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- What’s for dinner? Assessing the value of an edible invasive species and outreach actions to promote its consumptionPublication . Cerveira, Inês; Baptista, Vânia; Teodosio, Maria; Morais, PedroThe consumption of edible aquatic inva sive species has gained popularity as a means to minimize their impacts while easing pressure on native resources and ecosystems. Weakfish Cynoscion regalis (Bloch & Schneider, 1801) is one of the most recent invasive fish species in the Iberian Peninsula (Europe) which once sustained an important fishery in the native range (Northwest Atlantic Ocean). Portugal ranks third in the list of the world’s fish consumers, so promoting a weakfish fishery could at least minimize the impacts upon native species, since weakfish have innate traits that are appreciated by Portuguese fish consumers. However, introducing a new species to consumers is challenging owing to consumers’ habits and unfamiliarity with the species. So, we aimed to (i) evaluate the acceptance of weakfish by a panel of Portuguese fish consumers and (ii) create outreach actions—partnerships with local Chefs and press releases—to explain to a broader audience what invasive species are and promote the consumption of edible aquatic invasive species. We conducted a consumers survey that showed that weakfish has great chances of being well accepted by Portuguese fish consumers– 90% would buy weakfish because they appreciated its appearance, flavor, and texture, besides being a wild fish. The outreach actions reached a few million people because 46 online articles were pub lished, and three news pieces were broadcasted on national television. Our strategy increased the public’s awareness about weakfish as an invasive species, which could be adapted for other non-indigenous marine species elsewhere in the world.
- Swimming abilities of temperate pelagic fish larvae prove that they may control their dispersion in coastal areasPublication . Baptista, Vânia; Morais, Pedro; Cruz, Joana; Castanho, Sara; Ribeiro, L.; Pousão-Ferreira, P.; Leitão, Francisco Miguel de Sousa; Wolanski, E.; Teodosio, Maria AlexandraThe Sense Acuity and Behavioral (SAAB) Hypothesis proposes that the swimming capabilities and sensorial acuity of temperate fish larvae allows them to find and swim towards coastal nursery areas, which are crucial for their recruitment. To gather further evidence to support this theory, it is necessary to understand how horizontal swimming capability varies along fish larvae ontogeny. Therefore, we studied the swimming capability of white seabream Diplodus sargus (Linnaeus, 1758) larvae along ontogeny, and their relationship with physiological condition. Thus, critical swimming speed (U-crit) and the distance swam (km) during endurance tests were determined for fish larvae from 15 to 55 days post-hatching (DPH), and their physiological condition (RNA, DNA and protein contents) was assessed. The critical swimming speed of white seabream larvae increased along ontogeny from 1.1 cm s(-1) (15 DPH) to 23 cm s(-1) (50 and 55 DPH), and the distance swam by larvae in the endurance experiments increased from 0.01 km (15 DPH) to 86.5 km (45 DPH). This finding supports one of the premises of the SAAB hypothesis, which proposes that fish larvae can influence their transport and distribution in coastal areas due to their swimming capabilities. The relationship between larvae's physiological condition and swimming capabilities were not evident in this study. Overall, this study provides critical information for understanding the link between population dynamics and connectivity with the management and conservation of fish stocks.
- Assessing microplastic uptake and impact on omnivorous juvenile white seabream Diplodus sargus (Linnaeus, 1758) under laboratory conditionsPublication . Müller, Carolin; Erzini, Karim; Teodosio, Maria; Pousão-Ferreira, Pedro; Baptista, Vânia; Ekau, WernerPrevious laboratory feeding experiments, representing the state-of-the-art methodology to investigate micro-plastic (MP) ingestion and its impact for fish, tend to disregard both the significance of applying realistic MP densities and the potential relevance of biofilm-coating for ingestion probability. This experiment assessed the uptake of either pristine or biofilm-coated MP particles and the physiological impacts for juvenile white seab-ream for MP concentrations consistent with those found in the field along with natural prey over a course of 3.5 weeks. Results indicate the ability of juvenile D. sargus to discriminate between edible and non-edible prey. A distinct preference for biofilm-coated over pristine particles could not be verified. No significant impact on growth and condition was found except for high levels of MP ingestion. The outcomes highlight the importance of performing MP feeding experiments mimicking natural conditions to reliably assess the impact of MP on early life stages of fish.
