COVER
FAO FISHERIES TECHNICAL PAPER 295






The application of remote sensing technology to marine fisheries: an introductory manual




Table of contents

Authors:
M.J.A. Butler
Maritime Resource Management Service (MRMS) Inc.
Amherst, Nova Scotia, Canada
M.-C. Mouchot
Canada Centre for Remote Sensing (CCRS)
Ottawa, Ontario, Canada
V. Barale
TASK Research and Development
Via Verbano 2, 21027 Ispra (VA), Italy
C. LeBlanc
Maritime Resource Management Service (MRMS) Inc.
Amherst, Nova Scotia, Canada

The designations employed and the presentation of material in this publication do not imply the expression of any opinion whatsoever on the part of the Food and Agriculture Organization of the United Nations concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries.

M-40
ISBN 92-5-102694&-7

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying or otherwise, without the prior permission of the copyright owner. Applications for such permission, with a statement of the purpose and extent of the reproduction, should be addressed to the Director, Publications Division, Food and Agriculture Organization of the United Nations. Via delle Terme di Caracalla, 00100 Rome, Italy.

FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS Rome, 1988
© FAO


PREPARATION OF THIS DOCUMENT

The economic welfare of a nation or region is directly dependent on the resources available to it and on the ability of the people to use these resources to their benefit. The declaration of Exclusive Economic Zones (EEZ) by coastal states underlines the economic significance of fisheries resources. At one time the success of a fishing trip was dependent on a fishermen's keen sense of sight, smell and hearing. The modern science of remote sensing has expanded man's perceptions far beyond the limits of those human senses. This manual is intended to be an introduction to the rapidly developing field of remote sensing for persons involved in the study, management or utilization of fisheries resources, particularly in developing countries.

ACKNOWLEDGEMENT

The authors and editors would like to acknowledge the role of Dr. J.F. Caddy (Senior Fishery Resources Officer, Fisheries Department, FAO) and Mr. D. Kalensky, (Senior Officer, Technical Support Group, Remote Sensing Centre, FAO) who initated and supported this project.

T.T. Alfoldi of the Canada Centre for Remote Sensing (CCRS) provided professional advice and assistance on the content of the manual. N.M. Butler was responsible for the overall editing, particulary in terms of syntax, comprehension and continuity. We thank them for their efforts.

Dr. D. Jayasinghe and T. Perrott made significant contributions to the initial drafts of this manual. We also wish to acknowledge the assistance provided by G. Landi of FAO and by MRMS employees, namely: C.A. Speight, B.R. Rowley and M.L. McCourt for technical advice; M.E. Campbell for bibliographic research assistance; and M. Jones, M.P. Donovan and M. Stewart for the word processing. Also acknowledged for their constructive comments are the participants of the 12th UN/FAO International Training Course in Co-operation with the Government of Italy: Contribution of Remote Sensing to Marine Fisheries, Rome, Italy, 11–30 May 1987. Dr. R. Sudarshana of the Indian Institute of Remote Sensing provided valuable information concerning India's space programme. The cover of the manual was modified from an original design by K. Coldwell, a former student of cartography at the College of Geographic Sciences, Lawrencetown, Nova Scotia.

The production of this training manual was, in a very real sense, the result of a team effort by the authors, editors, advisors and word processing operators. We would like to recognize their collective endeavours.

Distribution: For bibliographic purposes this document should be cited as follows:
FAO Fisheries Department FAO Regional Fishery Officers Authors Marine Sciences (General) Butler, M.J.A. et al., 1988 The application of remote sensing technology to marine fisheries: an introductory manual. FAO Fish. Tech.Pap., (295):165 p.

ABSTRACT
The science and technology of remote sensing is introduced in terms of its history, concepts and language, and its application to the exploitation and management of marine fisheries. The physics of electromagnetic radiation is reviewed with reference to atmospheric and target interactions. The variety of sensor platforms and sensor types are described, the latter in the context of either global or sequential acquisition systems. Environmental satellites, their associated sensors and the techniques of digital image processing also are reviewed. Direct and indirect applications of remore sensing technology to fisheries are described in general, followed by a series of specific case studies. Recommended reference material, a glossary of terms and acronyms, sources of oceanographic satellite data and a selected list of training institutions conclude this manual.

