Fredrik Gröndahl

KTH Royal Institute of Technology | KTH · Department of Sustainable Development, Environmental Science and Engineering

This study collates compositional analysis of seaweeds data with information generated from in vitro gas production assays in the presence and absence of seaweeds. The aim was to assess and rank 27 native northern European seaweeds as potential feed ingredients for use to reduce methane emissions from ruminants. It provides information for use in f...

The versatility of microalgae biomass as candidates for various products and bioremediation needs motivates interests towards design and implementation of novel microalgae bioreactors. Conventional open-reactors are reliant on large quantities of sunlight and space while yields are constrained by outdoor environment conditions. Conversely, closed-r...

Beach wrack of marine macrophytes is a natural component of many beaches. To test if such wrack emits the potent greenhouse gas methane, field measurements were made at different seasons on beach wrack depositions of different ages, exposure, and distance from the water. Methane emissions varied greatly, from 0 to 176 mg CH 4 -C m ⁻² day ⁻¹ , with...

This paper outlines challenges and opportunities in operating underwater robots (so-called AUVs) on a seaweed farm. The need is driven by an emerging aquaculture industry on the Swedish west coast where large-scale seaweed farms are being developed. In this paper, the operational challenges are described and key technologies in using autonomous sys...

The blooming of beach-cast seaweed has caused environmental degradation in some coastal regions. Therefore, a proper treating and utilizing method of beach-cast seaweed is demanded. This study investigated the potential of producing bio-oil from pyrolysis of beach-cast seaweed and the effect of the ash-washing process. First, the raw and ash-washed...

A study has been conducted to shed light on the effect of cultivation parameters on growth and chemical composition of Saccharina latissima. Longline cultivation took place at two separate locations in the Koster archipelago on the Swedish west coast, centred around three experiments that explored duration of pre-deployment hatchery processes (Exp...

Marine eutrophication is a pervasive and growing threat to global sustainability. Macroalgal cultivation is a promising circular economy solution to achieve nutrient reduction and food security. However, the location of production hotspots is not well known. In this paper the production potential of macroalgae of high commercial value was predicted...

Anthropogenic consumption of nitrogen (N) and phosphorus (P) has pushed their respective planetary boundaries beyond a safe operating space causing environmental problems, and simultaneously, the depletion of finite mineral P resources is of growing concern. Previous research has found that marine biomass such as kelp, reed and mussels have a high...

Harvesting beach-cast can help mitigate marine eutrophication by closing land-marine nutrient loops and provide a blue biomass raw material for the bioeconomy. Cost–benefit analysis was applied to harvest activities during 2009–2018 on the island of Gotland in the Baltic Sea, highlighting benefits such as nutrient removal from the marine system and...

Acceptance by, and cooperation with relevant stakeholders in developing new sustainability initiatives when they are generally perceived as positive, is one of the keys for successful implementation of such new sustainability initiatives later on. It is remarkable, however, that ample literature exists about involving stakeholders in research proje...

The chapter starts with a short overview of the LCA methodology, and how it can be used to quantify the environmental impacts of seaweed supply chains. The next section introduces the ‘Seafarm-LCA’ taken from Thomas et al. (2021) as a case study for illustrating the environmental impacts of the preserved seaweed supply chain. Figures are based on t...

A blue-green bioeconomy revolution is underway in Europe, with particular attention being paid to the development of new or underutilized marine biomass resources. The wild harvest and mariculture of low-trophic non-fed species of marine biomass may be contributing to circular economies, the mitigation of environmental problems such as eutrophicati...

Recurring summer cyanobacteria blooms in the Baltic Sea has gained academic interests for decades. The harvest of wild cyanobacteria, for example, Nodularia spumigena, during summer blooms in the Baltic Sea has been studied in the past but lacked evaluation for environmental and economic performances. This study provides a first-hand assessment of...

Laminarin is a low-molecular-weight polysaccharide found in seaweed (kelp), often in equal concentrations to that in the commercially important hydrocolloid alginate. However, while alginate can be easily recovered by dissolution followed by acid precipitation, for laminarin, there is no such straightforward way of recovering it. Laminarin can be u...

Harvesting of marine biomass for various applications may generate ecosystem services that currently lack a market price. One of these is nutrient uptake, which could counteract eutrophication. Market-based instruments (MBIs) such as cap & trade, compensatory mitigation, and payment for ecosystem services could help internalize such positive extern...

