Carmen E. Morales

University of Concepción · Departamento de Oceanografía

Mesoscale and submesoscale processes that contribute to localized increases in nutrients in the sunlit layer can stimulate phytoplankton growth and community changes, but the mechanisms involved remain sparsely documented with in situ data in the case of Eastern Boundary Upwelling Systems (EBUSs) and of most ocean regions. The role of diapycnal mix...

Las Contribuciones Determinadas a nivel Nacional (NDC, por sus siglas en inglés) se han convertido en un instrumento clave para comprometer principalmente metas de mitigación y adaptación al cambio climático. Gestadas en el Acuerdo de París (2015) aspiran a cumplir dos de sus objetivos más ambiciosos: mantener el incremento de la temperatura global...

This is a scientific report solicited by the Dirección General del Territorio Marítimo y de Marina Mercante (DIRECTEMAR) of the Chilean Navy in June 2017. A foreign (Canadian) company had been making numerous appearances in the Chilean and International Press, and conducting an advertising campaign, to promote the commercial fertilization of Chilea...

Understanding the influence of mesoscale and submesoscale features on the structure of phytoplankton is a key aspect in the assessment of their influence on marine biogeochemical cycling and cross-shore exchanges of plankton in Eastern Boundary Current Systems (EBCS). In this study, the spatio-temporal evolution of phytoplankton size classes (PSC)...

In Eastern Boundary Upwelling Systems, cold coastal waters are separated from offshore by a strong cross-shore Sea Surface Temperature (SST) gradient zone. This upwelling front plays a major role for the coastal ecosystem. This paper proposes a method to automatically identify the front and define its main characteristics (position, width, and inte...

An approach that improves the spectral-based PHYSAT method for identifying phytoplankton functional types (PFT) in satellite ocean-color imagery is developed and applied to one study case. This new approach, called PHYSTWO, relies on the assumption that the dominant effect of chlorophyll-a (Chl-a) in the normalized water-leaving radiance (nLw) spec...

Seamounts in the Juan Fernandez Ridge, as well as in other seamount regions in the eastern South Pacific and in the world oceans, remain poorly studied ecosystems in terms of structure and functioning. Here, community respiration by epipelagic mesozooplankton in three seamounts of the Juan Fernandez Ridge, including the O`Higgins Seamount close to...

In eastern boundary current systems (EBCSs), submesoscale to mesocale variability contributes to cross-shore exchanges of water properties, nutrients, and plankton. Data from a short-term summer survey and satellite time series (January-February 2014) were used to characterize submesoscale variability in oceanographic conditions and phytoplankton d...

An intensification of upwelling-favorable winds in recent decades has been detected in some of the main eastern boundary current systems, especially at higher latitudes, but the response of coastal phytoplankton communities in the Humboldt Current System (HCS) remains unknown. At higher latitudes in the HCS (35-40°S), strong seasonality in wind-dri...

Zooplankton production is a critical issue for understanding marine ecosystem structure and dynamics, however, its time-space variations are mostly unknown in most systems. In this study, estimates of copepod growth and production (CP) in the coastal upwelling and coastal transition zones off central-southern Chile (∼35–37° S) were obtained from an...

The annual cycle and phenology of phytoplankton (satellite-derived chlorophyll-a, Chl-a) in the coastal upwelling region off central-southern Chile, their time-space variation, and the extent of their coupling with those of wind-driven upwelling (as Zonal Ekman Transport, ZET), Sea Surface Temperature (SST), and Photosynthetically Active Radiation...

The three-dimensional structure and the origin of mesoscale anticyclonic intrathermocline eddies (ITEs) in the coastal transition zone (CTZ) off central Chile (31-41°S) were analyzed through the combination of data from oceanographic cruises and satellite altimetry, and the application of an eddy-resolving primitive equation ocean model coupled wit...

Time-space fluctuations of chlorophyll-a (Chl-a) within the region off central-southern Chile (33-42 degrees S), and their association with meteorological-oceanographic conditions, were analyzed using satellite time series data (2002-2012). The mean distribution of moderate values of Chl-a (approximate to 0.5 mgm(-3)) in the northern section (33-38...

Cape Ghir (similar to 31 degrees N), in the Canary Current System, is an area of permanent coastal upwelling with maximum intensity in summer-autumn, when a strong across-shore thermal gradient and increased mesoscale activity are present. The effects of spatial (cross-shore transect with 7 stations) and temporal (5 dates: from December 2008 to Oct...

Mesoscale features are recurrently found in the Coastal Transition Zone (CTZ) off central-southern Chile (∼35–40°S), a region characterized by seasonal wind-driven coastal upwelling. In this study, oceanographic data from two consecutive cruises carried out during the upwelling season (January 2009) were combined with satellite time series data in...

