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

Artificial Seawater Media Facilitate Cultivating Members of the Microbial Majority from the Gulf of Mexico

ABSTRACT High-throughput cultivation studies have been successful at bringing numerous important marine bacterioplankton lineages into culture, yet these frequently utilize natural seawater media that can hamper portability, reproducibility, and downstream characterization efforts. Here we report the results of seven experiments with a set of newly developed artificial seawater media and evaluation of cultivation success via comparison with community sequencing data from the inocula. Eighty-two new isolates represent highly important marine clades, including SAR116, OM60/NOR5, SAR92, Roseobacter, and SAR11. For many, isolation with an artificial seawater medium is unprecedented, and several organisms are also the first of their type from the Gulf of Mexico. Community analysis revealed that many isolates were among the 20 most abundant organisms in their source inoculum. This method will expand the accessibility of bacterioplankton cultivation experiments and improve repeatability by avoiding normal compositional changes in natural seawater. IMPORTANCE The difficulty in cultivating many microbial taxa vexes researchers intent on understanding the contributions of these organisms to natural systems, particularly when these organisms are numerically abundant, and many cultivation attempts recover only rare taxa. Efforts to improve this conundrum with marine bacterioplankton have been successful with natural seawater media, but that approach suffers from a number of drawbacks and there have been no comparable artificial alternatives created in the laboratory. This work demonstrates that a newly developed suite of artificial-seawater media can successfully cultivate many of the most abundant taxa from seawater samples and many taxa previously only cultivated with natural-seawater media. This methodology therefore significantly simplifies efforts to cultivate bacterioplankton and greatly improves our ability to perform physiological characterization of cultures postisolation

Predicting sickness during a 2-week soccer camp at 3600 m (ISA3600)

Objectives\ud \ud To examine the time course of changes in wellness and health status markers before and after episodes of sickness in young soccer players during a high-altitude training camp (La Paz, 3600 m).\ud \ud Methods\ud \ud Wellness and fatigue were assessed daily on awakening using specifically-designed questionnaires and resting measures of heart rate and heart rate variability. The rating of perceived exertion and heart rate responses to a submaximal run (9 km/h) were also collected during each training session. Players who missed the morning screening for at least two consecutive days were considered as sick.\ud \ud Results\ud \ud Four players met the inclusion criteria. With the exception of submaximal exercise heart rate, which showed an almost certain and large increase before the day of sickness (4%; 90% confidence interval 3 to 6), there was no clear change in any of the other psychometric or physiological variables. There was a very likely moderate increase (79%, 22 to 64) in self-reported training load the day before the heart rate increase in sick players (4 of the 4 players, 100%). In contrast, training load was likely and slightly decreased (−24%, −78 to −11) in players who also showed an increased heart rate but remained healthy.\ud \ud Conclusions\ud \ud A >4% increased heart rate during submaximal exercise in response to a moderate increase in perceived training load the previous day may be an indicator of sickness the next day. All other variables, that is, resting heart rate, heart rate variability and psychometric questionnaires may be less powerful at predicting sickness