Nordic Blue Carbon https://nordicbluecarbon.no Sat, 05 Oct 2019 14:24:50 +0000 en-US hourly 1 https://wordpress.org/?v=5.5.1 Save the date: Norwegian Blue Forests Forum https://nordicbluecarbon.no/index.php/2019/08/12/save-the-date-norwegian-blue-forests-forum/ https://nordicbluecarbon.no/index.php/2019/08/12/save-the-date-norwegian-blue-forests-forum/#comments_reply Mon, 12 Aug 2019 08:03:14 +0000 http://nordicbluecarbon.no/?p=381 We are excited to announce the dates for this year’s event organized by the Norwegian Blue Forests Network.

When: Spring 2020

Where: Oslo, Norway (Venue TBC)

What: An arena to stimulate knowledge-exchange and discussions for a knowledge-based and future oriented management of blue forests both nationally and internationally.

Do you work with these ecosystems and want to be part of our discussions? Wait no more! Send us an email at nbfn@grida.no to register your interest.

 

Originally posted at: https://nbfn.no/2019/08/save-the-date-norwegian-blue-forests-forum/

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Blått karbon – En fagkveld om taredyrking og karbonlagring https://nordicbluecarbon.no/index.php/2019/05/08/blatt-karbon-en-fagkveld-om-taredyrking-og-karbonlagring/ https://nordicbluecarbon.no/index.php/2019/05/08/blatt-karbon-en-fagkveld-om-taredyrking-og-karbonlagring/#comments_reply Wed, 08 May 2019 10:25:20 +0000 http://nordicbluecarbon.no/?p=385 Tekna Havbruk og fiskehelse

Bli med på et faglig dypdykk om taredyrking og karbonlagring!

Taredyrking pekes på en som en av vekstnæringen i havbrukbransjen, men kan taredyrking også bidra til at Norge reduserer sine klimagassutslipp? Med storskalaproduksjon av rasktvoksende tare i høyproduktive havområder ligger det et stort potensiale til å fjerne klimagassutslipp fra atmosfæren. Bli med på fagkveld med Tekna Havbruk og fiskehelse, Tekna Klima og SINTEF OCEAN å lær mer om taredyrking og blått karbon!

Program:

Jorunn Skjermo fra SINTEF Ocean skal fortelle om forskningsprosjektet MACROSEA som er inne i sitt siste år. – MACROSEA har som mål å etablere en tverrfaglig kunnskapsplattform for industriell dyrking av makroalger under en rekke klimatiske, økologiske og fysiske forhold.

Kasper Hancke er senior forsker på NIVA i seksjon for marinbiologi, og utdannet innen biologisk oseanografi (PhD, NTNU, 2007). Han har spesialkompetanse innen mikro- og makroalgers rolle i marine økosystemer, og hvordan disse regulerer omsetning og transport av energi og karbon i næringsnettet.

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Arbeidsmøte i Granada om makroalgenes rolle i det globale karbonbudsjettet https://nordicbluecarbon.no/index.php/2019/05/07/arbeidsmote-i-granada-om-makroalgenes-rolle-i-det-globale-karbonbudsjettet/ https://nordicbluecarbon.no/index.php/2019/05/07/arbeidsmote-i-granada-om-makroalgenes-rolle-i-det-globale-karbonbudsjettet/#comments_reply Tue, 07 May 2019 07:53:47 +0000 http://nordicbluecarbon.no/?p=375 I tre intense dager var 16 forskere fra Europa, Australia og USA samlet i Granada for å diskutere makroalgenes rolle i det globale karbonbudsjettet. Fra Blå skog-nettverket stilte NIVAs Kasper Hancke og Hege Gundersen, samt Karen Filbee-Dexter fra HI. Det hele var ledet av Carlos Duarte og Dorte Krause-Jensen – også kjent som forfatterne av Nature-artikkelen fra 2016 som for første gang antydet at verdens makroalger potensielt lagrer like mye karbon som de andre blå skogtypene til sammen! Med utsikt til historiske Alhambra (se bildet) satt vi samlet og delte kunnskap om tareskoger og andre makroalgers utbredelse og produksjon, eksport til andre økosystemer, og endelige skjebne. «Estimates and guestimates» på rater og størrelser ble sent gjennom rommet og inn i et felles Google-dokument. Der vi ikke visste svaret måtte vi søke i litteraturen, og der vi ikke fant svar må vi forske videre! Vel hjemme igjen, jobbes det med å fullføre artiklene – og med denne produktive gjengen i arbeid, er det forventet å fullføre flere publikasjoner i løpet av året. Dermed er mange nye biter lagt i puslespillet om tarens og andre makroalgers rolle i karbonkretsløpet, og med det dets rolle i klimaregnskapet!

