Chemical compositions of bivalves shells: Anadara senilis, Crassostrea gasar, and Mytilus edulis and their potential for a sustainable circular economy

Abstract

The paradigm termed circular blue economy has become a concept that is greatly associated with the utilization of marine resources to ensure continued sustainability. Several constraints and limitations related to plants and plant products means human needs to look beyond green economy. The chemical constituents of animals also allow researchers to evaluate their growth and development. This study evaluates the proximate and chemical compositions of Anadara senilis, Crassostrea gasar, and Mytilus edulis, with emphasizes on their calcium and calcium carbonate contents and industrial importance. A total of 270 live bivalve samples were collected from March to May 2021 from Lagos Lagoon harbour. Each bivalve sample collected was opened to separate the flesh from the species’ shell, sun-dried and transported to the laboratory for analysis. One-way analysis of variance was adopted to estimate the significance level at 5% (P < 0.05). Post-HOC LSD test was performed to verify the disparity of mean. The results of this study revealed that Mytilus edulis shells had the highest moisture, crude protein, and crude fat at 1.15 ± 0.05%, 4.29 ± 0.43%, and 0.96 ± 0.15%, respectively and showed significant difference (P < 0.05). Anadara senilis shells had high levels of calcium (51.00 ± 2.87 mg/kg), magnesium (0.59 ± 0.23 mg/kg) and calcium carbonate (60.91 ± 2.50 mg/kg). Due to the high Ca and CaCO3 contents obtained, these shells can be processed alongside other biomaterials into food supplements, animal feeds, dental products, plant nutrient supplements, ornamental purpose, construction, agricultural industries among others. These would enhance the development of cottage industries, promotes farming of shell animals, help to alleviate the unemployment crisis and creation of wealth from substances which would have been regarded as waste.