Microplastic contamination in marine-cultured fish from the Pearl River Estuary, South China.

Microplastics are ubiquitous in the aquatic environment. However, the occurrence of microplastics in farmed fish is under-researched. Herein, microplastic abundance in the stomach and intestine of marine-cultured hybrid groupers (Epinephelus fuscoguttatus × Epinephelus lanceolatus) in the Pearl River Estuary (PRE) was examined. Microplastics were detected in all fish samples, with an average abundance of 35.36 n/individual or 0.62 n/g. The fish intestine contained more microplastics (23.91 n/individual, i.e., 1.10 n/g) than the stomach (12.80 n/individual, i.e., 0.37 n/g). In addition, the ingested microplastics were predominantly fibre-shaped (70.1%), and nearly 70% were smaller than 1 mm in diameter. Potential factors affecting the ingestion of microplastics by farmed hybrid groupers include fish diet and the availability of microplastics in their feeding habitat.

The influences of emotional factors on householders' decarbonizing cooling behaviour in a subtropical Metropolitan City: An application of the extended theory of planned behaviour.

Air-conditioning accounts for a vast amount of electricity consumption in Hong Kong, and household decarbonization of cooling is considered a vital means of reducing electricity use. However, little information is available on the determinants of household decarbonizing cooling behaviour, and emotional factors are often ignored in the pro-environmental behaviour literature. Thus, this study attempts to address this gap by applying an emotional extension of the theory of planned behaviour (TPB). A total of 295 valid responses were obtained using a questionnaire survey and tested via structural equation modeling (SEM). The incorporation of additional variables improves the explanatory power of the household decarbonizing cooling behaviour model, and the results reveal that subjective norms is the most influential factor, followed by affective connection to nature and negative anticipated emotions. Meanwhile, attitude towards the behaviour and perceived behavioural control are found to have a nonsignificant effect on behavioural intention. These findings not only highlight the importance of emotions in predicting electricity-saving behaviour, but also provide useful insights to formulate effective approaches for motivating citizens to engage in decarbonizing cooling behaviour at home.

Seasonal variation in the abundance of marine plastic debris in the estuary of a subtropical macro-scale drainage basin in South China.

Marine plastic debris, including microplastic debris (0.315-5mm) and large plastic debris (>5mm), was collected from 25 beaches in Hong Kong during a wet summer season (June-August 2014) and the following dry winter season (January-March 2015). Wilcoxon signed rank tests were used to compare the abundances and weights of seven categories of plastic debris between the two seasons. The results showed that the abundances and weights were significantly higher (p<0.05) in the wet season than in the dry season. Additionally, seasonal differences were detected only at the sites that were located on the west coast of Hong Kong and not at the sites on the east coast. These results suggest that the Pearl River Estuary on the west of Hong Kong plays a prominent role in the abundance and distribution of plastic debris in Hong Kong. In addition, the study indicates that estimates of microplastic abundance may be biased if samples are collected only during the wet or dry season if the sample locations are strongly influenced by a seasonal variation of riverine inputs, such as from the Pearl River.