SeaSense seaweed monitoring

Arribada Initiative C.I.C.

SeaSense seaweed monitoring

3D printable water quality sensors to monitor the health of responsibly grown seaweed

Portsmouth, United Kingdom

GBR

Nonprofit

Arribada has developed a low-cost seawater parameter sensor (SeaSense) for Coast4C, an impact-driven enterprise based in the Philippines that aims to become the world’s largest supplier of regenerative seaweed, benefiting the 4Cs of Community, Commerce, Conservation and Climate. Coast 4C combines the local ecological knowledge of marginalised smallholder seaweed farmers with sustainable methods and technological innovation to help lift livelihoods of coastal communities while improving conservation outcomes in marine areas. The SeaSense has been designed to be mounted alongside seaweed lines to monitor and track water quality over time, rising and falling with the tide to accurately monitor 6 different water parameters related to seaweed health. The SeaSense sensor provide a means to alerting local growers to climate-induced stresses, possible disease onset and evidence of change over time that can result in crop failure and affect seaweed growths and sustainable livelihoods. Arribada and Coast4C's vision is that the practice of growing regenerative seaweed should be replicated throughout the global tropics (with locally appropriate seaweed species) to benefit the estimated 400 million small-scale fishers living at the front-line of climate change, and to achieve this the monitoring of water quality and seaweed health at scale is critical.

The SeaSense sensor logs and monitors 6 vital water quality parameters to accurately identify local stresses that may affect seaweed growth and health. It is different to a traditional off-the-shelf water monitoring sensor in that it was co-designed with Coast4C's local team and seaweed growing community to be better suited for monitoring seaweed health at very low-cost vs a traditionally expensive seawater quality sensor that is unaffordable to growers. A specifically designed pole mount enables the sensor to rise and fall with the tide, attached with via a 3D printed cradle. Both the pole (locally sourced plumbing pipe) and the sensor's enclosure can be manufactured using recycled plastic. Because the sensor can be positioned directly alongside seaweed growing on a seaweed rack, accurate light / lux levels related to sedimentation or water clarity can be accurately assessed together with total dissolved solids, salinity, temperature, Ph and date / time. The electronics inside utilise an ultra low-cost RP2040 microcontroller and simple probe interface to make it easy to clean, with wireless connectivity enabling anyone with a basic Android smartphone to access data and easily share this with Coast4C for inference and guidance for growers based on the results of their data.

The primary users/customers of the SeaSense are small-scale seaweed farmers and fishers living in biodiversity hotspots. Over 90% of households in most of the communities that Coast4C work in depend on either (or both) seaweed farming or fishing. Seaweed farmers using SeaSense will benefit from improved crop yields and will be better able to react to and understand future climatic stresses if water quality changes over time. Additionally, by helping seaweed farmers to sustain and/or increase their production, sustainable livelihoods can be supported and income generated sustainably to help to reduce dependency on fishing, as well as enabling coastal communities to set aside larger protected areas of the sea that can both generate income, absorb CO2 and provide protection to fish stocks. Larger and more effective community-based marine protected areas (MPAs) are essential tools for maintaining marine biodiversity and replenishing fish stocks, and can be integrated with seaweed farming for mutual benefit. Lastly, although the Philippines contains over 1,500 marine protected areas, with an average size of 16 hectares they are too small to meet national and international conservation targets at present. Regenerative seaweed farming provides a solution to increasing MPAs, supporting local communities and achieving a zero neutral future.