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The international RAIA Observatory (www.marnaraia.org) resulted from the effort of 12 research and academic institutions and public agencies (Spanish and Portuguese) working in the field of meteorology and oceanography. The RAIA Observatory serves the main maritime activities of the Galicia-Northern Portugal Euroregion and contributes to collaborative observational networks. Under the framework of coastal risk management, environmental indicators are fundamental tools for the evaluation and mitigation of environmental risks, showing the current state and helping to predict future changes on ecosystem health regarding environmental risks. In last years, the different partners of the RAIA Observatory have identified 38 environmental indicators, in which 12 key risks affecting the ecosystem services of the Euroregion Galicia-Northern Portugal are being evaluated. Data was analyzed and compiled by the various partners of the RAIA Observatory and the development and optimization of the environmental indicators has been done according to the specifications provided by the European Environmental Agency (EEA) and the International Panel for Climate Change (IPCC). The resulting environmental indicators are included and shared on a publicly-accessible Web service, georeferenced and accompanied by graphics (https://marrisk.inesctec.pt/public/#!/indicators). So far, the current status of the indicators has allowed us to establish risk assessment protocols for the Euroregion, and identify critical gaps in temporal and spatial coverage. The inclusion of the environmental indicators in the RAIA Observatory is of great relevance for national and international data exchange and promotes future collaborations.

Over the past decades, as a consequence of human activity, there was an increase in nutrient inputs to the ocean and they are expected to enhance even more in the future. Coastal areas, accounting for a significant proportion of marine primary productivity, are the most vulnerable zones to anthropogenic impacts. The response of phytoplankton communities to an increase in organic and inorganic nutrients levels from natural allochthonous sources was assessed in microcosm experiments conducted in a coastal system affected by intermittent upwelling events (Ría de Vigo, NW Iberia). Three nutrient addition experiments were performed in spring, summer and autumn, when surface water was supplemented with 5 and 10% of atmospheric and riverine matter. Pico-, nano- and microphytoplankton abundances, chlorophyll a concentration (Chl a) and primary production rates (PP) were measured and compared with those in the control seawater sample (without additions) after 48 h of incubation. Simultaneous experiments with controlled additions of inorganic and organic nutrients were also performed in order to describe the limiting nutrient for phytoplankton growth at each experiment. The composition of the matter inputs and the structure of the phytoplankton communities determined the type of response observed. Phytoplankton responses varied among seasons, being positively correlated with dissolved inorganic nitrogen (DIN) concentrations. As expected, the phytoplankton responses to external nutrient inputs were stronger under low nutrient levels (summer) than when phytoplankton was already growing in nutrient replete conditions (spring). Null and negative responses to the natural inputs were observed in autumn, which suggests that the oceanic phytoplankton advected to this coastal system during downwelling events could be occasionally inhibited by these nutrient inputs. In a future global change scenario, characterized by enhanced nutrient inputs from riverine and atmospheric origin, the r

This data report contains oceanographic data collected along the geodesic between Sur Ridge (36.3 deg N, 122.4 deg W) and Hoke Seamount (32.1 deg N, 126.9 deg W). Tables of water properties (temperature, salinity, dissolved oxygen, and nutrients) are included, as well as figures which show results of bathymetric and ocean current measurements. Finally, a sample of video images of fauna observed on the summit of Hoke Seamount is included., Funding number: N6822107WRA0007.

The optical properties of coloured dissolved organic matter (CDOM) – absorption coefficient, induced fluorescence, and fluorescence quantum yield – were determined in the coastal eutrophic system of the Ría de Vigo (NW Spain) under two contrasting situations: a downwelling event in September 2006 and an upwelling event in June 2007. Significantly different optical properties were recorded in the shelf surface (higher absorption coefficient and lower quantum yield) and bottom (lower absorption coefficient and higher quantum yield) waters that entered the embayment during downwelling and upwelling conditions, respectively. Continental waters presented distinctly high CDOM levels. The spatial and temporal variability of the induced fluorescence to absorption coefficient ratio during the mixing of shelf and continental waters was used to quantify the relative importance of photochemical and microbial processes under these contrasting hydrographic conditions. Photochemical processes were dominant during the downwelling episode: 86% of the variability of CDOM can be explained by photochemical degradation. On the contrary, microbial processes prevailed during the upwelling event: 77% of the total variability of CDOM was explained by microbial respiration.