Originally posted at: https://nbfn.no/2019/05/arbeidsmote-i-granada-om-makroalgenes-rolle-i-det-globale-karbonbudsjettet/ 

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Burial of kelp carbon in deep water sediments in Frohavet https://nordicbluecarbon.no/index.php/2018/11/20/burial-of-kelp-carbon-in-deep-water-sediments-in-frohavet/ https://nordicbluecarbon.no/index.php/2018/11/20/burial-of-kelp-carbon-in-deep-water-sediments-in-frohavet/#comments_reply Tue, 20 Nov 2018 10:47:02 +0000 http://nordicbluecarbon.no/?p=388 This task has been executed by Kasper Hancke, Gunhild Borgersen, Anders Ruus and Marc Anglès d’Auriac at NIVA. The Nordic Blue Carbon (“Blått-karbon”) project was co-funded by The Norwegian Network for Blue Forests (NBFN.no) to increase the initial sample size of three to five sediment cores, thus being able to investigate carbon burial in a depth gradient from 300 down to 500 m. A field campaign was carried out 16-17. October 2018 at Frohavet in Trøndelag – an area assumed to have high kelp deposition rates. The sediment cores have been sliced, dated and analysed for different parameters to estimate the decomposition rate of organic carbon. Parameters analysed are contents of total of organic carbon (TOC) and chlorophyll, as well as different methods to identify source of carbon, such as genetic markers (DNA), lipids and stable isotopes. A manuscript on the degradation rates and long-term storage of kelp organic matter in Norwegian sediments is planned and assumed to be submitted to a peer review scientific journal by the end of the year.

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How Nordic marine forests can help fight climate change https://nordicbluecarbon.no/index.php/2018/09/20/how-nordic-marine-forests-can-help-fight-climate-change/ https://nordicbluecarbon.no/index.php/2018/09/20/how-nordic-marine-forests-can-help-fight-climate-change/#comments_reply Thu, 20 Sep 2018 06:43:10 +0000 http://nordicbluecarbon.no/?p=365 Despite the wealth of marine forests throughout the Nordics, we are yet to exploit their potential role in combating climate change. Here’s what we need to do.

Research suggests that are many reasons to fall in love with marine forests, even the seaweed that gets wrapped around your feet when taking a dip in the sea. In our previous article we explored how marine forests such as kelp and eelgrass provide a two-pronged approach to help combat climate change by soaking up CO2 from the atmosphere and locking it away at the seabed, so-called Blue Carbon. We also showed how they can help adapt to sea level rise, reduce coastal flooding and create oases of high pH. A number of governments around the world have already taken the first steps to mitigate and adapt to climate change by conserving and restoring marine forests. But remarkably, despite the wealth of marine forests throughout the Nordics, we are yet to fully explore these “Blue Carbon Strategies” and exploit its potential role in combating climate change. Fortunately, this is starting to change, but we still have quite a way to go. Here’s how we can get there.

Untapped potential of Blue Carbon in the Nordics

Despite the clear abundance of marine forests in the Nordics, their potential to store Blue Carbon has not yet been quantified. For this, we need to know the precise area, amount of biomass, and capacity for carbon burial which are all poorly resolved. The ‘best estimate’ for Blue Carbon stocks in the Nordics is that of eelgrass, which has been quantified for deep and shallow meadows of Denmark, shallow meadows of Finland and for a shallow meadow in Greenland. The carbon stocks at the seafloor below the widespread Danish eelgrass meadows are estimated to represent about 5.868 Mega tons (i.e. million tons) of carbon. In Finland, this is much smaller, about 0.019 Mega tons. Unfortunately, there are as yet no estimates for the Blue Carbon potential in Nordic kelp forests. Although modeling suggests that kelp forests in Norway have a biomass of nearly 80 million tons, taking up 30 million tons CO2 from the atmosphere each year. Even if just 10 per cent of this is eventually locked away as Blue Carbon, these forests represent a large potential carbon sink by anyone’s standards!

