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Octocorals are showing resilience to local and global stressors, while the decline in zooxanthellate corals continues. One of the processes that helps explain this ecological succession is the vertical growth of octocorals, which allows colonies to avoid stressors occurring at the substrate level. However, the growth and survival of octocorals could be affected by eutrophication, similar to what has happened with zooxanthellate corals. For this reason, the growth rate, mortality and survival of two octocoral species were determined along a eutrophication gradient in Cuba. A permanent band transect (250 × 2 m) was established on seven frontal reefs, and marked colonies were monitored for one year. The growth rates in height, width and colony area of Eunicea flexuosa and Plexaura kükenthali were significantly greater in the reefs near the polluted river basins. The eutrophication gradient, water visibility, and sediment accumulation on the bottom explained 36-78% of the variability in the growth of both species. The positive and significant correlations between the growth rate and stable nitrogen isotopes in both species and the microbiological variables, suggest that the contributions of dissolved inorganic nitrogen and organic matter from sewage discharge favor the growth of colonies. The eutrophication gradient did not explain the variability in mortality of either species in the short term, while hydrodynamic stress did. The results of this research highlight the resilience of both species and their ability to grow more rapidly in areas with eutrophic conditions, low water visibility, and greater sediment accumulation on the bottom, which may help explain the abundance of octocorals in the western tropical Atlantic.

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DNA metabarcoding and stable isotope analysis have significantly advanced our understanding of marine trophic ecology, aiding systematic research on foraging habits and species conservation. In this study, we employed these methods to analyse faecal and blood samples, respectively, to compare the trophic ecology of two Red-billed Tropicbird (Phaethonaethereus; Linnaeus, 1758) colonies on Mexican islands in the Pacific. Trophic patterns among different breeding stages were also examined at both colonies. Dietary analysis reveals a preference for epipelagic fish, cephalopods, and small crustaceans, with variations between colonies and breeding stages. Isotopic values (δ15N and δ13C) align with DNA metabarcoding results, with wider niches during incubation stages. Differences in diet are linked to environmental conditions and trophic plasticity among breeding stages, influenced by changing physiological requirements and prey availability. Variations in dietary profiles reflect contrasting environmental conditions affecting local prey availability.

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Sponges are widely spread organisms in the tropical reefs of the American Northwest-Atlantic Ocean, they structure ecosystems and provide services such as shelter, protection from predators, and food sources to a wide diversity of both vertebrates and invertebrates species. The high diversity of sponge-associated fauna can generate complex networks of species interactions over small and large spatial-temporal gradients. One way to start uncovering the organization of the sponge host-guest complex networks is to understand how the accumulated geographic area, the sponge morphology and, sponge taxonomy contributes to the connectivity of sponge species within such networks. This study is a meta-analysis based on previous sponge host-guest literature obtained in 65 scientific publications, yielding a total of 745 host-guest interactions between sponges and their associated fauna across the Caribbean Sea and the Gulf of Mexico. We analyzed the sponge species contribution to network organization in the Northwest Tropical Atlantic coral reefs by using the combination of seven complementary species-level descriptors and related this importance with three main traits, sponge-accumulated geographic area, functional sponge morphology, and sponges' taxonomy bias. In general, we observed that sponges with a widespread distribution and a higher accumulated geographic area had a greater network structural contribution. Similarly, we also found that Cup-like and Massive functional morphologies trend to be shapes with a greater contribution to the interaction network organization compared to the Erect and Crust-like morphos. Lastly, we did not detect a taxonomy bias between interaction network organization and sponges' orders. These results highlight the importance of a specific combination of sponge traits to promote the diversity of association between reef sponges and their guest species.

