How experimental physiology and ecological niche modelling can inform the management of marine bioinvasions?

Marine bioinvasions are increasing worldwide by a number of factors related to the anthroposphere, such as higher ship traffic, climate change and biotic communities' alterations. Generating information about species with high invasive potential is necessary to inform management decisions aiming to prevent their arrival and spread. Grateloupia turuturu, one of the most harmful invasive macroalgae, is capable of damaging ecosystem functions and services, and causing biodiversity loss. Here we developed an ecological niche model using occurrence and environmental data to infer the potential global distribution of G. turuturu. In addition, ecophysiological experiments were performed with G. turuturu populations from different climatic regions to test predictions regarding invasion risk. Our model results show high suitability in temperate and warm temperate regions around the world, with special highlight to some areas where this species still doesn't occur. Thalli representing a potential temperate region origin, were held at 10, 13, 16, 20 and 24 degrees C, and measurements of optimal quantum field (Fv/Fm) demonstrated a decrease of photosynthetic yield in the higher temperature. Thalli from the population already established in warm temperate South Atlantic were held at 18, 24 and 30 degrees C with high and low nutrient conditions. This material exposed to the higher temperature demonstrated a drop in photosynthetic yield and significant reduction of growth rate. The congregation of modelling and physiological approach corroborate the invasive potential of G. turuturu and indicate higher invasion risk in temperate zones. Further discussions regarding management initiatives must be fostered to mitigate anthropogenic transport and eventually promote eradication initiatives in source areas, with special focus in the South America. We propose that this combined approach can be used to assess the potential distribution and establishment of other marine invasive species. (C) 2019 Elsevier B.V. All rights reserved.National Council for Scientific and Technological Development (CNPq)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPQ)Sustainable prospection in ocean islands: biodiversity, chemistry, ecology and biotechnology (PROSPECMAR-Islands)Rede nacional de pesquisa em biodiversidade marinha (SISBIOTAMar)Foundation for the support of research and innovation in the State of Santa Catarina (FAPESC)Fundacao BoticarioCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)Pew FoundationFoundation for Science and Technology (FCT) of PortugalPortuguese Foundation for Science and Technology [SFRH/BPD/111003/2015, CCMAR/Multi/04326/2013, DL57/2016/CP1361/CT0035]Centre Mondial d'Innovation, Roullier GroupCNPqConselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPQ) [CSF 88888.884790/2014-00, 306917/2009-2]CAPESCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES) [PNADB 2338000071/2010-61]Instituto Nacional de Ciencia e Tecnologia para as Mudancas no Clima (INCT-MC)info:eu-repo/semantics/publishedVersio

Marine Heatwaves, Sewage and Eutrophication Combine to Trigger Deoxygenation and Biodiversity Loss: A SW Atlantic Case Study

Marine heatwaves (MHWs) are a major concern worldwide due to their increasing impacts in recent years, and these extreme events may trigger deoxygenation of coastal waters affected by sewage and eutrophication. Here we investigate the combined effects of MHWs and nutrient enrichment on the water quality and biodiversity of the Bay of Santa Catarina Island (Brazil). We used historical (1994–2020) sea surface temperature data from satellites and in situ physical, chemical and biological parameters to assess temporal trends. Oxygen levels have been decreasing whilst phosphorus levels have been increasing in the bay. During the austral summer of 2020 a regional sea surface heatwave was detected by satellite, lasting for 9 days and coinciding with our research cruise. During this period, seawater temperatures reached 29.8°C and anoxia was detected for the first time in the bay. A decrease in macrobenthic and phytoplankton community richness correlated with decreases in oxygen both through time and towards more urbanized areas. Overall, poor wastewater treatment is a key stressor that combined with MHWs to degrade coastal waters. Mitigation strategies are needed to minimize the impact of MHWs, including improved sewage treatment, restoration and conservation of wetlands and the use of nature-based technologies to promote coastal ecosystem recovery.</jats:p

Phytoplankton interannual variability at Cassino beach, southern Brazil (1992 2007), with emphasis on the surf zone diatom Asterionellopsis glacialis

A long-term study (monthly sampling, 1992 to 2007) was conducted in the surf zone of Cassino Beach, Southern Brazil, in order to detect possible natural and/or anthropogenic disturbances. Surface water temperature (6– 29°C) was the only parameter with predictable seasonal variation; salinity (14–38) was inversely related to rainfall (3.1–485.2 mm month−1) and low values followed extreme precipitation periods in 1997/1998 and 2002/2003 (El Niño years). Asterionellopsis glacialis and chlorophyll a presented high concentrations and peak frequency until 1998, when an intense mud deposition occurred with concomitant extreme rainfall. It affected the surf zone and beach, changing the hydrology and dissolved inorganic nutrient availability. Six phytoplankton species groups were recognized with distinct responses to this mud deposition. We conclude that large-scale climatic changes, like El Niño Southern Oscillation, in conjunction with human activities significantly altered the phytoplankton ecology of the highly dynamic Cassino Beach surf zone

From a water resource to a point pollution source: the daily journey of a coastal urban stream

The aim of this study was to understand how a stream ecosystem that flows from its fountainhead to its mouth inside a city, changes from a water resource to a point pollution source. A multidisciplinary descriptive approach was adopted, including the short-term temporal and spatial determination of physical, chemical, biological and ecotoxicological variables. Results showed that water quality rapidly decreases with increasing urbanization, leading the system to acquire raw sewage attributes even in the first hundred meters after the fountainheads. Despite the tidal circulation near the stream mouth being restricted by shallowness, some improvement of the water quality was detected in this area. The multidisciplinary evaluation showed to be useful for obtaining a more realistic understanding of the stream degradation process, and to forecast restoration and mitigation measures