Exchanges of nutrients and chlorophyll a through two inlets of Ria Formosa, South of Portugal, during coastal upwelling events

Cravo, Alexandra; Cardeira, Sara; Pereira, Catarina; Rosa, Mónica; Alcântara, Pedro; Madureira, Miguel; Rita, Filomena; Luís, Joaquim; Jacob, José

doi:10.1016/j.seares.2014.04.004

Cited by 27 publications

(22 citation statements)

References 45 publications

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“…This is supported by wind data from that period where a dominance of strong (north)western winds during several days preceding the sampling occurred, complying with the main upwelling conditions for this area (Relvas and Barton 2005). As a result, during this period, the system changed from a net nutrient exporter to a nutrient importer, as also reported recently by Cravo et al (2014) under upwelling conditions. Conditions that cause upwelling currents to reach the Ria Formosa are relatively rare (Brito et al 2012).…”

Section: Ocean Exchange: Seasonal Dynamics and Effects Of Stochastic supporting

confidence: 88%

Effects of External Nutrient Sources and Extreme Weather Events on the Nutrient Budget of a Southern European Coastal Lagoon

Malta

Stigter

Pacheco

et al. 2016

Estuaries and Coasts

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The seasonal and annual nitrogen (N), phosphorus (P), and carbon (C) budgets of the mesotidal Ria Formosa lagoon, southern Portugal, were estimated to reveal the main inputs and outputs, the seasonal patterns, and how they may influence the ecological functioning of the system. The effects of extreme weather events such as long-lasting strong winds causing upwelling and strong rainfall were assessed. External nutrient inputs were quantified; ocean exchange was assessed in 24-h sampling campaigns, and final calculations were made using a hydrodynamic model of the lagoon. Rain and stream inputs were the main freshwater sources to the lagoon. However, wastewater treatment plant and groundwater discharges dominated nutrient input, together accounting for 98, 96, and 88 % of total C, N, and P input, respectively. Organic matter and nutrients were continuously exported to the ocean. This pattern was reversed following extreme events, such as strong winds in early summer that caused upwelling and after a period of heavy rainfall in late autumn. A principal component analysis (PCA) revealed that ammonium and organic N and C exchange were positively associated with temperature as opposed to pH and nitrate. These variables reflected mostly the benthic lagoon metabolism, whereas particulate P exchange was correlated to Chl a, indicating that this was more related to phytoplankton dynamics. The increase of stochastic events, as expected in climate change scenarios, may have strong effects on the ecological functioning of coastal lagoons, altering the C and nutrient budgets.

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Section: Ocean Exchange: Seasonal Dynamics and Effects Of Stochastic supporting

confidence: 88%

Effects of External Nutrient Sources and Extreme Weather Events on the Nutrient Budget of a Southern European Coastal Lagoon

Malta

Stigter

Pacheco

et al. 2016

Estuaries and Coasts

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“…For example, ocean input is the dominant source of nutrients to estuaries of the US Pacific Northwest (Hickey & Banas, ). Ría Formosa (Portugal) imports ocean‐derived phytoplankton and phosphate following upwelling events (Cravo et al ., ). Saldanha Bay (South Africa) becomes stratified by intrusions of cold upwelled water but it mixes when upwelling is not active (Monteiroa & Largier, ).…”

Section: Discussionmentioning

confidence: 97%

Estuary–ocean connectivity: fast physics, slow biology

Raimonet

Cloern

2016

Global Change Biology

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Estuaries are connected to both land and ocean so their physical, chemical, and biological dynamics are influenced by climate patterns over watersheds and ocean basins. We explored climate-driven oceanic variability as a source of estuarine variability by comparing monthly time series of temperature and chlorophyll-a inside San Francisco Bay with those in adjacent shelf waters of the California Current System (CCS) that are strongly responsive to wind-driven upwelling. Monthly temperature fluctuations inside and outside the Bay were synchronous, but their correlations weakened with distance from the ocean. These results illustrate how variability of coastal water temperature (and associated properties such as nitrate and oxygen) propagates into estuaries through fast water exchanges that dissipate along the estuary. Unexpectedly, there was no correlation between monthly chlorophyll-a variability inside and outside the Bay. However, at the annual scale Bay chlorophyll-a was significantly correlated with the Spring Transition Index (STI) that sets biological production supporting fish recruitment in the CCS. Wind forcing of the CCS shifted in the late 1990s when the STI advanced 40 days. This shift was followed, with lags of 1-3 years, by 3- to 19-fold increased abundances of five ocean-produced demersal fish and crustaceans and 2.5-fold increase of summer chlorophyll-a in the Bay. These changes reflect a slow biological process of estuary-ocean connectivity operating through the immigration of fish and crustaceans that prey on bivalves, reduce their grazing pressure, and allow phytoplankton biomass to build. We identified clear signals of climate-mediated oceanic variability in this estuary and discovered that the response patterns vary with the process of connectivity and the timescale of ocean variability. This result has important implications for managing nutrient inputs to estuaries connected to upwelling systems, and for assessing their responses to changing patterns of upwelling timing and intensity as the planet continues to warm.

