An Investigation into the Poor Survival of an Endangered Coho Salmon Population

To investigate reasons for the decline of an endangered population of coho salmon (O. kisutch), 190 smolts were acoustically tagged during three consecutive years and their movements and survival were estimated using the Pacific Ocean Shelf Tracking project (POST) array. Median travel times of the Thompson River coho salmon smolts to the lower Fraser River sub-array were 16, 12 and 10 days during 2004, 2005 and 2006, respectively. Few smolts were recorded on marine arrays. Freshwater survival rates of the tagged smolts during their downstream migration were 0.0–5.6% (0.0–9.0% s.e.) in 2004, 7.0% (6.2% s.e.) in 2005, and 50.9% (18.6% s.e.) in 2006. Overall smolt-to-adult return rates exhibited a similar pattern, which suggests that low freshwater survival rates of out-migrating smolts may be a primary reason for the poor conservation status of this endangered coho salmon population

The relevance of size parameters as indicators of fishery exploitation in two West African reservoirs

Fish communities living within the artificial reservoirs of Manantali and Selingue in Mali are compared after the monitoring of small-scale fishery landings over 13 months (May 2002-June 2003). The fishing pressure constitutes the main difference of these two similar reservoirs. The effects of fishing on the structure of the fish communities are analyzed by using fish size spectra and derived indicators. In Selingue Reservoir, the fishing gears mostly target smaller species (mean length of 165 mm) than in Manantali Reservoir (mean length of 210 mm). Unlike in Selingue, the size structure does not change between seasons in Manantali. In Selingue, fishing practices that target the fish recruitment of the year constitute a structuring factor of the fish sizes observed in the catches. In spite of similar values of the slopes of the global fish communities' size spectra between the two reservoirs, they clearly display an intense exploitation at Selingue. Then, size-based spectra indicators represent a potential tool for assessing the impact of fishing on fish communities in small-scale fisheries

Assessment of sleep-related disorders in children with sickle cell disease

Sleep-related disorders (SRDs) are common in sickle cell disease, however, identification may be time-consuming. Simultaneous survey of multiple SRDs utilizing a simplified instrument would facilitate screening. A simplified questionnaire investigating SRDs [sleep-disordered breathing (SDB), restless legs syndrome (RLS), insomnia, parasomnias, and daytime effects of disrupted sleep] was administered to 2-18-year-old children with sickle cell disease. One hundred participants completed this 5-7 minute survey without difficulties: 54 awoke unrefreshed, 41 had short-term insomnia, 30 had sleep-maintenance insomnia, 21 had chronic sleep-onset insomnia, 54 had chronic habitual snoring and 11 met the criteria for RLS. Sleep-maintenance insomnia was associated with increased body mass index (BMI) (p = 0.001), and chronic sleep-onset insomnia was associated with higher hemoglobin (Hb) levels (p = 0.04). Survey-reported symptoms of SRDs were significantly higher than that reported in the general pediatric population. A fast and simplified SRD survey is feasible and suggests a high prevalence of SRDs in children with sickle cell disease