- Low-cost citizen science effectively monitors the rapid expansion of a marine invasive speciesPublication . Encarnação, João; Baptista, Vânia; Teodosio, Maria; Morais, PedroCitizen science and informed citizens have become fundamental in providing the first records and accounts about the expansion of numerous non-indigenous species. However, implementing a successful citizen science campaign can be expensive and particularly difficult for aquatic species. Here, we demonstrate how a low-cost citizen science campaign and its outreach plan in social and traditional media enabled to track the expansion of the Atlantic blue crab Callinectes sapidus Rathbun, 1896 along the coast of Algarve (southern Portugal, Europe). We describe the outreach strategy and a cost-benefit analysis of the first year of the citizen science campaign. Social media platforms allowed us to reach a significant number of citizens (over 31,500 clicks in Facebook publications), while traditional media gave national visibility to the citizen science campaign and biological invasions. In only 1 year, we documented the spread of the invasive Atlantic blue crab across the entire 140 km of the Algarve coast with 166 valid observations referring to 1747 specimens, submitted by 62 citizen scientists. We spent 0 € on the citizen science campaign, but considering the time invested in the campaign the cost would have summed up to 3,751 €, while the total minimum cost for one scientist to go to the field and retrieve the equivalent information would have exceeded 11,000 €. We used free online tools of communication to obtain the records about the Atlantic blue crab, instead of a dedicated web platform or mobile app, and handled social media accounts ourselves, which saved us at least 18,815 €. The citizen science campaign revealed that the Atlantic blue crab is unequivocally established in southern Portugal and that females appear to exhibit summer migrations to coastal areas to spawn as in the native area. Overall, our lowcost citizen science campaign effectively documented the rapid spread of a marine invasive species while providing some insights into its ecology. Our strategy can be easily replicated and implemented elsewhere in the world to tackle the ever-growing problem of biological invasions while increasing the scientific literacy of local populations.
- Replacement of Antarctic krill (Euphausia superba) by extruded feeds with different proximate compositions: effects on growth, nutritional condition and digestive capacity of juvenile European lobsters (Homarus gammarus, L.)Publication . Goncalves, Renata; Gesto, Manuel; Teodosio, Maria; Baptista, Vânia; Navarro-Guillén, Carmen; Lund, IvarExtruded feeds are widely used for major aquatic animal production, particularly for finfish. However, the transition from fresh/frozen to extruded/pelleted feeds remains a major obstacle to progressing sustainable farming of European lobster ( Homarus gammarus). The aim of the present study was to investigate the effects of using extruded feeds with different protein levels and lipid/carbohydrate ratios on growth, feed utilisation, nucleic acid derived indices (sRD) and digestive enzymatic activity of H. gammarus juveniles. Six extruded feeds were formulated to contain two protein levels (400 and 500 g/kg), with three lipid/carbohydrate ratios (LOW - 1:3; MEDium - 1:2; HIGH - 1:1). The extruded feeds were tested against Antarctic krill (Euphausia superba) used as control (CTRL). Overall, the CTRL and 500MED feed supported the highest growth and nutritional condition estimated by means of sRD, while the poorest results were observed for the 400HIGH and 400MED groups. The FCR was significantly lower in the CTRL than all extruded feeds, among which the most efficient, i.e., lower FCR, was the 500MED. The highest activity of trypsin and amylase in lobsters fed the 400MED and 400HIGH feeds points to the activation of a mechanism to maximise nutrients assimilation. The highest lipase activity observed for the 500LOW and 500MED groups indicates a higher capacity to metabolise and store lipids. Overall, the results suggest that the 500MED feed (500 g/kg protein, 237 g/kg carbohydrates and 119 g/kg lipids) is a suitable extruded feed candidate to replace Antarctic krill, commonly used to grow lobster juveniles.