In the coastal system off Concepción, time series observations at a fixed station (St. 18) have shown strong seasonal changes in the oceanographic environment of the upper layer (<35. m depth), accompanied by large increases in phytoplankton biomass during the spring-summer upwelling season. These blooms, dominated by microplanktonic diatoms, have...

Eleven years of satellite data on surface chlorophyll-a, wind, and altimetry were used to analyze the spatial and temporal variability of the phytoplankton biomass in the Peru–Chile Current System (PCCS; 10–40°S) and to examine the main mechanisms determining this variability. Multitaper Method–Singular Value Decomposition was used to identify stat...

This study describes the abundance and vertical distribution of microbial assemblages (from femto to nanoplankton) in the upwelling area off Concepción (~36oS), analyses their relationship to oceanographic conditions during the upwelling season (austral spring-summer: December 2002-March 2003), and explores microbial community inter-relationships;...

Copepod grazing impact on planktonic communities has commonly been underestimated due to the lack of information on naupliar feeding behaviour and ingestion rates. That is particularly true for small cyclopoid copepods, whose nauplii are mainly in the microzooplankton size range (<200μm). The trophic role of Oithona spp. nauplii was investigated of...

This study describes the abundance and vertical distribution of microbial assemblages (from femto to nanoplankton) in the upwelling area off Concepción (~36ºS), analyses their relationship to oceanographic conditions during the upwelling season (austral spring-summer: December 2002- March 2003), and explores microbial community inter-relationships;...

In the Humboldt Current System, the region off central-southern Chile has relatively high eddy kinetic energy, generating an extensive coastal transition zone (∼600 km offshore) in which coastally derived eddies are recurrent features. This energy might promote strong exchanges of water, biogeochemical properties, and plankton between the coastal u...

Both scientific and technical capacities are key issues for achieving the objectives of understanding the functioning of the oceans, conserving their health and resources, and predicting the impacts of climate change. Many international programmes related to ocean studies and monitoring, as well as those concerning global climate change, include 'c...

The oceanographic setting and the planktonic distribution in the coastal transition zone off Concepción (∼35–38°S, ∼73–77°W), an area characterized by its high biological production, were assessed during two different seasons: austral spring with equatorward upwelling favorable winds and austral winter with predominately northerly winds. Oceanograp...

In the highly productive region off central Chile, the structure and temporal and spatial variability of planktonic assemblages, and the factors that determine changes in this structure are poorly understood. In the region, wind-driven upwelling, heating by solar radiation and freshwater inputs are highly seasonal processes, which, together with hi...

The structure and functioning of nanoplanktonic assemblages in coastal upwelling areas have usually been overlooked in explorations of the productivity of these areas. As part of a multidisciplinary, time-series station in the coastal area off Concepción, seasonal variations (upwelling and non-upwelling) in the abundance and biomass of these assemb...

The vertical distribution and abundance of microbial assemblages and the grazing of nanoheterotrophs upon prokaryotes in oxic and suboxic waters were examined in two coastal upwelling areas off northern Chile where a shallow Oxygen Minimum Zone (OMZ) is characteristic. Prokaryotic prey included bacterioplankton and cyanobacteria (Synechococcus); bo...

The vertical and ontogenetic distribution, and diel vertical migration (DVM), of Eucalanus inermis in relation to the strong vertical gradient in oxygen concentration associated with an intense oxygen minimum zone (OMZ) were studied at a coastal area off northern Chile (20–21° S). A close relationship between the abundance of the whole copepod popu...

Ammonium (NH4+) cycling rates under different dissolved oxygen (DO) conditions in the water column, at a coastal upwelling area off northern Chile (similar to 23 degrees S), were estimated. Net NH4+ regeneration (eukaryotes and prokaryotes) and NH4+ oxidation (nitrifying bacteria) rates were examined by means of selective inhibitor assays (cyclohex...

The impact of grazing by natural assemblages of microzooplankton was estimated in an upwelling area (Concepción, Chile) during the non-upwelling season in 2003 and 2004. Seawater dilution experiments using chlorophyll a (Chl a ) as a tracer were used to estimate daily rates of phytoplankton growth and microzooplankton grazing. Initial Chl a concent...

Eucalanus inermis is an abundant species in the eastern tropical and subtropical South Pacific, including the oceanic and coastal waters off Chile and Peru. Its annual life cycle was studied through a time-series sampling (weekly intervals) during 2002, at a fixed coastal station at an upwelling site (Mejillones Bay, 23S) off northern Chile. The mo...

The coastal upwelling ecosystem of the Humboldt Current System off Peru and Chile exhibits strong interannual variability due to changes in the oceanographic conditions related to the El Ninõ (EN) Southern Oscillation. It is generally believed that major changes occur in the community structure and biological production of this system as a conseque...

