# Laminar _Ulva_ Species: A Multi-Tool for Humankind?
## 5 Commercial Potential
### Feed Aquaculture and Bioremediation  
Fed aquaculture (animal feed) is a growing industry, but according to scientists like [PERSON] [214; 215] and others [216; 217; 218], it dumps heavy loads of nutrients into coastal waters, potentially leading to the deterioration of local marine environments. A possible solution to this problem is to integrate seaweed into fish farming, that is, to combine fed aquaculture with extractive aquaculture (algaculture). There are already studies that combine seaweed culture with terrestrial fish tanks or open sea fish cages [219], as well as studies on _Ulva_ species used mainly from the point of view of treating lagoon effluents/land tanks [220].  
According to [PERSON] et al., 1996 [218], seaweed removed up to 90% of the nutrients discarded from intensive fish farming [219]. [PERSON] et al., 2011 [165] selected _U. lactuca_ to investigate its relevance in integrated aquaculture on the Red Sea (Saudi Arabia). The results confirm that tank-grown _Ulva_ was greatly effective in treating fish farming effluents. They also determined that the algae stalks require greater surface area than the overall size of the culture tank to absorb enough light for photosynthesis, and it functioned well with marine tilapia (_O. spilurus_), as well as with effluent from sea bream culture, _Sparus aurata_ in Israel. The literature also states that it is suitable for integration with shrimp systems (Kuruma, _Penaues japonicus_ larvae) resulting in greater survival and better growth of shrimp larvae and lower bacterial density due to high tolerance and affinity for ammonia absorption [165].  
[PERSON] et al., in 2015 [221], discovered that Nile tilapia given 5% seaweed outperformed those fed the control (and 10% seaweed). This study concluded that _U. lactuca_ bran may be used as a supplemental element in the diet of Nile tilapia without affecting their zootechnical performance, feed consumption, or body structure.  
[PERSON] et al., 2016 [222], working with _U. rigida_ stems, discovered that higher temperatures boosted nitrate and phosphate absorption when they were vegetative. However, the greater temperature resulted in negative nutrient intake during reproductive events, indicating that the thalli were releasing rather than absorbing nutrients from the ocean. Possibly due to the release of spores, nutrients are also discharged, and increasing temperature may increase the rate of decomposition, thereby increasing the rate of nutrient release. As a result, it was proposed that _Ulva_ species may actually be a source of nutrients when they reproduce, which has consequences for biofilter effectiveness, as sustaining a long-term vegetative state seemed to be crucial to improving _Ulva_ species' biofiltration effectiveness [220].  
We can thus say that the cultivation of algae along the coast can function as an effective biofilter to alleviate the problem of eutrophication throughout the world and provide benefits in fish growth; certain species can be used as bioindicators of nutrients in the water column, thus being able to improve aquaculture systems and restore ecosystems.