- The Influence of environmental factors and fishing pressure on catch rates of diplodus vulgarisPublication . Baptista, Vânia; Campos, Carlos J. A.; Leitão, FranciscoThe variability of coastal marine resources has been linked to environmental variability but the impacts of artisanal nearshore fishing activity and environmental factors interact in different ways. Time series, Min/Max Autocorrelation Factor, Generalised Least Squares and Dynamic Factor Analyses models were applied to examine the role of environmental factors (SST, NAO Index, Upwelling Index, Wind Magnitude, Easterly Wind Component, Northerly Wind Component, Coastal River Discharges) and fisheries effort on commercial catch rates of Diplodus vulgaris in the Northwest, Southwest and South Portuguese coast. Environmental factors were found to affect short-term variations of catch rates with a time lag of 2 years, according to the regions and seasons. In the Northwest, autumn wind magnitude and summer river discharges were positively correlated with D. vulgaris catch rates. In the Southwest, D. vulgaris catch rates were negatively associated with variations in winter sea surface temperature. In the South, catch rates were positively associated with yearly westerly wind component and yearly, winter and autumn river discharges whilst negatively associated with the North Atlantic Oscillation (NAO) Index. These results indicate that both large-scale climatic patterns and local hydrological factors can have an influential role in determining the abundance of D. vulgaris stocks. Fishery assessment should therefore incorporate information on ecosystem and environmental effects to help managers to make informed decisions on how to best regulate coastal fisheries.
- Climate change vulnerability assessment of the main marine commercial fish and invertebrates of PortugalPublication . Bueno-Pardo, Juan; Nobre, Daniela; Monteiro, J. N.; Sousa, Pedro M.; Costa, Eudriano; Baptista, Vânia; Ovelheiro, Andreia; Vieira, Vasco; Chicharo, Luis; Gaspar, Miguel; Erzini, Karim; Kay, Susana; Queiroga, Henrique; Teodosio, Maria; Leitão, FranciscoThis is the first attempt to apply an expert-based ecological vulnerability assessment of the effects of climate change on the main marine resources of Portugal. The vulnerability, exposure, sensitivity, adaptive capacity, and expected directional effects of 74 species of fish and invertebrates of commercial interest is estimated based on criteria related to their life-history and level of conservation or exploitation. This analysis is performed separately for three regions of Portugal and two scenarios of climate change (RCP 4.5 and RCP 8.5). To do that, the fourth assessment report IPCC framework for vulnerability assessments was coupled to the outputs of a physical-biogeochemical model allowing to weight the exposure of the species by the expected variability of the environmental variables in the future. The highest vulnerabilities were found for some migratory and elasmobranch species, although overall vulnerability scores were low probably due to the high adaptive capacity of species from temperate ecosystems. Among regions, the highest average vulnerability was estimated for the species in the Central region while higher vulnerabilities were identified under climate change scenario RCP 8.5 in the three regions, due to higher expected climatic variability. This work establishes the basis for the assessment of the vulnerability of the human activities relying on marine resources in the context of climate change.
