The Serra Spanish mackerel fishery (Scomberomorus brasiliensis – Teleostei) in Southern Brazil: the growing landings of a high trophic level resource

In fisheries, the phenomenon known as fishing down food webs is supposed to be a consequence of overfishing, which would be reflected in a reduction in the trophic level of landings. In such scenarios, the resilience of carnivorous, top predator species is particularly affected, making these resources the first to be depleted. The Serra Spanish mackerel, Scomberomorus brasiliensis, exemplifies a predator resource historically targeted by artisanal fisheries on the Brazilian coast. The present work analyzes landings in three periods within a 50-year timescale on the Parana coast, Southern Brazil, aiming to evaluate whether historical production has supposedly declined. Simultaneously, the diet was analyzed to confirm carnivorous habits and evaluate the trophic level in this region. Surprisingly, the results show that from the 1970’s to 2019 Serra Spanish mackerel production grew relatively to other resources, as well as in individual values. The trophic level was calculated as 4.238, similar to other Scomberomorus species, consisting of a case where landings increase over time, despite the high trophic level and large body size of the resource. The results agree with a recent global assessment that has demystified a necessary correlation between high trophic level and overexploitation, but possible factors acting on the present findings are discussed.

Lipid Indexes and Quality Evaluation of Omega-3 Rich Oil from the Waste of Japanese Spanish Mackerel Extracted by Supercritical CO2

Japanese Spanish mackerel (JSM) (Scomberomorus niphonius) is a marine fish species containing health-beneficial polyunsaturated fatty acids (PUFAs). In the present study, the quality of JSM by-products oils extracted by supercritical CO2 (SC-CO2) and organic solvent extraction was compared in terms of physico-chemical properties of the oils. Eicosapentaenoic acid (EPA) is one of the important polyunsaturated fatty acids present in SC-CO2-extracted skin and muscle oil 5.81 ± 0.69% and 4.93 ± 0.06%, respectively. The amount of docosahexaenoic acid (DHA) in SC-CO2-extracted skin and muscle oil was 12.56 ± 0.38% and 15.01 ± 0.28%, respectively. EPA and DHA are considered as important PUFAs for the development of brain function and the prevention of coronary heart diseases. Extracted oils showed considerable antioxidant activity. In the obtained oils, atherogenic index (AI) values varied from 0.72 to 0.93 and thrombogenic index (TI) ranged from 0.75 to 0.92, which is considered an acceptable level. Fatty acid composition, bio potentiality, thermogravimetric, and vitamin D analysis showed that oils extracted from JSM by-products can be a good source of oil for application in food, pharmaceutical and cosmetic industries. Therefore, the present research revealed the potentiality of green valorisation of S. niphonius by-products as a possible sustainable approach for targeting the era of zero waste.

INTRODUKSI LAMPU CELUP PADA PENGOPERASIAN JARING INSANG HANYUT

Peluang keberhasilan operasi penangkapan ikan dengan jaring insang hanyut sangat ditentukan oleh arah ruaya ikan terhadap posisi jaring. Ikan akan tertangkap jika arah renangnya terhadang oleh jaring. Penelitian mencoba meningkatkan peluang ikan tertangkap dengan memanfaatkan lampu celup. Tujuannya untuk menunjukkan bahwa penggunaan lampu celup akan meningkatkan jumlah ikan hasil tangkapan tanpa mengurangi komposisi jenisnya. Dua unit jaring insang dioperasikan secara bersamaan. Salah satu unit jaring insang dilengkapi dengan lampu celup. Hasil penelitian menunjukkan penggunaan lampu celup tidak mempengaruhi komposisi jenis ikan yang tertangkap, tetapi hanya mempengaruhi jumlah tangkapannya. Jumlah total ikan hasil tangkapan jaring insang yang dilengkapi lampu celup mencapai 3.521 ekor, atau 58,82% dari seluruh ikan hasil tangkapan, sedangkan jaring insang tanpa lampu celup sebanyak 2.465 ekor (41,18%). Rincian hasil tangkapan jaring insang yang dilengkapi lampu celup dan tanpa lampu celup adalah mackerel tuna (Euthynnus affinis) sebanyak 218 ekor dan 129 ekor, spanish mackerel (Scomberomorus commerson) (80; 50), needlefish (Tylosurus crocodilus) (7; 3), Indo-Pacific sailfish (Istiophorus platypterus) (4; 2), driftfish (Psenes cyanophrys) (2.838; 2.051), dan moonfish (Mene maculata) (374; 230). Kata kunci: high-brightness LEDs, jaring insang hanyut, komposisi jenis ikan, lampu celup

CARACTERIZAÇÃO DA PESCA COM REDE SERREIRA NO MUNICÍPIO DE RAPOSA-MA = CHARACTERIZATION OF FISHING WITH DRIFT GILLNET IN THE MUNICIPALITY OF RAPOSA-MA

