The Use of A Mobile Laboratory to Study
Temperature Response of Fish
DONALD S. CHERRY, Research Associate
KENNETH L. DICKSON, Assistant Professor
JOHN CAIRNS, Jr., Professor
Biology Department and Center For Environmental Studies
Virginia Polytechnic Institute and State University
Blacksburg, Virginia 24061
INTRODUCTION
Of the national freshwater resource, nearly half is temporarily utilized by power
companies and industry for condensing and cooling purposes (1). In addition, many aquatic
systems receive heavy metal, chemical, and various other contaminants associated with
industrial, chemical and mining pollutants. In many cases different types of pollutants are
released in a fashion that makes their stress on aquatic systems more severe than their
individual effects.
In water quality studies, several experimental procedures have been adapted to
determine the toxicological effects on fish populations resulting from heavy metal
concentrations, total hardness, pH turbidity, extremes of temperature and dissolved
oxygen concentrations. Many investigators have used "batch" tests for evaluation offish
response while others have utilized either continuous-flow tests (2), a serial-dilution
apparatus for continuous delivery of specified concentrations of materials in water (3), or a
proportional diluter (4).
Several investigators have designed devices to measure fish avoidance response to
varying concentrations of pollutants. Sprague (5, 6) monitored the avoidance of fish
populations to copper-zinc sulphate solutions in a horizontal trough of plexiglass tubing
that drained from the center. Studies that utilized similar schemes to form linear
concentration gradients were reported by Jones (7) and Shelford (8). Jones, et al (9)
monitored avoidance reactions of juvenile salmon to pulp-mill wastes in a "channeled
avoidance tank." Whitmore, et al (10) utilized the same procedure to evaluate avoidance
reactions of salmonid and centrarchid fishes.
Studies of temperature selection or preference of invertebrates and vertebrates have
been reviewed by Sullivan and Fisher (11). In most studies, devices have been constructed to
produce either a vertical, or more commonly, a hoirzontal gradient. Brett (12) used a
vertical gradient to test the temperature tolerance of young Pacific salmon. Ferguson (13),
using the procedure of Brett (12), compared preferred temperature offish in temperate lakes
and streams with results of laboratory investigations.
Several studies have utilized a horizontal, linear flow-through trough to determine
temperature preference by establishing a specific temperature gradient (11, 14, 15, and
others). The heat gradient was produced when cold water was introduced at one end of the
trough and gradually heated by a linear battery of heating units or sunlamps located
underneath at increasingly higher intensities. This procedure can also be used to study the
combined effects of industrial, chemical and mining pollutants and temperature changes
since some industries release chemical and thermal effluent simultaneously. The
components of the temperature preference unit may be incorporated underneath the trough
of the serial dilution apparatus that forms the chemical gradient (as in the procedure
reported by Mountand Warner (3) and by Mount and Stephen (16)) to produce a combined
thermal-chemical gradient.
129