Animals, Macaronesia, Rivers, Fishes, Madeira, Mercury - analysis, Geologic Sediments - chemistry, Water Pollutants, Chemical - analysis, Food Chain, Methylmercury Compounds - analysis, Environmental Monitoring - methods, Plankton, Zooplankton, Macaronésia, Macaronésia, Macaronésia, Macaronésia, Macaronésia, Macaronesian, Macaronésia, Macaronesian, Macaronés...