By Christian Pérez Mallea
‘Río Pescado’ (River Fish, in Spanish) is one of the oldest hatcheries in Chile and the first to operate in the region of Los Lagos, in the heart of the local salmon industry.
By Christian Pérez Mallea
This facility has been owned by Cermaq Chile since 2003 and it includes a mixture of new technologies, a marvelous landscape, and some very old stories.
When this hatchery began operations 42 years ago it was intended to produce smoked, pan-size trout, however within this century it has been converted to the production of Atlantic salmon smolts.
Located 40km northwest of Puerto Montt, ‘Río Pescado’ is at the mouth of the river of the same name, a few minutes away from the Calbuco Volcano, and near a couple of national parks, several lakes, native woodlands, and majestic waterfalls.
Smoked pan-size trout
Since its launch in 1975, this hatchery’s water inflow was obtained from the river Pescado. Water was then channeled through concrete pipes to soil raceways and fish ponds where juveniles were reared. In those years, this was a facility with an integrated production chain, from breeders to final product, and even a smokehouse.
The first feed pellets in the country were formulated and produced at these premises in 1978. That same year, this facility was the first Chilean company to export salmonids (frozen trout) to France.
Currently, this facility receives eyed-eggs from other Cermaq hatcheries in Chile. The hatchery is comprised of five rearing rooms and one hatching area. The water intake comes from several wells located within the 5ha site (~12 acres).
Two of those rearing rooms are recirculating aquaculture systems (RAS); another two are flow-through systems and one is a reuse system. All systems totalize 1,500m3 of rearing capacity.
In the RAS systems, 95% of the water is treated, while 20% passes by similar systems in reuse.
Flow-through systems are used from eyed-eggs to yolk-sac fry, while RAS systems are used from first feeding until smoltification.
At maximum capacity, the production unit employs about 18 people and delivers close to 1.6 million smolts of 100-150g per batch (four batches per year).
In the first production stages, with flow-through systems, the facility uses seven Comphatch hatching units, 17 tanks of 10m3 each for hatched-fry and 21 tanks of 9m3 for first feeding. For inflow disinfection, the hatchery uses Biolight UV filters.
According to Anada Espina, Manager of the flow-through System, eyed-eggs arrive at 5 °C to the
hatchery, which has an average ambient temperature of 8 °C. “Therefore, one of the first tasks is a temperature acclimation of 60-90 minutes, to avoid thermal shock,” says Anada “Then, there is a hydration process that lasts for about an hour to subsequently perform disinfection of eggs with Buffodine or iodine treated water”… Meanwhile, they use Bronopol against fungus infections.
Once eggs are manually placed in the hatching systems, the temperature is recorded daily and mortalities extracted as needed (every day or every other day).
Description of RAS
Both RAS systems were provided by the local supplier, Hydrogest. In this treatment system, when water leaves the fish tank it passes through Hydrotech and PRAqua drum filters, skimmers, fluidized sand biofilters and degassing units. Later, it goes to a Low Head Oxygenation (LHO) system, UV filter, and oxygenation cones. Then, water finally returns to the tanks.
In the largest RAS system, there are two drum filters, two skimmers and four biofilters of 42m3 each, with a maximum capacity of 75,000kg fish biomass.
Just before winter is when all vaccination procedures are being prepared. Currently, the company uses a pentavalent injectable vaccine (against ISA, SRS, Vibrio, IPN and Aeromonas).
Besides rearing and vaccination, RAS areas are used for grading/sorting and photoperiod manipulation before smoltification.
Details about the reuse
Cermaq Chile is implementing an individual reuse system at ‘Río Pescado’. This technology means the replacement of only 15% of the water, without the need to use a biofilter as in traditional RAS.
According to the company, this system has efficient biosecurity barriers, since it does not allow the interexchange of water between tanks. It also has low energy consumption and is adaptable to the size of any tank.
Feeding and monitoring
Between 40 and 45 days after hatching, fry have absorbed their yolk-sacs and first-feeding starts. This process is manual at the beginning. Two to three days later a semi-automatic feeder assists in the process. Meanwhile, juveniles are fed with Storvik disc feeders.
According to Diego Gomez, Manager of the RAS System, one of the RAS rooms in this facility is in the process of migrating to a different technology. Meanwhile, the other one operates with an OCEA automatic feeding system.
Regarding O2 and temperature, the first RAS system is monitored using B&G Water technology. The second one uses an Oxyguard system while it is in the process of migrating to a Steinsvik system.
— Christian Pérez Mallea
Eruption of the Calbuco volcano
‘Río Pescado’ is located 14km west of the Calbuco volcano which erupted in April, 2016 forming a column of ashes of about 17km height.
The authorities declared an emergency zone of 20km radius around the volcano. Therefore, all personal in the facility had to evacuate and only some days later were permitted to re-enter the premises for a few hours to collect and transfer fish to other freshwater facilities of the company. This limited access lasted for six weeks.
Diego Gomez explained that ‘Río Pescado’ did not suffer from structural losses owing to that event, unlike other production units located in the north and east sides of the volcano. Some facilities were bombarded by pyroclastic material or even wiped out by lahars (melting snow causing flooding of rivers).
After 42 years and despite a nearby volcano eruption, earthquakes, violent storms, river overflows and floods, this facility is still in operation as a fundamental milestone in the history of the Chilean salmon industry.