This study presents the first estimates of primary production (PP) from the Marine Ecological Time Series, Estación Permanente de Estudios Ambientales (EPEA) in the Argentine Sea and examines its relationship with phytoplankton community composition and environmental factors using data obtained between 2006 and 2019. Our findings indicate that PP at EPEA exhibits seasonal pulses, with an estimated annual average of 202 ± 115 g C m-2 yr-1, classifying the system as mesotrophic. The peak of PP occurred in spring associated with increased irradiance and water column stratification, and the dominance of diatoms, dinoflagellates, and haptophytes. Winter was the least productive season, characterized by low light levels and a deep mixed layer, with a prevalence of cryptophytes and ultraphytoplankton. In summer, PP was lower than in spring, and the community was dominated by picoplanktonic Synechococcus spp., adapted to low nutrients and high light. In autumn, PP increased relative to summer, associated with higher microphytoplankton biomass. A key finding was the decoupling between PP and total carbon biomass, highlighted by the high variability of the BC to ChlaS (BC/ChlaS) ratio. This ratio is crucial for linking carbon-based biogeochemical models with satellite-based PP models. Deviations from the expected seasonal patterns could point to the sensitivity of coastal PP to large-scale climate influences, such as the Southern Annular Mode (SAM) and the El Niño-Southern Oscillation (ENSO). Our results evidence the physiological adaptability of phytoplankton in this dynamic coastal environment and highlight the necessity of high-frequency sampling to improve primary productivity models in this under-sampled region.

The above article from Marine and Fishery Sciences (MAFIS) 35(3): 431-436 (https://doi.org/10.47193/mafis.3532022010902) has been retracted. The author has requested retraction after identifying that some data included in the article were not authorized for publication. Their inclusion was inadvertent, and the retraction is issued to maintain the integrity of the scholarly record.

The marine catfish Genidens barbus is a benthic and anadromous species distributed from Brazil to southern Argentina. Its presence during the non-reproductive period remains poorly documented. This study reported the first confirmed record of a female G. barbus outside the reproductive season, which was incidentally caught in the artisanal Argentine red shrimp (Pleoticus muelleri) fishery off the coast of Río Negro, Argentina (41° 05′ S-64° 03′ W) at a depth of 70 m. This finding provides novel evidence for the Patagonian population, suggesting that the species may occupy deeper marine habitats during non-reproductive periods. The presence of P. muelleri in the stomach content reinforces its benthophagous feeding habit and trophic association with the coastal benthic community. This record expands the current knowledge of the seasonal and ecological distribution of G. barbus, as well as conservation strategies. Given its status as a vulnerable species and the limited information available on its behavior outside estuaries, this finding makes a significant contribution to our understanding of Patagonian ichthyofauna and the sustainable management of its populations.

Xystreuris rasilis (Jordan 1891) is a flounder species from the southwestern Atlantic, perticularly abundant in high-salinity waters of the Buenos Aires Coastal Ecosystem and San Matías Gulf. It primarily feeds on benthic invertebrates and utilizes local frontal systems as breeding and nursery grounds. Analysis of a 406 bp fragment of the mitochondrial control region revealed high haplotype (h = 0.994) and nucleotide (n = 0.022) diversities. Genetic divergence between Necochea and San Antonio Oeste was low and not significant, with 18 unique haplotypes and no evident phylogeographic structure. Demographic analyses indicated long-term population stability, with the most recent common ancestor estimated at approximately 148,000 years ago. Results do not provide evidence for the existence of two discrete genetic units. Nevertheless, it is possible that the species experienced historical isolation followed by secondary contact between different lineages of the flounder X. rasilis.

A comprehensive understanding of a species life history is fundamental for effective fisheries management. This study contributes crucial, up-to-date information by analyzing the age structure and key biological parameters of southern blue whiting (Micromesistius australis) in the area defined by the 52° S-56° S parallels, based on data collected in 2019. It determined the population structure, growth parameters, and natural mortality using data from 2019 commercial bottom trawls and one research cruise. Analyzed specimens ranged from 26 to 59 cm total length (TL) in males and 26 to 64 cm TL in females. Length-frequency distributions were similar between sexes, with a main mode between 45 and 47 cm TL. Age analysis of 2,378 otoliths indicated a minimum age of two years and maximum ages of 20 years old. Significant differences in growth parameters were observed between sexes, primarily due to females having a larger asymptotic length. Von Bertalanffy growth function parameters were: females L¥ = 63.93 cm, K = 0.18 year-1, and t0 = -1.41 years; and males, L¥ = 57.43 cm, K = 0.21 year-1, and t0 = -1.39 years. The length-weight relationship also showed a significant sex difference. Length and age at 50% maturity were estimated at 35.25 cm TL and 2.93 years, respectively, with no significant differences between sexes. Estimates of instantaneous natural mortality ranged from 0.27 to 0.33 year-1. These findings provide valuable insights into M. australis life history in the region, relevant for future stock assessments and sustainable management strategies. The inclusion of Malvinas Islands data significantly enhances the robustness and applicability of these findings across the Southwest Atlantic.

The present work reports the occurrence of the deep-sea Caridea, Notostomus auriculatus Barnard, 1950 which represents the first record for the southwestern Atlantic Ocean. Organisms were caught during a fishing operation onboard the FV ‘Echizen Maru’ with a bottom trawl at the southeast of Isla de los Estados, Argentina, between 780 and 1,040 m depth. This record extends the spatial distribution of N. auriculatus.

