TABLE OF CONTENTS 



Page 



LIST OF TABLES v 



LIST OF FIGURES vii 



EXECUTIVE SUMMARY xiii 



1.0 INTRODUCTION 1 



1 . 1 Background 1 



1 .2 Dredged Material Disposal Mounds 6 



1 .2. 1 Dow/Stonington and 1991-1992 Disposal Activity 6 



1.2.2 USCGA and NL-94 Disposal Mounds 9 



1.3 Monitoring Activity 10 



1.3.1 August 1992 Monitoring Survey 10 



1.3.2 August 1995 Monitoring Survey 11 



1.3.3 September 1997 Monitoring Survey 12 



1.3.4 July 1998 Monitoring Survey 12 



1.3.5 NLDS Northern Region 13 



2.0 METHODS 14 



2.1 Bathymetry and Navigation 14 



2.1.1 1992 and 1995 Survey Activity 16 



2.1.2 1997 and 1998 Survey Activity 16 



2.1.3 Bathymetric Data Collection 19 



2.1.4 Bathymetric Data Processing 21 



2.2 REMOTS® Sediment Profile Photography 22 



2.2. 1 NL-91 and the Dow/Stonington (D/S) Mound Complex 28 



2.2.2 USCGA Mound 28 



2.2.3 NL-94 Mound 28 



2.2.4 Northern Region 33 



2.2.5 NLDS Reference Areas 33 



2.3 Dissolved Oxygen Sampling 40 



3.0 RESULTS 44 



3.1 D/S and NL-91 Disposal Mounds 44 



3.1.1 Bathymetry 44 



3.1.2 REMOTS® Sediment-Profile Photography 48 



3.1.2.1 August 1992 Survey 55 



3.1.2.2 August 1995 Survey 67 



3.1.2.3 September 1997 Survey 76 



