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- Co-limitation of phytoplankton by N and P in a shallow coastal lagoon (Ria Formosa): implications for eutrophication evaluationPublication . Domingues, Rita B.; Nogueira, Patricia; Barbosa, Ana B.The Ria Formosa coastal lagoon is a highly productive shallow ecosystem in southern Portugal, subjected to nutrient inputs from anthropogenic and natural sources. Nutrients are major abiotic drivers of phytoplankton in this system, but their effects on phytoplankton assemblages and the occurrence of nutrient limitation are still poorly understood. The main goal of this study was, thus, to evaluate the occurrence, type, and effects of nutrient limitation on phytoplankton community and specific functional groups in the Ria Formosa coastal lagoon. We conducted nutrient enrichment experiments with factorial additions of nitrogen (N) and phosphorus (P) using natural phytoplankton assemblages from distinct locations in the Ria Formosa, throughout a yearly cycle. Phytoplankton composition and abundance were evaluated using inverted and epifluorescence microscopies, and spectrophotometric methods were used for biomass. Limitation was defined as higher phytoplankton growth following enrichment with a particular nutrient in relation to the non-enriched control. The most common type of phytoplankton limitation was simultaneous co-limitation by N and P; diatoms, as r-strategists, were the most frequently limited group. Single N and P limitation, and serial P limitation were also observed, as well as negative responses to nutrient enrichment. Group-specific responses to nutrient enrichment were not reflected in the relative abundance of phytoplankton groups within the whole assemblage, due to the numerical dominance of pico-sized groups (cyanobacteria and eukaryotic picophytoplankton). Ambient nutrient ratios and concentrations did not predict phytoplankton nutrient limitation, given the different nutrient utilisation traits among phytoplankton functional groups. Therefore, nutrient ratios should not be used as indicators of nutrient limitation in eutrophication assessment.
- Seasonal and spatial variability of Phytoplankton primary production in a shallow temperate Coastal Lagoon (Ria Formosa, Portugal)Publication . B. Domingues, RitaCoastal lagoons are among the most productive ecosystems in the world, and they provide a wide range of ecosystem services and resources. In the Ria Formosa (southern Portugal), phytoplankton production has rarely been addressed. The main goal of this study is thus to evaluate the variability of phytoplankton production and photosynthetic characteristics over the seasonal cycle and in different locations (landward, urban, intermediate, and seaward boundaries) of the Ria Formosa coastal lagoon, subjected to distinct natural and anthropogenic stressors. Primary production was evaluated using the 14C incorporation technique, and photosynthetic parameters were estimated by fitting photosynthesis-irradiance curves. Primary production showed significant seasonal variations, with higher values in the summer associated with lower euphotic depths, higher water temperatures, and higher nutrient concentrations. No spatial differences were found for primary production or photosynthetic parameters. Primary production values were lower than previous estimates, which reflects an improvement in water quality in the Ria Formosa, but values are higher than primary production estimates for other temperate coastal ecosystems, which reflects the highly productive nature of this coastal lagoon.
- Short-term effects of climate change on Planktonic Heterotrophic Prokaryotes in a temperate Coastal Lagoon: Temperature Is good, ultraviolet radiation Is bad, and CO2 Is neutralPublication . B. Barbosa, Ana; Mosley, Benjamin A.; M. Galvão, Helena; Domingues, Rita B.Planktonic heterotrophic prokaryotes (HProks) are a pivotal functional group in marine ecosystems and are highly sensitive to environmental variability and climate change. This study aimed to investigate the short-term effects of increasing carbon dioxide (CO2), ultraviolet radiation (UVR), and temperature on natural assemblages of HProks in the Ria Formosa coastal lagoon during winter. Two multi-stressor microcosm experiments were used to evaluate the isolated and combined effects of these environmental changes on HProk abundance, production, growth, and mortality rates. The isolated and combined effects of increased CO2 on HProks were not significant. However, HProk production, cellular activity, instantaneous growth rate, and mortality rate were negatively influenced by elevated UVR and positively influenced by warming. Stronger effects were detected on HProk mortality in relation to specific growth rate, leading to higher HProk net growth rates and abundance under elevated UVR and lower values under warming conditions.
