Exploring public views on marine litter in Europe: Perceived causes, consequences and pathways to change.

Marine litter is a global challenge and society plays an important role via lifestyles and behaviour, including policy support. We analysed public perceptions of marine litter and contributing factors, using data from 1133 respondents across 16 European countries. People reported high levels of concern about marine litter, and the vast majority (95%) reported seeing litter when visiting the coast. The problem was attributed to product and packaging design and behaviour rather than lack of facilities or accidental loss of items. Retailers, industry and government were perceived as most responsible, but also least motivated and competent to reduce marine litter, whereas scientists and environmental groups were perceived as least responsible but most motivated and competent. Regression analyses demonstrated the importance of psychological factors such as values and social norms above sociodemographic variables. These findings are important for communications and interventions to reduce inputs of marine litter to the natural environment.

Acoustic discrimination between harbor porpoises and delphinids by using a simple two-band comparison.

A simple discrimination method between Delphinidae and Phocoenidae based on the comparison of the intensity ratios of two band frequencies (130 and 70 kHz) is proposed. Biosonar signals were recorded at the Istanbul Strait (Bosphorus) in Turkey. Simultaneously, the presence of the species was confirmed by visual observation. Two types of thresholds of two-band intensity ratios, fixed and dynamic threshold, were tested for identification. The correct detection and false alarm rates for porpoises were 0.55 and 0.06 by using the fixed threshold and 0.74 and 0.08 by using the dynamic threshold, respectively. When the dynamic threshold was employed, the appropriate threshold changed depending on the mix ratio of recorded sounds from both Delphinidae and Phocoenidae. Even under biased mix ratios from 26% to 82%, the dynamic threshold worked with >0.80 correct detection and <0.20 false alarm rates, whereas the fixed threshold did not. The proposed method is simple but quantitative, which can be applicable for any broadband recording system, including a single hydrophone with two frequency band detectors.