The influence of suspended mussel culture on the benthic–pelagic coupling was evaluated in the Ría de Vigo, in the coastal upwelling system of the NW Iberian Peninsula, during the month of July 2004. Measurements of water column properties were carried out at three stations in the Ría de Vigo: under a mussel raft (1), and at two reference sites in the main channel (2) and in the inner part (3) of the Ría. Dissolved nutrients, dissolved oxygen and inorganic carbon benthic fluxes were measured by means of a benthic chamber at stations 1 and 3. Sediment traps were deployed at 6 locations to estimate vertical fluxes. The water column structure at the three study stations was very similar, characterized by upwelling conditions during the second week of July and a posterior stratification showing a strong thermocline, with a depth fluctuation mainly modulated by the shelf wind regime. Vertical POC fluxes underneath the mussel raft (3gC m−2 d−1) were 3 times higher than those obtained between rafts and 10 times higher than in the main channel reference site. Dissolved oxygen, ammonium, silicate and phosphate benthic fluxes were significantly higher under the raft than at the inner Ría reference site. A 1D carbon budget showed the importance of benthic metabolism under the raft (2.3±0.8 g C m−2 d−1), being higher than the organic carbon produced at the photic layer (0.7±0.3 g C m−2 d−1), as a result of higher organic loading compared to the inner Ría reference site. The results show for the first time the important role that suspended mussel cultures play in the benthic–pelagic coupling in this coastal upwelling ecosystem., The influence of suspended mussel culture on the benthic–pelagic coupling was evaluated in the Ría de Vigo, in the coastal upwelling system of the NW Iberian Peninsula, during the month of July 2004. Measurements of water column properties were carried out at three stations in the Ría de Vigo: under a mussel raft (1), and at two reference sites in the main channel (2) and in the inner part (3) of the Ría. Dissolved nutrients, dissolved oxygen and inorganic carbon benthic fluxes were measured by means of a benthic chamber at stations 1 and 3. Sediment traps were deployed at 6 locations to estimate vertical fluxes. The water column structure at the three study stations was very similar, characterized by upwelling conditions during the second week of July and a posterior stratification showing a strong thermocline, with a depth fluctuation mainly modulated by the shelf wind regime. Vertical POC fluxes underneath the mussel raft (3gC m−2 d−1) were 3 times higher than those obtained between rafts and 10 times higher than in the main channel reference site. Dissolved oxygen, ammonium, silicate and phosphate benthic fluxes were significantly higher under the raft than at the inner Ría reference site. A 1D carbon budget showed the importance of benthic metabolism under the raft (2.3±0.8 g C m−2 d−1), being higher than the organic carbon produced at the photic layer (0.7±0.3 g C m−2 d−1), as a result of higher organic loading compared to the inner Ría reference site. The results show for the first time the important role that suspended mussel cultures play in the benthic–pelagic coupling in this coastal upwelling ecosystem.