Wild-captured lobster fisheries and cultured giant freshwater prawns (GFP) in Sri Lanka cater to high-end markets with significant exports. However, there is a notable gap in existing literature on value chain analysis and market performance aspects in both sectors. This study identified actor profiles and value chain dynamics in both sectors using structural mapping. Market performance was assessed through costs, margins, price spread, and marketing efficiency, with differentiation strategies proposed for sectoral growth. Data collection involved interviewer-administered questionnaires and in-depth interviews with 748 fishers, 44 collectors, and 12 exporters from December 2022 to March 2024. Results highlighted that the lobster value chain was highly export-driven, with a concentration on live trade and premium pricing. Fishers and collectors faced risks from fluctuating stocks and strict regulations, while exporters dealt with logistical and market volatility. Upstream actors often overexploit resources to increase yields, rather than improve quality, leading to unsustainable practices. To mitigate market challenges, actions like promoting products under branding tags such as ‘wild-caught lobster’ and ‘conventionally cultured GFP’, maintaining food safety and quality standards and optimizing logistics are essential for enhancing competitiveness. The GFP sector operates in both domestic and export markets, competing with commodity shrimp. While it provides employment, its financial performance is moderate, limited by high farming costs and pricing competitiveness. Differentiation efforts should focus on sustainable labeling, value-added products, direct exports, and catering to niche markets to boost profitability and reduce dependence on bulk markets.

The deep-sea ecosystems and biodiversity of Argentina are sensitive to the effects of climate variation such as warming, oxygen loss, and ocean acidification. This vulnerability is due to specific characteristics such as the presence of long-lived species, which can live for over 4,000 years, with very slow growth and reproduction rates, which depend on habitats with complex configurations. As a result, many deep-sea ecosystems affected by disturbances have a low probability of recovery, and if recovery occurs, it may take hundreds or even thousands of years. This document synthesizes the results of a Specialist Workshop that reviewed the current state of scientific knowledge and discussed its application to the management of Argentina’s deep sea, from an ecosystem-based perspective that considers climate variability. Argentina’s deep sea, spans depths ranging from 200 to 6,000 m, covering more than 70% of the national maritime territory, with an approximate area of 4.6 million km2. In the Argentine seabed, geomorphological and oceanographic complexity indicates a high potential to support extensive benthic biodiversity. However, knowledge about its ecosystems and the environmental management policies for this vast Argentine territory have been limited and fragmented, particularly regarding the incorporation of climate-related variables. Designing effective policies to protect its biodiversity and the multiple benefits these ecosystems provide to society implies robust technical advice, for which it is essential to strengthen scientific knowledge on Argentina’s deep-sea ecosystems and their interaction with climate variability, as well as sustained coordination and collaboration among all relevant sectors.

Marine resources in the Philippines are rapidly declining due to overfishing and habitat degradation, threatening biodiversity and the livelihoods of coastal communities and small-scale fishers. Crustaceans, like the blue swimming crab (Portunus pelagicus), which serve as a vital source of income for small-scale fishers, are among the most affected. To combat the depletion of fishery resources, the Philippine government implemented the National Blue Swimming Crab Policies and Plans (NBSCPP). This study focused on the perspectives of crabbers in northern Catanduanes to provide insights into the implementation and impact of the NBSCPP at the community level. Data were collected through interviews with 208 crabbers using a modified survey questionnaire based on the NBSCPP framework. Results revealed that the income of crabbers and their families fell significantly below the poverty threshold, a challenge further compounded by low levels of formal education, which limited their opportunities for alternative livelihoods. Crabbers demonstrated a general awareness of conservation and management policies, particularly on closed fishing seasons and size limits, and exhibited a positive attitude toward compliance and participation in conservation initiatives. However, socio-demographic characteristics such as education and income were not significantly associated with crabbers’ awareness or attitudes toward policy implementation. To enhance awareness and foster sustainable practices, the study recommended intensified information, education, and communication campaigns, stricter enforcement of regulations, and the development of alternative livelihood programs. These measures are critical to ensuring the long-term sustainability of the blue swimming crab population and supporting the livelihoods of communities in northern Catanduanes.

En los últimos años, la acústica pasiva se ha convertido en una herramienta eficaz para la detección de cetáceos, particularmente en especies difíciles de observar. Además de ser una técnica no invasiva, permite monitorear a los animales sin perturbarlos, independientemente de la visibilidad. Sin embargo, el alto costo del equipamiento asociado a esta técnica presenta un obstáculo significativo para países en vías de desarrollo. El objetivo del presente proyecto fue comparar las señales acústicas del delfín nariz de botella (Tursiops truncatus truncatus) obtenidas mediante un hidrófono autocontenido comercial y otro de bajo costo, fabricado artesanalmente. Para ello, se realizaron grabaciones en el establecimiento Aquarium Mar del Plata, Argentina, empleando ambos hidrófonos colocados de manera simultánea durante un periodo de 50 min. Se caracterizaron las señales obtenidas y se contabilizaron las señales tonales (silbidos) para cada instrumento. De cada silbido se obtuvieron parámetros robustos utilizando el programa Raven Pro. A partir del análisis de los silbidos coincidentes, se determinó que los parámetros medidos no presentaron diferencias significativas entre ambos instrumentos, demostrando la efectividad de los hidrófonos de bajo costo para registrar acústicamente a los delfines nariz de botella en ambientes controlados, con posibilidad de aplicarlos en otros entornos como mar abierto.