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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.
- The transatlantic introduction of weakfish Cynoscion regalis (Bloch & Schneider, 1801) (Sciaenidae, Pisces) into EuropePublication . Morais, Pedro; Teodosio, MariaWeakfish Cynoscion regalis (Bloch and Schneider, 1801) is a sciaenid fish native to the east coast of North America and has been recently collected in three areas of the Iberian Peninsula (Europe). We aimed to i) provide the first report of the presence of weakfish in Europe, ii) hypothesize the most likely introduction vector, iii) discuss the potential for ecological overlap between weakfish and meagre Argyrosomus regius (Asso, 1801), the native Sciaenidae species, and iv) highlight the importance of citizen science in the detection of nonnative species. Weakfish were captured in the Sado estuary (July 2014), Gulf of Cadiz (November 2015) and the adjacent Guadiana estuary (June 2016), and in two Galician Rías (June 2016). Anglers reported that weakfish was present in the Sado estuary for “some” years, while their presence was only noticed recently in the other two areas. We hypothesize that ballast water was the introduction vector, that weakfish established a reproducing population in the non-native range, and that it dispersed from the Sado estuary, a central region of its current distribution range. The Sado estuary might have been the introduction area for weakfish via ballast water because there is a busy transoceanic commercial port in the estuary. Moreover, they are not used in European aquaculture facilities, nor in the aquarium trade. The collected specimens were ≤50 cm, with average lengths of 30 cm, which corresponds to a median age of 2 years and to individuals capable of reproducing. As a result, the year of introduction must be before 2012. Weakfish have a similar ecological niche to meagre, but the outcome of potential interactions is uncertain. Citizen science, especially the initiative of local fishermen, was critical to detect this non-native species.
- 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.
- What are jellyfish really eating to support high ecophysiological condition?Publication . Morais, Pedro; Parra, María P.; Marques, Raquel; Angélico, Maria Manuel; Chainho, Paula; Costa, José Lino; Barbosa, Ana B.; Teodosio, Maria; Cruz, JoanaThe feeding ecology of Blackfordia virginica was evaluated concurrently with their ecophysiological condition in a temperate estuary. The diet of B. virginica is composed not only of metazooplankton, as commonly observed for other jellyfish species, but also of phytoplankton, ciliates and detritus. This feeding behavior might explain their good nutritional condition and sustainable growth during bloom peaks, when zooplankton abundance has already decreased significantly.
- The unexpected occurrence of late Sardina pilchardus (Walbaum, 1792) (Osteichthyes: Clupeidae) larvae in a temperate estuaryPublication . Morais, P.; Faria, Ana Margarida da Silva; Teodosio, Maria; Chícharo, LuísThe presence of sardine larval stages inside estuaries has generally been regarded as accidental and restricted to the lower part of estuaries. Sampling done with a zooplankton net in the Guadiana estuary corroborated this hypothesis. Late sardine larvae (32.8 ± 2.0 mm) were, however, unexpectedly collected with an otter trawl, 14 km upstream from the mouth of the estuary. Thus, this work intends to: (1) discriminate and compare the abiotic characteristics of the sites where maximum abundance of sardine larval stages were registered, when captured with a zooplankton net, with the characteristics of the sites where late sardine larvae were collected with an otter trawl; (2) demonstrate that the presence of the late sardine larvae inside the Guadiana estuary was not accidental. The average salinity of the site were late larvae where collected was 4.2 ± 2.3, i.e. 87.3% lower than the average salinity where maximum abundance of early larvae was registered. We suggest that the presence of the late sardine larvae inside the Guadiana estuary was not accidental. In order to migrate to that location and remain in the estuary, counteracting river inflow, these late larvae must have employed active migration and retention strategies. New methodologies need to be implemented for routine sampling of all larval stages of sardine, in order to achieve a complete understanding of their life cycle.
- 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.
- Benthic food webs support the production of sympatric flatfish larvae in estuarine nursery habitatPublication . Dias, Ester; Morais, Pedro; Faria, Ana M.; Antunes, C.; Hoffman, Joel C.Identifying nursery habitats is of paramount importance to define proper management and conservation strategies for flatfish species. Flatfish nursery studies usually report upon habitat occupation, but few attempted to quantify the importance of those habitats to larvae development. The reliance of two sympatric flatfish species larvae, the European flounder Platichthys flesus and the common sole Solea solea, on the estuarine food web (benthic versus pelagic), was determined through carbon and nitrogen stable isotope analysis. The organic matter sources supporting the production of P.flesus and S.solea larvae biomass originates chiefly in the benthic food web. However, these species have significantly different C-13 and N-15 values which suggest that they prey on organisms that use a different mixture of sources or assimilate different components from similar OM pools (or both).
