Pamela A. Fernández

• PhD
• Professor (Associate) at Universidad de Los Lagos

The kelp genus Macrocystis presents populations recognizable by distinct morphological traits, which has raised discussions on its taxonomical status. Recently, whole genome sequencing arose global evidence of Macrocystis ecomorphs “integrifolia” and “pyrifera” being genetically distinct. In the southern hemisphere, both ecomorphs maintain a separa...

Effects of pH, temperature and light on carbon metabolism in Macrocystis pyrifera gametophytes

The responses of seaweed species to increased CO2 and lowered pH (Ocean Acidification: OA) depend on their carbon concentrating mechanisms (CCMs) and inorganic carbon (Ci) preferences. However, few studies have described these mechanisms in the early life stages of seaweeds or assessed the effects of OA and its interactions with other environmental...

Editorial: Sustainable seaweed aquaculture: Current advances and its environmental implications

We report for the first time the occurrence of the Japanese kelp Saccharina japonica on the Pacific coast of southern Chile following an illegal introduction for aquaculture purposes. In November 2020, a citizen complaint indicated that the non-native kelp was being illegally farmed in Canal Caicaén. Specimens of the non-native kelp were collected...

Macrocystis pyrifera is a major habitat forming kelp in coastal ecosystems of temperate regions of the northern and southern hemispheres. We investigated the seasonal occurrence of adult sporophytes, morphological characteristics and reproductive phenology at two sites within a wave-protected harbour and two wave- exposed sites in southern New Zeal...

Macrocystis pyrifera, es una macroalga parda que habita ecosistemas costeros con diferentes patrones de abundancia y reproducción dependiendo de su grado de exposición al oleaje. En el norte de Chile, M. pyrifera está presente durante todo el año, con un patrón reproductivo en invierno, independiente del grado de exposición al oleaje. Pero en el su...

Changes in the seawater carbonate system due to ocean acidification (OA) such as reduced seawater pH and aragonite saturation state (Ωarg) can negatively affect the production and maintenance of bivalves ´shells (calcification). Thus, OA have the potential to adversely affect mussel aquaculture worldwide. Physiological process such as mussel respir...

The capacity of marine organisms to adapt and/or acclimate to climate change might differ among distinct populations, depending on their local environmental history and phenotypic plasticity. Kelp forests create some of the most productive habitats in the world, but globally, many populations have been negatively impacted by multiple anthropogenic...

The performance and survival of macroalgae is largely determined by their ability to adjust to varying environmental conditions. In this study, we investigated the short-term response of the giant kelp Macrocystis pyrifera to varying temperatures (6, 17 and 24 °C) and low and high nitrate conditions (5 μM and 80 μM nitrate) on lipid and fatty acid...

Alexandrium catenella, the main species associated with harmful algal blooms, has progressively increased its distribution through one of the most extensive and highly variable fjord systems in the world. In order to understand this successful expansion, we evaluated the effects of different salinities, light intensity, temperatures, nitrogen (N) f...

Local and global changes associated with anthropogenic activities are impacting marine and terrestrial ecosystems. Macroalgae, especially habitat-forming species like kelp, play critical roles in temperate coastal ecosystems. However, their abundance and distribution patterns have been negatively affected by warming in many regions around the globe...

With ongoing climate change, aquaculture faces environmental challenges similar to those of natural ecosystems. These include increasing stress for calcifying species, e.g. macroalgae and shellfish. In this context, ocean acidification (OA) has the potential to affect important socioeconomic activities, including shellfish aquaculture, due to chang...

Kelp forests around the world are under increasing pressure from anthropogenic stressors. A widespread consequence is that in many places, complex and highly productive kelp habitats have been replaced by structurally simple and less productive turf algae habitats. Turf algae habitats resist re-establishment of kelp via recruitment inhibition; howe...

Ocean warming (OW), ocean acidification (OA) and their interaction with local drivers, e.g., copper pollution, may negatively affect macroalgae and their microscopic life stages. We evaluated meiospore development of the kelps Macrocystis pyrifera and Undaria pinnatifida exposed to a factorial combination of current and 2100-predicted temperature (...

Carbonic anhydrase (CA) plays an important physiological role in all biological systems by accelerating the interconversion of CO2 and HCO3⁻. In algae, CA is essential for photosynthesis: external CA (CAext) dehydrates HCO3⁻, enhancing the supply of CO2 to the cell surface, and internal CA (CAint) interconverts HCO3⁻ and CO2 to maintain the inorgan...

Finfish aquaculture is an activity that has experienced an explosive global development, but presents several environmental risks, such as high nitrogen outputs with potential eutrophication consequences. Therefore, the integration of seaweed aquaculture with the aim of decreasing nitrogen emissions associated with intensive salmon farming has been...

The responses of macroalgae to ocean acidification could be altered by availability of macronutrients, such as ammonium (NH4⁺). This study determined how the opportunistic macroalga, Ulva australis responded to simultaneous changes in decreasing pH and NH4⁺ enrichment. This was investigated in a week-long growth experiment across a range of predict...

Seawater carbonate chemistry estimates. Measurements of total pH (pHT) and total alkalinity (AT) are described in the methods. AT was measured as 2111.42 ± 18.33 (mean ± SEM) (n = 7). Salinity is assumed to be 35%. Temperature is assumed to be 16.5°C (the average temperature throughout the experiment) MFC = mass flow controller. DIC = dissolved ino...

Las macroalgas son complejos componentes productivos de las costas marinas, actuando como alimento, hábitat y semillero para múltiples organismos asociados. El calentamiento y acidificación oceánica (CAO) pueden afectar la fisiología de las macroalgas, produciendo cambios en su abundancia y distribución. Disminuciones de poblaciones de macroalgas n...

