11 pages., via online journal., Fish farmers need to take into account many factors, including climate-related risks, when making decisions to invest in stocking ponds or cages in rivers. Officials, experts, and other fish farmers try to influence these decisions by communicating information about risks verbally or using text messages. Recurrent mass mortality events associated with droughts and floods suggest some communication efforts have been ineffective. Theories of risk communication make different predictions about what elements make messages influential. The purpose of this study was to improve understanding of the potential influence of inserting tactical messages into a communication text on the decision behavior of fish farmers with respect to climate-related risks. Experiments were carried out on hand-held tablets with 1050 fish farmers as subjects. Fish farmers were asked to imagine they faced a risk of drought, water shortage, flood, or increasing risks of drought in a drying climate. They were also given a plausible response measure that would require some investment, and then asked to indicate how likely they would adopt that measure. Farmers’ intentions to take risk reduction actions in long-term adaptation increased when the message they received re-affirmed that they were susceptible to the threat, an impact was likely or that the response to the risk was an effective measure. For shorter-term risk reduction measures, the effect of re-affirming response efficacy was to suppress intentions to act. This study found no evidence that appeals to fear, guilt, or anxiety emotions work; references to social norms, behavioral control, and benefit versus cost arguments also failed to increase intentions to act. The findings of this study supported some propositions of common risk communication theories but not others. The methods and findings are useful for improving the design of communications aimed at informing farmers about climate-related risks.