Climatic and oceanographic drivers of plankton community dynamics in the Portuguese upwelling coastal system

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Antifungal and Antioxidant Properties of Chitosan Polymers Obtained from Nontraditional Polybius henslowii Sources

Publication . Avelelas, Francisco; Horta, André; Pinto, Luís F.V.; Marques, Sónia Cotrim; Nunes, Paulo; Pedrosa, Rui; Leandro, Sérgio Miguel

Chitin was extracted from Polybius henslowii, a swimming crab, captured in large quantities throughout the Portuguese coast by purse seine vessels as bycatch. After standard chitin extraction procedures, water-soluble chitosan products were obtained via two di erent methods: (1) N-acetylation with the addition of acetic anhydride and (2) a reaction with hydrogen peroxide. The chemical structure and molecular weight of chitosan derivatives, water-soluble chitosan (WSC) and chitooligosaccharides (COS), were confirmed by Fourier Transform Infrared Spectroscopy (FT-IR) and gel permeation chromatography (GPC).Antioxidant and metal chelation activities were evaluated, and the growth inhibition capacity was tested on four phytopatogens. The chitooligosaccharides from pereopods (pCOS) and shell body parts (sCOS) inhibited all fungal species tested, particularly Cryphonectria parasitica with 84.7% and 85.5%, respectively. Both radical scavenging and antifungal activities proved to be dose-dependent. Chitooligosaccharides with a low molecular weight (2.7, 7.4, and 10.4 Kg mol􀀀1) showed the highest activity among all properties tested. These results suggested that chitosan derivatives from P. henslowii raw material could potentially be used against phytopathogens or as ingredient in cosmetics and other products related to oxidative stress.

2019Journal article

Open access

WGEUROBUS – Working Group ‘‘Towards a EURopean OBservatory of the non-indigenous calanoid copepod Pseudodiaptomus marinUS’’

Publication . Uttieri, M.; Aguzzi, L.; Cigliano, R. Aiese; Amato, A.; Bojanic, N.; Brunetta, M.; Camatti, E.; Carotenuto, Y.; Damjanovic, T.; Delpy, F.; Olazabal, A. de; Di Capua, I.; Falcão, J.; Fernandez, M.L.; Foti, G.; Garbazey, O.; Goruppi, A.; Gubanova, A.; Hubareva, E.; Iriarte, A.; Khanaychenko, A.; Lucic, D.; Marques, S.C.; Mazzocchi, M.G.; Mikus, J.; Minutoli, R.; Pagano, M.; Pansera, M.; Percopo, I.; Primo, A.L.; Svetlichny, L.; Rozic, S.; Tirelli, V.; Uriarte, I.; Vidjak, O.; Villate, F.; Wootton, M.; Zagami, G.; Zervoudaki, S.

Since 2007, the non-indigenous calanoid copepod Pseudodiaptomus marinus Sato, 1913 has been increasingly recorded in numerous European sites, spreading at an unexpectedly fast pace over a short time-span. This species presents specific biological and behavioural traits which make it of particular interest for ecological and applied research topics. On 29–30 January 2018, 29 scientists from nine European Countries established the EUROBUS (Towards a EURopean OBservatory of the nonindigenous calanoid copepod Pseudodiaptomus marinUS) Working Group (WG). This WG aimed at creating a European network of institutions and researchers working on the various aspects of the biology and ecology of P. marinus, with an open forum where sharing experience and know-how among WG participants. This brought to an updated distribution map of P. marinus in European waters, as well as to the identification of priority research lines and potential joint initiatives under the WGEUROBUS umbrella. This contribution, stemming from the experts participating at the WG, represents the manifesto of the current and future initiatives developed within WGEUROBUS.

2020Journal article

Restricted access

Effects of ocean acidification and warming on the development and biochemical responses of juvenile shrimp Palaemon elegans (Rathke, 1837)

Publication . Maia, Simão; Marques, Sónia C.; Dupont, Sam; Neves, Marta; Pinto, Henrique J.; Reis, João; Leandro, Sérgio M.

