Anadromous fish as biomarkers for the combined impact of marine and freshwater heavy metal pollution.

Rivers along the eastern seaboard of the United States and Canada are becoming increasingly contaminated with heavy metals. This includes the Tusket River (Nova Scotia, Canada) which empties into the Gulf of Maine, near the Bay of Fundy. Whether anadromous fish such as alewife (Alosa pseudoharengus), exposed both to marine and freshwater contaminants, are accumulating these heavy metals and experiencing any changes in their morphology was explored in this study. Adult (4-6 years of age) Tusket River alewife (n = 38) were harvested and had external examinations including morphometrics (fork length, weight). Biopsies were taken and structural abnormalities noted. Morphometric data was compared to historical alewife reference data from 1985. Biopsies of muscle, liver and kidney had heavy metal profiles assessed. Major findings of this study include detectable levels (µg/g wet weight) of a number of heavy metals and concerning maximum concentrations achieved of arsenic (liver: 14 µg/g), cadmium (kidney: 2.6 µg/g), mercury (liver: 0.26 µg/g), magnesium (muscle: 460 µg/g), selenium (kidney: 4.0 µg/g) and zinc (liver: 38.0 µg/g). As well, reduced body weight for length and in 87% of fish, presence of spine curvatures (3-24°) not visible externally were noted. This study is the first detailed report in alewife of key tissue heavy metals, some at levels of concern, reductions in weight for length and spine abnormalities. These findings validate concerns regarding potential impacts of deteriorating conditions of rivers and their surrounding waters such as the Gulf of Maine on anadromous fish species.

Essential and non-essential heavy metal levels in key organs of winter flounder (Pseudopleuronectes americanus) and their potential impact on body condition.

This study explored whether winter flounder, a benthic species, are potentially exposed to contaminants such as heavy metals released from the sediment of the Bay of Fundy/Gulf of Maine, both critical habitats identified to have increases in heavy metal levels. Experimentally in fish, exposure to certain heavy metals resulted in reduced weight for length and structural abnormalities, but it is unknown if this occurs in wild fish. Winter flounder (n = 72), harvested between 2015 and 2018 from the aforementioned western Atlantic region of Canada/USA, had detectable levels of most heavy metals, with some exhibiting levels of concern (arsenic, cadmium, lead, selenium, zinc) in muscle, liver, and kidney. A 1.4% incidence of structural abnormalities was noted. When compared to 1980 regionally matched flounder data, the 2018 flounder had significantly reduced weight for length, exacerbated with age. Clearly winter flounder are affected by worsening heavy metal contaminant levels in this geographic area.

Lower liver transplant success in females: gender differences in metabolic response to global ischemia.

BACKGROUND: Research has shown that gender plays a significant role in the metabolic processes of different organs and that transplanting livers of females into male or female recipients has significantly higher failure rates. To understand why, this study examined whether gender differences exist in various metabolic responses of livers to ischemia. METHODS: The following metabolic liver parameters in Sprague-Dawley rats (male, n = 14; and female, n = 18) were examined; adenosine triphosphate (ATP) and lactate expressed as micromoles/g dry weight, and hydrogen ion content [H+] expressed as 10(-8) mol/L. In vivo liver biopsy specimens were compared with ischemic biopsy specimens at 3, 10, 15, 30, and 45 minutes (37 degrees C). RESULTS: In vivo female ATP values (9.9 +/- 0.8) were similar to males (9.8 +/- 0.9) and both had early, rapid decline during ischemia reaching 20% of baseline by 10 minutes of ischemia. In contrast, male liver lactate accumulation peaked by 3 minutes and at much lower levels (35 +/- 13), whereas female liver lactate peaked by 10 minutes at 71 +/- 11. For the rest of the ischemic period, female livers exhibited significantly (P < .05) greater lactate accumulation. Female liver H+ levels also increased to higher levels (55 +/- 10) than the male livers (37 +/- 7) and this pattern was significantly (P < .05) different from 10 minutes onward. CONCLUSIONS: Although livers of females ultimately have similar ATP profiles to livers of males, they experienced more rapid and greater degree of tissue lactate and H+ accumulation during ischemia. Therefore, female livers have increased acidosis during ischemia, which could adversely affect transplant outcome.