NEWS RELEASE FROM
Vaki Aquaculture Systems Ltd
The need for monitoring the migration of fish in rivers has never been as great as today, with declining stocks, polluted rivers and growing aquaculture production in critical areas.
Vaki Aquaculture Systems Ltd. has been a leading company in developing equipment for counting and measuring the size of live fish since 1986. The Riverwatcher is a product of continuous R&D, based on proven technology in exposed conditions in the aquaculture industry.
Monitoring without handling the fish
The Riverwatcher is a counter for use in fish ladders, barrier dams or other places where fish swim through a restricted passage. Various versions are available, and the Riverwatcher can be adapted to local conditions in each individual instance. The Riverwatcher consists of a computer unit, a scanner unit with a data bank and cables, a digital camera system and a computer program for processing the data.
The Scanner is installed in fish ladders, pools, traps or similar places where all the fish in the river have to pass. It consists of two scanner plates (20 x 60 cm) inside a frame, the distance between them being from 10 to 45 cm. Inside the scanner, light diodes send infra-red light beams to receivers on the other side. When a fish swims through the net of light beams, the resulting silhouette image is used to count and estimate the weight of each fish. Each individual image is memorised in the control unit so that the counting can be verified afterwards.
The Computer Unit receives the information from the scanner and stores it. The temperature of the water is measured at programmable intervals and the date and time of day that each fish passes the counter is also recorded. In this way their movements can be correlated with environmental factors. The power supply consists of solar panels and a deep cycle battery.
The PC program is used to analyse and present the data from the Riverwatcher. It is possible to examine the migration pattern of the fish over a particular period, by size groupings or for a particular time of the day. You can also examine temperature records for a particular period, and analyse the silhouette images of each fish to verify the counting.
The camera unit combines both infrared- and video technology. When a fish passes through the infrared scanner it triggers the camera that records a digital images, or video clip of the passing fish. The advantage of this method is that the user, who examines the data, can quickly go through the images on the computer and determine their species (or even population and sex). Information is automatically stored in a database file among other data on time of passage, size, temperature and a shadow image of the fish from the infrared scanner.
Riverwatcher Forums in Europe
In April VAKI will be hosting two events around the Riverwatcher, one at The Diehl´s Hotel, Koblenz Germany and one at Park Inn by Radison, Oslo Airport, Norway. This will provide a platform for several stakeholders such as scientists, fishing clubs, river owners, environmental authorities and others interested in learning about new technology to monitor fish and hear about several case studies from around the world. A Riverwatcher will be set up for demonstration at the Koblenz event but delegates will also have opportunity to visit the local power station and see the Mosel Riverwatcher in action. A new visitor center at the site has a glass wall facing into the fishway and our local experts promise some migration movement during drinks and discussions at the site!
The forums:
In Koblenz
April 17-18th, 2012
At the event you will get the opportunity to see the Mosel Riverwatcher in action. The forum is divided into two sections.
Day 1: starts at 12.00 noon to 5.00 pm.
Day 2: starts at 9.00 am to 12.00 noon.
In Oslo
April 19th, 2012
the Oslo seminar is set up as a one day event from 9.00 am to 5.00 pm.
Registration here. Seminar fee is 75 EU. Invoice will be sent after the seminar.
Early registrants get a special price at the Diehls Hotel (90 EUR) if they send an e-mail to the Hotel and mention the Seminar.
Last Riverwatcher seminar was held in Sacramento CA in 2010 and was a huge success. Don´t miss this first seminar in Europe, since Iceland 2009!
Contact Magnus for futher information at magnus@vaki.is
The advantages of the Riverwatcher
- Comparison of catch figures and the movement pattern of the fish to calculate the exploitation rate
- Comparison of the movement pattern of the fish from one year to another
- Evaluation of the results of rearing and smolt releases
- Assessment of the influence of different environmental factors
- Assessment of the efficiency of the fish ladder
- Valuable data for better fisheries management
The installations
The Riverwatcher is used in more than 300 sites all over the world including Iceland, Scandinavia, Ireland, UK, USA, Canada, Spain, Portugal, Poland, the Czech Republic, Germany and Switzerland.. In the presentation I will show some results from different rivers in Scandinavia, UK and N-America.
