STEREO-VIDEO SURVEYS OF DEEP WATER HABITATS 
M. R. Shortis 1 , J. W. Seager 2 , A. Williams 3 , and B. A. Barker 3 
’Science, Engineering and Technology Portfolio, RMIT University, GPO Box 2476V, Melbourne 3001, Australia 
2 SeaGIS P/L, PO Box 1085 Bacchus Marsh, 3340, Australia 
3 CSIRO Marine and Atmospheric Research, GPO Box 1538 Hobart, 7001, Australia - 
mark.shortis@rmit.edu.au 
Commission V, WG 5 
KEY WORDS: Stereo-Video, Towed Body, Deep Water, Fisheries, Marine Habitat 
ABSTRACT: 
Towed body systems of various configurations have been used for many years to map the seabed. Until recently, single video 
camera systems were widely used to gather qualitative data, or collect often low-accuracy quantitative data using laser dot patterns 
projected into the field of view. The introduction of stereo-video systems has enabled the capture of accurate and reliable spatial 
information with estimates of accuracy and precision. CSIRO has recently adopted stereo-video on a towed body system used for 
habitat mapping and biodiversity survey work in the deep ocean (100 to 2,000 m depths). This paper provides an overview of the 
research context, describes the towed body system, reports on the use of stereo-video and the calibration of the system. Applications 
of the system to managing marine biological resources are illustrated using examples from surveys undertaken recently off south east 
Australia. 
1. INTRODUCTION 
Global attention on marine benthic biodiversity conservation 
has rapidly increased over the last few decades, primarily due to 
the depletion of fish stocks and degradation of the environment. 
The response to a widespread concern for effective 
conservation has resulted in the implementation of Marine 
Protected Areas (MPAs), which has consequently generated the 
need for multi-scale maps of seabed habitat (Williams et al., 
2005). In addition, the acknowledgement that fisheries need to 
be managed for ecological sustainability, rather than simply on 
the basis of regulating catch or effort, has generated the need to 
understand and quantify the interactions of fishing gear with the 
benthic environment (Hobday et al., 2006; McShane et al., 
2007). 
Australia is developing a national network of MPAs in offshore 
waters where virtually all areas are expected to be deeper than 
SCUBA diving depths (>50 m); this is the case off south 
eastern Australia where the first part of the network has been 
declared (DEWR, 2007). Further, a large proportion of total 
fisheries catches in Australia are taken below SCUBA depths, 
leading to a requirement for remote data capture to survey and 
monitor deep water regions. 
activities. Information from surveys is being integrated to 
produce habitat maps at various scales of resolution so that the 
multi-scale structure of benthic habitats (figure 1) can be 
understood and natural regions can be identified as planning 
units. 
Research information on deep seabed habitats has to be 
gathered remotely and information is required from many 
locations, consequently towed camera systems are an integral 
part of the mapping capability. Towed systems are able to take 
data along many kilometres of transects, and traverse rough and 
steep seabed topography. A key role for geo-referenced video 
sequences is to provide fine-scale detail that complements 
coarser scale of mapping provided by hydro-acoustics (Kloser 
et al., 2007). This integration of scales is needed to understand 
the broad scale issues across the fishery regions or management 
planning units as a whole. 
This paper describes a towed body system developed in 
Australia for these purposes, and focusses on the incorporation 
of stereo-cameras that enable quantitative data to be taken from 
imagery. Applications of the data for managing marine 
biological resources are illustrated with a range of examples. 
Figure 1. Multi-scale mapping of habitats - regional, feature 
and fine scales. 
As a consequence, deep benthic 1 habitats are being mapped to 
support the development of an integrated and ecosystem-based 
approach to plan (Kloser et al., 2007) and manage human 
l 
Living on the surface of bottom sediments in a water body. 
2. TOWED BODY SYSTEM 
The primary survey tool is a towed camera platform that 
records continuous, medium resolution stereo-video sequences 
and intermittent high-resolution digital still images along 
transects. The platform operates to depths of 2,000 metres and 
is connected to the vessel via a 3,200 metre steel-armoured 
cable containing fibre-optic and conducting wires. Two PAL 
video cameras, configured as a stereo-pair, transmit live video 
sequences that are recorded on time-coded DV tape. The 
recordings are indexed to navigation data from the differential 
global positioning system (DGPS) on the vessel and links to 
ultra short baseline (USBL) tracking beacon data on the towed 
body, so that imagery can be accurately geo-located. Geo