PREFACE

This manual is designed for personnel from departments of fisheries and other agencies who are responsible for the development and management of marine resources. The manual does not presume that the reader has extensive knowledge of either fisheries or the science of remote sensing.

The importance of the fishery sector to the economy of most nations is now widely recognized. Because of the increasing demand for fishery products and the need to exploit marine resources in a cost effective manner, the introduction and application of modern techniques have become important considerations. The rapidly developing science of remote sensing is but one of these technologies. It is not a panacea but, as this manual indicates, it does have considerable potential for assisting fishermen, fishery scientists and managers, air-sea rescue authorities, and many other personnel with responsibilities in this natural resource sector. To date, fisheries applications for remotely sensed information have been the prerogative of the fishing fleets of industrialized nations. This situation will change, however, with the increasing awareness of remote sensing applications, the increasing availability of remotely sensed data, the increasing demand and provision for training, and the belated recognition that one of the first and most widely used remote sensing techniques, that of aerial photography, is readily available to all nations.

The manual is designed to introduce the reader to some of the fundamental concepts of remote sensing and its application to fisheries. In addition it will provide a basic understanding of the language of remote sensing, including the plethora of acronyms.

The introduction, Section 1, provides a historical overview, introduces the reader to basic remote sensing terminology and indicates the types of fisheries-related studies to which remote sensing technology can be applied. Section 2 reviews the properties of electromagnetic radiation and its interaction with the atmosphere and oceans. Sections 3 and 4 consider the variety of sensor platforms and systems, respectively, which have applications to oceanography in general and fisheries in particular. The major environmental satellites and their marine-related sensors are reviewed in terms of their technical specifications in Section 5. The tasks and techniques associated with processing digital images and analyzing remotely acquired data are considered in Section 6. The applications of remote sensing to fisheries are further developed in Section 7 in terms of direct and indirect methods of fish detection and fishery assessment, and of aids to fishing operations. Section 8 considers twenty-two case studies which collectively cover the majority of applications of remote sensing to fisheries from a theoretical and a practical perspective. The Bibliography, Section 9, identifies a selection of topical remote sensing texts and scientific papers which should be used to supplement this manual. The two volume “Manual of Remote Sensing” edited by R.N. Colwell and published by the American Society of Photogrammetry provides a particularly detailed coverage of the subject.

Four appendices comprise, respectively, a Glossary of Terms and Acronyms; Sources of Oceanographic Satellite Data; a Selected List of National and International Institutions which provide training in remote sensing technology and, finally, Conversion Tables for units of measurement commonly used in remote sensing.

In conclusion, the manual is not intended to be all-inclusive. Reference to specialized texts should be made whenever supplementary information is required. With the knowledge gained from reviewing this manual, the reader should feel confident to assess remote sensing applications in relation to the problems of fisheries exploitation and management, and to communicate with remote sensing specialists.

Hyperlinks to non-FAO Internet sites do not imply any official endorsement of or responsibility for the opinions, ideas, data or products presented at these locations, or guarantee the validity of the information provided. The sole purpose of links to non-FAO sites is to indicate further information available on related topics.

