EDP Foz Tua Otter (Lutra lutra) [transects] - Ecological Monitoring Program (2011-17)

Study Extent

The data were collected in the rivers Douro and Tua sub-basins, in the municipalities of Carrazeda de Ansiães, Vila Flor, Alijó, Murça and Mirandela, S. João da Pesqueira and Tabuaço.

Sampling

Sampling was designed to cover the course of the lower river Tua and its main tributaries from the mouth up to the northern limit of the Foz-Tua dam, and the downstream part of the three Douro tributaries, up to 5 km. Up to 24 sampling transects were setup in the Tua sub-basin and one more was located in each of the four Douro tributaries (systematically recorded only for 2011). Each transect up to 600 m was performed along the margins, looking for signs of presence (mostly scats) in suitable places (prominent stones and vegetation in the margins of the water line). The transect was interrupted when the presence of the otter was detected, but never before 200 m had been prospected. Each plot was visited once in dry or light rain periods (June-July), to minimize the chance of leaching of the fecal material. The scats potentially attributed to the species were stored and taken to the laboratory to molecular identification. Only presence/absence information was retained.

Quality Control

All identifications were performed by qualified technicians

Method steps

1. To be completed

The taxonomic coverage of this dataset spans 1 phylum, 1 class, 1 order, 1 family, 1 genus and 1 species.

1. Mammalia
   rank: class
2. Carnivora
   rank: order
3. Mustelidae
   rank: family

The data were collected in selected sampling points in the rivers Tua and Douro sub-basins (Northeast Portugal), including the whole course of river Tua and its main tributaries and river Tuela and the downstream stretches of rivers Pinhão, Távora and Torto, in the Douro basin, in the municipalities of Carrazeda de Ansiães, Vila Flor, Alijó, Murça and Mirandela, S. João da Pesqueira and Tabuaço.