Toxic metal enrichment and boating intensity: sediment records of antifoulant copper in shallow lakes of eastern England

Tributyltin (TBT), an aqueous biocide derived from antifouling paint pollution, is known to have impacted coastal marine ecosystems, and has been reported in the sediment of the Norfolk and Suffolk Broads, a network of rivers and shallow lakes in eastern England. In the marine environment, the 1987 TBT ban has resulted in expanded use of alternative biocides, raising the question of whether these products too have impacted the Broads ecosystem and freshwaters in general. Here we examine the lake sediment record in the Norfolk and Suffolk Broads for contamination by copper (Cu) (as an active biocide agent) and zinc (Zn) (as a component of booster biocides), to assess their occurrence and potential for causing environmental harm in freshwater ecosystems. We find that, after the introduction of leisure boating, there is a statistically significant difference in Cu enrichment between heavily and lightly boated sites, while no such difference exists prior to this time. At the heavily boated sites the onset of Cu enrichment coincides with a period of rapid increase in leisure boating. Such enrichment is maintained to the present day, with some evidence of continued increase. We conclude that Cu-based antifouling has measurably contaminated lakes exposed to boating, at concentrations high enough to cause ecological harm. Similar findings can be expected at other boated freshwater ecosystems elsewhere in the world

Recruitment Potential of a Green Alga Ulva flexuosa Wulfen Dark Preserved Zoospore and Its Development

The recruitment potential and the ability of Ulva flexuosa Wulfen zoospores to survive darkness were tested under different conditions in the present study. The dark preserved zoospore was cultured under a two-factor experimental design to test the effect of salinity and nitrate, effect of salinity and phosphate, effect of light and salinity, and effect of light and phosphate. The recruitment (germination and growth) of zoospores was significantly affected by light and salinity. The nitrate concentration of 20 µmol.l−1 was found to initiate the process of germination and its subsequent growth and, its effect appeared greatest under 25 psu condition. While nitrate enhances the growth of biomass more than phosphate, both show a positive interactive effect on biomass increase when crossed with salinity. The combined effect of 25 psu salinity and 8 µmol.l−1 phosphate exhibited higher biomass growth. There was a significant effect of light and salinity on the biomass of zoospore, though there was no significant interaction between the two factors. There was an increase in biomass of growing zoospores to increase in light intensity and 80 µmol.m−2.s−1 of light intensity was considered optimal. Similarly, high light intensity condition favored higher biomass growth and there was significant interaction between light (80 µmol. m−2. s−1) and phosphate (4 µmol. l−1) in high salinity (35 psu) condition. The result of this study showed that dark preserved zoospores of U. flexuosa have the potential for recruitment and it gives us an understanding how different factors play a role in the process of recruitment

A Strategy for the Proliferation of Ulva prolifera, Main Causative Species of Green Tides, with Formation of Sporangia by Fragmentation

Ulva prolifera, a common green seaweed, is one of the causative species of green tides that occurred frequently along the shores of Qingdao in 2008 and had detrimental effects on the preparations for the 2008 Beijing Olympic Games sailing competition, since more than 30 percent of the area of the games was invaded. In view of the rapid accumulation of the vast biomass of floating U. prolifera in green tides, we investigated the formation of sporangia in disks of different diameters excised from U. prolifera, changes of the photosynthetic properties of cells during sporangia formation, and development of spores. The results suggested that disks less than 1.00 mm in diameter were optimal for the formation of sporangia, but there was a small amount of spore release in these. The highest percentage of area of spore release occurred in disks that were 2.50 mm in diameter. In contrast, sporangia were formed only at the cut edges of larger disks (3.00 mm, 3.50 mm, and 4.00 mm in diameter). Additionally, the majority of spores liberated from the disks appeared vigorous and developed successfully into new individuals. These results implied that fragments of the appropriate size from the U. prolifera thalli broken by a variety of factors via producing spores gave rise to the rapid proliferation of the seaweed under field conditions, which may be one of the most important factors to the rapid accumulation of the vast biomass of U. prolifera in the green tide that occurred in Qingdao, 2008

Influences of club connectedness among young adults in Western Australian community-based sports clubs

Background: Along with physical benefits, community-based sport provides opportunities to enhance connectedness, an important protective factor of social and emotional health. However, young Australians participating in sport have been found to drink alcohol at higher levels than their non-sporting peers, and many clubs serve unhealthy food and beverages. This study explored the association between the dependent variable, level of alcohol consumption (AUDIT-C) and connectedness to club and other health behaviours among young people aged 18-30 years who play club sport in Western Australia. Methods: An online cross sectional survey measured levels of alcohol consumption (AUDIT-C), alcohol-related harm, connectedness (including volunteering and team cohesion), mental wellbeing, healthy food options and club sponsorship among young adults aged 18-30 years involved in sports clubs in Western Australia (n = 242). Relationships and association between the dependent variable (AUDIT-C) and independent variables were assessed. Results: Male sportspeople were more likely to drink alcohol at high-risk levels than females (p <.001), and respondents belonging to a club that received alcohol-related sponsorship were more likely to drink at high-risk levels (p =.019). Females were significantly more likely to want healthy food and beverage options provided at their clubs (p = 0.011). When all factors were considered team cohesion (p = 0.02), alcohol expectations (p = <.001), occurrences of experienced alcohol-related harm (p = <.001) and length of club membership (p = 0.18) were significant predictors of high-risk AUDIT-C (R 2 =.34, adjusted R 2 =.33, F (4, 156) = 20.43, p = <.001). High-risk AUDIT-C and club connectedness predicted strong team cohesion (R 2 =.39, adjusted R 2 =.39, F (2, 166) = 53.74, p = <.001). Conclusions: Findings from this study may inform policy and practice to enhance healthy behaviours among young adults participating in community sports clubs in Australia and other countries