Yuval Gur

PhD Candidate

Prof. Ezri Terezi
Prof. Nitai Drimer ( Mechanical Engineering )

Consutant: Dr. Alvaro Israel (Israel oceanographic & Limnological Research)

The influence of different structural forms of aquacultural open-sea algae cultivation tanks on the growth rate of the algae

It is generally accepted that the fields of marine environment and agriculture fields face various challenges. The most consequential of them are biodiversity reduction, changes in nutrients balance in the sea, shortage of valuable land, and worldwide increasing need of protein resources for humans. There is now much evidence that open-sea algae cultivation may have a significant potential in facing those challenges.

In the last century, biodiversity reduction in the marine environment increased due to industrial fishing and the rapid expansion of the coastal population (McCauley et al., 2015). Biochemical flows, especially phosphorus and nitrogen cycle, are also imbalanced due to human activity such as fertilizers remaining and sewage that flows to rivers and the oceans (Steffen et al., 2015). In the field of agriculture, the lack of land for agriculture derives from soil erosion and desertification, urbanization, and climate change (Zabel, Putzenlechner, & Mauser, 2014). And lack of protein sources is deriving from global population growth and changes in socio-demographics. (Henchion, Hayes, Mullen, Fenelon, & Tiwari, 2017). These facts cause a global search for the next sustainable source of protein.

Open-sea algae cultivation may be a sustainable and ecological solution for the challenges mentioned. As part of the natural function of algae in the marine ecosystem, using photosynthesis, the algae absorb carbon dioxide and release oxygen (Beer & Koch, 1996). Furthermore, it absorbs nitrogen and phosphorus at high rates (Neori, Shpigel, & Ben-Ezra, 2000) and contains a high ratio of protein (Shpigel, Neori, Popper, & Gordin, 1993). There is an ongoing effort to foster farming and mariculture to offshore cultivation for more than two decades (Krause & Stead, 2017) due to the potential of the open-seas to supply a sustainable and efficient infrastructure for the solution of the multiple challenges presented above.

Although the ongoing efforts, offshore algae cultivation methods, and equipment have developed slowly over a long time due to technological and operational difficulties, moreover, the existing cultivation methods are using devices and equipment that is not designed primarily for aquaculture. Withal, almost none of the research work in these fields are from the design research discipline. Using design tools as an alternative approach can innovate this research field significantly. The absence of designers in this field can link to the limitation in the exploration of the structural forms of those open-sea algae cultivation platforms.

The research presents a process of design, development and optimization of open-sea algae cultivation methods using advanced design tools and nature-centered design. The research aim is to compare various forms and function factors; to find a better design system for growing algae in a marine agriculture environment.