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Corals are colonial animals within the Phylum Cnidaria that form coral reefs, playing a significant role in marine environments by providing habitat for fish, mollusks, crustaceans, sponges, algae, and other organisms. Global climate changes are causing more intense and frequent thermal stress events, leading to corals losing their color due to the disruption of a symbiotic relationship with photosynthetic endosymbionts. Given the importance of corals to the marine environment, monitoring coral reefs is critical to understanding their response to anthropogenic impacts. Most coral monitoring activities involve underwater photographs, which can be costly to generate on large spatial scales and require processing and analysis that may be time-consuming. The Marine Ecology Laboratory (LECOM) at the Federal University of Rio Grande do Norte (UFRN) developed the project "#DeOlhoNosCorais" which encourages users to post photos of coral reefs on their social media (Instagram) using this hashtag, enabling people without previous scientific training to contribute to coral monitoring. The laboratory team identifies the species and gathers information on coral health along the Brazilian coast by analyzing each picture posted on social media. To optimize this process, we conducted baseline experiments for image classification and semantic segmentation. We analyzed the classification results of three different machine learning models using the Local Interpretable Model-agnostic Explanations (LIME) algorithm. The best results were achieved by combining EfficientNet for feature extraction and Logistic Regression for classification. Regarding semantic segmentation, the U-Net Pix2Pix model produced a pixel-level accuracy of 86%. Our results indicate that this tool can enhance image selection for coral monitoring purposes and open several perspectives for improving classification performance. Furthermore, our findings can be expanded by incorporating other datasets to create a tool that streamlines the time and cost associated with analyzing coral reef images across various regions.

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Different tissues are used for stable isotope analysis in cetacean investigations. However, variation in the isotopic composition of tissues with different turnover rates has been reported for cetaceans. To better understand stable carbon and nitrogen isotopes (δ13C and δ15N) in skin compared to other tissues, this study assessed the isotopic variation among the liver, muscle, and skin of Guiana dolphins (Sotalia guianensis), as well as the influence of sex on these variations. No differences were found in δ13C among male tissues, but females showed lower values in the liver compared to muscle and skin. Differences in δ15N were observed among all tissues, with different variation patterns for males and females. Four females were distinguished from males and other females by their 13C depletion in all tissues and δ15N variation pattern. We conclude that skin and muscle may be equivalent in δ13C values for Guiana dolphins. The multiple-tissue analysis brings new insights into their feeding ecology and provides background for stable isotope analysis using non-destructive sampling techniques in small cetaceans.

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This study focused on gathering available information on Pleuroncodes monodon, a widely distributed crustacean in the Humboldt Current System. Off the Chilean coast, this species presents benthic habits and constitutes the main resource of the industrial crustacean fishery; many studies have been carried out on its life cycle during the last century. In contrast, off the coast of Peru, this species exhibits mainly pelagic habits, with latent information gaps on aspects of its life history and no commercial fishery activities, such as catching, taking or harvesting from the marine environment. P. monodon is an ecologically important species, as a source of energy for its predators, which include invertebrates, birds, marine mammals and fish of commercial interest. Thus, P. monodon seems to play a key role in this ecosystem, mainly as an intermediate link between top predators and the first links in the food chain. In addition, this species presents various adaptation strategies to the changing oceanographic parameters of the areas it inhabits, even tolerating hypoxic environments and great depths in order to avoid being predated. Likewise, from an economic viewpoint, it has a high commercial value as a marine bioresource with great potential in the pharmaceutical and food industries. Considering this, more studies must be carried out to corroborate the biological, ecological, and fishing importance of this species in order to generate efficient management measures and ensure a sustainable fishery.

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Introduction: Coral-reef communities are considered one of the most biodiverse, but also most threatened, marine ecosystems, and the accelerating loss of habitat over the past decades warrants active intervention. Objective: The present study demonstrates the successful implementation of a low-impact restoration technique in three Central Mexican Pacific degraded coral communities, using a protocol based on natural fragmentation (''fragments of opportunity") of the branching coral Pocillopora spp., considered the most abundant and primary carbonate-producing coral species of the Eastern Tropical Pacific. Methods: The restoration program was implemented in two offshore and one inshore coraline areas. The relationships between seawater temperature and coral survival, growth, and attachment rate were assessed over one year, with 183 fragments monitored each month. Results: The mean coral growth rate was 3.3 ± 0.1 mm mo-1, with annual growth rates in length and width of 39.9 ± 14.2 and 36.5 ± 19.5 mm yr-1, respectively. Self-attachment efficiency was 78 % and the survival rate was high (84 %). The growth rate differed significantly among reefs. Conclusions: Upon monitoring directly fragmented corals over a year, growth rates were deemed high enough to merit active restoration in the region. However, our data show that structural and abiotic differences and seasonal variability must be considered overall in successful long-term coral community restoration initiatives in the eastern Pacific region.

