Spatiotemporal patterns of distribution of large predatory sharks in Calabria (central Mediterranean, southern Italy)
During the 2000-2009, a survey study on the spatiotemporal patterns of distribution of large predatory sharks was carried out in the Calabria region. A total of 12 species were recorded and among them the blue shark Prionace glauca and the bluntnose sixgill shark Hexanchus griseus were the most comm...
| Main Authors: | , , , , , , , , |
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| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Institute of Oceanography and Fisheries
2012
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| Subjects: | |
| Online Access: | https://hrcak.srce.hr/89737 https://hrcak.srce.hr/file/132868 |
| Summary: | During the 2000-2009, a survey study on the spatiotemporal patterns of distribution of large predatory sharks was carried out in the Calabria region. A total of 12 species were recorded and among them the blue shark Prionace glauca and the bluntnose sixgill shark Hexanchus griseus were the most common ones. Also of interest was the frequency of species such as Carcharodon carcharias, Sphyrna zygaena and Cetorhinus maximus. 57% of all reported records derived from the Tyrrhenian side of the region and 43% on the Ionian side. A significant relationship between season of the year versus number of records was found, but this could be related to the small number of observers that were active during the winter months. The presence of Sphyrna lewini is reported for the study area; this species was previously recorded only in the western part of the Mediterranean Sea. This paper also provides evidence of the second and first documented accounts of white shark predation upon Tursiops truncatus and Stenella coeruleoalba, respectively, in the Mediterranean Sea. The recovering of Ionian Sphyrna zygaena populations and the declining of Lamna nasus populations were also noted. U razdoblju od 2000 do 2009, provedeno je istraživanje prostorno-vremenskih obrazaca raspodjele velikih grabežljivih morskih pasa u talijanskoj regiji Calabria. Ukupno je zabilježeno 12 vrsta, te su među njima najčešće bili zastupljeni morski pas modrulj Prionace glauca i glavonja Hexanchus griseus. Zanimljiva je i učestalost vrsta kao što su velika bijela psina Carcharodon carcharias, mlat Sphyrna zygaena i psina golema Cetorhinus maximus. Od svih prijavljenih nalaza 57% je ostvareno na Tirenskoj strani regije, a 43% na Jonskoj strani. Ustanovljena je značajna povezanost između godišnjih doba u odnosu na broj zapisa, ali to bi moglo bi se moglo odnositi na mali broj promatrača koji su bili aktivni tijekom zimskih mjeseci. Prisutnost Sphyrna lewini je ustanovljena na istraživanom području: ova vrsta je prethodno bila zabilježena samo u zapadnom dijelu ... |
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