Hilsa shad (Tenulosa ilisha) is Bangladesh’s most important single-species fishery that contributes to 11% of total catch and employment for millions of people. However, heavy metals (HMs) toxicity in the edible organs of T. ilisha and their plausible public health threats have received weak attention. To provide insights on this issue, we determined, using ICP-MS, the concentration of Zn, Cu, Cr (VI), Pb, and Cd in the edible organs of five different sizes of T. ilisha and the surface water collected from the Padma–Meghna River confluence, Chandpur (Bangladesh). Multivariate analysis indicated that T. ilisha gills and liver contained higher HMs than muscle, and the surface water was below the safety limits. The study revealed that only Cr crossed the safety limits and bioaccumulated in the smaller-sized gills and liver. To assess the public health risks, target hazard quotient (THQ), total THQ (TTHQ) and carcinogenic (CR) risks were calculated. Only Cr imposed non-carcinogenic risks to consumers, while TTHQ showed higher chronic health risks. There was no CR risk measured for consumers, except for the largest-sized gills for children. Randomly positive relations between HMs and sizes were found; whereas, consistently positive relations were found among the tissue types. The outcomes of our study may aid policymakers in managing pollutants, especially the Cr sources in the greater Chandpur regions.

Epiphytic algae in mangrove forests contribute to high productivity in these unique mangrove ecosystems. A general survey of mangrove-associated macroalgae was conducted during February–March (dry season) and November–December (wet season) in the Sundarbans Mangrove Forest, Bangladesh. Different macroalgae were collected from mangrove pneumatophores, roots, and branches of trees. During this survey, a small and inconspicuous species of Chondria was encountered from the upper-middle of the intertidal zone in the Malancha River (22°5′11.37″ N and 89°13′12.37″ E). External–internal anatomical traits were examined and the sample was identified as Chondria intertexta Silva, a new record for the algal flora of Bangladesh. Furthermore, its geographical distribution and some other ecological notes are also discussed.