info:eu-repo/semantics/published

Time series of wind-stress data, AVHRR and SeaWiFS satellite images, and in situ data from seven cruises are used to assemble a coherent picture of the hydrographic variability of the seas off the Northwest Iberian Peninsula from the onset (September-October) to the cessation (February-May) of the Portugal coastal counter current (PCCC). During this period the chemistry and the biology of the shelf, slope and ocean waters between 40° and 43°N have previously been undersampled. Novel information extracted from these observations relate to: 1. The most frequent modes of variability of the alongshore coastal winds, covering event, seasonal and long-term scales; 2. The conspicuous cycling between stratification and homogenisation observed in PCCC waters, which has key implications for the chemistry and biology of these waters; 3. The seasonal evolution of nitrite profiles in PCCC waters in relation to the stratification cycle; 4. The Redfield stoichiometry of the remineralisation of organic matter in Eastern North Atlantic Central Water (ENACW) - the water mass being transported by the PCCC; 5. The separation of coastal (mesotrophic) from PCCC (oligotrophic) planktonic populations by a downwelling front along the shelf, which oscillates to and fro across the shelf as a function of coastal wind intensity and continental runoff; and 6. The photosynthetic responses of the PCCC and coastal plankton populations to the changing stratification and light conditions from the onset to the cessation of the PCCC. © 2003 Elsevier Science Ltd. All rights reserved., SCOPUS: re.j, info:eu-repo/semantics/published

Hydrographic data collected along the West Coast of North America between January 1997 and January 1999 have been compiled into a web-based Atlas of the 1997–8 El Nin˜o event. This paper discusses the organization of the Atlas, describes the data that were incorporated into the Atlas and explains how vertical and horizontal distributions for the different properties were constructed. Examples of figures from the Atlas are shown. 

Nutrient conditions off central California during the 1997–98 El Nin˜o are described. Data were collected on 11 cruises from March 1997 to January 1999 along a hydrographic section off central California, as well as every two weeks at a coastal station in Monterey Bay. Perturbations associated with El Nin˜o are shown as anomalies of thermohaline and nutrient distributions along this section. The anomalies were obtained by subtracting seasonal averages for the period from April 1988 to April 1991 from the 1997–98 observations. The first indications of El Nin˜o conditions (high sea levels) were observed at Monterey between late May and early June 1997, but the coastal nutricline did not begin to deepen until August 1997. It reached maximum depth of 130 dbar in January 1998 at the time that maximum sea level anomalies were observed. During this period: (1) the highest subsurface temperature anomalies coincided with subsurface nutrient anomaly minima at the depth of the pycnocline; (2) southern saline and nutrient-poor waters occupied the upper 80 dbar of the water column along the entire section; and (3) nitrate levels were close to zero in the euphotic zone, collapsing the potential new primary production in the coastal domain. At the end of February 1998, the nutricline shoaled to 40 dbar at the coast although it remained anomalously deep offshore. Higher temperatures and lower nutrient levels were observed for the entire section through August 1998 although in contrast with the previous winter, there was a strong freshening mainly due to an onshore movement of subarctic waters.

Oceanographic conditions off Central California were monitored by means of a series of 13 hydrographic cruises between February 1997 and January 1999, which measured water properties along an oceanographic section perpendicular to the California Coast. The 1997–98 El Niño event was defined by higher than normal sea levels at Monterey, which began in June 1997, peaked in November 1997, and returned to normal in March 1998. The warming took place in two distinct periods. During June and July 1997, the sea level increased as a result of stronger than normal coastal warming below 200 dbars and within 100 km of the coast, which was associated with poleward flow of saltier waters. During this period, deeper (400–1000 dbar) waters between 150–200 km from shore were also warmed and became more saline. Subsequently, sea level continued to rise through January 1998, mostly as a result of the warming above 200 dbars although, after a brief period of cooling in September 1997, waters below 200 dbar were also warmer than normal during this period. This winter warm anomaly was also coastally trapped, extending 200 km from shore and was accompanied by cooler and fresher water in the offshore California current. In March and April 1998, sea level dropped quickly to normal levels and inshore waters were fresher and warmer than the previous spring and flowed southward. The warming was consistent with equatorial forcing of Central California waters via propagation of Kelvin or coastally- trapped waves. The observed change in heat content associated with the 1997–98 El Niño was the same as that observed during the previous seasonal cycle. The warming and freshening events were similar to events observed during the 1957–58 and 1982–83 El Niños.