Introducción: Las comunidades de arrecifes de coral se consideran uno de los ecosistemas marinos con mayor biodiversidad, pero también los más amenazados, y la pérdida acelerada de hábitat en las últimas décadas justifica la implementación de una intervención activa. Objetivo: El presente estudio demuestra la implementación exitosa de una técnica de restauración de bajo impacto basada en la fragmentación natural (''fragmentos de oportunidad") del coral ramificado Pocillopora spp., la cual es la especie coralina más abundante y principal productora de carbonato del Pacífico Oriental Tropical. Métodos: El programa de restauración se implementó en dos sitios lejos de la costa y un sitio cercano a la costa, con comunidades coralinas degradadas. Las relaciones entre la temperatura del agua de mar y la supervivencia, el crecimiento y la tasa de adhesión de los corales se evaluaron durante un año con 183 fragmentos monitoreados cada mes. Resultados: La tasa media de crecimiento coralino fue de 3.3 ± 0.1 mm mo-1, con tasas de crecimiento anual en largo y ancho de 39.9 ± 14.2 y 36.5 ± 19.5 mm año-1, respectivamente. La eficiencia de la auto-adherencia fue del 78 % y la tasa de supervivencia fue alta (84 %). La tasa de crecimiento difirió significativamente entre los arrecifes. Conclusiones: Al monitorear directamente los corales fragmentados durante un año, las tasas de crecimiento se consideraron lo suficientemente altas como para merecer una restauración activa en la región. Sin embargo, nuestros datos muestran que las diferencias estructurales y abióticas y la variabilidad estacional deben considerarse en general en las iniciativas exitosas de restauración de comunidades de coral a largo plazo en la región del Pacífico oriental.

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Identifying the areas of the world with suitable environmental conditions for the establishment of invasive species represents a fundamental basis for preventing their impacts. One of the most widely used tools for this is ecological niche modeling. Nonetheless, this approach may underestimate the specie's physiological tolerances (it's potential niche) since wildlife populations of species usually do not occupy their entire environmental tolerance. Recently, it has been suggested that incorporating occurrences of phylogenetically related species improves the prediction of biological invasions. However, the reproducibility of this technique remains unclear. Here, we evaluated the generality of this protocol by assessing whether the construction of modeling units above species level improves the capacity of niche models to predict the distribution of 26 target marine invasive species. For each, we constructed supraspecific modeling units based on published phylogenies by grouping the native occurrence records of each invasive species with the records of its phylogenetically closest relative. We also considered units at species level, including only the presence of records in the native areas of the target species. We generated ecological niche models for each unit with three modeling methods (minimum volume ellipsoids - MVE, machine learning algorithms - Maxent and a presence-absence method - GLM). In addition, we grouped the 26 target species based on whether or not the species are in environmental pseudo-equilibrium (i.e., it occupies all habitats where it can disperse) and have any geographical or biological constraints. Our results suggest that the construction of supraspecific units improves the predictive capacity of correlative models to estimate the invasion area of our target species. This modeling approach consistently generated models with a higher predictive ability for species in non-environmental pseudo-equilibrium and with geographical constraints.

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Although many marine ecosystems have been adversely impacted by human activities,1 some are now recovering due to reductions in fishing pressure.2-4 Here, we document the recovery of an ecosystem subjected to intense anthropogenic activity for over 200 years, the Clyde Sea.5 This region once had productive fisheries for herring (Clupea harengus) and other fish, but these disappeared at the turn of the century.6,7 Using acoustic surveys of the pelagic ecosystem, we found that the Clyde Sea supports 100 times as many forage fish as in the late 1980s. However, herring has now been replaced by sprat (Sprattus sprattus), despite virtually no fishing on herring for 20 years. A combination of a warming sea,6 bycatch of herring in the prawn (Nephrops norvegicus) fishery,8,9 and susceptibility of herring to poor recruitment may have contributed to this unexpected recovery. We compare this to similar unexpected "recoveries" involving unforeseen ecosystem effects, such as the return of hake (Merluccius merluccius) to the North Sea;10,11 the recent expansion of the pelagic squat lobster, "munida," (Pleuroncodes monodon) off Peru;12 and the increase in scallop (Placopecten magellanicus) numbers on Georges Bank.13 The lack of a current sprat fishery in the Clyde presents a unique opportunity to develop an alternative industry for its seafaring community: ecotourism. Charismatic megafauna (whales, dolphins, and seabirds) that people will pay to see14 will, in time-if not already15,16-be drawn in by the abundance of forage fish now present, further restoring the biodiversity of the region after centuries of overexploitation.