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“…Except in periods of heavy rains, the freshwater input to the lagoon is negligible, salinity remaining approximately 36 all year long (Águas 1985, Falcão andVale 1990). Spatial distribution of nutrients and chlorophyll a is highly influenced by internal processes, such as sediment-water interactions, and exchanges with the sea (Cravo et al, 2014, Falcão and Vale 1990. In addition to diffuse sources in the watershed, discharges of domestic effluents and boat traffic increase drastically in summer with tourism (Cravo et al 2012, Mudge andBebianno 1997).…”

Section: Study Area and Sampling Designmentioning

confidence: 99%

Enhanced trace element concentrations in tissues of the clam <em>Ruditapes decussatus</em> transplanted to areas influenced by human activities (Ria Formosa, Portugal)

et al. 2017

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Summary:To examine the extent to which human activities near the Ria Formosa coastal lagoon influence the accumulation of trace elements (TE) in Ruditapes decussatus, individuals were transplanted from a natural bank located in the lower lagoon to three sites located in clam growth grounds under the influence of a small city (Faro), a fish farming centre (Olhão) and a site near the lagoon inlet (Lavajo). Concentrations were determined in substrate of the clam grounds and in the digestive gland, gills, mantle plus siphons, and remaining tissues of clams in four periods of the year. These measurements were accomplished with the monthly survey of the gametogenic stages, condition index, proteins, glycogen, total lipids, pH and osmolarity of hemolymph. Arsenic, Cu, Mn, V, Cr and Pb were preferentially linked to the digestive gland, while Cd was linked to the gills. TE concentrations in the digestive gland and remaining tissues were higher in winter, most likely reflecting additional inputs associated with rain. The lack of disruptions in biological parameters and the prolonged period of spawning and gonad recovery in clams suggest that the current TE availability in the lagoon has a minor influence on the reproductive cycle and hence on clam production. Keywords: trace elements; biological parameters; Ruditapes decussatus; Ria Formosa. Aumento de la concentración de elementos traza en tejidos de la almeja Ruditapes decussatus trasplantada a zonas influenciadas por actividades humanas (ría Formosa, Portugal)Resumen: Para examinar en qué medida las actividades humanas cercanas a la laguna costera ría Formosa influyen en la acumulación de elementos traza (ET) en Ruditapes decussatus, se trasplantaron individuos desde un banco natural situado en la parte baja de la laguna a tres sitios localizados en zonas de cultivo de almejas bajo la influencia de una ciudad pequeña (Faro), un centro piscícola (Olhão) y cerca de la entrada de una laguna (Lavajo). Se determinaron las concentraciones de ET en el substrato de locales y en la glándula digestiva, branquias, manto más sifones, y en los tejidos restantes de las almejas en cuatro períodos a lo largo de un año. Estas mediciones fueron realizadas con el estudio mensual de las etapas gametógenas, índice de condición, proteínas, glicóneo, lípidos totales, pH y osmolaridad de la hemolinfa. El As, Cu, Mn, V, Cr y Pb fueron relacionados preferencialmente a la glándula digestiva, mientras que el Cd fue a las branquias. La concentración de ET en la glándula digestiva y los tejidos restantes fue más elevada en invierno, probablemente reflejando los aportes adicionales asociados con la lluvia. La falta de alteraciones de los parámetros biológicos, el período prolongado de desove y la recuperación de las gónadas en las almejas sugieren que la disponibilidad actual de ET en la laguna tienen una influencia menor durante el ciclo reproductivo y, por lo tanto, en la producción de almejas.

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Exchanges of nutrients and chlorophyll a through two inlets of Ria Formosa, South of Portugal, during coastal upwelling events

Cited by 27 publications

References 45 publications

Effects of External Nutrient Sources and Extreme Weather Events on the Nutrient Budget of a Southern European Coastal Lagoon

Effects of External Nutrient Sources and Extreme Weather Events on the Nutrient Budget of a Southern European Coastal Lagoon

Estuary–ocean connectivity: fast physics, slow biology

Enhanced trace element concentrations in tissues of the clam <em>Ruditapes decussatus</em> transplanted to areas influenced by human activities (Ria Formosa, Portugal)

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