Fish kill forecasting a priority for DOST-ASTI’s continuous metbuoy development

22 Oct 2024 10:43 AM

Quezon City, Philippines – The Department of Science and Technology - Advanced Science and Technology Institute (DOST-ASTI) has upgraded its meteorological buoy (metbuoy) system to include vital water quality parameters, aiming to address the recurring fish kill incidents in Philippine freshwaters. This enhancement comes as a response to the pressing need for real-time data on water conditions to better understand and mitigate the causes of this environmental threat.

From 2011 to 2014, the DOST-ASTI worked in close cooperation with the DOST – Metals Industry Research and Development Center (DOST-MIRDC) to develop a low-cost and locally-designed metbuoy for offshore monitoring. This development aimed to complement the existing scientific buoys used by the DOST – Philippine Atmospheric, Geophysical, and Astronomical Services Administration (DOST-PAGASA) to improve maritime safety and enhance ocean observation systems in the Philippines. The original design of the metbuoy included a payload that gathers hydrometeorological sensor data, such as air pressure, air temperature, wind speed, wind direction, wave height, wave period, and sea surface temperature.

Figure 1. The original metbuoy design deployed at Aborlan, Palawan on 4 September 2014.

Following extensive research and consultations with the DOST Regional Office IV-A, the Bureau of Fisheries and Aquatic Resources Regional Field Office IV-A, and the Local Government Unit of San Nicolas, Batangas, the team recognized the need to address the frequent fish kill situations in Taal Lake and identified this as an opportunity to broaden the metbuoy’s payload capabilities.

On 25 May 2023, DOST-ASTI successfully redeployed the improved version of the metbuoy in a portion of Taal Lake within the area of San Nicolas, Batangas. After continuous and ongoing developments, this enhanced metbuoy currently incorporates water quality sensors that detect pH levels, ammonium, dissolved oxygen, dissolved oxygen saturation, specific conductivity, water temperature, water salinity, and water pressure on top of the previously mentioned hydrometeorological data. Improvements on LTE and Long-Range (LoRa) communications, firmware over-the-air (FOTA) implementation, short-range wireless system configuration via Bluetooth, and local base station interface software are also underway.

Figure 2. The enhanced metbuoy being attached to the main mooring line on the day of redeployment, 25 May 2023.

Data from the metbuoy can be viewed in real-time on the PhilSensors website and Android application, both in tabular and graphical views. Historical data and API access may also be provided by the team on a per-request basis.

Figure 3. A preview of the pH value and water pressure parameters on the home dashboard of the PhilSensors website.

The improved metbuoy proved its capabilities when the BFAR Regional Office IV-A compared the data they gathered with the data generated by the metbuoy to assess water quality during a fish kill event in Taal Lake from 13-15 July 2023. This event affected 241 fish cages, resulting in an estimated total damage of 586.38 metric tons with a market value of ₱54.685 million. Not only did the metbuoy data show similar dissolved oxygen levels with measurements made by BFAR, it also identified a downtrend in water quality parameters a month before the fish kill occurred (Figure 5). This observation concluded that the metbuoy was instrumental in the assessment of water quality in the areas near the site of deployment, aided with further water quality monitoring and analysis in affected areas of Taal Lake. This also demonstrates that the metbuoy has the capability to generate short-term water quality forecasts.

Figure 4. Data from the metbuoy showed that the dissolved oxygen level near San Nicolas, Batangas was already decreasing a month before the fish kill phenomenon occurred.

In present developments under the Metbuoy+ project, the team is comprehensively monitoring the metbuoy’s performance across all technological aspects, with a primary focus on fulfilling real-time monitoring of Taal Lake’s quality to forecast and proactively prevent fish kills within its area of coverage. The team is also looking into designing a scaled-down version of the metbuoy that maintains full functionality to cut deployment costs as well as provide a more accessible and affordable option for potential stakeholders.