Instrumentation and Monitoring in Aquaculture

Instrumentation and Monitoring

Introduction

Equipment for measuring and recording of various parameters is more and more commonly used in aquaculture, especially in intensive aquaculture. Such equipment controls and adjusts the environ-mental conditions to obtain optimal production results. Until now several of the measurements have been taken manually, which is normally more time consuming and labour intensive, and therefore results in fewer measurements. During the past few years, there has been rapid development in the automation of instruments and monitoring systems that can also be used in the aquaculture industry, mainly based on developments in electronics and computer science. Therefore many of the trivial manual measurements are now carried out by specially designed instruments, releasing manpower for more important intellectual tasks and to improve the production results, especially in intensive aquaculture.

One reason for using instruments is to automate the management of fish farming as much as possible. For example, video cameras and image analysis can be used to monitor fish and give alarm signals if odd behaviour is observed. The biological processes underlying fish production are, however, both complex and difficult, unlike the production of nails. Even with today’s knowledge, it is only a dream to believe that it is possible to fully replace the fish farmer with instruments and robots.

When buying and installing instruments, the requirements for maintenance and calibration, adjusted for special circumstances must be taken into account. The values read from the measuring equipment must be reliable; otherwise the result can be more damaging than if no measuring equipment were used at all. This implies that maintenance and running costs must be included in the price of an instrument, not just the purchase cost. Extra effort must be given to maintenance of instruments used to monitor water quality. This also includes frequent calibration according to the manufacturer’s instructions so that the values shown are reliable. Depending on the type of instrument, the sensors may have a limited duration, so must be exchanged at fixed intervals.

Measurement of biological performance has also increased during the past few years as a result of the increased focus on profitability in intensive fish farming. By automatically measuring development in terms of weight and total fish biomass, it is possible to control the development and intervene if something does not correspond to the production plans.

Due to the large expense involved and the amount of technical equipment that can fail, it is increasingly common to have a total monitoring system on the farm, which also includes a significant use of computer tools. On land-based farms using pumps for the water supply or in farms with re-use of water such systems are essential.

There is much general literature available describing measurements, instruments and sensors.