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Given the ecological and biogeochemical importance of rhodolith beds, it is necessary to investigate how future environmental conditions will affect these organisms. We investigated the impacts of increased nutrient concentrations, acidification, and marine heatwaves on the performance of the rhodolith-forming species Lithothamnion crispatum in a short-term experiment, including the recovery of individuals after stressor removal. Furthermore, we developed an ecological niche model to establish which environmental conditions determine its current distribution along the Brazilian coast and to project responses to future climate scenarios. Although L. crispatum suffered a reduction in photosynthetic performance when exposed to stressors, they returned to pre-experiment values following the return of individuals to control conditions. The model showed that the most important variables in explaining the current distribution of L. crispatum on the Brazilian coast were maximum nitrate and temperature. In future ocean conditions, the model predicted a range expansion of habitat suitability for this species of approximately 58.5% under RCP 8.5. Physiological responses to experimental future environmental conditions corroborated model predictions of the expansion of this species' habitat suitability in the future. This study, therefore, demonstrates the benefits of applying combined approaches to examine potential species responses to climate-change drivers from multiple angles.

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The widespread importance of variable types of primary production, or energy channels, to consumer communities has become increasingly apparent. However, the mechanisms underlying this "multichannel" feeding remain poorly understood, especially for aquatic ecosystems that pose unique logistical constraints given the diversity of potential energy channels. Here, we use bulk tissue isotopic analysis along with carbon isotope (δ13 C) analysis of individual amino acids to characterize the relative contribution of pelagic and benthic energy sources to a kelp forest consumer community in northern Chile. We measured bulk tissue δ13 C and δ15 N for >120 samples; of these we analyzed δ13 C values of six essential amino acids (EAA) from nine primary producer groups (n = 41) and 11 representative nearshore consumer taxa (n = 56). Using EAA δ13 C data, we employed linear discriminant analysis (LDA) to assess how distinct EAA δ13 C values were between local pelagic (phytoplankton/particulate organic matter), and benthic (kelps, red algae, and green algae) endmembers. With this model, we were able to correctly classify nearly 90% of producer samples to their original groupings, a significant improvement on traditional bulk isotopic analysis. With this EAA isotopic library, we then generated probability distributions for the most important sources of production for each individual consumer and species using a bootstrap-resampling LDA approach. We found evidence for multichannel feeding within the community at the species level. Invertebrates tended to focus on either pelagic or benthic energy, deriving 13-67% of their EAA from pelagic sources. In contrast, mobile (fish) taxa at higher trophic levels used more equal proportions of each channel, ranging from 19% to 47% pelagically derived energy. Within a taxon, multichannel feeding was a result of specialization among individuals in energy channel usage, with 37 of 56 individual consumers estimated to derive >80% of their EAA from a single channel. Our study reveals how a cutting-edge isotopic technique can characterize the dynamics of energy flow in coastal food webs, a topic that has historically been difficult to address. More broadly, our work provides a mechanism as to how multichannel feeding may occur in nearshore communities, and we suggest this pattern be investigated in additional ecosystems.

