ABSTRACT
The Negombo Lagoon is a coastal lagoon influenced by local communities that introduce waste into its ecosystem. This study examined seven sewage entry points, out of which five sites were chosen for oyster sampling based on availability. Physicochemical and microbiological parameters of water (measured in triplicate at each site, n = 84) and oyster samples (total length, TL > 6 cm, n = 30) were assessed. Variation in regional coliform contamination was analyzed employing a one-way analysis of variance (ANOVA). Results indicated that the northern part of the lagoon exceeded recommended coliform thresholds for swimming (total coliform concentration (TCC) < 126 most probable number (MPN)) and seafood consumption (TCC < 100 MPN/g), indicating the presence of Escherichia coli. Water quality indices affirmed fecal pollution, except in the southern part of the lagoon. Furthermore, the study found high oyster consumption (76.7 %), elucidating that oysters from the northern part of Negombo Lagoon pose health risks.
Subject(s)
Crassostrea , Humans , Animals , Sri Lanka , Ecosystem , Swimming , SeafoodABSTRACT
We empirically ascertained the impact of COVID-19 pandemic on fisheries sector of Sri Lanka, focusing on the year 2020 which helps identify changes in production and income of the sector. Daily wage and monthly income of stakeholders in the pre-pandemic period are well above the national minimum daily wage and monthly income of the workers in Sri Lanka. Defensive measures taken to curb rapid spread of COVID-19 have given a shock to all stakeholders of the sector. Health and safety measures imposed to avert the spreading of pandemic have compelled the stakeholders to incur extra costs. Study indicates significant impact of the pandemic on production and income of the stakeholders in the fisheries value chain. Comparison of total fish production during 2015-2020 confirms the impacts on the sector and, changes in fish production and income in 2020 completely coincide with COVID-19-time line. Severity of impacts is stakeholder and area specific. Fisheries districts in western province are highly impacted over the other districts. DPSIR framework captures the status of social system and unfolds existing problems in the sector, enabling decision-makers to take policy decisions for future actions. Government of Sri Lanka has taken several steps to revive the sector, and stakeholders have shown an adaptive capacity to cope with impacts of the pandemic. Present crisis in the sector is far from over and, short-term impacts are likely to be followed by long-term crises, thus measures should be taken to revive the sector in new normal conditions and the post-pandemic era.
ABSTRACT
This study investigated the potential toxic effects of environmentally relevant nitrate concentrations on development, growth, and mortality of early life stages of common hour-glass tree frog, Polypedates cruciger. Tadpoles from hatchlings through pre-adult were exposed to environmentally relevant nitrate concentrations detected in Mirissa, Sri Lanka. Newly hatched, external gill stage, and internal gill stage tadpoles were exposed to potassium nitrate for bioassay tests. No behavioral changes or abnormalities were observed in control and nitrate-induced group. However, detected environmental nitrate concentration significantly increased (p < 0.05) the growth of the tadpoles up to 25 days old. Results revealed that newly hatched and external gill stage was more susceptible to the nitrate pollution than internal gill stage. The results suggest that environmentally relevant nitrate can cause mortality on the amphibian population in ecosystems associated with agro-pastoral activities through altering the growth and direct toxicological effects on the survivorship.