Periodic Report Summary - OPTOCO2FISH (Development of an Opto-chemical Carbon Dioxide Sensor for Aquaculture and Oceanography Applications)
The aim of OPTOCO2FISH is to develop an optical based CO2 sensor for the continuous monitoring of CO2 levels in aqueous solutions in the fields of fish farming and oceanography. The sensor will consist of a sensitive membrane, an optical unit, an electronic core and a mechanical enclosure.
Project objectives:
- First, due to the fields of application - fish farming and oceanography - precise specifications of the sensor and of the measurement unit to be defined by evaluation of user-requirements and producer knowledge.
- Study of the effect of dissolved CO2 on farmed fish and determination of CO2 levels in different aquaculture production systems (sea cages, ponds, Flow through systems...).
- CO2 sensitive membrane: synthesis of stable sensitive dyes follow by development of sensitive membrane including protective layer.
- Electronic core: development of an interrogation unit for decay-time measurement.
- Development of production process of sensitive membrane and calibration routine.
- Appropriate field tests to approve the sensor specifications and usability.
Work performed and results:
1/ Specifications of CO2 sensor have been defined with all relevant parameters (measurement range, accuracy, temperature range, response time, operation time...) for both applications fish farming and oceanography.
2/ The literature review of the physiological effects of CO2 on different species of fish demonstrate that all teleosts show a highly comparable compensation mechanism for hypercapnia. Hypercapnia is a situation where the concentration of CO2 is increasing.
The effects and consequences of hypercapnia depend on the duration and concentration of exposure. For most species, mild effects are found at prolonged exposure to <5 mmHg. Chronic exposure to elevated CO2 concentrations (>15 mmHg) generally result in severe physiological disturbance, as well as secondary effects as inhibited growth and swimming behaviour, and can eventually lead to high mortality rates in several species.
3/ The inventory of CO2 levels at farms is in progress. This task aims to establish dissolved CO2 concentrations in fish farms covering the most important production systems used and fish species cultured in the EU.
4/ The report of the relative importance of the CO2 level in aquaculture has been done. It must be noted that CO2 control is of high importance in species - system combinations like salmon smolts produce in flow through systems and recirculation systems (RAS).
5/ Sensitive membrane is a key component of the CO2 sensor. This is a three layers system consequently, sensitive membranes have been developed by testing donor/acceptor dye combination, polymer matrix and necessary protective coating. Best candidates have been tested for a detailed characterisation (sensitivity, stability, response time).
The literature review about physiological effects of CO2 in fish and high levels of CO2 in many systems in fish farms indicate that CO2 sensor could be a efficient equipment for optimum monitoring in fish farms. Identification of promising dye-polymer combinations open the way to development of a prototype for preliminary test in laboratory and field test.
Project objectives:
- First, due to the fields of application - fish farming and oceanography - precise specifications of the sensor and of the measurement unit to be defined by evaluation of user-requirements and producer knowledge.
- Study of the effect of dissolved CO2 on farmed fish and determination of CO2 levels in different aquaculture production systems (sea cages, ponds, Flow through systems...).
- CO2 sensitive membrane: synthesis of stable sensitive dyes follow by development of sensitive membrane including protective layer.
- Electronic core: development of an interrogation unit for decay-time measurement.
- Development of production process of sensitive membrane and calibration routine.
- Appropriate field tests to approve the sensor specifications and usability.
Work performed and results:
1/ Specifications of CO2 sensor have been defined with all relevant parameters (measurement range, accuracy, temperature range, response time, operation time...) for both applications fish farming and oceanography.
2/ The literature review of the physiological effects of CO2 on different species of fish demonstrate that all teleosts show a highly comparable compensation mechanism for hypercapnia. Hypercapnia is a situation where the concentration of CO2 is increasing.
The effects and consequences of hypercapnia depend on the duration and concentration of exposure. For most species, mild effects are found at prolonged exposure to <5 mmHg. Chronic exposure to elevated CO2 concentrations (>15 mmHg) generally result in severe physiological disturbance, as well as secondary effects as inhibited growth and swimming behaviour, and can eventually lead to high mortality rates in several species.
3/ The inventory of CO2 levels at farms is in progress. This task aims to establish dissolved CO2 concentrations in fish farms covering the most important production systems used and fish species cultured in the EU.
4/ The report of the relative importance of the CO2 level in aquaculture has been done. It must be noted that CO2 control is of high importance in species - system combinations like salmon smolts produce in flow through systems and recirculation systems (RAS).
5/ Sensitive membrane is a key component of the CO2 sensor. This is a three layers system consequently, sensitive membranes have been developed by testing donor/acceptor dye combination, polymer matrix and necessary protective coating. Best candidates have been tested for a detailed characterisation (sensitivity, stability, response time).
The literature review about physiological effects of CO2 in fish and high levels of CO2 in many systems in fish farms indicate that CO2 sensor could be a efficient equipment for optimum monitoring in fish farms. Identification of promising dye-polymer combinations open the way to development of a prototype for preliminary test in laboratory and field test.