University of Gdansk, Faculty of Oceanography and Geography, Institute of Oceanography, Department of Marine Chemistry and Environmental Protection, Al. Marszałka Piłsudskiego 46, 81-378 Gdynia, Poland.
University of Gdansk, Faculty of Oceanography and Geography, Institute of Oceanography, Department of Marine Chemistry and Environmental Protection, Al. Marszałka Piłsudskiego 46, 81-378 Gdynia, Poland.
Sci Total Environ. 2020 May 15;717:137050. doi: 10.1016/j.scitotenv.2020.137050. Epub 2020 Jan 31.
This study focused on evaluating the elimination of Hg by Baltic grey seals (Halichoerus grypus grypus) via faeces and pelage. In addition, we investigated the potential for ecosystem contamination via these routes. Faeces and fur were collected in 2014-2017 from captive adult grey seals and their pups. The concentrations of total mercury (THg) and methylmercury (MeHg) were measured in the samples. The amount of mercury eliminated in a labile form (the sum of the bioavailable Hg(II) and methylmercury) was also determined. An adult seal removed about 46% of mercury supplied with food via the faeces, of which only 17% was MeHg. Considering that mercury is mainly supplied to the body as MeHg, it can be assumed that mercury excreted along with faeces has undergone transformation inside the animal body. Despite the much higher THg and MeHg concentrations measured in fur, the incorporation of mercury into newly formed fur is a less effective method of Hg elimination removing just 4% of mercury entering the body via the alimentary route. The presence of mercury in lanugo is evidence of maternal transfer. First droppings of the pups were characterised by the highest content of MeHg and a low THg concentration. Then, despite the limited supply of mercury with food, and the rapid growth of the pup, the concentration of THg increased, suggesting that mercury started to be transformed into less toxic forms. It was estimated that faeces and fur expelled by seals could deliver about 800 g of mercury to the Baltic Sea. For both faeces and fur, most of the mercury (>95% for excrements and >85% for fur) was expelled in a labile form that can be quickly recycled.
本研究专注于评估波罗的海灰海豹（Halichoerus grypus grypus）通过粪便和皮毛消除汞的能力。此外，我们还研究了通过这些途径对生态系统造成污染的可能性。在 2014 年至 2017 年期间，我们从圈养的成年灰海豹及其幼崽身上采集了粪便和皮毛样本。测量了样本中总汞（THg）和甲基汞（MeHg）的浓度。还测定了以不稳定形式（生物可利用的 Hg(II)和甲基汞的总和）排出的汞量。一只成年海豹通过粪便排出了约 46%摄入的食物中的汞，其中只有 17%是 MeHg。考虑到汞主要以 MeHg 的形式供应给动物体，可以假设与粪便一起排出的汞在动物体内发生了转化。尽管皮毛中测量到的总汞和甲基汞浓度要高得多，但将汞纳入新形成的皮毛中是一种去除效率较低的汞消除方法，仅能去除通过饮食途径进入体内的汞的 4%。在胎毛中存在汞表明这是母体转移的证据。幼崽的第一次粪便特征是 MeHg 含量最高，而总汞浓度较低。然后，尽管食物中汞的供应量有限，而且幼崽生长迅速，总汞浓度增加，这表明汞开始转化为毒性较低的形式。据估计，海豹排出的粪便和皮毛可能会向波罗的海输送约 800 克汞。对于粪便和皮毛，大部分汞（排泄物中超过 95%，皮毛中超过 85%）以不稳定形式排出，可以快速回收。
