Investigating an aquatic system as a route of entry for multiple environmental contaminants into Kruger National Park, South Africa

克鲁格国家公园（KNP）是一个200万公顷的保护区，也是联合国教科文组织世界遗产，居住着数百种哺乳动物（包括狮子，豹子，犀牛，大象和水牛）和鸟类（包括许多秃鹫，鹰和鹳物种），其中许多物种具有重要的保护意义。然而，虽然国家立法保护公园的陆地边界，但环境污染物可以通过一些河流进入，特别是奥利凡特河。Olifants河发源于Highveld地区，向东北偏北流动，流经KNP，最终进入莫桑比克。沿着它在国家公园外的长度，污染物来源包括：煤炭和金属开采（增加酸性废水和重金属），灌溉农业地区（径流，含有农药和化肥），以及几个城镇（增加未经处理的废水）。这些污染源和这个独特的保护区的共存，有助于研究生态系统的健康状况和生活在这些不同景观中的动物，这些景观受到人为活动的不同影响。在2008年和2009年，以及此后的零星事件中，尼罗河鳄鱼和莫桑比克罗非鱼在奥利凡特河沿岸的一些地点相继死亡。在这两个物种中，脂肪组织的炎症性炎症被确定为死亡原因。确切的原因尚未确定，但有人认为，河流系统中的有机和/或无机污染物耗尽了这些动物体内的自由基清除剂，降低了它们代谢膳食脂肪酸的能力，导致了胰腺炎。拟议的研究包括评估在KNP内外Olifants河流域的沉积物、水、无脊椎动物、鱼类和鳄鱼中有机和无机污染物的水平，以及鱼类和鳄鱼的健康状况。这将有助于评估污染物在多个营养水平上的分布和生物利用度，以及它们对动物健康的潜在影响。

Kruger National Park (KNP) is a 2 million hectare protected area, and a UNESCO World Heritage Site, inhabited by hundreds of mammalian species (including lions, leopards, rhinos, elephants and buffalos) and avian species (including numerous vulture, eagle and stork species), with many species of conservation importance. However, while national legislation protect the terrestrial boundaries of the park, environmental pollutants can enter by a number of rivers, particularly the Olifants River. The Olifants River begins in the Highveld region, flowing north-north-east, through KNP, and ultimately enters Mozambique. Along its length outside KNP, contaminant sources include: coal and metal mining (adding acid wastewater and heavy metals), areas of irrigated agriculture (with runoff, containing pesticides and fertilisers), and several towns and cities (adding untreated wastewater). The co-location of these sources of contamination, and this unique conservation area, facilitates a study exploring the health of the ecosystem and the animals living in these contrasting landscapes, which have been variably influenced by anthropogenic activities.In 2008 and 2009, and sporadically since then, dieoffs of Nile crocodiles and Mozambique tilapia occurred at a number of sites along the Olifants. Pansteatitis, an inflammatory condition of fat tissue, was identified in both species as the cause of death. A definitive cause has not been determined, but it has been suggested that organic and/or inorganic contaminants in the river system deplete free oxygen radical scavengers in these animals, reducing their ability to metabolise dietary fatty acids, resulting in pansteatitis.The proposed study involves assessing levels of organic and inorganic contaminants in sediment, water and invertebrates, fish and crocodiles at sites along the Olifants River system within and outside KNP, and health of the fish and crocodiles. This will enable assessment of the distribution and bioavailability of contaminants throughout multiple trophic levels, and their potential impact on animal health.