Helene Frigstad

Helene Frigstad
Norwegian Institute for Water Research | NIVA

PhD in Chemical Oceanography

About

38
Publications
5,620
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312
Citations

Publications

Publications (38)
Article
Full-text available
Vegetated coastal and marine habitats in the Nordic region include salt marshes, eelgrass meadows and, in particular, brown macroalgae (kelp forests and rockweed beds). Such habitats contribute to storage of organic carbon (Blue Carbon – BC) and support coastal protection, biodiversity and water quality. Protection and restoration of these habitats...
Technical Report
Full-text available
Blue forests, such as rockweed beds and seagrass meadows, are considered important natural sinks for carbon and thereby play a vital role in climate regulation, mitigation and adaptation. Kelp forests grow on rocky bed substrates and have therefore no local sedimentation of produced biomass. Kelp has therefore not yet been considered to contribute...
Method
Full-text available
Nordic blue forests are coastal vegetated habitats, such as kelp forests, eelgrass meadows and rockweed beds, that are important natural sinks for carbon and thereby climate regulation. They also play an important role in climate adaptation. Simultaneously, blue forests are at high risk from climate change and other human impacts, such as eutrophic...
Presentation
Talk at the 2021 ASLO Aquatic Science Meeting
Book
Full-text available
This report presents the main findings of the Nordic Blue Carbon Project (2017–2020) on the areal distribution and carbon budget of blue forests (kelp forests, seagrass meadows and rockweed beds) in the Nordic region. We have identified the main ecosystem effects of climate change and other human pressures on Nordic blue forests, tested the effect...
Article
Full-text available
Declining atmospheric nitrogen (N) deposition, through reduction in the direct input of inorganic N, may result in less inorganic N being leached from soils to freshwaters (dissolved inorganic N = DIN). Declining sulphur deposition, through reducing the ionic strength in soil water, increases the solubility and mobility of organic soil compounds an...
Technical Report
Full-text available
This report describes the results of a literature review on increased light attenuation and biological effects in Norwegian waters and comparable global coastal regions. An overview of research projects on increased light attenuationis given.
Technical Report
Full-text available
The monitoring program "Ecosystem Monitoring in Coastal Water - ØKOKYST" aims at monitoring the environmental status in selected areas along the Norwegian coast according to vannforskriften (the Water Framework Directive). Subprogram Norskehavet Sør I includes Ulsteinvik and Geirangerfjorden. All the biological quality elements obtained at least “g...
Technical Report
Full-text available
The monitoring program "Ecosystem Monitoring in Coastal Water - ØKOKYST" aims at monitoring the environmental status in selected areas along the Norwegian coast according to vannforskriften (the Water Framework Directive). Subprogram Skagerrak includes 14 water bodies within the area of outer Oslofjord and the Grenlandfjords. The overall condition...
Article
Full-text available
Coastal ecosystems are of high ecological and socioeconomic importance and are strongly influenced by processes from land, sea, and human activities. In this study, we present physical, chemical, and biological observations over two consecutive years from three study regions along the Norwegian coast that represent a broad latitudinal gradient in c...
Presentation
Dedicated fieldwork to quantify missing key values in the Nordic carbon cycle, with significance for carbon storage in the Nordic kelp forest.
Article
Full-text available
Organic matter (OM) in aquatic systems is either produced internally (autochthonous OM) or delivered from the terrestrial environment (ter-OM). For eutrophication (or the reverse-oligotrophication), the amount of autochthonous OM plays a key role for coastal ecosystem health. However, the influence of ter-OM on eutrophication or oligotrophication p...
Chapter
Full-text available
World Seas: An Environmental Evaluation, Second Edition, Volume One: Europe, The Americas and West Africa provides a comprehensive review of the environmental condition of the seas of Europe, the Americas and West Africa. Each chapter is written by experts in the field who provide historical overviews in environmental terms, current environmental s...
Presentation
This is a very short presentation given at NIVAs yearly institute seminar in January 2018.
Poster
Poster with an oral introduction at the GEOHAB Conference May, Santa Barbara, California, USA, 7-11. May 2018.
Book
Full-text available
This report represents the annual report of the Blue Carbon project in 2017, and presents preliminary results and progress. It also provides a summary of the workshop "Status of Nordic carbon cycling in blue forests" organized the 16-17 of November 2017.
Technical Report
Full-text available
The Aust-Agder and Vest-Agder counties include municipalities along the Norwegian Skagerrak coast, from Risør in the east to Flekkefjord in the west. Through the “Partnership for blue growth”, the coastal municipalities aim to facilitate blue growth in the region, and there is a need for science-based knowledge on which opportunities the ocean prov...