Anthropogenic CO2 emissions have led to the warming and acidification of the oceans. Although, there is a growing of evidence showing that simultaneous occurrence of ocean acidification and ocean warming are threats to marine organisms, information on their combined effect on coastal shrimp species remains scarce. The purpose of this study was to estimate the combined effects of seawater acidification and warming on growth-related traits and biochemical responses of P. elegans juveniles. In this work, shrimp were exposed for 65 days at 4 experimental conditions: pH 8.10 * 18 ◦C, pH 7.80 * 18 ◦C, pH 8.10 * 22 ◦C, pH 7.80 * 22 ◦C. The results showed that low pH decreases the lipid content by ~13% (p < 0.05). Higher temperature reduced the condition factor by ~11%, the protein content by ~20%, the PUFA by ~8,6% and shortened moulting events by 5 days (p > 0.05) while the SFA increased ~9.4%. The decrease in condition factor and protein was however more prominent in organisms exposed to the combination of pH and temperature with a decrease of ~13% and ~21%, respectively. Furthermore, essential fatty acids as EPA and DHA also decreased by ~20% and ~6.6% in low pH and higher temperature condition. Despite this study suggest that warming may have a greater impact than acidification, it has been shown that their combined effect can exacerbate these impacts with consequences for the shrimp’s body size and biochemical profile.

2022Journal article

Restricted access

Evidence for changes in estuarine zooplankton fostered by increased climate variance

Publication . Marques, Sónia Cotrim; Pardal, Miguel Ângelo; Primo, Ana Lígia; Martinho, Filipe; Falcão, Joana; Azeiteiro, Ulisses; Molinero, Juan Carlos

Estuaries are among the most valuable aquatic systems in terms of their services to human welfare. They offer an ideal framework to assess multiscale processes linking climate and food web dynamics through the hydrological cycle. Resolving food web responses to climate change is fundamental to resilience management of these threatened ecosystems under global change scenarios. Here, we examined the temporal variability of the plankton food web in the Mondego Estuary, central Iberian Peninsula, over the period 2003 to 2012. The results pointed out a cascading effect from climate to plankton communities that follow a non-stationary behavior shaped by the climate variance envelope. Concurrent changes in hydrographic processes at the regional, that is, upwelling intensity, and local, that is, estuarine hydrology, scales were driven by climatic forcing promoted by the North Atlantic Oscillation; the influence of which permeated the physical environment in the estuary affecting both autotrophic and heterotrophic communities. The most conspicuous change arose around 2008 and consisted of an obvious decrease in freshwater taxa along with a noticeable increase in marine organisms, mainly driven by gelatinous zooplankton. The observed increase in small-sized cosmopolitan copepods, that is, Clausocalanus arcuicornis, Oithona plumifera, thermophilic species, that is, Penilia avirostris, and gelatinous zooplankton suggests a structural change in the Mondego plankton community. These results provide empirical support to the expectation that expanding climate variance changes plankton structure and functioning, likely fostering trophic interactions in pelagic food webs.

2018Journal article

Restricted access

Medusa polyps adherence inhibition: A novel experimental model for antifouling assays

Publication . Pinteus, Susete; Lemos, Marco F.L.; Freitas, Rafaela; Duarte, Inês M.; Alves, Celso; Silva, Joana; Marques, Sónia C.; Pedrosa, Rui

Although in the last decades significant advances have been made to improve antifouling formulations, the main current options continue to be highly toxic tomarine environment, leading to an urgent need for new safer alternatives. For anti-adherence studies, barnacles and mussels are commonly the first choice for experimental purposes. However, the use of these organisms involves a series of laborious and time-consuming stages. In the present work, a new approach for testing antifouling formulations was developed under known formulations and novel proposed options. Due to their high resilience, ability of surviving in hostile environments and high abundance in different ecosystems, medusa polyps present themselves as prospect candidates for antifouling protocols. Thus, a complete protocol to test antifouling formulations using polyps is presented, while the antifouling properties of two invasive seaweeds, Asparagopsis armata and Sargassum muticum, were evaluated within this new test model framework. The use of medusa polyps as model to test antifouling substances revealed to be a reliable alternative to the conventional organisms, presenting several advantages since the protocol is less laborious, less time-consuming and reproductive. The results also show that the seaweeds A. armata and S. muticum produce compounds with anti-adherence properties being therefore potential candidates for the development of new greener antifouling formulations.

2020Journal article

Restricted access