- Harnessing the power of social media to obtain biodiversity data about cetaceans in a poorly monitored areaPublication . Morais, Pedro; Afonso, Luís; Dias, EsterThe study and conservation of cetaceans benefit from systematic studies and non systematic records about sightings and strandings. However, iEcology (internet ecology) was critical for numerous ecological studies and should be in the toolkit of cetacean ecologists. We hypothesize that iEcology is irreplaceable to obtain diversity data about cetaceans in poorly monitored regions that coincide with touristic destinations, where whale-watching companies go out to sea regularly and post their sightings on social media. Our study assessed the advantages and disadvantages of iEcology while obtaining the first broadscale and long-term assessment about cetaceans’ diversity off the Algarve, a European tourist destination with numerous whale-watching companies. We retrieved 1,299 time-referenced records about 15 species posted on Facebook and Instagram between 2011 and 2020. Data collected from Biodiversity4All, an online citizen science biodiversity database, disclosed georeferenced records about nine species made between 2008 and 2020, however, the number of records was 15.8 times lower than social media posts. We obtained information about 16 species, two of which were never mentioned in the scientific literature [Balaenoptera musculus, Balaenoptera edeni (record made in 2021)] and five species were only mentioned in the gray literature. Previous assessments were restricted in time, published in the gray literature, and only reported six and 11 species. So, social media was essential to obtain the first broadscale and long-term assessment of cetaceans’ diversity off the Algarve. The main advantages of iEcology were the possibility to obtain data collected over one decade and its low cost. The main disadvantages are the impossibility to obtain georeferenced records from social media, the difficulty to estimate the number of individuals in large groups, and the presence of rare species can be inflated if multiple whale-watching companies report the same individual(s) while they migrate along the coast. Nonetheless, these disadvantages can be mitigated. Overall, we endorse the use of iEcology to increase the ecological knowledge about cetaceans which might be the only tool to study them in numerous regions across the world. The contributions of whale-watching companies are invaluable, so we recommend the implementation of a standardized cetacean observation log as a relevant source of data for conservation.
- Merging anchovy eggs abundance into a hydrodynamic model as an assessment tool for estuarine ecohydrological managementPublication . Morais, P.; Martins, Flávio Augusto Bastos da Cruz; Chicharo, Maria Alexandra Teodosio; Lopes, J.; Chícharo, LuísThe impoundment of rivers by large dams is the biggest direct anthropogenic impact on the hydrological cycle. However, dams can help solving eutrophication in estuaries by controlling flow pulses, which in turn might enhance the advection of fish larval stages from their spawning and nursery areas. Thus, this work aimed to merge data on the abundance of anchovy eggs with MOHID hydrodynamic model for the Guadiana estu ary, allowing dam/basin managers to set river discharge scenarios that might mitigate/prevent eutrophication, without compromising the presence of fish larval stages inside the estuary. Data on anchovy larval stages were assessed in the Guadiana estuary and adjacent coast and three simulation setups were developed. In Simulation A, anchovy eggs abundance was merged in the hydrodynamic model to compare the outputs with data on the abundance, distribution and development stage of anchovy eggs and larvae. In Simulation B, lagrangian particles were incorporated in the model to determine the percentage of particles released from the upper, middle and lower estuary that remain in the estuary along 10 days, in two tidal situations and in seven river discharge scenarios. In Simulation C, the abundance of anchovy eggs was merged in the model to select the discharge scenario(s) that do not compromise the presence of anchovy larval stages in the estuary. Results confirmed the spawning and nursery areas of anchovy and showed that scenarios B (Qmax¼20m3 s 1) and C (Qmax¼50m3 s 1) should be applied during neap tides. The choice between scenarios depends on the degree of eutrophication, the effectiveness of an inexistent monitoring program and on plankton response experiments to flushing and increased nutrient loading. This work produced an easy-to-use management tool for Guadiana managers, serving as an example to other estuarine sites around the world. Ultimately, this work suggests that river flow management must be guided by robust ecological studies, under an adequate sociological framework and adopting sustainable economic principles to maintain and improve the ecosystem services.