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The aim of this study was to screen and quantify 23 pharmaceutical compounds (including illicit drugs), at two sampling points near the diffusers of the Guarujá submarine outfall, State of São Paulo, Brazil. Samples were collected in triplicate during the high (January 2018) and low (April 2018) seasons at two different water column depths (surface and bottom). A total of 10 compounds were detected using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Caffeine (42.3-141.0 ng/L), diclofenac (3.6-85.7 ng/L), valsartan (4.7-14.3 ng/L), benzoylecgonine (0.3-1.7 ng/L), and cocaine (0.3-0.6 ng/L) were frequently detected (75% occurrence). Orphenadrine (0.6-3.0 ng/L) and atenolol (0.1-0.3 ng/L), and acetaminophen (1.2-1.4 ng/L) and losartan (0.7-3.4 ng/L), were detected in 50% and 25% of the samples, respectively. Only one sample (12.5%) detected the presence of carbamazepine (< 0.001-0.1 ng/L). Unexpectedly a lower frequency of occurrence and concentration of these compounds occurred during the summer season, suggesting that other factors, such as the oceanographic and hydrodynamic regimes of the study area, besides the population rise, should be taken into account. Caffeine presented concentrations above the surface water safety limits (0.01 µg/L). For almost all compounds, the observed concentrations indicate nonenvironmental risk for the aquatic biota, except for caffeine, diclofenac, and acetaminophen that showed low to moderate ecological risk for the three trophic levels tested.

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Kajikia audax, Thunnus albacares, Katsuwonus pelamis, and Auxis spp. occupy high and middle-level trophic positions in the food web. They represent important sources for fisheries in Ecuador. Despite their ecological and economic importance, studies on pelagic species in Ecuador are scarce. This study uses stable isotope analysis to assess the trophic ecology of these species, and to determine the contribution of prey to the predator tissue. Isotope data was used to test the hypothesis that medium-sized pelagic fish species have higher δ15N values than those of the prey they consumed, and that there is no overlap between their δ13C and δ15N values. Results showed higher δ15N values for K. audax, followed by T. albacares, Auxis spp. and K. pelamis, which indicates that the highest position in this food web is occupied by K. audax. The stable isotope Bayesian ellipses demonstrated that on a long time-scale, these species do not compete for food sources. Moreover, δ15N values were different between species and they decreased with a decrease in predator size.(AU)

Kajikia audax, Thunnus albacares, Katsuwonus pelamis e Auxis spp. ocupam posições tróficas intermedias e/ou elevadas nas cadeias alimentares. Estas espécies representam um importante recurso pesqueiro no Ecuador. Apesar da sua importância económica e ecológica, estudos nestas espécies pelágicas no Ecuador são raras. Este estudo usa isótopos estáveis para avaliar o seu nível trófico de modo a determinar a contribuição das suas presas para os tecidos destes predadores. Dados dos isótopos foram usados para testar a hipótese de que estas espécies de peixes pelágicos possuem valores mais elevados de δ15N do que daqueles das presas consumidas, e que não existe uma sobreposição entre os valores de δ13C e δ15N. Resultados mostram que valores mais elevados de δ15N para K. audax, seguidos por T. albacares, Auxis spp. e K. pelamis, indicam que a posição mais elevada na cadeia alimentar é ocupada por K. audax. Elipses Bayesianas de isótopos estáveis demonstram que, a uma escala de longo-termo, estas espécies de peixes não competem pelos recursos. Adicionalmente, os valores de δ15N são diferentes entre espécies de peixe estudadas e estes valores decrescem com a diminuição do tamanho do predador.(AU)

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Kajikia audax, Thunnus albacares, Katsuwonus pelamis, and Auxis spp. occupy high and middle-level trophic positions in the food web. They represent important sources for fisheries in Ecuador. Despite their ecological and economic importance, studies on pelagic species in Ecuador are scarce. This study uses stable isotope analysis to assess the trophic ecology of these species, and to determine the contribution of prey to the predator tissue. Isotope data was used to test the hypothesis that medium-sized pelagic fish species have higher δ15N values than those of the prey they consumed, and that there is no overlap between their δ13C and δ15N values. Results showed higher δ15N values for K. audax, followed by T. albacares, Auxis spp. and K. pelamis, which indicates that the highest position in this food web is occupied by K. audax. The stable isotope Bayesian ellipses demonstrated that on a long time-scale, these species do not compete for food sources. Moreover, δ15N values were different between species and they decreased with a decrease in predator size.(AU)

