Causes of extirpations in the Wadden Sea, an estuarine area in the Netherlands

The various causes of extirpation of marine and estuarine species were inve stigated for the Dutch Wadden Sea to gain an impression of their relative i mportance. I obtained data from geological, archaeological, historical, and biological publications. At least 10 species of algae, 10 invertebrates, 1 3 fishes, 5 birds, and 4 marine mammals became extinct during the past 2000 years. Habitat destruction played a part in at lease 26 cases, overexploit ation in at least 17, and pollution in at least 3. Causes of the disappeara nce of two species are unknown. Introduction of exotic marine species was n ot involved in any of the extirpations. I compared this pattern of extincti on to that of worldwide extinctions of marine and estuarine species, which have been attributed to overexploitation, habitat destruction, and in two c ases to the introduction of terrestrial predators to the breeding habitats of marine birds. The results imply that conservation of marine species shou ld address overexploitation and habitat destruction as the main causes of e xtinction.