First step: Good estimates of marine forests

It’s clear that we need better information about the true extent of marine forests and their contribution to carbon burial: Not least because this is a necessary step for establishing a standard methodology to include Blue Carbon in national inventories of greenhouse gas emissions.

Specifically, for marine forests to be included in national inventories in a legally binding way, the carbon captured by these forests must be “accountable” and “actionable.”

This means that we need to know:

  1. the full extent of marine forests in our Nordic areas and around the world
  2. present solid documentation of their carbon sink capacity
  3. show that the sinks can be managed by specific actions to control the amount of carbon stored.

Only then, can we manage marine forests and potentially include Nordic Blue Carbon in our national carbon reporting. For macroalgal and kelp forests, this task is particularly demanding as they export carbon to sinks far away from the forests, which require novel fingerprinting techniques to detect and attribute the carbon stocks they support.

Blue Carbon is already a part of the Paris Agreement

The first step towards this came in 2013, when the UN International Panel on Climate Change issued guidelines for how this might be done for wetlands, including seagrasses, tidal marshes, and mangroves. But it did not include kelps and other macroalgae, as it only recently became clear that they may be a substantial Blue Carbon store. So far, 29 nations, including Iceland and a number of tropical countries, have included Blue Carbon in their nationally determined contributions for mitigating climate change under the Paris Agreement. While about 60 nations have included Blue Carbon under their adaptation actions. This is supported by the “Blue Carbon Partnership”, which supports nations in developing national objectives to address climate change using Blue Carbon strategies, and the “Blue Carbon Initiative,” which is coordinating two international working groups to advise on the research that is still needed, as well as project implementation, and policy priorities.

Pan-Nordic projects are now under way

Meanwhile, the first Nordic initiatives are under way to fill the Blue Carbon knowledge gaps in the North. For example, in Denmark, the Villum Foundation has funded the project “Marine Forests” (“Havets Skove”). This is a one-year collaboration between the University of Southern Denmark, Aarhus University, the Geological Survey of Denmark and Greenland, and the Danish Technical University (DTU-Aqua), which aims to provide an initial quantification of the area of Danish marine forests and their associated ecosystem services, including Blue Carbon. And the Independent Research Fund Denmark has funded the project CARMA: CARbon sequestration by Greenland’s MArine forests in a warming Arctic – a 3-year project starting 1. December 2018 with the aim of exploring the role of Arctic kelp forests in carbon sequestration. The project is led by Department of Bioscience and the Arctic Research Centre at Aarhus University.In Norway the three-year project, “Blue Carbon” (Blått karbon, 2017-19) has been funded by the Norwegian Environment Agency, through the Nordic Council of Ministers. The project is lead by the Norwegian Institute for Water Research (NIVA), in collaboration with Institute of Marine Research and GRID-Arendal, Norway, Aarhus University in Denmark, Åbo Akademi University in Finland, and the University of Gothenburg, Sweden. This project will provide an updated overview of the carbon cycle of blue forests, including kelp, eelgrass, and rockweed in the Nordic countries. This project will also provide a knowledge basis for evaluating the potential for including kelp carbon in national carbon reporting, following IPCC Guidelines for National Greenhouse Gas inventories. Hopefully, these are the first of many initiatives in a long-term effort to quantify the role of Nordic marine forests in the fight against climate change. Sustainable management of these important ecosystems, which are particularly widespread along the shores of Nordic nations, could be an important step to both adapt to, and mitigate, climate change.

Originally posted at: https://sciencenordic.com/climate-change-climate-solutions-denmark/how-nordic-marine-forests-can-help-fight-climate-change/1458309

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Marine forests – Nature’s own carbon capture and storage https://nordicbluecarbon.no/index.php/2018/09/18/marine-forests-natures-own-carbon-capture-and-storage/ https://nordicbluecarbon.no/index.php/2018/09/18/marine-forests-natures-own-carbon-capture-and-storage/#comments_reply Tue, 18 Sep 2018 07:02:18 +0000 http://nordicbluecarbon.no/?p=372 Kelp forests and seagrass meadows soak up carbon dioxide and help protect our coasts against rising seas. Just two reasons why we should learn to love our marine forests.