TABLE OF CONTENTS

1.INTRODUCTION
 1.1Historical Overview
 1.2Basic Terms and Concepts
 1.3Fisheries Applications
2.ENERGY SOURCES AND INTERACTIONS
 2.1Electromagnetic Radiation and its Properties
 2.2Atmospheric Interactions
 2.3Target Interactions
3.SENSOR PLATFORMS
 3.1Boats
 3.2Balloons
 3.3Aircraft
 3.4Satellites
  3.4.1Orbital parameters
   3.4.1.1Geosynchronous orbit
   3.4.1.2Sun-synchronous (Heliosynchronous) orbit
4.SENSOR SYSTEMS
 4.1Global Acquisition Systems
  4.1.1Aerial cameras
   4.1.1.1Focal length (f)
   4.1.1.2 Angle of view (d)
   4.1.1.3 Scale (s)
   4.1.1.4 Contrast
   4.1.1.5 Resolution
   4.1.1.6Film speed
  4.1.2The Return Beam Vidicon camera
 4.2Sequential Acquisition Systems
  4.2.1Passive sensors
   4.2.1.1Spatial characteristics of passive sensors
   4.2.1.2Spectral and radiometric characteristics of passive sensors
  4.2.2Active sensors
   4.2.2.1Echo-sounders and sonars
   4.2.2.2Radars
   4.2.2.3Lidars
5.ENVIRONMENTAL SATELLITES
 5.1The LANDSAT Series
  5.1.1The first generation: LANDSAT-1, 2, 3
   5.1.1.1MultiSpectral Scanner (MSS)
  5.1.2The second generation: LANDSAT-4, 5
   5.1.2.1Thematic Mapper (TM)
 5.2The NOAA Series
  5.2.1The first generation: NOAA-2 to 5
  5.2.2The second generation: TIROS-N, NOAA-6 to 9
   5.2.2.1Advanced Very High Resolution Radiometer (AVHRR)
 5.3Heat Capacity Mapping Mission (HCMM)
  5.3.1 Heat Capacity Mapping Radiometer (HCMR)
 5.4NIMBUS Series
  5.4.1Coastal Zone Colour Scanner (CZCS)
 5.5SEASAT-A
  5.5.1Scanning Multichannel Microwave Radiometer (SMMR)
  5.5.2Radar Altimeter (Alt)
  5.5.3SEASAT-A Satellite Scatterometer (SASS)
  5.5.4Synthetic Aperture Radar (SAR)
 5.5.5 Visible and Infrared Radiometer (VIRR)
 5.6GOES/METEOSAT Series
 5.7SPOT
  5.7.1Haute Résolution Visible (HVR) radiometer
 5.8Space Shuttle and Space Stations
 5.9Bhaskara Series
 5.10MOS-1
 5.11Satellites of the Future
  5.11.1IRS-1
  5.11.2ERS-1
  5.11.3TOPEX
  5.11.4NROSS
  5.11.5OCI
  5.11.6RADARSAT
  5.11.7The Sea Wide Field Sensor (Sea WIFS) Program
  5.11.8Earth Observing System (EOS)
6.DIGITAL IMAGE PROCESSING
 6.1Digital Images
  6.1.1Image display
 6.2Image Processing
  6.2.1 Radiometric corrections
  6.2.2Geometric corrections
  6.2.3Image enhancement
   6.2.3.1Contrast enhancement
   6.2.3.2Edge enhancement
   6.2.3.3Colour enhancement
   6.2.3.4Multi-image enhancement
   6.2.3.5Density slicing
  6.2.4Image interpretation
   6.2.4.1Image classification
   6.2.4.2Pattern recognition
7.APPLICATION OF REMOTE SENSING TO FISHERIES
 7.1Direct Methods of Fish Detection
 7.2Indirect Methods of Fishery Assessment
  7.2.1Surface optical properties
   7.2.1.1Diffuse attenuation coefficient
   7.2.1.2Total suspended matter (seston)
   7.2.1.3Yellow substance
   7.2.1.4Chlorophyll pigments
   7.2.1.5Macrophytes
  7.2.2Surface temperature
  7.2.3Circulation features
  7.2.4Salinity
  7.2.5Oil pollution
  7.2.6Sea state
 7.3General Aids to Fishing Operations
8.REMOTE SENSING CASE STUDIES
 8.1Case Study No. 1
  Hara, I., 1985,
  Moving direction of Japanese sardine school on the basis of
  aerial surveys. Bull.Japan.Soc.Sci.Fish., 51(12):1939–45
 8.2Case Study No. 2
  Bazigos, G.P. et al., 1979,
  Aerial frame survey along the southwest coast of India. Rome,
  FAO, UNDP/FAO Pelagic fishery investigation project on the
  southwest coast of India. FIRM-IND/75/038:104 p.
 8.3Case Study No. 3
  Blindheim, J., G.H.P. de Bruin and G. Saetersdal, 1979,
  A survey of the coastal fish resources of Sri Lanka. Report
  No. 2, April - June 1979. Reports on surveys with R/V DR.
  FRIDTJOF NANSEN. Bergen, Institute of Marine Reasearch, 63 p.
 8.4Case Study No. 4
  Roithmayr, C.M., 1970,
  Airborne low-light sensor detects Iuminescing fish schools at
  night. Commer.Fish.Rev., 32(12):42–51
 8.5Case Study No. 5
  Cram, D.L., 1979,
  A role for the NIMBUS-9 coastal zone colour scanner in the
  management of a pelagic fishery. Fish.Bull./Visserij-Bull.,
  Cape Town, (11) : 1–9
 8.6Case Study No. 6
  Caraux, D. and R.W. Austin, 1983,
  Delineation of seasonal changes of chlorophyll frontal bound-
