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The jaws of the Greenland shark have high levels of mercury. Hg of cartilage in comparison with skin and muscle from the same specimen makes it possible to apprehend the distribution of the pollutant in the body. The level of the pollutant between jaw, skin and fresh meat (muscle) shows a strong correlation. The muscle is the most contaminated element in comparison with the skin and cartilage. The species presents the highest levels among different groups of sharks and the results are in accordance with previous studies. Marine ecosystems in the Arctic are globally contaminated by mercury (atmosphere, water, sediments, food web). The methylmercury reduces blood calcium levels, directly affecting the metabolism of cartilage cells. Even if cases of malformations could not be observed in the Greenland shark, numerous cases for other shark species have been documented in connection with heavy metals (e.g., Hg), and in particular for aplacental viviparous with potential morphological anomalies on embryos. The situation of the Greenland shark is worrying due to the conservation status, the fishing catches, the tardive sexual maturity and reproduction, the climate change and the level of mercury on its organism. The results incite to recommend ecological, environmental and fisheries management measures. [ABSTRACT FROM AUTHOR]

The ocean has always been a source of inspiration for past and present civilizations, especially for those involved in fishing activities. The regular fishing of large pelagic fish by past societies using harpoons has been demonstrated, with several studies reporting the discovery of an important fishery of large pelagic fish (including swordfish) dating from as early as the sixth millennium BCE on the North Chilean Pacific Coast. The swordfish (Xiphias gladius) is a cosmopolitan, highly migratory species found in all warm and temperate oceans and seas, and mercury is known to bioamplify along food webs, increasing with the trophic level of organisms up to these top predators. This study, therefore, analyzes and compares the mercury levels of archeological and modern vertebrae in swordfish. The archeological fish remains were recovered during excavation of the Zapatero archeological site on the northern coast of Chile, and the modern vertebrae were collected from specimens caught in the Pacific Ocean. The archeological vertebrae showed lower levels of mercury in comparison with those of current individuals, despite their larger size. However, the elevated Hg levels in archeological vertebrae proved the presence of naturally occurring mercury in the mid‐Holocene. Analyses on modern vertebrae confirmed the anthropic origin of mercury in the marine food web. Mercury biomagnifies through the marine food chain to swordfish (and humans) and did so even during the Holocene (bioaccumulation phenomenon). This study evidences that vertebrae and bones are potentially good biomarkers of mercury, including for archeological fish remains, and that the possible harmful effects on the health of past human communities can be analyzed and explained by the high consumption of fish. [ABSTRACT FROM AUTHOR]