Highlights ► Wave heights have a significant effect on the extent of macroalgal canopies. ► Hydrodynamics explains most of intra-community structural variations. ► In situ pressure measurements enable smallscale evaluation of wave heights. Please note that this is an author-produced PDF of an article accepted for publication following peer review. The definitive publisher-authenticated version is available on the publisher Web site.

In recent years, development of sustainable and ecological food production is of worldwide interest. It seems clear that this phenomenon is causing a changes in the aquaculture focused research, with the development of new integration systems. However, it is still necessary to understand different aspects involved in new integrated systems, including co-culture systems such as shrimp and seaweed. This study evaluated the effect of green seaweed as food source on white shrimp Penaeus vannamei intestinal bacterial communities. Survival, growth performance and feed utilization were evaluated after a 4-week experimental trial with shrimp P. vannamei fed with only pellet (P), only U. clathrata (UC), clathrata+pellet (UCP), Ulva only U. lactuca (UL) and Ulva lactuca+pellet (ULP). No significant differences observed between U. lactuca+pellet (ULP) and Ulva clathrata+pellet (UCP) compared to the control (P). Analysis of intestinal bacterial communities revealed significant differences on community variation in ULP, UL and UC in respect to the control (P) (p<0.05). We found that Proteobacteria is the major phylum in all treatments, followed by Bacteroidetes for UC, UCP and UL and Actinobacteria for P and ULP treatments. Relative abundance of Vibrio was higher in the control (P), showing a significant decrease in UC treatment. The results of this study provide information about changes in the intestinal bacterial community of shrimp by incorporatin the green seaweeds U. clatratha and U. lactuca as natural feed. Our findings provide a better understanding of integrated aquaculture systems, specifically those utilizing seaweed as a natural feed source.