  aries in Mediterranean coastal waters with NIMBUS-7 coastal
  zone colour scanner data. Remote Sensing Environ.,
  13(3):239–49
 8.7Case Study No. 7
  Kemmerer, A.J., 1980,
  Environmental preferences and behaviour patterns of Gulf
  menhaden (Brevoortia Patrouns) inferred from fishing and
  remotely sensed data. ICLARM Conf. Proc., (5):345–70
 8.8Case Study No. 8
  Lasker, R. et al., 1981,
  The use of satellite infrated imagery for describing ocean
  processes in relation to spawning of the northern anchovy
  (Engraulis mordax). Remote Sensing Environ., 11 : 439–53
 8.9Case Study No. 9
  Cornillon, P. et al., 1986,
  Sea Surface temperature charts for the souhtern New England
  fishing community. Marine Technology Society Journal,
  20(2) : 57–65
 8.10Case Study No. 10
  Laurs, R.M. et al., 1984,
  Albacore tuna catch distributions relative to environmental
  features observed from satellites.
  Deep-Sea Res., 31(9) : 1085–99
 8.11Case Study No. 11
  Montgomery, D.R. et al., 1986,
  The applications of satellite-derived ocean color products to
  commercial fishing operations. Marine Technology Society
  Journal, 20(2):72–86
 8.12Case Study No. 12
  Feldman, G.C., 1986,
  Variability of the productive habitat in the Eastern
  Equatorial Pacific. EOS, Transactions, American Geophysical
  Union, 67(9):106–8
 8.13Case Study No. 13
  Barale, V. et al., 1986,
  Space and time variability of the surface color field in the
  Northern Adriatic Sea. J.Geophys.Res., 91(C11):12957–74
 8.14Case Study No. 14
  Pringle, J.D. and R.E. Duggan, 1983,
  A remote sensing technique for quantifying lobster fishing
  effort. Can.Tech.Rep.Fish.Aquat.Sci., 1217:16 p.
 8.15Case Study No. 15
  Bour, W., L. Loubersac and P. Rual, 1986,
  Thematic mapping of reefs by processing of simulated SPOT
  satellite data: application to the Trochus niloticus biotope
  on Tetembia Reef (New Caledonia). Mar.Ecol.Prog.Ser., 34:243–9
 8.16Case Study No. 16
  Jensen, J.R. et al., 1980,
  Remote sensing techniques for kelp surveys.
  Photogramm.Eng.Remote Sensing, 46(6):743–55.
 8.17Case Study No. 17
  Belsher, T. and M. Viollier, 1984,
  Thematic study of the 1982 SPOT simulation of Roscoff and the
  west coast of the Contentin peninsula (France). In Proceedings
  of the Eighteenth International Symposium on remote sensing of
  environment, Paris, France. Ann Arbor, Environment Research
  Institute, pp. 1161–6
 8.18Case Study No. 18
  Armstrong, R.A., 1983,
  Marine environments of Puerto Rico and the Virgin Islands:
  automated mapping and inventory using LANDSAT data.
  Caribbean Fishery Management Council, 37p.
 8.19Case Study No. 19
  Middleton, E.M. and J.L. Barker, 1976,
  Hydrographic charting from LANDSAT satellite: a comparison
  with aircraft imagery. In Oceans '76. Second combined
  conference, Marine Technology Society/Institute of Electrical
  and Electronics Engineers. New York, IEEE Inc. and Washington,
  D.C., MTS, (CH 1118–90 EC):6 p.
 8.20Case Study No. 20
  Roy, S.E., 1978,
  Sea surface temperature and related measurements of the South
  Caribbean Sea, utilizing GOES, NOAA and GOSSTCOMP data for
  locating structures. In Proceedings of the Seventh annual
  remote sensing of earth resources conference. Tullahoma,
  Tennessee, University of Tennessee, Space Institute, pp.261–87.
 8.21Case Study No. 21
  Mattie, M.G. and D.E. Lichy, 1980,
  SEASAT dtection of waves, currents and inlet discharge.
  Int. J. Remote Sensing 1(4): 377–98.
 8.22Case Study No. 22
  Tanaka, S. et al., 1983,
  Accuracy of direct measurement of mean surface water velocity
  of the Kuroshio using multi-temporal NOAA-6 imageries. In
  Proceedings of the Seventeenth International Symposium on remote
  sensing of environment, Ann Arbor, 1983. Ann Arbor, Michigan,
  Environment Research Institute, pp. 933–44.
 9.BIBLIOGRAPHY
APPENDIX A GLOSSARY OF TERMS AND ACRONYMS
APPENDIX B SOURCES OF OCEANOGRAPHIC SATELLITE DATA
APPENDIX C SELECTED LIST OF NATIONAL AND INTERNATIONAL INSTITUTIONS WHICH PROVIDE TRAINING IN REMOTE SENSING TECHNOLOGY
APPENDIX D CONVERSION TABLES

