Patterns in stream fish assemblage structure and function associated with a PCB gradient

The relevance of European Biota Quality Standards on the ecological water quality as determined by the multimetric macro-invertebrate index: A Flemish case study

European Biota Quality Standards (EQS_biota), for compounds with low water solubility and high biomagnification, were created to sustain water quality and protect top predators and humans from secondary poisoning. In reality, for multiple compounds, an exceedance of these standards is often reported in literature without a decrease in ecological water quality determined by biotic indices. In the present study, threshold concentrations were defined in biota (from 44 sampling locations throughout Flanders (Belgium)), above which a good ecological water quality, assessed by the Multimetric Macroinvertebrate Index Flanders (MMIF), was never reached. Threshold values were compared to current EQS_biota. Accumulated perfluoroctane sulfonate (PFOS), mercury (Hg), hexabromocyclododecane (HBCD), polybrominated diphenyl ethers (PBDEs), dioxins and polychlorinated biphenyls (PCBs) concentrations were measured in muscle tissue of European yellow eel (Anguilla anguilla) and perch (Perca fluviatilis). Fluoranthene and benzo(a)pyrene were also analyzed in translocated mussels (Dreissena bugensis, D. polymorpha and Corbicula fluminea). Threshold values could only be calculated using a 90th quantile regression model for PFOS (in perch; 12 µg/kg ww), PCBs (in eel; 328 µg/kg ww) and benzo(a)pyrene (in mussels: 4.35 µg/kg ww). The lack of a significant regression model for the other compounds indicated an effective threshold value higher than the concentrations measured in the present study. Alternatively, the 95th percentile of concentrations measured in locations with a good ecological quality (MMIF≥0.7), was calculated for all compounds as an additional threshold value. Finally, fish concentrations were standardized for 5% lipid content (or 26% dry weight content for PFOS and Hg). Threshold values for PFOS and benzo(a)pyrene and the 95th percentiles for dioxins and fluoranthene were comparable to the existing standards. For all other compounds, the 95th percentile was higher than the current EQS_biota, while for HBCD, it was lower. These results strongly advise revising and fine-tuning the current EQS_biota, especially for ∑PBDE and HBCD.

Exposure to a common urban pollutant affects the survival and swimming behaviour of creek chub (Semotilus atromaculatus)

Anthropogenic effects on the aquatic environment are ever present and ever increasing and while a plethora of aquatic contaminants are known to affect fishes, one ubiquitous and increasingly prevalent world-wide urban runoff pollutant is frequently disregarded, and that is pet waste. While dog waste has been identified as a significant factor contributing to bacteria and nutrient loading within receiving waters and the associated water quality changes are known to affect fishes, the impact of uncollected dog faeces on urban fish populations has never been directly investigated. In this study we exposed creek chub (Semotilus atromaculatus), a widespread tolerant stream minnow, to various realistic concentrations of dog waste as simulated urban park runoff testing both fresh and dried dog faeces in both stagnant and aerated water for 96 h to investigate the impact on fish survival and behaviour. Creek chub percentage mortality increased significantly relative to controls and across an exposure gradient and was likely caused by anoxic conditions. Survivors were initially smaller while those that died were initially larger and presented with abnormal abdominal subdermal lesions post-exposure. Additional indicators of physiological stress included significantly increased rates of aquatic surface respiration and changes in flume test derived swimming motivation metrics with increased exposure concentrations. Both mortality and behavioural responses were alleviated by aeration. Furthermore, trials with fresh and dried faeces differed only in time-to-death and swimming metrics where results from dried trials were similar to those from aerated experiments. Results demonstrated the impact that the global dog waste management problem can have on aquatic communities with effects on creek chub likely to be more severe for less pollution-tolerant species and also likely to be exacerbated under future scenarios that consider climate change and increased urbanization.

On the Cutting Edge of Research to Conserve At-Risk Species: Maximizing Impact through Partnerships

Today's conservation challenges are complex. Solving these challenges often requires scientific collaborations that extend beyond the scope, expertise, and capacity of any single agency, organization, or institution. Conservation efforts can benefit from interdisciplinary collaboration, scientific and technological innovations, and the leveraging of capacity and resources among partners. Here we explore a series of case studies demonstrating how collaborative scientific partnerships are furthering the mission of the US Fish and Wildlife Service (USFWS), including: (1) contaminants of emerging concern in the Great Lakes Basin, (2) Poweshiek skipperling conservation, (3) using technology to improve population survey methods for bats and monarch butterfly, and (4) Big River restoration in the Southeast Missouri lead mining district. These case studies illustrate how strategic and effective scientific collaboration is a multi-stage process that requires investment of time and resources by all participants. Early coordination and communication is crucial to aligning planned work with scientific and decision-making needs. Collaborations between USFWS and external scientists can be mutually beneficial by supporting the agency mission while also providing an avenue for innovative research to be directly applied in conservation decisions and management actions.

Deformity, Erosion, Lesion, and Tumor Occurrence, Fluctuating Asymmetry, and Population Parameters for Bluntnose Minnow (Pimephales notatus) as Indicators of Recovering Water Quality in a Great Lakes Area of Concern, USA

The Grand Calumet River is an industrial river and a Great Lakes Area of Concern in southwestern Lake Michigan, USA. Recovery end points require well-formulated designs to assess the use of occurrence of internal and external anomalies, fluctuating asymmetry, and population indicators to determine recovery from the water-quality Beneficial Use Impairments of fish tumors and deformities. A paired-watershed approach using three reaches within the study area was sampled weekly and separated into near- and far-field reaches, whereas the Little Calumet River, Indiana Dunes National Lakeshore, served as a control. Field-collected Pimephales notatus were inspected for occurrence of deformities, erosion, lesion, and tumor (DELT) anomalies, measured for body symmetry, and dissected to ascertain sex and the condition of internal organs. Morphometric measurements (p ≤ 0.000), internal organ conditions (p = 0.001), and sex ratios of the fish (p = 0.001) were significantly different between the control and P. notatus test populations. The near-field individuals had the highest incidence of DELT occurrence (70 %) followed by the far-field reaches at Roxana Marsh (45 %) and Kennedy Avenue (41.9 %). Morphometric analysis showed significant differences between body size and shape and age class structure between populations. No test-reach individual lived to reach age >2 years. Gonads and livers from Grand Calumet individuals were found to be blackened, ruptured, and decreased in thickness. None of the fish from test study reaches displayed sexual structure in a 1:1 ratio. High sediment-contaminant concentrations for polycyclic aromatic hydrocarbon metals in the Grand Calumet River correlated (r (2) = 0.998) with decreased population fitness and decreased individual reproductive health.