Abstract Promoting the consumption of edible aquatic invasive species has gained popularity to minimize its impacts while easing pressure on native resources. 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 top fish consumers, so promoting a weakfish fishery could at least help minimize the impacts upon native species, since weakfish have innate traits that are likely 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 public what invasive species are and promote the consumption of edible aquatic invasive species. The survey that we conducted to Portuguese fish consumers showed that weakfish has great chances of being well accepted by the public – 90% of consumers would buy weakfish because they appreciated its appearance, flavour, and texture, besides being a wild fish. The outreach actions reached a few million people because 46 online articles were published, and three news pieces broadcasted on national television. Overall, our strategy greatly increased the public’s awareness about invasive species, which can be replicated elsewhere in the world.
Animal migration is the seasonal movement from one region to another and can involve thousands of individuals journeying across continents and oceans.Scientists often use electronic and physical tags to track the movements of migratory fish.However, these tags only work on bigger fish and only give a limited picture of where the fish have been.However, scientists discovered how to use fish otoliths ("ear stones") to reveal the secret journey of migrating fish over their entire lifetime.Otoliths grow a new layer every day of the fish's life, producing growth bands just like a tree.The otoliths incorporate chemical elements from the water as the fish grow and move, providing a chemical map of where the fish have been.The growth bands also tell us how long
Abstract The occurrence of scyphozoan blooms is frequently reported in coastal areas, suggesting a need to assess its impacts on trophic webs. However, many scyphozoan species remain understudied with regard to their feeding ecology. Here, feeding selectivity experiments were conducted to learn about the possible prey preference of Catostylus tagi among mesozooplankton prey and estimate feeding rates. In general, C. tagi demonstrated a relative positive selection on small prey as cyclopoid copepods (Oithona spp. and Oncaea spp.), copepod nauplii as well as non-swimming prey (fish eggs), and ingestion rates increased with prey concentration. Further in situ studies must be conducted during summer blooms, to determine the predatory impact, retrieving data of C. tagi and prey abundance, particularly in important nursery areas such as estuaries.
New information on weakfish introduction vectors, its invasive status, distribution, and use as a fishing resource arose after the publication of “The transatlantic introduction of weakfish Cynoscion regalis (Bloch & Schneider, 1801) (Sciaenidae, Pisces) into Europe” by Morais and Teodósio (2016). Currently, the first known report of weakfish in Europe dates back to September 2009, with a specimen captured in the Schelde estuary (Belgium/The Netherlands). This fact suggests that weakfish could have been introduced into Europe via multiple and independent ballast water introduction events, and not through a point-source introduction event with subsequent dispersion as previously hypothesized. It is also unlikely that Schelde weakfish migrated southwards to colonize Iberian aquatic ecosystems. Weakfish have established a population in the Gulf of Cádiz region and have already reached an invasive status in the Sado estuary (Portugal). Weakfish were also captured in several other locations along the Portuguese coast, including the Tagus and Mira estuaries at least since 2013 or 2014, and the Ria Formosa lagoon in 2017. Tagus anglers caught weakfish specimens of ~1 kg and ~40 cm in November 2016, which corresponds to fish of 3+ years of age in the native range. The presence of weakfish in the Tagus estuary is still fairly unknown to local anglers. Sado weakfish has already been sold in local fish markets in southern Portugal for 3 to 10 € kg−1. However, we consider that the weakfish sale price is underrated in comparison with other wild species (e.g., meagre, seabass, gilthead seabream). Increasing sale price will convince fishers to use weakfish as a new fishing resource; however, it is necessary to promote the species among consumers and evaluate consumers’ preference in respect to other species. A putative biological threat might turn into a new valuable fishing resource by implementing adequate management solutions.