- Place attachment, risk perception, and preparedness in a population exposed to coastal hazards: a case study in Faro Beach, southern PortugalPublication . Domingues, Rita; Jesus, Saúl; Ferreira, OscarLiving by the coast is a high-risk choice, but most people do it voluntarily. At Faro Beach, a heavily urbanized settlement located on a sandy barrier peninsula exposed to coastal hazards, houses and roads were destroyed due to storm action. However, residents feel safe living there and have no intentions of relocating. The development and implementation of coastal management plans and disaster risk reduction measures require the understanding of psychological drivers of residents’ risk perception and behaviours. Thus, the main goal of this study is to evaluate the relationships between place attachment, risk perception, and preparedness in Faro Beach. We hypothesized that place attachment and past experience with hazards would have a negative effect on risk perception, while risk perception would positively influence preparedness. We administered a self-report questionnaire to 131 residents, and analysed the data using partial least squares modelling. Results show that stronger place attachment is associated with lower risk perception, as residents tend to accept the risk as part of their environment. Experience contributed to higher risk perception in Faro Beach residents, most likely because residents have had direct and personal experience with hazards and are fully aware of the consequences. In addition, risk perception was negatively associated with preparedness; although residents’ risk perception is moderate, probably due to risk normalisation, they still make some preparations to deal with a potential disaster. This study is useful for the design and implementation of more sustainable coastal management plans, as it validates the relevance of affective variables in risk perception and preparedness.
- Evaluating underwater light availability for Phytoplankton: mean light intensity in the mixed layer versus attenuation CoefficientPublication . Domingues, Rita B.; Barbosa, Ana B.The use of several light-related variables, such as the Secchi disc depth, the euphotic depth, and in particular, the diffuse attenuation coefficient (Kd), is deeply rooted in phytoplankton research, but these are not the most appropriate indicators of the amount of light available for photosynthesis. We argue that the variable of interest for phytoplankton is the mean light intensity in the mixed layer (Im), which represents the mean light to which phytoplankton cells are exposed throughout their life cycle, while being continuously mixed in the mixed layer. We use empirical data collected in different coastal ecosystems in southern Portugal to demonstrate why Im should be the preferred metric instead of the deeply rooted Kd. We show that, although the relationship between Im and Kd is inversely proportional, it is not always strong or even significant. Different Im values can be associated with the same Kd, but distinct Im have different physiological effects of phytoplankton. Therefore, Kd does not capture the amount of light available for photosynthesis, given that, unlike Im, Kd calculation does not consider the depth of the mixed layer. Therefore, we urge phytoplankton researchers to consider the measurement and calculation of Im when evaluating light-related processes in phytoplankton ecology.
- Unusual red tide of the dinoflagellate Lingulodinium polyedra during an upwelling event off the Algarve coast (SW Iberia)Publication . Domingues, Rita B.; Lima, Maria JoãoLow biomass, but highly toxic algal blooms are frequent in the Ria Formosa coastal lagoon and adjacent coastal zone (southern Portugal), usually associated with specific oceanographic and nutrient conditions. In June 2019, a massive bloom of the dinoflagellate Lingulodinium polyedra developed along the coast, causing water discolouration, and the closure of beaches and of bivalve harvesting, with significant socioeconomic consequences. This study aims to evaluate the relationships between phytoplankton composition and environmental conditions before, during, and after the L. polyedra bloom. Water samples were collected in the Ria Formosa coastal lagoon throughout June and July 2019 for determination of nutrient and chlorophyll-a concentration using spectrophotometric methods. Phytoplankton composition and abundance were evaluated using inverted microscopy. Upwelling intensity was estimated considering a wind-based index, the cross-shore Ekman transport. Results show strong relationships between phytoplankton community composition and nutrients, particularly a positive relationship between centric diatoms and nitrogen, and a negative relationship between several dinoflagellate genera, and phosphorus and silicon. L. polyedra was not significantly associated with any nutrient variable, most likely due to its mixotrophic capabilities. A clear phytoplankton succession, typical of eastern boundary upwelling locations, was observed throughout the different bloom phases, from dominance of type II dinoflagellates (Heterocapsa, Prorocentrum) in the pre-bloom period, to dominance of L. polyedra (type V) during the bloom, and finally dominance of centric diatoms in the post-bloom period. However, the L. polyedra bloom was not associated with upwelling relaxation, but rather with an active upwelling event. (c) 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
- Orthorexia nervosa in yoga practitioners: relationship with personality, attitudes about appearance, and yoga engagementPublication . B. Domingues, Rita; Carmo, CláudiaPurpose Disordered eating symptoms and a high prevalence of orthorexia nervosa can be found in yoga practitioners. Given that yoga is increasingly used as a complementary treatment for eating disorders (ED), understanding the relationship between yoga practice and the development of disordered eating is crucial to guide treatment recommendations. The goal of this work is, therefore, to study the relationships between orthorexia nervosa (ON) and potential risk factors for ON, in an international sample of experienced yoga practitioners. Method An online questionnaire that included several psychometric instruments was responded by 469 yoga practitioners. Instruments used were the Teruel orthorexia scale, Yoga immersion scale, Passion scale, Frost multidimensional perfectionism scale, Self-discipline scale of NEO-PI-R, Drive for thinness scale of EDI, and Beliefs about appearance scale. Descriptive statistics, correlational analysis and multiple regression were used to evaluate relationships between ON and the other variables. Results The main predictors of orthorexia nervosa were the drive for thinness and a healthy orthorexia, suggesting that, like in anorexia and bulimia, orthorexic individuals are also concerned with food quantity and physical appearance, rather than just food quality. Conclusions The potential effects of yoga on eating behaviours and attitudes of long-term practitioners, particularly the high prevalence of orthorexia nervosa and the concern for physical appearance, should be taken into consideration when using yoga as prevention or treatment for eating disorders.
