Conservation activities in the Olo river

• Main Author: Martinho, António
• Publication Date: 2018
• Other Authors: Teixeira, Amílcar, Varandas, Simone
• Language: eng
• Source: Repositórios Científicos de Acesso Aberto de Portugal (RCAAP)
• Download full: http://hdl.handle.net/10198/19007
• topic: Conservation; Freshwater fishes; Olo river; Rivers

The management model of sport fishing in the Olo River ZPR makes eleven years of its existence in the present year. This watercourse extends over a significant area of the Alvão Natural Park, flowing through valleys embedded in different municipalities. These studies carried out in 2007 and 2013 allowed the design of a Sport Fishing Management Plan at the catchment scale. This watercourse has been subject to a special regulation (Olo River Reserved Fishing Area), since 2008. Results showed that is now possible to better know the age, growth, physical condition of the fish communities, as well as their relation with the different habitats types. The information collected over this time period permitted the adoption of measures to improve the conservation status of aquatic ecosystems such as management of the main fish species (Salmo trutta), and recovery of riparian vegetation. The production of river trout in the Marão Hatchery from parents caught in the Olo river upper reaches and the lodgment of this progeny in the same areas (ex-situ conservation action) together with the banks plantation with Salix spp., Fraxinus spp. and Alnus glutinosa, were practices used. The success of the introduction of embryonated eggs and newborn brown trout fry should be confirmed by new monitoring. As regards the afforestation actions, these proved fruitless. Habitat conservation and recovery actions (removal of litter, consolidation of banks with riparian planting, repopulation with fry and embryonated eggs with genetic material from the river itself, exclusive use of fishing gear in accordance with catch and release practice, ...) were designed to increase and improve the distribution of native fish populations. Also, awareness-raising actions developed with fishermen and other development agents promoting sustainable fishing practices of exploited resources should be continued, contributing to the improvement of the conservation status of these natural resources.