Sensitivity of lake sturgeon (Acipenser fulvescens) early life stages to 2,3,7,8‐tetrachlorodibenzo‐P‐dioxin and 3,3′,4,4′,5‐pentachlorobiphenyl

Abstract

The aquatic food web of the Great Lakes has been contaminated with polychlorinated biphenyls (PCBs) since the mid-20th century. Threats of PCB exposures to long-lived species of fish, such as lake sturgeon (Acipenser fulvescens), have been uncertain because of a lack of information on the relative sensitivity of the species. The objective of the present study was to evaluate the sensitivity of early-life stage lake sturgeon to 3,3',4,4',5-pentachlorobiphenyl (PCB-126) or 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure. Mortality, growth, morphological and tissue pathologies, swimming performance, and activity levels were used as assessment endpoints. Pericardial and yolk sac edema, tubular heart, yolk sac hemorrhaging, and small size were the most commonly observed pathologies in both TCDD and PCB-126 exposures, beginning as early as 4 d postfertilization, with many of these pathologies occurring in a dose-dependent manner. Median lethal doses for PCB-126 and TCDD in lake sturgeon were 5.4 ng/g egg (95% confidence interval, 3.9-7.4 ng/g egg) and 0.61 ng/g egg (0.47-0.82 ng/g egg), respectively. The resulting relative potency factor for PCB-126 (0.11) was greater than the World Health Organization estimate for fish (toxic equivalency factor = 0.005), suggesting that current risk assessments may underestimate PCB toxicity toward lake sturgeon. Swimming activity and endurance were reduced in lake sturgeon survivors from the median lethal doses at 60 d postfertilization. Threshold and median toxicity values indicate that lake sturgeon, like other Acipenser species, are more sensitive to PCB and TCDD than the other genus of sturgeon, Scaphirhynchus, found in North America. Indeed, lake sturgeon populations in the Great Lakes and elsewhere are susceptible to PCB/TCDD-induced developmental toxicity in embryos and reductions in swimming performance. Environ Toxicol Chem 2017;36:988-998. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

Sensitivity of a Model Reptile, the Common Snapping Turtle (Chelydra serpentina), to In Ovo Exposure to 2,3,7,8‐Tetrachlorodibenzo‐p‐Dioxin and Other Dioxin‐Like Chemicals

“…Median in ovo lethal dose (LD50) to 2,3,7,8‐tetrachlorodibenzo‐ p ‐dioxin in common snapping turtle (present study indicated with an arrow) compared with species of birds (light gray) and fish (dark gray) that have been investigated. LD50 values are as reported previously (Buckler et al, 2015; Cohen‐Barnhouse et al, 2011a; Elonen et al, 1998; Park et al, 2014; Powell et al, 1998; Tillitt et al, 2017; Toomey et al, 2001; Walker et al, 1992; Walker & Peterson, 1994; Yamauchi et al, 2006). …”

Reproductive status of a remnant Lake sturgeon (Acipenser fulvescens) population: Spawning and larval drift in the lower Fox River, Wisconsin

“…Furthermore, high quality nursery habitats exist in downstream reaches of this system (Daugherty et al, 2009), and were used long‐term by acoustically tagged young‐of‐year Lake Sturgeon (Tucker, 2020), satisfying “settle and establishment” phases. In addition, habitat remediation (e.g., PCB removal, dredging, and capping) is ongoing throughout the LFR and Lower Green Bay (e.g., Cat Island Restoration) and is expected to improve river conditions and habitats for fish and wildlife (see Tillitt et al, 2017), including Lake Sturgeon. This research suggests the “spawn phase” for Lake Sturgeon below De Pere Dam may be hindered by poor incubation conditions (i.e., desiccation, retention, algae, and predation), subsequently resulting in a poor “drift phase”.…”

Predicting Early Life Stage Mortality in Birds and Fishes from Exposure to Low‐Potency Agonists of the Aryl Hydrocarbon Receptor: A Cross‐Species Quantitative Adverse Outcome Pathway Approach

“…Dose–response curves for early life stage mortality that were predicted using EC Threshold or EC50 as input variable in the corresponding qAOPs were validated against 25 experimental dose–response curves from the published literature that reported measured concentrations and percentage of mortality for each dose (Brunstrom and Reutergardh 1986; Brunstrom and Lund 1988; Brunstrom 1989, 1990; Spitsbergen et al 1991; Walker et al 1994; Walker and Peterson 1994; Powell et al 1996, 1998; Elonen et al 1998; Hoffman et al 1998; Cohen‐Barnhouse et al 2011; Eng et al 2014, 2017; Tillitt et al 2017). These 25 scenarios represent 9 species of birds, 7 species of fish, and 5 different DLCs.…”