Com o propósito de estimar a produção do peixe serra (Scomberomorus brasiliensis) e de sua fauna acompanhante, foram acompanhados desembarques de uma embarcação componente da frota serreira que atua ao longo do litoral maranhense e está sediada no município de Raposa. O controle nos desembarques caracterizou a composição e abundância dos pescados no período de janeiro de 2009 a dezembro de 2010, totalizando 17 desembarques. Um total de 27 espécies pertencentes a 16 famílias e 8 ordens, foram registradas nos desembarques. Em relação ao peso, a família Scombridae superou as demais, representando 50,02% da biomassa, seguida da Sciaenidae (21,60%) e Carangidae (11,13%). As 6 principais espécies desembarcadas, respondem por 81% do total desembarcado, destacando-se Scomberomorus brasiliensis, Cynoscion microlepidotus e Sarda sarda. Das espécies capturadas, 74,07% foram classificadas como acidentais, as espécies acessórias não ultrapassaram 14,81%, enquanto as constantes foram representadas em menos de 11,11% dos desembarques. O rendimento médio estimado das pescarias na região foi de 361 Kg/hora.AbstractTo estimate the production of Spanish mackerel (Scomberomorus brasiliensis) and its by-catch were accompanied by a landing craft fleet serreira component that acts along the coast of Maranhão and is based in the Raposa. The control landings characterized the composition and abundance of fish in the period January 2009 to December 2010, a total of 17 landings. A total of 27 species belonging to 16 families and eight orders were recorded in the landings. A total of 27 species belonging to 16 families and 8 orders were recorded in the landings. Regarding weight, the family Scombridae surpassed the others, representing 50.02% of the biomass, then the Sciaenidae (21.60%) andCarangidae (11.13%). Six species account for approximately 81% of total landings, most abundant being Scomberomorus brasiliensis, Cynoscion microlepidotus and Sarda sarda. Of the species caught, 74.07% were classified as accidental, the species accessory did not exceed 14.81%, while the constants were represented in less than 11.11% of the landings. The estimated average yield of the fisheries in the region was 361 kg / hour.

Distribution and Catch Rate Characteristics of Narrow-Barred Spanish Mackerel (Scomberomorus commerson) in Relation to Oceanographic Factors in the Waters Around Taiwan

This study investigated the relationship of the catch rates (CRs) of Spanish mackerel (Scomberomorus commerson) with oceanographic factors in the waters around Taiwan by using high-resolution fishery and environmental data for the period 2011–2016. The investigation results revealed that trammel nets accounted for 69.79% of the total catch of S. commerson and were operated mostly in the Taiwan Strait (TS). We noted seasonal variations in the distribution of high CRs. These CRs were observed in the southwestern TS, including the waters along the southwestern coast of Taiwan and around the Penghu Islands, and extended to the Taiwan Bank during autumn; they increased in winter. To predict the spatial and temporal patterns of Spanish mackerel density and their relationship with oceanographic and spatiotemporal variables, generalized additive models were used. These models explained 48.4% of the total deviance, which was consistent with the assumed Gaussian distribution. Moreover, all variables examined were significant CR predictors (p < 0.05). Latitude and longitude were the key factors influencing the spatiotemporal distribution of S. commerson, and sea surface chlorophyll a concentration was a key oceanographic factor. Observing projected changes in El Niño/Southern Oscillation events for S. commerson revealed that CRs were higher and distributed further southward during La Niña events than during other events. We inferred that the S. commerson distribution gradually moved toward the southwest with the northeast monsoon, which was enhanced during La Niña in winter.

Demographics of Scomberomorus commerson in the Central Taiwan Strait

The narrow-barred Spanish mackerel Scomberomorus commerson is an economically essential species; however, few studies have investigated its demographic structure in the northwestern Pacific, which includes Taiwan’s waters. This study examined the growth parameters, age composition, mortality, and sex ratio of S. commerson catches by examining sagittal otoliths and other biological data collected in a 3-year project from June 2018 to June 2021. The transverse sections of sagittal otoliths exhibited alternating translucent and opaque zones, in annual cycles, and this observation was validated by otolith edge analysis. Opaque zones began to form in October; the growth peaked in December and lasted until March. Growth parameters were estimated for female (L∞ = 144.1 cm fork length [FL], k = 0.39 y−1, to = −0.85 y) and male (L∞ = 136.0 cm FL, k = 0.32 y−1, to = −1.49 y) specimens. The maximum recorded FL, body weight, and age were 159.0 cm, 27 kg, and 9.2 y for female and 135.0 cm, 17.8 kg, and 7.2 y for male specimens. Rapid growth was observed for both sexes, with FL reaching 66.8 ± 14.2 cm in female specimens and 70.1 ± 11.0 cm in male specimens during the first year of life. An age–length key based on the direct otolith aging and FL dataset (N = 646) was used to estimate the age composition of 3-year catches measured at landing (N = 16,133). The results verified that the S. commerson currently caught in the central Taiwan Strait are mainly young fish aged 1+ to 2+ y. The estimated fishing mortality (0.27 y−1) and exploitation rate (0.30) suggested that overfishing was not occurring in this stock. The findings of this study have helped clarify the population dynamics of the S. commerson in the Taiwan Strait, and the biological parameters reported herein can aid the management and conservation to ensure the sustainability of this species in this region.

Interaction of Carbon Dots from Grilled Spanish Mackerel with Human Serum Albumin, γ-Globulin and Fibrinogen

The potential biological effects of food-borne carbon dots (FCDs) generated during food heating procedures on human health has received great attention. The FCDs will be inevitably exposed to blood proteins along with our daily diet to produce unknown biological effects. In this study, the interaction between FCDs extracted from grilled Spanish mackerel and three main types of human plasma proteins including human serum albumin (HSA), human γ-globulin (HGG) and human fibrinogen (HF) was reported. It was found that the grilled Spanish mackerel FCDs could affect the morphology, size and surface electrical properties of the three proteins. The interaction between the FCDs and proteins had different effects on the secondary structure of the three proteins through a static mechanism. The tested HSA, HGG, and HF could adsorb FCDs to reach saturation state within 0.5 min after the adsorption happened. The binding affinity of the FCDs to the plasma proteins was sorted as follows: HF > HGG > HSA. The results of FCDs interacted with plasma proteins provided useful information in the assessment of the safety of FCDs in our daily diet.