LIST OF FIGURES

2.1An electromagnetic wave and its compoents
2.2Electromagnetic spectrum showing bands employed in remote sensing
2.3Plot of radiance from a blackbody against wavelength, with temperature as a variable
2.4Transmission of energy through the atmosphere as a function of wavelength
2.5Specular and diffuse radar reflection
2.6Spectral reflectance of ocean water and thinlayer of crude oil
2.7Effect of emissivity differences on radiant temperature
2.8aLight absorption by 10 m of pure water as a function of wavelength
2.8bVariation of light transmission as a function ofdepth for various sea waters
3.1Orbits of satellites
4.1Principal components of a single-lens frame camera
4.2Components of a passive microwave signal
4.3Thermal IR scanning system
4.4LANDSAT MSS orientation
4.5General characteristics of a push-broom radiometer
4.6The concept of Angular Field of View (AFOV) or scanning angle and Instantaneous Field of View (IFOV)
4.7aPrinciple of operation of side looking radar
4.7bPropagation of one radar pulse
4.7cResulting antenna return
4.8A synthetic aperture radar system
4.9Scatterometer output from iceberg as a function of time for different angles of incidence
4.10Principle of operation of airborne lidar bathymetric system
4.11Principle of operation of airborne fluorescence lidar
5.1aLANDSAT configuration
5.1bTypical daytime LANDSAT orbit paths for a single day
5.1cLANDSAT orbits over the United States on successive days
5.2SEASAT-A configuration
5.3Positions of the five geo-synchronous meteorological satellites that provide global weather watch capabilities
5.4METEOSAT data collecting system
5.5Attributes of the SPOT system
5.6ERS-1 configuration
7.1Suspended sediment concentrations in the Bay of Fundy, Canada, as derived from LANDSAT MSS data
7.2Chlorophyll concentrations off the West coast of France, derived from a CZCS image (July 1981)
7.3Colour infrared aerial photograph (1:10,000) of the Chausey Islands, France, taken on April 24, 1982, at low tide
7.4sea surface temperature image of the Northwest Atlantic Ocean recorded by IR radiometer aboard NOAA-9
7.5SEASAT image of the Strait of Juan de Fuca taken on August 13, 1978, at an altitude of 805 km
7.6Visible band image from GOES West taken at 18:00 on November 15, 1984
8.1Flight line for visual observation on September 22, 1984
8.2Flight line for visual observation on September 23, 1984
8.3Changes in oval-shape school sketched from vertical or oblique photography
8.4The changes of the elongate and the intermediateshape schools expressed in the same manner as Figure 8.3
8.5Pictorial chart of the distribution of the marine fishing boats covered by the AFS in the project area by one degree of latitude
8.6Dimensions of the sound beam from the echo sounder at 20 m echo depth in relation to the distance between trawl doors and wind ends of the trawl net
8.7Example of “Type A” echo recordings of demersal and semi-demersal fish
8.8Example of “Type B” echo recordings of dispersed pelagic fish
8.9Example of “Type C” echo recordings of schooling small pelagic fish among recordings of dispersed larger pelagic fish (Type B)
8.10A large luminescing school of thread herring, 160 m (500 ft.) in diameter, amplified by airborne low-light sensor
8.11Plankton distribution and observed positions of pilchard shoal (school) groups - cumulative over 10 days
8.12Monitoring of chlorophyll frontal boundaries in the Golfe de Lion throughout 1979
8.13Classification of LANDSAT MSS data from May 20, 1975 into high and low probability menhaden fishing areas for the eastern half of the Mississippi Sound
