Experimental site of Lapitxuri

Scientific & technical context:

INRAE built the experimental spawning channel of Lapitxuri in 1980 as part of the "Salmon" plan (state, regional and ministry funding). The objective was to study optimal conditions for developing Atlantic salmon in a semi-natural environment and to define the scientific basis for producing juveniles for restocking, with a view to technology transfer. Since then, many scientific projects have used the site, which is particularly original and unique  in Europe, to conduct experiments in ecology and study fish behaviour (growth, dispersal, reproduction, etc.).

Description of the facilities:

The channel was built at the head of the Nivelle River basin in the town of Aïnhoa. The absence of intensive agricultural and human activity ensures that the water has good physico-chemical quality and contains no pollutants. Mean temperatures range from 4-20°C throughout the year. The site’s breeding facility is free from viral haemorrhagic septicaemia and infectious haematopoietic necrosis (approval no. 64330056) and is monitored annually by the Aquaculture Health Protection Group of Aquitaine (GDSA) and Office of Veterinary Services of the Pyrénées-Atlantiques department (DDSV 64) . The site has four tools:

•  A spawning channel fed by diverting the Lapitxuri stream, with a gradient of 2%, a length of 130 m and a succession of 13 reaches (each 10 m x 2.8 m). The inflow is adjustable from 50-150 l.s^-1, and an automated pumping/recirculation system moves the water upstream of the channel to compensate for the low flows of the diverted stream. Its particle size (10-80 mm) and physical parameters (water height, area and connectivity of the reaches, etc.) can be adjusted. Anti-bird nets prevent predation of fish. One of the channel’s innovations is the ability to study fish behaviour using underwater observation chambers and video equipment. At night, aerial  infrared lights allow certain behaviours to be monitored.

• Eight troughs (each 10 m x 0.5 m, depth: 0.25 m) are used to conduct experiments on young stages of salmonids. Sets of grids or pitfalls can be adapted. Shading nets limit water warming, algae development and bird predation. The troughs are supplied with water filtered at 15 μm that flows at a maximum rate of 52 l.s^-1 and are equipped with a passive safety system to prevent a power outage from interrupting the water supply.

•  An incubation laboratory to incubate and monitor small batches of eggs or fry. It is equipped with two cabinets of Heath incubation trays (capacity of 160,000 eggs), 6 incubator troughs and 6 bins of 60 L each. It is supplied with water filtered at 15 μm to avoid clogging the trays in the event of flooding.

•  A breeding platform equipped with 16 Swedish-type basins of 4 m² each and 8 basins of 1 m² each. It is used to house fish and potentially rear juveniles for on- or off-site experiments (natural environment, technical platform, etc.).

Contact : Jean-Christophe Aymes

Location