Mercury offloading in gametes and potential adverse effects of high mercury concentrations in blood and tissues of Atlantic Goliath Grouper Epinephelus itajara in the southeastern United States

Mercury (Hg) is a ubiquitous and non-essential heavy metal that highly toxic to aquatic organisms. Few studies examine Hg its effects on wild fish populations. Here, we investigated the potential of exposure large long-lived marine species conservation concern, vulnerable Atlantic Goliath Grouper Epinephelus itajara. Our objectives were (1) measure (methyl-Hg; total = combined methyl-Hg inorganic-Hg) concentrations in whole blood (WB) gametes (eggs sperm); (2) investigate relationships between muscle liver with WB gametes; (3) liver, muscle, hematological plasma biochemical analytes; (4) relationship pigmented macrophage aggregates tissue sections. We found several lines evidence for adverse health reproduction by high WB, gametes, including all tissues well above observable ranges freshwater fishes from experimental studies; gamete among highest recorded fishes, seasonal patterns suggesting females offload significant amounts into their eggs during spawning season; Methyl-Hg was followed sperm, eggs, WB; there correlations various (5) vitellogenin positively correlated female concentrations, abnormally males, direct endocrine effects; (6) aggregate count percent area. This work will help guide future research examining role as an additional stressor