In evaluating carbon flux in coastal and oceanic waters off central Chile (~36°S), the grazing pressure by copepod size-assemblages and the gravitational flux from the surface layer were estimated during two contrasting seasons: spring upwelling (October 1998) and winter (July 1999) periods. Grazing pressure upon phytoplankton biomass was small (<5...

The central-south area of Chile (VIII region) presents a system of bays (~36°30'-37º S), including the bays of Concepcion (BC), San Vicente (BSV) and Coronel in the eastern boundary of the Gulf of Arauco (SOGA). This system has been recognized as an important center for the spawning and recruitment of fish species during the winter. In the present...

The central-south area of Chile (VIII region) presents a system of bays (similar to 36 degrees 30'-37 degreesS), including the bays of Concepcion (BC), San Vicente (BSV) and Coronel in the eastern boundary of the Gulf of Arauco (SOGA). This system has been recognized as an important center for the spawning and recruitment of fish species during the...

Chlorophyll-a (chl-a) distribution and associated physical (temperature, salinity) and chemical (dissolved oxygen) conditions off northern Chile (Humboldt Current System), during the austral summer (February–March) and autumn (May) of 1994, were studied in the region bounded by [similar]18–24°S and 70–72°W (out to [similar]200 km from the coast; 0–...

The low oxygen concentration (<2 ml L-1) at relatively shallow depths (<100 m) in the coastal upwelling zone and in the adjacent oceanic area is a distinct feature of the eastern boundary Humboldt Current System (HCS) off Peru and northern Chile; it affects the distribution of pelagic organisms and is associated with an important denitrification re...

The role of vertical migrant zooplankton, with both seasonal/ontogenetic and daily strategies, in the active transport of carbon and nitrogen out of the surface layer in the North Atlantic is analysed. The data used were obtained mainly during the Joint Global Ocean Flux Study (JGOFS)-North Atlantic Bloom Experiment (NABE) (1989-1990) in the North...

The large industrial fishery development that turn Chile into the third fishing nation in the world is described, and recent regulatory innovations introduced by new Fishery and Aquaculture legislation are reviewed. In addition to classical Fishery management tools, different types of limited entry systems are now defined in the law and applicable...

Using vertical profile data from the upwelling system off northern Chile, the slopes of dissolved oxygen/nutrient concentration regressions have been analysed, in conjunction with a value of 1.4 for the molar ratio of net community oxygen production to nitrate-driven carbon dioxide assimilation, to investigate the stoichiometric inter-relationships...

The mesoscale distributions of chlorophyll-a (Chl-a) and associated physical and chemical variables off the northern coast of Chile are described using quasi-synoptic data obtained during the austral winter (August–September) and spring (November–December) of 1993. Surface temperature, salinity and chlorophyll-a data were collected in the region bo...

This study analyses the patterns of distribution and abundance of anchovy (Engraulis ringers) larvae off northern Chile (18°-24°S), within the coastal zone (out to 100 nm) and their relationship to the oceanographic conditions in the top layer (0-200 m depth) . The data were derived from surveys undertaken from 1990 to 1995, during each winter (Jul...

The physical and chemical structure of the upper 100 m of the water column and biological parameters were measured during spring bloom development along a 20°W transect rom 60 to 47°N in June 1989. At 60°N, the situation was that of a late bloom: weak and intermittent stratification, high nutrient concentrations, and high and variable phytoplankton...

Copepod grazing and abundance were measured during a 6 week time series at a Lagrangian drifting station in temperate waters of the NE Atlantic (46–50°N, 15–19°W) during spring 1990. Copepod assemblages, in the mesozooplankton size range, were fractionated into three size classes (200–500, 500–1000 and 1000–2000 μm) and dominant groups were analyse...

The North Atlantic was the site for the 1989 JGOFS Pilot Study, an international study of ocean fluxes in relation to the carbon cycle. In this paper we present preliminary estimates of the grazing pressure by copepod assemblages at four stations: 60, 56, 52 and 47-degrees-N, along the JGOFS 20-degrees-W transect, during June-July. Three major size...

At a station (NFLUX), occupied for 10 days in the northern Sargasso Sea, we assembled data to test the hypothesis that diel migrant biota in the open ocean induce a downward flux of dissolved inorganic nitrogen that is significant in relation to the passive flux under gravity of particulate organic nitrogen at the base on the photic zone. We founf...

Diet selection of the Chilean stone crab Homolaspis plana (Milne-Edwards, 1834) was studied using the optimal foraging theory to explain its feeding strategy. The hypothesis that H. plana prefers prey species of the highest prey (energy) value was experimentally tested on adult crabs during 1980–1981. Food value was defined as the ratio between cal...