Sublethal toxicant effects on fish foraging behavior: Empirical vs. mechanistic approaches

Abstract

Previous studies of toxicant effects on fish foraging behavior and predator‐prey interactions have taken a strictly empirical approach. The most common observation of altered feeding behavior was cessation of feeding or reduction in the amount of artificial food consumed. Changes in the number of live prey attacked and captured, latency to feed and capture efficiency have also been documented. Predator‐prey tests have placed major emphasis on toxicant effects on the ability of prey to escape predation. Several different test systems, as well as model ecosystems, have been used. It is difficult to evaluate the sensitivity of these behavioral tests in relation to standard chronic tests. There was no consistency in test design, and few studies provided information on chemical effects on reproduction or growth in conjunction with behavioral effects. These empirical studies have little basis in ecological theory and do not allow development of testable hypotheses a priori to field verification of laboratory results. Few laboratory feeding studies have been verified in the wild. A mechanistic approach to feeding studies using optimal foraging and bioenergetics models may provide sensitive tests of contaminant effects that may be readily verified in the field. Model simulations demonstrate how toxicant effects on components of fishes' predation sequence can modify the size‐frequency distribution of prey in the fishes' diet and how reductions in the amount of food consumed may alter growth.

The effect of pollutants on sensory systems and behaviour of aquatic animals

“…Hg between 0.01 and 0.1 ppm for 24 h increasingly caused the impairment of escape responses by mosquito fish preyed on by bass (KANIA and O' HARA, 1974) and Cd at 0.4 ppm for 24 h (and 0.025 ppm for 21 d) increased the vulnerability of fathead minnows to bass (SULLIVAN et al, 1978). SANDHEINRICH and ATCHISON (1990) summarized sublethal effects of pollutants on fish foraging behaviour. Copper causes cessation of feeding or reduced food consumption in rainbow trout at 0.01-0.1 ppm, in brook trout at 0.09 ppm, and in perch at 0.04-0.08 ppm while Zn has the same effect on Atlantic salmon at 0.42 ppm and zebra fish at 3.7 ppm.…”

Human Therapeutic Plasma Levels of the Selective Serotonin Reuptake Inhibitor (SSRI) Sertraline Decrease Serotonin Reuptake Transporter Binding and Shelter-Seeking Behavior in Adult Male Fathead Minnows

“…Most early studies focused solely on directly quantifiable response measures, such as avoidance, coughs, or body tremors. 35 More recently, there has been a transition to identify changes in behaviors that have greater ecologically relevance, such as foraging, 36,37 feeding rates, 21,25,38 predator –prey interactions, 39 reproduction, 40 and social hierarchies. 41 Further, neuropsychopharmacology, neuropathology, and psychopathology studies commonly employ fish models to understand anxiety, stress, and fear.…”

Effects of cadmium on foraging behaviour of lake charr, Salvelinus namaycush

“…Among various aspects of behaviour, feeding seems especially promising for providing a good combination of sensitivity and ecological relevance (Bull & McInerney 1974, Sandheinrich & Atchison 1990, Little et al 1990) Bull & McInerney (1974 examined the behaviour of juvenile coho salmon, Oncorhynchus kisutch exposed to fenitrothion for 96 h, and suggested that of the various behaviours tested, feeding was the most sensitive indicator of low-level contamination. Little et al (1990) measured and compared various behavioural responses of rainbow trout exposed to sublethal concentrations of insecticides and herbicides for 96 h, and found changes in feeding behaviour to be a consistently sensitive response.…”

“…More specifically, foraging behaviour has been identified as being sensitive to toxicant stress, ecologically relevant, and suitable for quantification (Sandheinrich & Atchison 1990). As feeding is directly related to growth and survival, any changes in feeding, even relatively subtle ones, may have far-reaching effects on populations in the field.…”