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The article reports on a study about the effects of aquatic weed or Ranunculus removal on freshwater pearl mussels and juvenile salmonids in the River Spey, Scotland. The conservation status of M. margaritifera in the River Spey is endangered by the rapid spread of invasive Ranunculus. Ranunculus roots appear to alleviate significant depositions of fine sand that are detrimental both to pearl mussels and salmonid fry. The study showed that the physical removal of Ranunculus had no substantial impact either on pearl mussels or on salmon and trout fry and that there are no realistic control solutions and complete eradication of the Ranunculus from the River Spey based on the methods available.

Rod catches at four sites on the River Spey were analysed over the period 1970-1991. The year-by-year trends and seasonal patterns of rod catches varied according to site location. During the 1970s and 1980s the spring salmon catch from the Spey as a whole declined, mirroring a decline in catch at the lower sites in the river early in the year. Catches at the study sites did not always follow trends in the fishery as a whole, however, illustrating that the catch at any given site is not a simple function of the total number of available fish in the river. In the first 2 years of the 1990s the decline in early season catches continued, accompanied by a more general drop in catches throughout the angling season at three out of four sites. [ABSTRACT FROM AUTHOR]

Focuses on a study which examined the effect of Atlantic salmon's riverine migration pattern in rod catches. Migratory behavior of salmon; Methodology of the study; Comparison between the distributions of rod catch and radio-tagged salmon.

There is some evidence that the river migration success of Atlantic salmon smolts, on their first migration to sea, varies both spatially and temporally. However, we have only a poor understanding of what may be driving this variation. In this study, we used acoustic telemetry to quantify the spatial and temporal variations in river migration success in Atlantic salmon smolts on their first migration to sea. In total 4120 Atlantic salmon smolts migrating through 22 rivers in Scotland, England, Ireland, and Northern Ireland over multiple years were included in the study. Individuals were defined as successful migrants if detected leaving the river to enter marine waters. The results show significant temporal (up to 4 years) and spatial (river) variations in migration success, with overall between-river migration success varying from 3.4% to 97.0% and between years from 3.4% and 61.0%. Temporal variation in migration success was river specific, with some rivers being more temporally stable (exhibiting little variation between years) than others. Across all rivers and years, individual migration success was predicted positively by body condition and negatively by tag burden. The rate of migration success for a population (migration success standardized to a common river distance [proportion km -1 ]) was predicted by a number of environmental factors. The proportion of river catchment that comprised wetland and woodland positively predicted migration success, whereas the proportion of grassland and peatland in a catchment negatively predicted the rate of migration success. Although the mechanisms through which these effects may be operating were not directly examined in this study, we discuss some potential routes through which they may occur., (© 2024 The Author(s). Journal of Fish Biology published by John Wiley & Sons Ltd on behalf of Fisheries Society of the British Isles.)

Gastric interoception refers to the processing of sensory stimuli originating in the gut. Previous research has found that gastric interoception (measured using a water load task) is associated with drive for thinness in young Western women. However, associations with broader facets of body image and in diverse national groups have not been previously investigated. To address these issues, we asked samples of adults in the United Kingdom (UK; N = 91, women n = 54) and Malaysia (N = 100, women n = 50) to complete a 2-stage water load task (WLT) and measures of positive body image (i.e., body appreciation, functionality appreciation). The results indicated that a greater change in the intensity of self-reported WLT-related sensations was associated with significantly higher body appreciation and functionality appreciation after accounting for gender identity, body mass index, and national group. Behavioural performance on the WLT was significantly associated with body appreciation and functionality appreciation for the Malaysian sample, but not the UK adults, after accounting for gender identity and body mass index. These findings extend previous research by demonstrating that there are significant associations between facets of gastric interoception and previously unexplored facets of body image in both Western and non-Western settings., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Research on positive body image has infrequently considered sexual minority orientations beyond lesbians, gay men, and bisexual persons. Indeed, there is no existing research on the relationships between body image and asexuality, which refers to a lack of sexual attraction to anyone or anything. In two studies, we rectified this by examining associations between asexuality - operationalised as a continuous construct - and indices of positive body image. In Study 1, 188 Britons from the community completed measures of asexuality and body appreciation. Once the effects of self-identified sexual orientation, relationship status, and body mass index (BMI) had been considered, asexuality was found to be significantly and negatively associated with body appreciation in women and men. In Study 2, an online sample of 377 Britons completed measures of asexuality, body appreciation, functionality appreciation, body acceptance from others, and body image flexibility. Beyond the effects of sexual orientation, relationship status, and BMI, asexuality was significantly and negatively associated with all four body image constructs in men, and with body appreciation and functionality appreciation in women. Although asexuality only explained a small proportion of the variance in positive body image (3-11%) and further studies are needed, the relationship appears to be stable.

Effective population size (Ne) is an important parameter in the conservation of genetic diversity. Comparative studies of empirical data that gauge the relative accuracy of Ne methods are limited, and a better understanding of the limitations and potential of Ne estimators is needed. This paper investigates genetic diversity and Ne in four populations of wild anadromous Atlantic salmon (Salmo salar L.) in Europe, from the Rivers Oir and Scorff (France) and Spey and Shin (Scotland). We aimed to understand present diversity and historical processes influencing current population structure. Our results showed high genetic diversity for all populations studied, despite their wide range of current effective sizes. To improve understanding of high genetic diversity observed in the populations with low effective size, we developed a model predicting present diversity as a function of past demographic history. This suggested that high genetic diversity could be explained by a bottleneck occurring within recent centuries rather than by gene flow. Previous studies have demonstrated the efficiency of coalescence models to estimate Ne. Using nine subsets from 37 microsatellite DNA markers from the four salmon populations, we compared three coalescence estimators based on single and dual samples. Comparing Ne estimates confirmed the efficiency of increasing the number and variability of microsatellite markers. This efficiency was more accentuated for the smaller populations. Analysis with low numbers of neutral markers revealed uneven distributions of allelic frequencies and overestimated short-term Ne. In addition, we found evidence of artificial stock enhancement using native and non-native origin. We propose estimates of Ne for the four populations, and their applications for salmon conservation and management are discussed.