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Pristine coastal environments are the key to Hawaii's worldwide fame and attraction to tourists, yet their economic value remains understudied. This article examines preferences for characteristics associated with beach recreation in Oahu, Hawaii, among residents and tourists. Consideration is given to sand quality, water quality, congestion levels, and swimming safety conditions in the context of a choice experiment. The choice experiment conveys attribute levels almost entirely through pictures, and results suggest that this novel portrayal is well understood by respondents. Excessive congestion and water quality are regarded as the most important beach attributes, specifically the avoidance of poor water quality in favor of a chance to experience excellent water quality. Some evidence suggests that significantly different willingness to pay (WTP) exists among residents and tourists on Oahu with poor water quality and excellent water quality being more important to tourists, while residents place greater value on avoiding excessive congestion. [ABSTRACT FROM AUTHOR]

Water quality monitoring in Hanalei Bay, Kaua'i (Hawai'i, USA) has documented intermittent high concentrations of nutrients (nitrate, phosphate, silica, and ammonium) and fecal indicator bacteria (FIB, i.e., enterococci and Escherichia coli) in nearshore waters and spurred concern that contaminated groundwater might be discharging into the bay. The present study sought to identify and track sources of nutrients and FIB to four beaches in Hanalei Bay and one beach outside the bay, together representing a wide range of land uses. 223Ra and 224Ra activity, salinity, nutrient and FIB concentrations were measured in samples from the coastal aquifer, the nearshore ocean, springs, the Hanalei River, and smaller streams. In addition, FIB concentrations in beach sands were measured at each site, and the enterococcal surface protein (esp) gene assay was used to investigate whether the observed FIB originated from a human source. Nutrient concentrations in groundwater were significantly higher than in nearshore water, inversely correlated to salinity, and highly site specific, indicating local controls on groundwater quality. Fluxes of groundwater into Hanalei Bay were calculated using a mass-balance approach and represented at least 2-10% of river discharges. However, submarine groundwater discharge (SGD) may provide 2.7 times as much nitrate+nitrite to Hanalei Bay as does the Hanalei River. It may also provide significant fluxes of phosphate and ammonium, comprising 15% and 20% of Hanalei River inputs, respectively. SGD-derived silica inputs to the bay comprised less than 3% of Hanalei River inputs. FIB concentrations in groundwater were typically lower than those in nearshore water, suggesting that significant FIB inputs from SGD are unlikely. Positive esp gene assays suggested that some enterococci in environmental samples were of human fecal origin. Identifying how nutrients and FIB enter nearshore waters will help environmental managers address pressing water quality issues, including exceedances of the state Enterococcus water quality standard and nutrient loading to coral reefs. [ABSTRACT FROM AUTHOR]

Rapid qPCR methods for enumerating enterococci can provide results in a few hours, thereby enhancing public health protection. Analysis of 140 samples collected from 11 beaches in Hawaii for enterococci using EPA Method 1611 revealed that a majority (70%) of samples yielded unusable data using the recommended protocol due to DNA losses during extraction. The DNA loss was correlated to the presence of suspended coralline sand. Acidification of samples alleviated or removed the interference, enabling successful method application. There were significant correlations across the three methods evaluated (Enterolert®/Method 1600 R2 = 0.85, Enterolert®/ Method 1611 R2 = 0.78 and Method 1600/1611 R2 = 0.82). When samples were not compromised, there was also good agreement among methods for beach management decisions. This study presents a protocol for beach areas with coralline sands, and re-emphasizes the need to use appropriate controls to prevent underestimation of bacterial concentrations at recreational beaches. Image 1 • Application of EPA Method 1611 for enterococci is hampered in Hawaii. • DNA is lost during the rapid extraction protocol. • DNA loss is likely due to coralline sediment present in Hawaiian coastal water. • Acidification of coastal water samples prior to filtration is recommended. • Good agreement between beach management decisions based on the different methods. [ABSTRACT FROM AUTHOR]