8.14Distribution of anchovy eggs superimposed on the thermal image of the Southern California Bight
8.15NOAA/NESDIS (National Environmental Satellite Data and Information Service) oceanographic analysis chart for June 18, 1984
8.16Subsection of the NOAA/NESDIS chart shown in Figure 8.15, modified by NMFS (National Marine Fisheries Service)
8.17Enlargement of the region east of Long Island, mailed to fishermen
8.18Satellite data collection and processing network utilized by National Marine Fisheries Service (Southwest Fisheries Centre)
8.19Central California daily albacore catches,27 September to 2 October, 1981, superimposed on the NOAA-7 AVHRR sea surface temperature,30 September, 1981, 14:02 PST
8.20Central California daily albacore catches,27 September to 2 October, 1981, superimposed on the NIMBUS-7 CZCS blue-green colour ratio and phytoplankton pigment concentration, 29 September, 1981, 11:30 PST
8.21Chart forwarded by telecopier to radio facsimile broadcast stations for subsequent transmission to participating fishing vessels
8.22Representative chart generated as part of fisheries demonstration effort
8.23Map of the eastern equatorial Pacific Ocean, showing the major features of the submarine bathymetry
8.24Cumulative frequency distributions of satellite-derived phytoplankton pigment concentrations (in milligrams per cubic metre) versus the percentage of total cloud-free surface area covered by each concentration range for the eastern equatorial Pacific, as observed by the CZCS
8.25Frequency distributions of satellite-derived phytoplankton pigment concentrations (in milligrams per cubic metre) versus the percentage of total cloud-free surface area covered by each concentration range for the region 0°–10°S, 87°–78°W, as observed by the CZCS
8.26Average conditions of the surface colour field in the Northern Adriatic Sea: 1979 yearly (a) mean and (b) standard deviation of phytoplankton pigment concentration; 1980 yearly (c) mean and (d) standard deviation of phytoplankton pigment concentration
8.27Comparison of monthly averaged Po river outflow (in cubic metres per second) with Po river plume scale and western coastal layer scale (in kilometres) for the period from August 1978 to December 1980
8.28Map of buoy locations - actual fishery
8.29Tetembia reef: general themes
8.30Tetembia reef: hard bottom themes
8.31Example of high altitude CIR photography (original scale 1:125,000) and manually interpreted kelp acreage surveys on four dates
8.32Kelp acreage surveys derived from four dates of LANDSAT image processing
8.33Digital processing of SPOT image
8.34Classified image of St. John, US Virgin Islands
8.35The charted depth contour (5 m) in the study site in comparison with the binary print of the OCS-4 radiance-value distribution pattern for a single grey level in this depth range
8.36SEASAT SAR image
8.37“Sea Mark” chase method for current vector measurement

LIST OF TABLES

1.1Representative fish types observable from low-level aircraft
4.1Radar wavelengths and frequencies used in remote sensing
5.1LANDSAT-2 MSS characteristics
5.2LANDSAT TM characteristics
5.3NOAA-7 - AVHRR characteristics
5.4HCMM - HCMR characteristics
5.5NIMBUS-7 CZCS characteristics
5.6NIMBUS-7/SEASAT - SMMR characteristics
5.7SEASAT - Radar Altimeter characteristics
5.8SEASAT - Radar Scatterometer characteristics
5.9SEASAT - SAR characteristics
5.10METEOSAT - Scanning Radiometer characteristics
5.11SPOT - HRV characteristics