Search

Mangrove forests of Ecuador's Gulf of Guayaquil are ecologically, culturally, and economically important to local communities relying on them for artisanal fishing, ecotourism, and related businesses. However, these ecosystems have experienced significant degradation by anthropogenic impacts such as anthropogenic marine debris. On one hand, plastics have improved the ease of life and safety for local people of the region; however, plastic pollution threatens the health of the mangrove ecosystem and these communities. This interdisciplinary study explores perceptions of marine litter and its impacts on community well-being based on surveys conducted in Puerto Hondo and Santay Island, two mangrove communities in the Gulf of Guayaquil, in 2019 and 2021. Santay Island respondents expressed that marine litter is an extreme issue affecting their well-being, while Puerto Hondo respondents reported less concern. Authors suggest Puerto Hondo's geographic link to Guayaquil city has transitioned the community into a "peri-urban" landscape, where community members increasingly look inland for basic needs. Conversely, Santay Island, isolated by estuarine water, is physically linked to the mangroves. It is suggested that as communities spend less time in the mangroves, whether geographically or socially separated, marine litter becomes "out of sight, out of mind" despite its ongoing impacts on local food security and historical heritage. This work illustrates the complexities of plastic use and marine debris. To foster equitable plastic waste governance for exposed coastal Ecuadorian communities, policies must not only account for these intricacies but also actively engage with and listen to local perspectives. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract Water and sediment quality, macrobenthos diversity and mercury levels were assessed in the Salado Estuary, Gulf of Guayaquil (Ecuador) during 2008, 2009 and 2014. Severe hypoxia, anoxia and large fluctuations of salinity occurred in an impacted sector within Guayaquil city relative to a mangrove area within the Salado Mangroves Faunal Production Reserve. Significant inter-site and temporal differences were observed for dissolved oxygen, salinity, total dissolved solids, percentage of silts and clays, and species diversity. Macrobenthos' species richness for both sectors was greater during 2008. Sediments revealed high concentrations of total mercury (THg) (1.20–2.76 mg kg−1 dw), exceeding Ecuador's SQG (0.1 mg kg−1 dw). Sediment THg were significantly lower in 2014 than 2008/09. Biota sediment sccumulation factor values for mussels (3.0 to 34), indicate high bioaccumulation potential from mercury-contaminated sediments. This work highlights the need to develop stronger environmental policies to protect the Salado Estuary from anthropogenic stressors. Highlights • The ecotoxicological and biological conditions of the Salado Estuary were assessed. • High mercury concentrations in sediments and mangrove mussels exceeded Ecuador's SQG. • Oligochaetes were the dominant macrobenthos and bioindicator of local contamination. • Mussels served as bioindicator to monitor mercury pollution in the Salado Estuary. • Anthropogenic pollution is linked to declining environmental quality in the estuary. [ABSTRACT FROM AUTHOR]

Abstract: The work presented here reports the expression of immune-related genes during ontogenesis in the oyster Crassostrea gigas. Expression patterns of 18 selected genes showed that RNAs detected in oocytes and 2–4 cell embryos are of maternal origin and that gene transcription starts early after fertilization. The expression patterns of 4 genes (Cg-timp, Cg-tal, Cg-EcSOD and Drac3) suggested that hemocytes appear in the gastrula-trochophore stages. The localization of Cg-tal expression suggested that hematopoietic cells were derived from vessels and/or artery endothelia cells. Moreover, a bacterial challenge affected the level of expression of genes. Indeed, a change in expression levels was observed for Cg-LBP/BPI, Cg-timp, Drac3 and Cg-MyD88 genes in larval stages upon exposure to non-pathogenic bacteria. In early juveniles, a modulation was also observed for Cg-LBP/BPI, Cg-timp, Cg-MyD88 and for Cg-tal, according to the concentration of bacteria. Altogether, the results showed that studying the appearance of immunocompetent cells through their ability to express immune-related genes is a tool to gain insight the ontogenesis of the oyster immune system. [Copyright &y& Elsevier]