7 research outputs found

    Do Didymosphenia Geminata Blooms Affect Fishes in the Kootenai River Basin?

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    Didymosphenia geminata (Didymo) is a nuisance algae that can cover entire streambeds under certain environmental conditions. Numerous studies have shown that it changes the composition of stream invertebrates. Fishes in many headwaters are known to feed almost exclusively on invertebrates. Thus, there is concern changes to the amount or type of invertebrates caused by Didymo blooms will impact fishes such as trout, charr, and sculpin. In the Kootenai River basin of Montana and British Columbia, we examined stream invertebrates and fish diets, condition, and growth across 25 streams during the summers of 2018 and 2019. The severity of Didymo blooms in these streams ranged from 0 – 80% coverage of the entire streambed. In 2018, we observed significant shifts in the types of stream invertebrates available to trout in Didymo-affected streams. However, trout diets and growth rate were not affected. In 2019, trout, charr, and sculpin diets in streams with severe Didymo blooms were similar to streams with little to no Didymo. Condition of all three types of fish were unaffected. We therefore conclude that summer Didymo blooms have no obvious impacts on the diet, condition, or growth of these fishes. We suggest further studies document potential impacts during winter months and on sensitive invertebrates such as freshwater mussels

    Consequences of Didymo Blooms in the Transnational Kootenay River Basin

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    Stream habitat changes that affect primary consumers often indirectly impact secondary consumers such as fishes. Blooms of the benthic algae Didymosphenia geminata (Didymo) represent one such habitat change known to affect stream macroinvertebrates. However, the potential indirect trophic impacts on fish consumers via modifications to their diet are poorly understood. The overall goal of this project was to determine if Didymo blooms in streams of the Kootenay River basin of British Columbia and Montana affect the condition and growth of fishes, and to see whether trophic mechanisms were responsible for any observed changes. We therefore quantified the diet, condition, and growth rate of trout, charr, and sculpin in a paired, Didymo vs. reference study, during the summer of 2018 and across a gradient of Didymo abundance in 2019. In the 2018 study, trout diets were 81% similar despite obvious differences in the composition of macroinvertebrate assemblages between the Didymo and reference streams. Trout abundance was higher in the stream with Didymo, but the amount of invertebrates in the drift was higher in the stream without Didymo. Growth rate and energy demand by individual trout was similar between the two streams. In the 2019 study, across a gradient of coverage, Didymo abundance was correlated only with the percent of aquatic invertebrates in trout diets and did not affect diets of charr or sculpin. Variation in fish condition was low across study streams. Thus, Didymo blooms may impact trout diets to a small extent, but we found no evidence this impact translates to changes in condition or growth. The relationship of fish abundance to Didymo blooms bears further study, but we found no obvious trophic mechanisms that would explain any differences. We suggest future studies prioritize research on potential impacts during winter months and on species with limited mobility that may be most greatly impacted by Didymo

    Protecting Endangered Species in the USA Requires Both Public and Private Land Conservation

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    Crucial to the successful conservation of endangered species is the overlap of their ranges with protected areas. We analyzed protected areas in the continental USA to assess the extent to which they covered the ranges of endangered tetrapods. We show that in 80% of ecoregions, protected areas offer equal (25%) or worse (55%) protection for species than if their locations were chosen at random. Additionally, we demonstrate that it is possible to achieve sufficient protection for 100% of the USA’s endangered tetrapods through targeted protection of undeveloped public and private lands. Our results highlight that the USA is likely to fall short of its commitments to halting biodiversity loss unless more considerable investments in both public and private land conservation are made

    Using forensic geochemistry via fish otoliths to investigate an illegal fish introduction

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    Illegal fish introductions create some of the most challenging problems for resource managers because of their potential to harm existing recreational fisheries and their impact on species of conservation concern. Determining the origin of a suspected illegal fish introduction can aid managers in preventing the colonization and subsequent ecosystem impacts of introduced species. In this study, we used forensic geochemistry via fish otoliths to investigate an illegal Walleye introduction in Swan Lake, Montana, which provides critical habitat for threatened Bull Trout and native Westslope Cutthroat Trout. Core to edge geochemical profiles of 87Sr/86Sr and Sr/Ca ratios in the Walleye otoliths revealed that these fish had been introduced to Swan Lake within the past growing season and their geochemical signature matched that of Walleye sampled from Lake Helena, Montana located 309 road kilometers away. This research highlights application of a tool fisheries managers can use to identify the natal waterbody source of illegally introduced fish.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

    Protocol for CAMUS Delphi Study: A Consensus on Comprehensive Reporting and Grading of Complications After Urological Surgery.

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    BACKGROUND Reproducible assessment of postoperative complications is essential for reliable evaluation of quality of care to enable comparison between healthcare centres and ensure transparent patient counselling. Currently, significant discrepancies exist in complication reporting and grading due to heterogeneous definitions and methodologies. OBJECTIVE To develop a standardised and reproducible assessment of perioperative complications and overall associated morbidity, to allow for the construction of a uniform language for complication reporting and grading. DESIGN, SETTING, AND PARTICIPANTS The 12-part REDCap-based Delphi survey was developed in conjunction with methodologist review and experienced urologist opinion. International urologists, anaesthetists, and intensive care unit specialists will be included. A minimum sample size of 750 participants (500 urologists and 250 critical care specialities) is targeted. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS The survey assesses participant demographics, opinion on complication reporting and the proposed Complications After Major & Minor Urological Surgery (CAMUS) reporting recommendations, grading of intervention events using the existing Clavien-Dindo classification and the proposed CAMUS classification, and rating of various clinical scenarios. Consensus will be defined as ≥75% majority agreement. If consensus is not reached, then subsequent Delphi rounds will be performed under steering committee guidance. RESULTS AND LIMITATIONS Twenty-one participants completed the draft survey. The median survey completion time was 128 min (interquartile range 88-135). The survey revealed that 90% of participants believe that the current complication classification systems are useful but inaccurate, while 100% of participants believe that there is a universal demand for reporting consensus. Several amendments were made following feedback. Limitations include complexity of the proposed supplemental grades and time to completion of the survey. CONCLUSIONS To ensure comprehensive and comparable complication reporting and grading across centres worldwide, a conclusive uniform language for complication reporting must be created. We intend to address shortcomings of the current complication reporting and classification systems with a new CAMUS classification system developed through multidisciplinary expert consensus obtained through a Delphi survey. Ultimately, standardisation of urological complication reporting and grading may improve patient counselling and quality of care. PATIENT SUMMARY The reporting and grading of operative complications that occur during or after an operation and associated costs provide a means to stratify quality of patient care. Current complication reporting and classification systems are not standardised and somewhat inaccurate, and thus significantly underestimate patient morbidity and surgical risk. This Delphi survey will provide the basis for the creation of a uniform complication reporting and grading system. Our new system may allow improved reporting and grading between centres, and ultimately improve patient counselling and care

    Effects of pre-operative isolation on postoperative pulmonary complications after elective surgery: an international prospective cohort study

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