Seaweeds contain a myriad of nutrients and bioactives including proteins, carbohydrates and to a lesser extent lipids as well as small molecules including peptides, saponins, alkaloids and pigments. The bioactive bromoform found in the red seaweed Asparagopsis taxiformis has been identified as an agent that can reduce enteric CH4 production from li...

Seaweed cultivation and processing industries could contribute to sustainable blue growth and the European bioeconomy. This article contributes a case study evaluation of environmental sustainability of preserved brown seaweed Saccharina latissima by means of environmental life cycle assessment of a pilot facility in Sweden. The study accounts for...

Seaweed cultivation is a large industry worldwide, but production in Europe is small compared to production in Asian countries. In the EU, the motivations for seaweed farming may be seen from two perspectives; one being economic growth through biomass production and the other being the provisioning of ecosystem services such as mitigating eutrophic...

Special attention has been paid to sustainable macroalgae cultivation in Europe. The question on where suitable cultivation areas lie, without conflicting with current marine socio-economic activities and respecting the environment, remains a great challenge. Considering 13 criteria critical to seaweed farming such as depth, shipping traffic, and d...

Macroalgal mass blooms and accumulating beach-cast are increasing problems in many coastal areas. However, beach-cast is also a potentially valuable marine bioresource, e.g. as a biofertiliser in coastal agriculture. One limiting factor in use of beach-cast as a fertiliser is uncertainty regarding the cadmium (Cd) concentration depending on beach-c...

Seaweed cultivation attracts growing interest and sustainability assessments from various perspectives are needed. The paper presents a holistic qualitative assessment of ecosystem services affected by seaweed cultivation on the Swedish west coast. Results suggest that supporting, regulating and provisioning services are mainly positively or non-af...

A new approach to process Saccharina latissima algal biomass was developed using sodium citrate and a polyvalent cation-specific resin to sequentially extract the alginate into several usable fractions. The fractionation was performed in a cyclic manner, utilizing a stepwise removal of the native polyvalent ions present in the algae to isolate frac...

Seaweeds are presently explored as an alternative source to meet the future protein demand from a growing world population with an increasing welfare level. Present seaweed research largely focuses on agri-technical and economic aspects. This paper explores directions for optimizing the cultivation, harvesting, transport and drying of seaweed from...

Efforts are on the way on the Swedish West Coast to develop the capacity for cultivation of marine resources, notably of kelps. Given that this is a region of great natural and national heritage, public opposition to marine developments has been identified as a possible risk factor. This survey thus sought to shed light on awareness levels, percept...

Meeting human development needs and at the same time protecting the earth’s life support systems will require a transition away from fossil resources towards a bio-based economy. Cultivating marine algae constitutes a promising alternative to terrestrial crops for biomass production. It can provide the base for a biorefinery producing food, feed, b...

Eutrophication is one of the most serious global threats to coastal areas. One effect of eutrophication is seasonal macroalgal blooms. As a consequence, large amounts of beach-cast algae are today reported from coastal areas worldwide. In this study, we analyze nonmarket benefits by capturing local residents' Willingness To Pay (WTP) for an environ...

Eutrophication is one of the most serious global threats to coastal areas. One effect of eutrophication is seasonal macroalgal blooms. As a consequence, large amounts of beach-cast algae are today reported from coastal areas worldwide. In this study, we analyze nonmarket benefits by capturing local residents' Willingness To Pay (WTP) for an environ...

In this study we evaluate a project-based learning course called Applied Ecology, within the master program Sustainable Technology at the Division of Industrial Ecology, at KTH—Royal Institute of Technology in Stockholm, Sweden. The case study in the course is focused on the effects of a relatively large Bay, “Burgsviken”, situated on the island Go...

A turn to more sustainable resources has lead the research during the last decades to algae. Algae is a resource that has been utilized for thousands of years offering a variety of possibilities. Nevertheless modern technology were able to uncover algae’s great potential and pave the way for alternative uses such as biofuel and biomaterial producti...

Eutrophication combined with climate change has caused ephemeral filamentous macroalgae to increase and drifts of seaweed cover large areas of some Baltic Sea sites during summer. In ongoing projects, these mass occurrences of drifting filamentous macroalgae are being harvested to mitigate eutrophication, with preliminary results indicating conside...

