A biogeochemical model for North and Northwest Iberia: some applications

The Coastal and Ocean modeling group at the Spanish Institute of Oceanography (IEO) has a broad experience in hydrodynamic modeling with ROMS in the area of West and North Iberia. Our main task consists of providing insight on the coastal and ocean dynamics in support to the intense IEO ecosystem and fisheries research in the area. The NW coast of Iberia is characterized by high levels of primary production that result from relatively frequent and intense inputs of nutrients caused by upwelling, especially in spring and summer. Primary production sustains wealthy fisheries and aquaculture industries, which constitute a prime economic activity in the region. As a first approach to understand the ecosystem variability in the area we focused on the spring bloom. A high resolution (~3 km) configuration of the ROMS physical model with atmospheric forcing coming from the regional agency Meteogalicia (http://www.meteogalicia.es), which has shown to represent the main features of the shelf and slope circulation in the area, was run coupled to the Fasham-type Fennel biogeochemical model (N2PZD2). Any biogeochemical model aimed at providing a reliable representation of the dynamics of a certain area should be tuned according to its characteristics. In an upwelling system, the composition of phytoplankton varies from the beginning to the end of the bloom. When nutrients and irradiance are high, diatoms are the dominant group, whereas flagellates become more important when upwelling relaxes and, consequently, nutrients and light intensity decrease. In the NW Iberian coast, it has been found that Chaetoceros socialis is the dominant diatom species during the spring bloom (Bode et al, 1996, 1998). For this reason, we have decided to use parameters that are characteristic of plankton at the spring bloom. In particular, the parameters of Chaetoceros socialis have been considered for the unique phytoplankton class of the model. We will show comparisons of the model results for 2006 and 2007 with observations at weekly and daily time scales (MODIS chlorophyll-a images, in situ observations from the “Instituto Español de Oceanografía” Pelacus cruises). The spring bloom is reasonably reproduced in the NW and N coasts in time, space and intensity. The variability between the primary production in 2006 and 2007 can be related to the oceanographic conditions thanks to the use of a numerical model. The results are promising and encourage us to move forward to increase the complexity of our models and broaden their range of application. We will show some examples of the use of the IEO models to get some insight on sardine recruitment variability and harmful algal bloom prediction

The IEO coastal observatory: understanding variability of coastal circulation and ecosystem response off North and North West Iberia

ATLANTOS; GAI

Modeling Iberian sardine Early Life Stages dynamics

The Iberian sardine (Sardina pilchardus) constitutes a traditional target species in western Iberia that remains to be economically important in Portugal and, to a lesser extent, in Galicia (NW Spain). The time series of recruitment shows ups and downs in the last decades. According to the ICES Advice 2013 for regions VIII and IXa, the biomass of age 1 sardine and older has decreased since 2006 and recruitment has been below the long term average since 2005. In order to understand these fluctuations, a Lagrangian model to simulate sardine Early Life Stages (ELS), this is, egg and larvae stages, has been set up. The results of a high resolution hydrodynamic model for North and Northwest Iberia have been used as an input of the Lagrangian model Ichthyop (Lett et al., (2008)) to simulate ELS advection and dispersion. Ichthyop has been adapted to sardine by including some biological behavior. A biogeochemical model coupled to the hydrodynamic model was also used to get some insight on recruitment for years 2006 2007

Modelling the hydrodynamic conditions associated with Dinophysis blooms in Galicia (NW Spain)

The northwestern Iberian coast (Galician Rías and shelf) is frequently affected by toxic harmful algal blooms (HABs) (mainly Dinophysis spp.), leading to lengthy harvesting closures in a region where aquaculture has a strong socioeconomic impact. The project ASIMUTH (http://www.asimuth.eu) aimed to develop forecasting capabilities to warn of impending HABs along the European Atlantic coast. Simulations with the ROMS model (hydrodynamical and ecological simulations complemented with Lagrangian particle tracking simulations) of the Galician coastal circulation have been performed in the framework of the ASIMUTH project to characterize and forecast oceanographic conditions before and during HAB periods. In this work, we present the Galician ASIMUTH forecast system and demonstrate its skill in predicting HAB transport and its usefulness to provide assessment for the management of the areas affected by toxic outbreaks. Experience gained during DSP events in 2005 and 2013 is shown. We also describe the Galician pilot HAB bulletins, aimed at distributing forecasts of HAB events that might induce closures of harvesting areas or, when the areas are already closed, at giving information on forthcoming oceanographic conditions that could favour or hamper the opening of an area. Our results show that the model forecasts and the bulletins can provide early warning of the risk of Dinophysis spp. events and the risk of closures linked to the presence of DSP toxins above regulatory levels in harvesting areas.Versión del editor3,083

Numerical simulations with the ASIMUTH forecast system for understanding and forecasting HAB events in Galicia (NW Spain)

Simulations with the model ROMS (hydrodynamical and ecological simulations complemented with Lagrangian particle-tracking simulations) have been performed in the framework of the project ASIMUTH (http://www.asimuth.eu) which aims to develop forecasting capabilities to warn of impending harmful algal blooms (HABs) along the European Atlantic coast. In this contribution, we will report on the skill of the ASIMUTH forecast system in predicting transport of HABs and in assessing the area affected by HABs in the upwelling-influenced Galician rias (NW Spain) with the experience gained in years 2013 and 2014.ASIMUTH FP7/26186

Towards a HAB forecast service in the Galician region

We will present the recent developments of our forecasting capabilities to warn of impending harmful algal blooms (HABs) in Galicia, where aquaculture has a strong socio-economic impact. A HAB warning service for monitoring agencies and the aquaculture industry has been developed as a demonstration of a Copernicus marine downstream service coupled to the MyOcean service. In this contribution, we describe the Galician ASIMUTH forecast system and demonstrate its skill in predicting HAB transport and its usefulness to provide assessment for the management of the areas affected by toxic outbreaks. We also describe the Galician pilot HAB bulletins, aimed at distributing forecasts of HAB events that might induce closures of harvesting areas or, when the areas are already closed, at giving information on forthcoming oceanographic conditions that could favour or hamper the opening of an area. Our results show that the model forecasts and the bulletins can provide early warning of the risk of Dinophysis spp. events and the risk of closures linked to the presence of toxins above regulatory levels in harvesting areas.Instituto Español de Oceanografí