Evaluating the relative effects of local (e.g. eutrophication) and global (e.g. ocean acidification, OA) environmental change is important to predict how marine macroalgae might respond to future oceanic conditions. In this study, the effects of nitrate supply, and hence tissue nitrogen status, and OA on the N metabolism, growth and photosynthetic...

The absorption of anthropogenic CO2 by the oceans is causing a reduction in the pH of the surface waters termed ocean acidification (OA). This could have substantial effects on marine coastal environments where fleshy (non-calcareous) macroalgae are dominant primary producers and ecosystem engineers. Few OA studies have focused on the early life st...

Anthropogenic atmospheric emissions of CO2 are responsible for simultaneous ocean warming (OW) and ocean acidification (OA). These global events can have important impacts on marine fleshy macroalgae and coastal ecosystems. To understand the effects of OW and OA on the early life history stages of native (Macrocystis pyrifera) and invasive (Undaria...

Ocean acidification (OA), the ongoing decline in seawater pH, is predicted to have wide-ranging effects on marine organisms and ecosystems. For seaweeds, the pH at the thallus surface, within the diffusion boundary layer (DBL), is one of the factors controlling their response to OA. Surface pH is controlled by both the pH of the bulk seawater and b...

Anthropogenic CO2 emissions are driving a temperature increase of 4°C and a pH reduction from 8.10 to 7.65 (ocean acidification, OA) in the ocean surface by 2100. The concentration of free toxic Cu2+ is also increasing due to OA. These changes may affect the physiology of macroalgae, especially their susceptible early life stages. Our objective was...

Anthropogenic CO2 emissions are driving a temperature increase of 3°C and a pH reduction from 8.10 to 7.65 (ocean acidification, OA) in the ocean surface by 2100. The concentration of free toxic Cu2+ is also increasing due to OA. These changes may affect the physiology of macroalgae, especially their susceptible early life stages. Our objective was...

Under ocean acidification (OA), the 200 % increase in CO2(aq) and the reduction of pH by 0.3-0.4 units are predicted to affect the carbon physiology and growth of macroalgae. Here we examined how the physiology of the giant kelp Macrocystis pyrifera is affected by elevated pCO2/low pH. Growth and photosynthetic rates, external and internal carbonic...

Ocean uptake of anthropogenic CO2 is projected to decrease surface seawater pH (8.10) by 0.30 - 0.32 units by 2100, termed ocean acidification (OA). However, pH inside kelp canopies can naturally vary between 7.65 ‐ 8.86 daily, and pH near the benthos varies from 7.00 to 8.30. The giant kelp Macrocystis pyrifera and the invasive kelp Undaria pinnat...

Carbon physiology of a genetically identified Ulva rigida was investigated under different CO 2(aq) and light levels. The study was designed to answer whether (1) light or exogenous inorganic carbon (Ci) pool is driving growth; and (2) elevated CO 2(aq) concentration under ocean acidification (OA) will downregu-late CA ext -mediated HCO À 3 dehydra...

The combined effects of elevated CO2 (aq) and nitrate (NO3–) supply on the carbon and the nitrogen physiology of Macrocystis pyrifera (hereafter Macrocystis) were investigated. We hypothesized that: (1) NO3– assimilation, the size of the internal NO3– pool, and total tissue N content, will depend on NO3– supply and (2) a higher CO2 concentration wi...

Carbon physiology of a genetically identified Ulva rigida was investigated under different CO2(aq) and light levels. The study was designed to answer whether (1) light or exogenous inorganic carbon (Ci) pool is driving growth; and (2) elevated CO2(aq) concentration under ocean acidification (OA) will downregulate CAext-mediated inline image dehydra...

Under ocean acidification (OA), the 200 % increase in CO2(aq) and the reduction of pH by 0.3-0.4 units are predicted to affect the carbon physiology and growth of macroalgae. Here we examined how the physiology of the giant kelp Macrocystis pyrifera is affected by elevated pCO2/low pH. Growth and photosynthetic rates, external and internal carbonic...

Macrocystis pyrifera is a widely distributed, highly productive, seaweed. It is known to use bicarbonate (HCO3 (-) ) from seawater in photosynthesis and the main mechanism of utilization is attributed to the external catalyzed dehydration of HCO3 (-) by the surface-bound enzyme carbonic anhydrase (CAext ). Here, we examined other putative HCO3 (-)...

Ocean uptake of anthropogenic CO2 is projected to decrease surface seawater pH (8.10) by 0.30-0.32 units by 2100, termed ocean acidification (OA). However, pH inside kelp canopies can naturally vary between 7.65-8.86 daily, and pH near the benthos varies from 7.00 to 8.30. The giant kelp Macrocystis pyrifera and the invasive kelp Undaria pinnatifid...

This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as doi: 10.1111/jpy.12247-14-058 This article is protected by copyright. All...

The reproductive patterns of Macrocystis pyrifera are strikingly different in the Northern and Southern hemispheres. In California, USA, M. pyrifera reproduces throughout the year, irrespective of wave-exposure. In northern Chile, in both wave-sheltered and exposed locations, it has a seasonal reproductive pattern in winter; in southern Chile, wave...

Macrocystis pyrifera is a widely distributed, highly productive, seaweed. It is known to use bicarbonate (HCO3-) from seawater in photosynthesis and the main mechanism of utilization is attributed to the external catalyzed dehydration of HCO3- by the surface-bound enzyme carbonic anhydrase (CAext). Here, we examined other putative HCO3- uptake mech...

The distribution, abundance and diversity of modern dinoflagellate cyst assemblages were investigated in sediments from the inshore seas of southern Chile (438089–548559 S) at eight sites from April 2004 to Janu-ary 2005. A total of 24 cyst types were recorded, of which 12 and five were identified at the species and genus lev-els, respectively. Din...