Involvement of recreational anglers in the eradication of alien brook trout from high altitude lakes

Stocking programmes for recreational angling are primarily responsible for the spread and ecological impact of introduced sh in high-altitude, originally shless lakes. In 2013, the Gran Paradiso National Park started an eradication campaign of brook trout by intensive gill-netting. Local anglers were invited to attend two angling sessions to start the eradication before gill-netting in an experimental lake, as part of an education action devoted to these critical stakeholders. The angling sessions turned out to be a valuable help for the eradication campaign and the aim of this study is to report on the outcomes of these angling sessions. Angling techniques were highly size-selective, removing a substantial part of the adult population and of the sh biomass, but their contribution to the eradication of small sh (<15cm) was irrelevant. Therefore, angling cannot completely eradicate age-structured populations. However, there is scope to use angling sessions as a support for eradication campaigns and as an emergency measure for recent sh introduc- tions. Similar actions should be considered whenever a sh eradication programme is planned. These ndings, however, do not imply a general endorsement for angling within protected areas

Behind the impact of introduced trout in high altitude lakes: adult, not juvenile fish are responsible of the selective predation on crustacean zooplankton

Introduced fish seriously affect zooplankton communities in mountain lakes, often leading to the loss of large species. Selective predation is recognized to be the ultimate cause of such a strong impact. Here we describe the selection of zooplankton prey by analyzing the stomach contents of more than 300 brook trout (Salvelinus fontinalis) inhabiting seven alpine lakes in the Gran Paradiso National Park (western Italian Alps). Our results show that planktivory is much more common in young fish, which feed on a larger number of taxa, but also adult fish maintain the ability to feed on zooplankton. There is a direct dependence between the length of zooplankton prey and the length of their fish predators, and adult, not juvenile fish are responsible of the selective predation on large crustacean zooplankton, which drive the impact of introduced fish throughout the entire zooplankton community. In some rare cases, large zooplankton populations develop in the presence of brook trout, and planktivory can become an important temporary resource for adult fish during the ice-free season. Thus, in the early stages of the establishment of non-native trout in alpine lakes, large-bodied zooplankton may represent an important food resource

The degree of intratumor mutational heterogeneity varies by primary tumor sub-site

Citation: Ledgerwood, L. G., Kumar, D., Eterovic, A. K., Wick, J., Chen, K., Zhao, H., . . . Thomas, S. M. (2016). The degree of intratumor mutational heterogeneity varies by primary tumor sub-site. Oncotarget, 7(19), 27185-27198. doi:10.18632/oncotarget.8448Additional Authors: Chien, J.;Mills, G. B.;Grandis, J. R.;Thomas, S. M.In an era where mutational profiles inform treatment options, it is critical to know the extent to which tumor biopsies represent the molecular profile of the primary and metastatic tumor. Head and neck squamous cell carcinoma (HNSCC) arise primarily in the mucosal lining of oral cavity and oropharynx. Despite aggressive therapy the 5-year survival rate is at 50%. The primary objective of this study is to characterize the degree of intratumor mutational heterogeneity in HNSCC. We used multi-region sequencing of paired primary and metastatic tumor DNA of 24 spatially distinct samples from seven patients with HNSCC of larynx, floor of the mouth (FOM) or oral tongue. Full length, in-depth sequencing of 202 genes implicated in cancer was carried out. Larynx and FOM tumors had more than 69.2% unique SNVs between the paired primary and metastatic lesions. In contrast, the oral tongue HNSCC had only 33.3% unique SNVs across multiple sites. In addition, HNSCC of the oral tongue had fewer mutations than larynx and FOM tumors. These findings were validated on the Affymetrix whole genome 6.0 array platform and were consistent with data from The Cancer Genome Atlas (TCGA). This is the first report demonstrating differences in mutational heterogeneity varying by subsite in HNSCC. The heterogeneity within laryngeal tumor specimens may lead to an underestimation of the genetic abnormalities within tumors and may foster resistance to standard treatment protocols. These findings are relevant to investigators and clinicians developing personalized cancer treatments based on identification of specific mutations in tumor biopsies

Recovery of high mountain Alpine lakes after the eradication of introduced brook trout Salvelinus fontinalis using non-chemical methods

The final publication is available at Springer via http://dx.doi.org/10.1007/s10530-018-1867-0Fish stocking is a serious threat to originally fishless mountain lakes. We used non-chemical eradication methods (i.e. gillnetting and electrofishing) in four high mountain lakes in the Gran Paradiso National Park (Western Italian Alps) to eradicate alien brook trout Salvelinus fontinalis. Data of amphibians, macroinvertebrates, zooplankton, chlorophyll-a, nutrient concentrations, and water transparency were used as indicators of the recovery process. All treated lakes were returned to their original fishless condition in spite of their different sizes and habitat complexity, without permanent negative side-effects for native species. Several ecological indicators showed that many impacts of introduced fish can be reversed over a short time period following eradication. The present study adds to a still growing body of specialized literature on the recovery of habitats after the eradication of alien species and provides further evidence that physical eradication methods are effective and can be part of a more general strategy for the conservation of high mountain lake biota

Predation by introduced fish can magnify the terrestrial arthropod subsidies in mountain lakes

A portion of the terrestrial subsidies to lentic habitats consists of arthropods. In high mountain, originally fishless lakes, terrestrial arthropods are an important seasonal food resource for introduced fish. Here we investigate how brook trout Salvelinus fontinalis can alter the input of terrestrial arthropods in ten high mountain lakes contrasting for their stocking history (with and without fish, or manipulated for fish eradication). We used a food consumption model to calculate the minimum and maximum number/biomass of arthropods consumed by fish and we found that they can exceed several folds the number/biomass of arthropods sinking into the lakes, at least under the metabolic rates expected for fish for most of the summer. We interpret this result as an indirect indication that arthropods usually cannot overcome the surface tension at the lake surface and that fish can work as a vector across the water-air interface. We infer that pathways for dead and alive arthropods to leave the lakes do exist and fish can transfer into the water column many arthropods whose fate was leaving the lakes, which may have overlooked ecological and conservation implications.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author