- Short-term effects of winter warming and acidification on phytoplankton growth and mortality: more losers than winners in a temperate coastal lagoonPublication . Domingues, Rita B.; Barreto, Marcelle; Brotas, Vanda; Galvão, Helena M.; Barbosa, Ana B.Changes in temperature and CO2 are typically associated with climate change, but they also act on shorter time scales, leading to alterations in phytoplankton physiology and community structure. Interactions among stressors may cause synergistic or antagonistic effects on phytoplankton dynamics. Therefore, the main goal of this work is to understand the short-term isolated and interactive effects of warming and high CO2 on phytoplankton nutrient consumption, growth, production, and community structure in the Ria Formosa coastal lagoon (southern Portugal). We performed microcosm experiments with temperature and CO2 manipulation, and dilution experiments under temperature increase, using winter phytoplankton assemblages. Phytoplankton responses were evaluated using inverted and epifluorescence microscopy. Overall, phytoplankton growth and microzooplankton grazing on phytoplankton decreased with warming. Negative antagonist interactions with CO2 alleviated the negative effect of temperature on phytoplankton and cryptophytes. In contrast, higher temperature benefited smaller-sized phytoplankton, namely cyanobacteria and eukaryotic picophytoplankton. Diatom growth was not affected by temperature, probably due to nutrient limitation, but high CO2 had a positive effect on diatoms, alleviating the effect of nutrient limitation. Results suggest that this winter phytoplankton assemblage is well acclimated to ambient conditions, and short-term increases in temperature are detrimental, but can be alleviated by high CO2.
- Assessing environmental attitudes in Portugal using a new short version of the Environmental Attitudes InventoryPublication . B. Domingues, Rita; Gonçalves, GabrielaMost environmental problems are caused and/or enhanced by human behaviour; thus, it is crucial to understand environmental attitudes that underlie individual's behaviour towards the environment. In Portugal, a highly vulnerable region to environmental change and serious local-scale natural hazards, environmental attitudes have never been systematically addressed. Therefore, the main goal of this study is to evaluate environmental attitudes in a Portuguese sample using the most appropriate short version of Milfont & Duckitt's Environmental Attitudes Inventory (Journal of Environmental Psychology, 30(1) 80-94, 2010). Reliability and validity analyses showed that the 36-item version of the Environmental Attitudes Inventory (EAI-36) was more adequate than the 24-item version. Using EAI-36, preservation and utilisation emerged as orthogonal dimensions, forming the vertical structure of environmental attitudes, and were negatively and moderately correlated in the Portuguese sample, expressing an ecocentric viewpoint. Mean scores for the first- and second-order factors were similar to values from other developed countries. Differences in age, gender and study area were found, with older participants, women and individuals from the natural sciences showing higher levels on preservation and lower on utilisation.
- Growth and grazing mortality of microbial plankton in a shallow temperate Coastal Lagoon (Ria Formosa, SW Iberia)Publication . Santos, Yohann; Mosley, Benjamin A.; Nogueira, Patricia; Galvão, Helena; Domingues, RitaMicrozooplankton grazing is widely recognized as an important process of heterotrophic prokaryote and phytoplankton biomass removal. However, few studies have specifically addressed microbial mortality in the Ria Formosa coastal lagoon. This study aimed to assess the growth and mortality of heterotrophic prokaryotes and phytoplankton in this ecosystem using the dilution technique. The results revealed significant seasonal variations in the growth and grazing rates of both heterotrophic prokaryotes and phytoplankton, with mean grazing rates slightly exceeding the mean potential instantaneous growth rates. This indicates that microzooplankton consume a substantial proportion of both microbial groups in the lagoon. For specific phytoplankton taxa, the wide range of observed grazing rates suggests grazer selectivity, highlighting the need for future research to examine the dynamics of each phytoplankton group more closely.