How pelagic fish larvae find suitable nursery habitats? A comparison between Atlantic temperate and tropical ecosystems

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Environmental variability and fishing effects on artisanal flatfish fisheries along the Portuguese coast

Publication . Baptista, Vânia; Blasco, Ignacio Pérez; Bueno-Pardo, Juan; Teodosio, Maria; Leitão, Francisco

Assessing the effects of fishing activity and environmental variability on fishing species might help to understand their fluctuations and to manage them accordingly. However, despite the increasing number of studies linking fisheries and environmental data, few had a multi-species approach considering flatfish species and different age groups. Therefore, this study aims to determine the effects of environmental and fishing related variables on commercial flatfish species across different regions of the Portuguese coast. For that, sea surface temperature, North Atlantic Oscillation, upwelling index, wind components, river discharges and fishing effort were related to landings per unit effort (LPUE) of five commercial flatfish species (Pleuronectes platessa, Dicologlossa cuneata, Microchirus spp., Solea lascaris, and Solea solea) fished by the artisanal fleet along different regions of Portuguese coast (Northwestern coast, Southwestern coast, and Southern coast), using a multi-model statistical approach from 1989 to 2009. The fishing effort had the same effect along the life cycle and was negatively related with LPUE trends for most of the species. Regarding to environmental variability, during early phases (larval to juvenile - age-group-0) the factors that affected the recruitment, in addition to being related to the physiological needs (e.g., sea surface temperature) of individuals that will trigger growth and survival, were related to larval transport and dispersion from offshore spawning areas to coastal nursery habitats beyond (e.g., wind components and upwelling). For juvenile and young-adult phases (age-groups I and II), the effects of environmental variability appeared to be linked to physiological needs important for growth and maturation (e.g., temperature). Concluding, different effects were observed depending on the region, species, and life-cycle phase. Therefore, these environmental-fishing relationships should be used when managing local fishing resources.

2022-10Journal article

Open access

Dynamics of Decapoda larvae communities in a southwest Iberian estuary: Understanding the impact of different thermal regimes

Publication . Monteiro, Marta; Cruz, Joana; Azeiteiro, Ulisses; Marques, Sónia Cotrim; Baptista, Vânia; Teodosio, Maria

Environmental conditions play a pivotal role in shaping the dynamics of meroplanktonic communities, which represent a vital life stage, crucial for successful recruitment. Specifically, temperature can impact the survival and duration of larval development in decapod crustacean species. The objective of this study is to analyze the community of decapod larvae in the Guadiana estuary, located in southwest Iberia. The analysis focuses on the community's taxonomic composition, temporal variability, and the influence of environmental factors. Particularly, the study emphasizes investigating the impacts of different thermal regimes on the abundance of these assemblages. A comprehensive zooplankton sampling program was conducted at a single station in the lower estuary, from 2014 to 2022. The decapod larvae assemblages are dominated by Upogebia spp., followed by Diogenes pugilator, Panopeus africanus, Afropinnotheres monodi, and Polybius henslowii species. The results of structural equation modeling unveiled a strong influence of water temperature and salinity on the community, while chlorophyll-a concentration, river runoff, and the large-scale climatic mode North Atlantic Oscillation (NAO) revealed no impact on the abundance of these assemblages. Overall, the community and the main taxa displayed a positive linear trend in response to increased salinity. However, the effect of increasing temperature varied among species. In the current climatic scenario, water temperature emerges as a critical factor in predicting seasonal variation of the assemblages' abundances, exhibiting a marked seasonality during spring and summer. Predictive models used to investigate future scenarios, Representative Concentration Pathway (RCP) 2.6 and RCP 8.5, defined by the International Panel on Climate Change (IPCC), where the temperature is expected to rise 2 degrees C and 4.3 degrees C by 2100, suggest the possibility for an alteration in assemblages' composition, where the abundances of D. pugilator, the second most abundant species, tend to decrease abruptly. Reported evidence, coupled with the typical Mediterranean climate of the region, where extreme climatic events, like marine heatwaves, are becoming more frequent, the high connectivity with the Mediterranean Sea, where invasion by non-indigenous species is increasing, also connected with changes in freshwater discharges, may trigger significant alterations in species dominance and abundance, with ecological and socio-economic implications.

2023-11Journal article

Restricted access

Applying ecohydrology to promote a nature-based solution

Publication . Teodosio, Maria; Faria, Silvana; Baptista, Vânia; Wolanski, Eric

This chapter aims to develop an ecohydrological modelling approach to propose an environmental engineering solution based on historical nature-based information to alleviate the severe water degradation problem within Luanda Bay, Angola. This solution would improve local communities' ecosystem health and quality of life. The model suggests a simple and practical solution to solving the pollution problem by opening a cut from the bay's shallows to the sea. This will essentially reproduce an old bay opening to the sea, which was filled early in the last century. The residence time of water in the shallows of Luanda Bay would be reduced to about one week by excavating the channel over the land is straightforward. This should return the system to a more natural state and improve the water quality for recreational activities, increase the quality of marine food resources, reduce toxic algae blooms, and improve the quality of life of people in the area. Nevertheless, preventing pollutants from reaching Luanda Bay is the only long-term solution to restore a healthy environment in Luanda Bay

2024Book part

Open access