s x 
s é 
" 
x " = * Foy A 
; £. I & . “a er 
- i , 
S - . ; Y > i 
x Um 3  ? y . d 
* . x s 3 
& + « i x T " 
» > . 
: = ibo C 
ne a s 1 
boa A 
FIGURE 5. Waterfowl photographed vertically from five metres. Species such 
as common eider, black duck, pintail, teal, and mallard are present. 
Descriptions of sizes and shapes of birds on such photographs can be 
used in identification on aerial photographs (Photograph courtesy of 
J.D. Heyland, Quebec Wildlife Service). 
scenic values, erosion, sedimentation and the destruction of wildlife habitat. 
Remote sensing makes its contribution in the preparation of inventories of existing 
resources, in the surveillance of human activity and in the monitoring and study of 
the ecological systems of the oceans and coasts (McEwan, Kosco and Carter, 1976; 
Klemas, Bartlett and Rogers, 1975). 
In the surveillance of human activity, a great deal of attention has focussed 
on off-shore oil and gas exploration and on oil spills. This involves the application 
of aerial photography and other sensors in the mapping of the extent and dispersal 
of oil slicks (Figure 7) and the development of new sensors such as raman and 
fluorescence inducing lasers, which some day may make it possible not only to 
detect and map oil spills and to monitor the progress of clean-up operations, but 
also to identify the oil and thus to provide evidence for legal action against 
polluters. Satellite imagery, particularly from Landsat, has also proved its value in 
the assessment of turbidity of water bodies. Several recent reports, for example, 
Scherz, Van Domelen, Holtje and Johnson (1974) and Scarpace, Wade and Fisher 
(1974) report on correlations between Secchi disc readings and Landsat data. The