible answers to some basic questions has been outlined by different authors (Ram 2000; Lundegard, Sweeney, and Ririe 2000). Hence, Ram highlights several issues that occur typically in environmental disputes:
When and how did the release occur? What was the source of release? Who contributed to the problem? What historical industry practices and regulatory practices were in place
at the time? Did the release occur during an insurance coverage period? How much will it cost to clean up? If the cleanup is already completed, were the costs necessary and
appropriate? How should the costs be allocated among the responsible parties?
