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- Influence of oceanography and larvae behaviour on recruitment of temperate fishes: the importance of physics-biology links to manage fisheries at a local scalePublication . Baptista, Vânia; Teodósio, Maria A.; Leitão, Francisco; Wolanski, EricA central question in the ecology of fishing resources is understanding the mechanisms behind recruitment variability. This thesis aimed to analyse the factors responsible for recruitment variability of two economically relevant species, in Portugal, white seabream (Diplodus sargus) and two-banded seabream (Diplodus vulgaris). The temporal variability in sea surface temperature (SST) was studied over specific regions of the Portuguese coast, along the last decades. The effects of changes in environmental variables and fishing pressure on these resources were evaluated, using a multi-model approach. Swimming capabilities of fish larvae and their behavioural responses to environmental cues, potentially relevant for the selection of nursery areas and recruitment, were determined using Ria Formosa coastal lagoon and white seabream as a case study. The analysis of SST during the period 1980-2010 showed a generalized warming along the Portuguese coast, with region- and season-variable tendencies. The effects of environmental and fishing variability on the landings were species-specific, and also varied depending on region and season. The swimming ability of white seabream larvae, as well as their exploratory activity, increased during ontogeny. However, this species did not select any of the environmental stimuli tested. The exploratory behaviour of white seabream larvae presented consistent individual differences throughout ontogeny, indicating that the personality traits emerge early in their life cycle.The integration of these results into an individual-based model showed that both the location of spawning sites and directional swimming capabilities are important determinants of the ingress success of white seabream into a nursery area, as the Ria Formosa lagoon. Thus, the integration of region- and season-specific oceanographic and fishing processes, as well as fish larvae behaviour and dispersion modelling, and supported climate change scenarios, are required for improving the estimates of fish recruitment.
