Carbon Sources Supporting Macro-Invertebrate Communities in Restored Mangrove Forests from Hau Loc, Thanh Hoa, Vietnam

Abstract

Mangrove forests are important in providing habitats for complex communities of terrestrial and marine fauna. Moreover, they are recognized as highly productive ecosystems in providing nutrients to mangrove food webs or exporting them to nearby coastal waters. In the present study, stable isotopes of carbon and nitrogen were applied to examine the changes in the diets of benthic invertebrate communities following mangrove restoration. The isotope signature of invertebrate tissues varied among the forest ages and locations and ranged from 3.7 ± 1.0 to 13.9 ± 1.1‰ and −26.6 ± 0.5 to −15.0 ± 0.4‰ for δ15N and δ13C, respectively. The results showed that the food source assimilation of macro-invertebrates is slightly altered from a mixture of benthic microalgae and marine phytoplankton in the mudflat to a combination of benthic microalgae and sediment organic matter in the Sonneratia caseolaris and the Kandelia obovata forests. Therefore, the diets of macro-invertebrates varied following forest ages and the position of the forest in the intertidal zone. These insights from the present study are useful for the effective conservation and restoration of mangrove forests in Vietnam and worldwide.

Sources of sedimentary organic carbon in coastal ecosystems from the Tien Yen Bay, Quang Ninh

“…The mangrove forest biomass is significantly higher than seagrass, which provides a vital source of OC for coastal waters. The POM in coastal water and estuaries in sampling areas was higher than the previous research in Thanh Hoa, Red River Delta [4,22]. This pattern may be related to the geomorphological settings of Tien Yen Bay, causing the mangrove materials to not be accessible and exported to open water, leds to low values of δ 13 C in POM samples [21].…”

“…[1][2]. They also provide critical ecological functions and services such as nursing habitat, feeding zone, breeding grounds for aquatic species, waterbirds, migratory birds, and providing high economic benefits for humans [3][4][5]. Recently, mangrove forests have been degraded globally due to human activities such as aquaculture, urbanization, industry, and agriculture [6][7].…”

Tidal zone effects on the diet composition of leaf-eating crabs in natural mangrove communities: a stable isotope analysis

“…According to Feng et al (2017), changes in the structure of mangrove vegetation communities can affect the availability and palatability of food sources for leaf-eating crabs. Van Hieu et al (2020) discovered that crabs primarily feed on phytoplankton and benthic microalgae in mudflats, while in Sonneratia caseolaris and Kandelia candel forests, their diet consists mainly of benthic microalgae and sediment organic matter. Past studies have shown differences in the food sources of crabs in mangrove margin areas and forest interior areas (Kruitwagen et al, 2010).…”