Kajikia audax, Thunnus albacares, Katsuwonus pelamis e Auxis spp. ocupam posições tróficas intermedias e/ou elevadas nas cadeias alimentares. Estas espécies representam um importante recurso pesqueiro no Ecuador. Apesar da sua importância económica e ecológica, estudos nestas espécies pelágicas no Ecuador são raras. Este estudo usa isótopos estáveis para avaliar o seu nível trófico de modo a determinar a contribuição das suas presas para os tecidos destes predadores. Dados dos isótopos foram usados para testar a hipótese de que estas espécies de peixes pelágicos possuem valores mais elevados de δ15N do que daqueles das presas consumidas, e que não existe uma sobreposição entre os valores de δ13C e δ15N. Resultados mostram que valores mais elevados de δ15N para K. audax, seguidos por T. albacares, Auxis spp. e K. pelamis, indicam que a posição mais elevada na cadeia alimentar é ocupada por K. audax. Elipses Bayesianas de isótopos estáveis demonstram que, a uma escala de longo-termo, estas espécies de peixes não competem pelos recursos. Adicionalmente, os valores de δ15N são diferentes entre espécies de peixe estudadas e estes valores decrescem com a diminuição do tamanho do predador.(AU)

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Causal mechanisms for broad-scale reef fish diversity patterns are poorly understood and current knowledge is limited to trends of species richness. This work compared the effects of ecological drivers on components of fish diversity across reefs spanning over 2.000 km of the tropical Brazilian coastline. A quarter of communities' diversity is accountable to common and dominant species, while remaining species are rare. Low-latitude sites were more diverse in rare species. Communities along the coast share common and dominant species, which display high densities across all reefs, but differ in rare species that show abundance peaks in particular reef morphotypes. The disproportionate distribution of rare species reveals a higher vulnerability of these communities to impacts and stochastic density fluctuations. Uneven conservation efforts directed to these morphotypes pose a threat to the maintenance of a paramount component of the reef fish diversity represented by rare species.

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Bioaccumulation of Hg and Cd from food is a complex ecological process that has been oversimplified in the past. Common dolphins (Delphinus delphis) provide a powerful model to biomonitor metal concentrations in marine environments worldwide. We combined proportions-based nutritional geometry with metal analysis, stomach content analysis and the proximate composition of prey, to yield novel insights into the accumulation of Hg and Cd. Our analysis showed an age-related accumulation trend for Cd and Hg in kidney and liver, with highest concentrations found at 18 years of age. When viewed through the lens of nutritional ecology, Argentine anchovy (58.1 Mass %) and South American long-finned squid (22.7 Mass %), provided most of the dietary intake of protein (P) and lipids (L) (P:L ratio = 2.6:1.0) and also represented the main source for Cd and Hg levels accumulated in their bodies. This study presents unprecedented evidence on metal accumulation in relation to age and nutritional intake in a marine predator.

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Whale watching in Patagonia began in 1973, with the southern right whale (Eubalaena australis) as a target. Thus far, only short-term effects of whale watching on behaviour have been evaluated. The southern right whale population is increasing locally and expanding to adjacent areas. We evaluated boat effects on the biological system through the analysis of breathing rate, linearity, reorientation rate and total distance travelled. Short-term movement patterns of SRW in the area are not severely affected by whale watching operations in Puerto Pirámide at this level of activity. However, significant changes in breathing rates in the presence of boats deserve further attention considering that whales return the same location. In light of the present work, the whales that breed at Península Valdés may be tolerant to whale watching boats.

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Coastal urbanization is leading to the accumulation of anthropogenic litter. Understanding the distribution and habitat use of litter by marine biota is important to predict how organisms will respond to anthropogenic changes. We assessed the density, distribution and composition of surface macro-litter (SML) in mangrove forests in Buenaventura (Colombia) and analysed how these microhabitats are used by marine biota. SML density ranged from 2 to 314 g m-2 (0.22 to 35.5 items m-2), implying that mangrove forests surrounding Buenaventura city are among the most polluted coastal areas in the World. Biological assemblages colonizing SML differed according to position on the forest and litter type. The encroachment of SML in mangrove forest enables a seemingly transient colonization of resident and immigrant biota from intertidal rocky shores and subtidal hard bottoms. The successful colonization of SML poses questions regarding the potential for plastics or their leaching chemicals to transfer through food webs.

