Precautionary rules for exotic trout aquaculture in fishless shallow lakes of Patagonia: minimizing impacts on the threatened hooded grebe (Podiceps gallardoi)

• 1. Conflicts between habitat use and conservation are inherent to the management of wetlands. A major challenge for their management is to preserve habitat while addressing the demands from multiple users. In southern Patagonia (Argentina), a growing aquaculture activity based on rainbow trout introductions in shallow lakes is generating concerns about the effects on the waterbird fauna, including some endemic species.
• 2. Generalized linear models (GLM) were used to analyse data on the endemic hooded grebe (Podiceps gallardoi) collected over a diverse set of lakes to: (1) build presence‐absence models as a function of environmental variables; (2) assess current and potential overlap with trout aquaculture; (3) explore the power of alternative lake assignment algorithms based on habitat variables to segregate critical habitat and aquaculture activities; and (4) explore the correlation between the probability of grebe presence and their abundance in given lakes.
• 3. Hooded grebe presence is clearly correlated with macrophyte cover, lake area, and water conductivity. Medium size lakes, with a combination of emerging macrophytes, adjacent to open water areas had the highest probability of both hooded grebe presence and abundance.
• 4. Different lake allocation scenarios are identified that could grant significant protection to hooded grebes without substantial losses for trout producers. The a priori probability to hold hooded grebe, assigned by the model based on lake characteristics, provides a tool that can be used by managing authorities to derive precautionary management rules to regulate aquaculture and to preserve primary hooded grebe habitat. Copyright © 2009 John Wiley & Sons, Ltd.