Article
What is the temporal variability of the elemental stoichiometry of marine microbial communities across ocean regions? To answer this question, we present an analysis of environmental conditions, particulate organic carbon, nitrogen, and phosphorus concentrations, and their ratios across 20 time-series (3 – 25 years duration) representing estuarine,...
Article
Full-text available
In this study we present hydrography, biogeochemistry and sediment trap observations between 2003 and 2012 at Porcupine Abyssal Plain (PAP) sustained obser- vatory in the Northeast Atlantic. The time series is valu- able as it allows for investigation of the link between sur- face productivity and deep ocean carbon flux. The region is a perennial s...
Article
Full-text available
In this study we present hydrography, biogeochemistry and sediment trap observations between 2003 and 2012 at Porcupine Abyssal Plain (PAP) sustained observatory in the northeast Atlantic. The time series is valuable as it allows for investigation of the link between surface productivity and deep ocean carbon flux. The region is a perennial sink fo...
Article
Full-text available
This study evaluates long-term mean fluxes of carbon and nutrients to the upper 100 m of the Iceland Sea. The study utilises hydro-chemical data from the Iceland Sea time series station (68.00° N, 12.67° W), for the years between 1993 and 2006. By comparing data of dissolved inorganic carbon (DIC) and nutrients in the surface layer (upper 100 m), a...
Article
Full-text available
We present high-resolution autonomous measurements of carbon dioxide partial pressure p(CO2) taken in situ at the Porcupine Abyssal Plain sustained Observatory (PAP-SO) in the northeast Atlantic (49° N, 16.5° W; water depth of 4850 m) for the period 2010–2012. Measurements of p(CO2) made at 30 m depth on a sensor frame are compared with other auton...
Article
Full-text available
Fluxes of carbon and nutrients to the upper 100 m of the Iceland Sea are evaluated. The study utilises hydro-chemical data from the Iceland Sea time-series station (68.00° N, 12.67° W), for the years between 1993 and 2006. By comparing data of dissolved inorganic carbon (DIC) and nutrients in the surface layer (upper 100 m), and a sub-surface layer...
Article
Full-text available
We present high-resolution autonomous measurements of carbon dioxide partial pressure p(CO2) taken in situ at the Porcupine Abyssal Plain sustained Observatory (PAP-SO) in the northeast Atlantic (49° N, 16.5° W; water depth of 4850 m) for the period 2010–2012. Measurements of p(CO2) made at 30 m depth on a sensor frame are compared with other auton...
Article
Full-text available
Studying more than 3600 observations of particulate organic carbon (POC) and particulate organic nitrogen (PON), we evaluate the applicability of the classic Redfield C:N ratio (6.6) and the recently proposed Sterner ratio (8.3) for the Arctic Ocean and pan-Arctic shelves. The confidence intervals for C:N ranged from 6.43 to 8.82, while the average...
Article
Full-text available
A 20-year time series from the Norwegian Coastal Current was explored to examine the effects of advected nutrient supply from the southern North Sea and of large-scale climate variability on hydrography, nutrients and particulate organic matter (seston), focusing on trends in the January to April period in the upper layers (0-30 m). The interannual...
Article
Full-text available
Seston is suspended particulate organic matter, comprising a mixture of autotrophic, heterotrophic and detrital material. Despite variable proportions of these components, marine seston often exhibit relatively small deviations from the Redfield ratio (C:N:P = 106:16:1). Two time-series from the Norwegian shelf in Skagerrak are used to identify dri...
Article
Seston is suspended particulate organic matter, comprising a mixture of autotrophic, heterotrophic and detrital material. Despite variable proportions of these components, marine seston often exhibits relatively small deviations from the Redfield ratio (C:N:P = 106:16:1). Two time-series from the Norwegian shelf in Skagerrak are used to identify dr...

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Projects

Projects (5)
Project
- To study the spatial dynamics and temporal variations in bio-optical components as well as remote sensing reflectances in Norwegian coastal waters and Lakes - Changes in the light attenuation - Remote sesning water quality and status assessment applications for the water framework directive -Work towards operational services for water quality products based on remote sensing data
Project
Use existing monitoring infrastructure (WFD) to monitor effects of climate change.
Project
Project financed by the Research Council of Norway 2018-2021. The objective is to provide relevant and up-to-date information on water quality for users involved in water management in the Skagerrak and Oslofjord regions, based on model-data integration with a state-of-the-art coupled physical and biochemical models and monitoring programs for water quality in these waters, in support of ecosystem-based management of Norwegian fjords, coastal waters and seas.