Trophic relationships with Penaeoidea shrimp and bycatch fauna explored by fishery of Ubatuba littoral, São Paulo

Ubatuba (São Paulo) is a region of faunal transition, where there is a process of mixture and instability of tropical and temperate water masses. The study area belongs to a continental platform localized in southeast Brazil, and shrimp trawling is one of the most used methods. Peneid shrimps are main marine profitable resources collected, and pink shirmp (Farfantepenaeus brasiliensis e Farfantepenaeus paulensis) and sea-bob shrimp (Xiphopenaeus spp.) are one of them. With the trawling crescent in Ubatuba, benthic comunities have been receiving a lot of attention, because of the ecological concern with possible impacts that this activities can cause in the environment. Therefore, objectives of this present study are identify and distinguish seasonal variation of trophic web, and identify food preference of high valued shirmp (pink shrimp, sea-bob shrimp and white shrimp). Stable isotope analyses were made in the collected organisms, and with values of δ13C, food preference can be determined, and with δ15N, trophic relationships and trophic level are observed. Thereby, this region had an elevated biodiversity of species, which had modifications during the year, and consequently available resources were different. The knowledge about trophic positions, food preferences and trophic web are fundamental for the management of fish resources, and biodiversity of Ubatuba. (AU)