Biodiversity loss in the genus Artemia in the Western Mediterranean RegionLocal populations extinctions depend on intrinsic factors related to the biology of species, as well as on direct threats of stochastic and/or deterministic type. The species of the genus Artemia (Branchiopoda, Anostraca), conspicuous inhabitants of hypersaline ecosystems, are suffering an important biodiversity loss. Their persistence is dramatically affected by deterministic factors threatening their biotopes. Among these deterministic factors the loss of habitats and the introduction of exotic invasive species are the most relevant. This paper aims to summarize the information available on: a) the abandonment of solar salterns in the Western Mediterranean region; b) the present distribution of the exotic invasive species Artemia franciscana populations in Spain, Portugal, Italy and France; c) several reproductive parameters obtained from the study of life tables, performed for several autochthonous species and strains and the invasive species. These traits, linked to the quantitative and qualitative offspring output, allow an experimental approach to the understanding of the fitness superiority of the invasive species, as well as to the competitive displacement of the autochthonous Artemia species in the Western Mediterranean region.
The sperm whale, Physeter macrocephalus, was the most captured great whale in the Azores Archipelago by land-based whaling and nowadays is the most appealing species for whale watching, one of the archipelago's principal sources of tourism. Our objective was to compare number of sightings during whaling and whale watching activities. Our main question to address the possible impact of past whaling in recent whale watching is: does a present-day eco-tourist sight more or fewer sperm whales than a whaler could sight in the past? For that, a compilation of data resulting both from past whaling records and recent whale watching records was conducted. We obtained a total of 727 independent sightings of sperm whales during a total of 280 different days of sperm whaling between 1947 and 1973. A total of 1767 sperm whale sightings were made during 1133 days of whale watching activities, between 1997 and 2008. The sperm whale sighting per unit of effort average was significantly higher in the past (35.68) than in the present (12.06). In the Azores, captures over the decades greatly decreased the number of sperm whales in the region and twenty years after the end of sperm whaling a reduced number of recent sightings were found.
Historical science may play an important role in helping understanding and shaping the future of the world's oceans and to comprehend present day effects and conditions. Regarding cetaceans, historical accounts may be extremely useful to add new data to their occurrence and distribution in poorly studied regions. In Portugal, historical sources indicate that toninhas (possibly common dolphins Delphinus delphis) were observed since the 13th Century and were captured in large numbers during the late 19th and 20th Centuries. Historical occurrences given by naturalists and scientific surveys conducted by biologists indicate their regular presence with particular preference for certain areas. Also, recent observations of opportunity resulted in the same kind of accounts. Between 1976 and 1978, a study on captured cetaceans along the Portuguese shore found at fish markets was conducted and resulted in a total count of 45 cetaceans. Most captures were of small cetaceans (87% common dolphins), even though four baleen whales were registered. These cetacean captures were part of a local non-industrial fishery, as they were not the main target, but rather opportunistic catches or even by-catches of other fisheries. Delphinids were not protected by law at the time and were caught with hand harpoons or accidentally drowned in fish nets, sometimes sold at major fish markets such as Sesimbra, Peniche and Póvoa de Varzim. In geographical areas where recent cetacean sightings are rare and information is sparse, such as Portugal, it becomes important to take advantage of alternative sources of data. Our contribution towards the compilation of relevant historical and ‘forgotten’ science such as old natural observations, whaling data and observations of opportunity stresses the relevance of using historical data to access past occurrence and distribution of cetaceans.
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