Interest to harvest wild cyanobacteria exists due to the environmental and socioeconomic risks during cyanobacteria blooms coupled with demands for nonterrestrial-based alternatives for biofuel sources. This research, therefore, sought to estimate the wild cyanobacteria harvesting potential using Nodularia spumigena, and using the Baltic Sea as the...

Several ongoing projects are harvesting maritime biomass from the Baltic Sea for eutrophication mitigation and utilisation of the recovered biomass. Some of this biomass comprises common reed (Phragmites australis), one of the most widespread vascular plants on Earth. Reed utilisation from eutrophied coastal areas needs to be evaluated. Therefore,...

The interest in harvesting biomass from the Baltic Sea has increased in recent years. However, there is a lack of available data on macroalgae biomass and of cost-effective methods for site-specific quantification of macroalgae. In this study, macroalgae biomass has been quantified in Trelleborg and thus the nutrient reduction that could be achieve...

Providing electricity from renewable sources is of key importance both to reduce depletion of fossil fuels and reduce emissions of greenhouse gasses. Many of the renewable energy technologies are not ideal for electricity networks. Reservoir hydropower is most ideal as it can store energy efficiently, and can be made quickly available in cases of p...

This study evaluated the impact of socio-economic and lifestyle changes on nutrient loads and water quality in Haapsalu Bay, the Baltic Sea between 1995-1996 and 2003-2004. Monthly monitoring data of water quality in four rivers discharging to the bay and seawater at five sea stations were used. External input of TN to the bay remained almost uncha...

Eutrophication is a major threat to the Baltic Sea, causing algae blooms and hypoxic bottoms. Ecological engineering methods aiming at help mitigating the nutrient imbalance problems have already been initiated or are being planned in the coastal zones of the Baltic Sea. This includes harvesting of reed, macro algae and blue mussels as nutrient and...

Blooms of Cyanobacteria are a major concern during the summer period in the Baltic Sea Proper. The nitrogen-fixing Nodularia spumigena forms massive toxic blooms in the surface layers, with a concentration of biomass in the uppermost 1-m water layer. This pilot study describes the construction and test of a Nodularia collecting device during the su...

To inform the future practices to be employed for handling waste water and grey water at the Swedish Antarctic station, Wasa, in Dronning Maud Land, the Swedish Polar Research Secretariat took the initiative to survey the practices of the 28 nations with stations in Antarctica. A questionnaire was sent out to all members of the Antarctic Environmen...

During the years 1982 to 1986, the life cycles and population dynamics of three scyphozoans, Aurelia aurita (L.), Cyanea capillata (L.) and C. lamarckii (Person and Lesueur), were studied in the Gullmar Fjord on the Swedish west coast. The settling of planulae, strobilation of scyphistomae and release of ephyrae were followed on ceramic settling pl...

During the years 1926-29 Torsten Gislén pioneered quantitative investigations on hard-bottom epibioses in Gullmarsfjorden on the Swedish west coast using hard-hat diving equipment. At stations in the fjord previously studied by Gislen, series of transects on vertical rock walls were stereophotographed in 1986-87 to a depth of 30 m. The quantitative...

In an investigation carried out in the Gullmar Fjord, western Sweden, the autecology of the scyphozoans Aurelia aurita (L.) and Cyanea capillata (L.), has been studied. This paper focuses on results concerning C. capillata, but comparisons with Aurelia aurita are made and discussed. The main period of strobilation was in winter and early spring. Th...

The cosmopolitan scyphomedusa Aurelia aurita is the most common jellyfish in the coastal waters of Sweden. The effects on the pelagic ecosystem caused by predation, in connection with mass occurrences of Aurelia, are believed to be considerable. However, the causes behind the great variations in Aurelia abundance are not fully understood. In this p...

This paper describes field and laboratory observations on the relationship between a nudibranch gastropod (Coryphella verrucosa) and the development of populations of the scyphozoan Aurelia aurita.Predation tests showed that C. verrucosa ingests Aurelia polyps at a high rate (up to 200 polyps × d−1) and that this predation, which occurs mainly in O...

The occurrence and growth of Aurelia aurita were studied by means of field sampling with Bongonets from October 1982 until June 1983. By means of a rig with settling plates, placed at 10 m depth close to the sampling area, the settling of planulae, strobilation of scyphistomae and the release of ephyrae were followed. The abundance of ephyrae durin...