- Invasive fish keeps native feeding strategy despite high niche overlap with a congener speciesPublication . Cerveira, Inês; Dias, Ester; Baptista, Vânia; Teodosio, Maria; Morais, PedroWeakfish Cynoscion regalis (Bloch and Schneider, 1801) is one of the most recent invasive fish in the Iberian Peninsula (Europe). Weakfish has established in the Sado estuary (Portugal) since the early 2010s, and fishers and anglers have expressed concern about its impacts on native prize fish. However, almost a decade later, there is no information on the ecology of weakfish in the non-native area. So, we aimed to assess weakfish feeding strategy and feeding plasticity through stomach content analysis to evaluate if these factors may contribute to its invasiveness, as well as to determine the ecological overlap between weakfish and three native prize fish - European bass, white seabream, and particularly meagre (since they are taxonomically closer), through carbon and nitrogen stable isotopes. Our results demonstrate that Sado's weakfish has a generalist feeding strategy and preys the same functional groups it targets in the native area, therefore feeding strategy may weigh on invasiveness but not feeding plasticity. Weakfish, meagre, and European bass were in the same trophic level and weakfish exhibited higher trophic overlap with meagre, suggesting that weakfish could directly impact meagre if food and habitat become limiting. This study is the first assessment about weakfish ecology in the non-native area and our findings are an excellent starting point to understand this invasion. It can also be useful for management programmes that promote weakfish consumption to minimize its impacts, alleviate fishing pressure on native species, and raise public awareness.
- The Atlantic blue crab Callinectes sapidus Rathbun, 1896 expands its non-native distribution into the Ria Formosa lagoon and the Guadiana estuary (SW-Iberian Peninsula, Europe)Publication . Morais, Pedro; Gaspar, Miguel; Garel, Erwan; Baptista, Vânia; Cruz, Joana; Cerveira, Inês; Leitão, Francisco; Teodosio, MariaThe Atlantic blue crab Callinectes sapidus Rathbun, 1896 is native in the western Atlantic, however it is a non-indigenous species across Europe since 1900, among other world regions. In this paper, we report the first occurrences of this species in the Ria Formosa lagoon and in the Guadiana estuary (SW-Iberian Peninsula, Europe) which occurred in 2016 and July 2017, respectively. We hypothesize that the introduction of this species into these ecosystems might be due to the expansion of the Guadalquivir estuary population through natural processes (larval advection, active movement), or due to unintended introduction events after being transported aboard fishing boats, or, less likely, through ballast water. Changes in Guadiana's river flow after the construction of the Alqueva dam might also explain the presence of another non-indigenous species in the Guadiana estuary. The hypotheses presented, regarding the introduction of the Atlantic blue crab into these ecosystems and of its co-occurrence with other decapod species, are framed in a broader context to serve as a future research framework. The use of the Atlantic blue crab as a new fishing resource is also proposed, namely if it is to be used exclusively by local communities and if no deleterious impacts upon other fisheries and the ecosystem occur from this new fishery.
- Northerly wind trends along the Portuguese marine coast since 1950Publication . Leitão, Francisco; Relvas, Paulo; Canovas, Fernando; Baptista, Vânia; Teodosio, M. A.Wind is a marine coastal factor that is little understood but has a strong interaction with biological productivity. In this study, northerly wind trends in three regions of the Portuguese coast (Northwestern: NW, Southwestern: SW, and Southern: S) were analyzed. Two datasets with long-term (ICOADS: 1960-2010) and short-term data (Satellite: 1989-2010) were used to complement one another. The study revealed the northerly wind yearly data to be non-stationary and highly variable between years. Overall, the northerly wind intensity increased throughout the 1960s regardless of the area and dataset. Between 1960 and 2010, the northerly wind increased at a linear rate of 0.24, 0.09, and 0.15ms-1 per decade in the NW, SW, and S coastal regions, respectively. The rate was higher in recent decades (1988-2009), with the wind intensity increasing by 0.4, 0.3, and 0.3ms-1 per decade in the NW, SW, and S regions, respectively. Analyses of the sudden shifts showed significant increases in northerly wind intensities after 2003, 2004, and 1998 in the NW, SW, and S coast, respectively. Exceptions were found for autumn (September for short-term data), when a decrease in northerly winds was observed in recent decades, regardless of the area, and for summer, when no changes in wind trends were recorded in the NW and SW. The long-term data also showed a major increase in northerly winds in winter (January and February), which is the recruitment season for many small and medium-sized pelagic fish. The increase in the intensity of the northerly winds over the past two decades and the past half-century occurred at a higher rate than was estimated by the IPCC for the next century.
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