Spatio-temporal variation of subtidal macrobenthic fauna and the ecological assessment of Longkou Artificial Island construction in Bohai Sea, China

Abstract

Decabromodiphenyl ether (BDE209) has been subject to restrictions since 2018 in developed countries but is still manufacturing in China. Decabromodiphenyl ethane (DBDPE) is widely used as a replacement for BDE209. To better understand the behaviors and fates of these legacy and novel brominated flame retardants (BFRs), water samples were collected from the estuaries of 36 rivers that drain into the Bohai Sea (BS) and North Yellow Sea (NYS) in 2017 and 2018. The results showed that BDE209 was still the predominant compound with a median concentration of 2470 pg L À1 , whereas DBDPE had a median concentration of 129 pg L À1 . Spatially, relatively high concentrations were observed in the rivers near Laizhou Bay (LB), which is the manufacturing hub of BFRs. BDE209 concentrations were significantly higher in dry season than in wet season, which indicates a dominant process of dilution by precipitation during the wet season. DBDPE concentration showed no significant seasonal difference. This implies that wet deposition was the major additional source of DBDPE during the wet season, and the concentration increased further during the autumn as a result of a time-lag effect. The BFR concentrations in urban rivers were lower than those reported by a study undertaken in August 2013. An increase in the BFR concentrations in rural rivers since 2013 suggested increases in the use and non-point source emissions of BFRs in some remote aquatic environments. The estimated annual inputs of BDE209 and DBDPE into the BS were ~95.9 kg yr À1 and ~26.8 kg yr À1 , respectively, whereas those into the NYS were ~24.1 kg yr À1 and ~8.38 kg yr À1 . The results revealed an ecological risk of BDE209 in winter especially in the Xiaoqing River, thus suggesting the impact of BDE209 on the aquatic environment and human health.

The Relationship between Salinity and Benthic Fauna Diversity and Abundance at Songkhla Port, Thailand

“…The study of the relationship between environmental factors and fouling organisms by CCA at the Songkhla port of the Songkhla lagoon revealed that salinity and transparency were the main environmental parameters correlated with diversity and abundance of benthic fauna. This result is also congruent with many prior studies in other areas in the tropical zone, supporting the concept that salinity interacts with the structure of the benthic community (Alipoor, Rahimibashar, and Alior, 2011;Xiaojing et al, 2019;Ysebaert et al, 2003). In addition, benthic organisms were identified as barnacles, Eriphiidae, and megalopa (crustacean); Arcidae, Mytilidae, and Tellinidae (mollusks); and Lumbrineridae (polychaetes), corroborating the strong influence of these two parameters.…”

“…The density can be addressed from a different viewpoint of which group would favor the ecological habitat. The three main groups found in this study are distributed widely in the aquatic ecosystem, are highly prevalent in the marine habitat because of their ecological function, and are normally numerous compared with other groups (Bozorgchenani, Seyfabadi, and Shokri, 2018;Xiaojing et al, 2019). The settlement observed by panel sampling can indicate larva are available and living in the habitat.…”