The physical, chemical and biological perturbations in central California waters associated with the strong 1997–1998 El Niño are described and explained on the basis of time series collected from ships, moorings, tide gauges and satellites. The evolution of El Niño off California closely followed the pattern observed in the tropical Pacific. In June 1997 an anomalous influx of warm southerly waters, with weak signatures on coastal sea level and thermocline depth, marked the onset of El Niño in central California. The timing was consistent with propagation from the tropics via the equatorial and coastal wave-guide. By late 1997, the classical stratified ocean condition with a deep thermocline, high sea level, and warm sea surface temperature (SST) commonly associated with El Niño dominated the coastal zone. During the first half of 1998 the core of the California Current, which is normally detected several hundred kilometers from shore as a river of low salinity, low nutrient water, was hugging the coast. High nutrient, productive waters that occur in a north–south band from the coast to approximately 200 km offshore during cool years disappeared during El Niño. The nitrate in surface waters was less than 20% of normal and new production was reduced by close to 70%. The La Niña recovery phase began in the fall of 1998 when SSTs dropped below normal, and ocean productivity rebounded to higher than normal levels. The reduction in coastal California primary productivity associated with El Niño was estimated to be 50 million metric tons of carbon (5 × 1013gC). This reduction certainly had deleterious effects on zooplankton, fish, and marine mammals. The 1992–1993 El Niño was more moderate than the 1997–1998 event, but because its duration was longer, its overall chemical and biological impact may have been comparable. How strongly the ecosystem responds to El Niño appears related to the longer-term background climatic state of the Pacific Ocean. The 1982–1983 and 1992–1

Nitrate and ammonium uptake and ammonium regeneration rates were measured with 15N incubations during the austral summer period of 1995–1996 in the Bransfield Strait region (Antarctica). The objective was to quantify new and regenerated production in three zones that included stations with high phytoplankton biomass dominated by large and chain-forming diatoms (Strait of Gerlache) or colonies of Phaeocystis (Bellingshausen Sea), and stations with low phytoplankton biomass and high abundance of Cryptophyceae and other flagellates (western Bransfield Strait). All zones were characterized by high nitrate (>10 mmolNm 3) and low ammonium (generally o1 mmolNm 3) concentrations. Phytoplankton production in the high-biomass zones was sustained mainly by ammonium, and ammonium regeneration was enough to supply microplankton demands at daily scales. The average values of f ratio for Bellingshausen Sea and Gerlache Strait stations were 0.39 and 0.42, respectively. Despite the high biomass observed, chlorophyll-specific inorganic nitrogen uptake was low in these areas when compared with stations in the western Bransfield Strait, where a new bloom (based on nitrate) was developing (mean f ratio of 0.64). Dominance of flagellates and small diatoms, accumulations of nitrite, and ammonium regeneration rates exceeding upate rates in the western Bransfield Strait suggest that the bloom was a secondary succession stage. The variability in phytoplankton composition and nitrogen dynamics can be interpreted as a consequence of the diversity of environments in this region, but also as the result of the different temporal stages of seasonal succession of microplankton. Our results show that instead of a gradual change from nitrate-based to ammonium-based production as the summer season progressed, secondary blooms using nitrate as the primary nitrogen source may develop in areas like the western Bransfield Strait during mid summer. Rapid nitrogen uptake and growth efficiencies during activ

A transect off Point Sur, California (36 degrees 20'N), was occuplied bimonthly from April 1988 to May 1990 to resolve spatial and temporal patterns in the physics and chemistry of the California Current System. Alongshore velocity fields and the chemical parameter N* [Gruber and Sarmiento, 1997] show coherence. Subartic waters, conveyed by the California Current (CC), were characterized by high N* values, which in the region of poleward flow of the California Undercurrent (CU) a minimum of N* (N* <-5 umolkg-1) was observed.