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Radiation, both photosynthetic active radiation (PAR, l = 400-700 nm) and Ultraviolet (UVR, l = 280-400 nm) is one of the key factors regulating algal distribution in aquatic environments. Pyropia acanthophora and Grateloupia turuturu have been found over upper rocky shore areas in Southern Brazil, occupying the same niche space. The first species is native and the second one is exotic and considered a potential invader of South Atlantic. The aim of the present study was to evaluate the effects of radiation on physiological responses of both species and infer mechanisms that allow their niche competition in the environment. Samples were cultured in the following conditions: associated or separated, and with an addition of PAR, PAR + UVA (PA) and PAR + UVA + UVB (PAB), totalizing six factorial treatments during 5 days of exposure. Photosynthetic responses of Fv/Fm and ETR were daily evaluated. At the beginning and at the end of the experiment, samples were analyzed for pigment content (chlorophyll a and phycobiliproteins), and mycosporine-like amino acids (MAAs), while oxygen evolution was evaluated at the end of the experiment. As the main results, G. turuturu died when cultivated in PAB conditions. P. acanthophora presented higher amounts of chlorophyll a than G. turuturu during the whole experiment. Phycoerythrin and Fv/Fm remained constant in P. acanthophora but diminished for G. turuturu in UV treatments. ETR was higher for samples that were cultivated in associative treatment. The presence of G. turuturu in the same flask enhanced MAA synthesis in P. acanthophora, regardless of radiation condition. In addition, UV radiation can be a factor controlling species distribution and could counteract the spreading of invasive species, like G. turuturu, allowing P. acanthophora survival in upper rocky shore zones of the natural ecological distribution area.

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The influence of the moon cycles on the ichthyofauna has been little studied in the surf zone. In this study, the number of species, density and biomass were evaluated as a function of the moon. A total of 49 species distributed in 24 families were captured in two areas of Miramar beach. The mean density was significant high in the weaning and low in the new moon, while density and biomass together showed differences for areas. The most abundant species were Anchoa tricolor and Trachinotus falcatus (new moon), and Anchovia clupeoides showed significant differences in the waning moon. The RDA indicates that turbidity influenced significantly the presence of two species group. The group I were represented by Stellifer brasiliensis, Trachinotus goodei, A. clupeoides, Chilomycterus spinosus and Conodon nobilis that occurred on the waning and new phases in both areas, while the group II were represented by Polydactylus virginicus and Haemulopsis corvinaeformis in the full moon. The surf zones may also be strongly governed by the lunar phases. Therefore, the results found in this study, showed that the biological interactions between the species with turbidity and moon might explain the density and biomass variations for some species in the surf zone.(AU)

A influência das fases lunares sobre a ictiofauna tem sido pouco estudada na zona de arrebentação. Nesse estudo, foram avaliadas, o número de espécies, densidade e a biomassa da ictiofauna em função da lua. Foram capturadas 49 espécies distribuídas em 24 famílias em duas áreas na Praia de Miramar. A densidade foi significativamente elevada nas luas minguante e nova. Além disso, a densidade e biomassa juntas mostraram diferenças entre as áreas. As espécies mais abundantes na lua nova foram Anchoa tricolor e Trachinotus falcatus, e Anchovia clupeoides teve uma maior abundancia na lua minguante. O RDA, indicou que a turbidez influenciou significativamente a presença de dois grupos distintos. O grupo I, representado por Stellifer brasiliensis, Trachinotus goodei, A. clupeoides, Chilomycterus spinosus e Conodon nobilis estiveram presentes nas luas minguante e nova em ambas as áreas, e o grupo II, representado por Polydactylus virginicus e Haemulopsis corvinaeformis na lua cheia. As zonas de arrebentação também podem ser reguladas fortemente pelas fases lunares. Os resultados mostraram que as interações biológicas entre as espécies com a turbidez e as fases lunares podem explicar as variações de densidade e biomassa para algumas espécies na zona de arrebentação.(AU)

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