Mangrove forest is a natural resource typical of tropical coasts, which has multiple benefits with a very broad impact when viewed from social, economic and ecological aspects. Management of natural resources must be very prudent because it takes a long time to be able to recover when damage / extinction has occurred. The purpose of this study was to determine the composition of mangrove species, the structure of mangrove forest vegetation (species density, relative density of species, frequency of species, relative frequency of species, species cover, relative cover of species and important values) and to determine the level of damage. Extraction of mangrove vegetation using the "spot check" method. The transects are drawn perpendicular to the coastline along the mangrove vegetation. The composition of mangrove species were 7 species, namely Rhizophora apiculata, R. stylosa, Bruguirea gymnorrhiza, Ceriops tagal, Sonneratia alba, Xylocarpus granatum and Aegiceras floridum. In the vegetation structure, the highest density and relative density were found in Rhizophora stylosa and the lowest was Xylocarpus granatum. The highest species and relative frequencies were Rhizophora stylosa, R. apiculata and the lowest were Bruguiera gymnorrhiza. The highest type and closure were Sonneratia alba and the lowest was Ceriops tagal. Meanwhile, the highest importance was in Sonneratia alba and the lowest was Xylocarpus granatum. Overall, the density value of mangrove species on Manomadehe Island is 2796 trees / ha so that the condition of the mangrove forests on Manomadehe Island is still in the good category (very dense).

Continuous exposure to an area with a sound above the threshold level is one of the triggers for noise pollution in public spaces. Public spaces are spaces where people of all ages gather for leisure activities, recreation, etc. The purpose of this study was to find the average dBA value of noise, community perceptions regarding the comfort of sound in coastal public spaces, and the relationship between the dBA value and the existing sound comfort standards. The focus of this research is to contribute to a public space that is free from noise pollution. The study was conducted on the coast of Manado, precisely in the Boboca monument area, using mixed methods through the formula LAeq 10 minutes and Leq daylight to get the standard value of noise. The results found noise numbers in the range 77.4 – 80.2 dBA, this value has exceeded the required standard of 50 dBA, and the results of the perception are also supportive, which is dominant in public perception. It means that coastal public spaces in the Boboca monument area have been exposed to noise pollution.