Marine forests are really something rather special, and we don’t just say that because we all study them. They consist of kelps that grow on rocky shores and seagrass meadows, saltmarsh, and mangroves on stretches of sandy seafloor. They are widespread in shallow waters across the globe where they are home to a wide variety of creatures including cod and many other fish. But what also makes them so special is their two-pronged approach to help combat climate change. Research has shown that not only do they capture carbon dioxide (CO2) from the atmosphere and lock it away as “Blue Carbon” in the ocean, they can also help us to adapt to some of the impacts of climate change, including sea level rise, coastal flooding and ocean acidification. Here’s why we should all learn to love our marine forests.

Marine forests remove CO2 from the atmosphere

Lets first consider how these marine forests soak up carbon dioxide. Over the past decade, scientists have become increasingly aware that marine forests play a role in global carbon sequestration, that is the ability to extract CO2 from the atmosphere and lock it away at the ocean floor as “Blue Carbon”. Most research has focussed on seagrasses (check out the gallery above to see a photo of a seagrass meadow), saltmarsh, and mangroves, which grow on soft seafloor in shallow coastal habitats around the globe (see map below). These plants trap their own leaf fall and dead roots, which gradually accumulate on the seafloor beneath. They also trap and store carbon-containing particles from the water. This is what we refer to as a “carbon sink.”

In fact the carbon sinks that form beneath these marine forests store just as much carbon as forests on land and accumulate at a much faster rate.

Kelp: a previously overlooked contributor to Blue Carbon

Kelp is another, often overlooked, type of marine forest. By contrast, forests of kelps and other large algae (macroalgae) grow on rocks and stones. Here, material does not accumulate directly on the seabed beneath them and so it was generally assumed that macroalgae did not support any carbon sinks. This is despite the fact that they form the most widespread and productive marine forests in the global coastal ocean, estimated to cover about 3.4 million square kilometres (see the map below). However, research shows that ocean currents transport much of the “leaf fall” of macroalgae away from the forests, and our research published in Nature Geoscience shows that part of this is then locked away in carbon sinks elsewhere, often in the deep ocean. You can see an animation of this process in the interactive graphic above. We now know that these previously overlooked carbon sinks could be vast. We recently calculated that export of carbon from macroalgal forests may lock away around 173 Teragrams of carbon each year. That’s the same amount of carbon locked away by seagrasses, saltmarsh, and mangroves combined! This is not yet a precise estimate, as we don’t know the full distribution of kelp and macroalgal forests around the world, and we still need to better quantify the amount of carbon that they take up, release, and ultimately store away. But what is clear, is that macroalgae are indeed important, if thus far neglected, players in a Blue Carbon context.

The vast Nordic marine forests

Larger marine forests store more carbon. And so the extensive coastlines of the Nordic countries, which are dominated by eelgrass meadows in soft-sediment areas and kelp forests along rocky shores, form important carbon sinks. But still we do not know their magnitude. Danish coastal waters are a particular hot spot of eelgrass, which thrive in the large shallow and gently sloping soft sediments. Eelgrass extends along most of Denmark’s 7,300 kilometre long coastline and is estimated to cover up to 1,345 square kilometres. In fact, the only area where it doesn’t grow is the exposed North Sea coast. Eelgrass also occurs along the Baltic Sea coastline all the way to the Finnish archipelago. Small populations occur in sheltered sandy areas along the coast of Norway, Iceland, and southern Greenland. The Nordic countries are also home to a large fraction of the world’s kelp forests. The rocky coastlines of Norway, Greenland, Iceland, and the Faroe Islands, represents roughly 20 per cent of the global coastlines, which all represent potential areas for kelp to thrive. However, the actual area covered by kelp in these regions remains to be discovered. Finland and the east coast of Sweden have no kelp forests due to the low salinity of the Baltic Sea, but other macroalgal species, such as rockweed, thrive under those conditions. Nordic saltmarsh areas are also yet to be quantified.

The global distribution of marine forests around the world. (Map: Lærke Rosenberg / ScienceNordic. Kelp distribution from Filbee-Dexter and Wernberg, 2018. Mangroves, salt marsh, and seagrass distributions from The Blue Carbon Initiative).

Marine forests and climate change adaptation

So far we have discussed how marine forests can trap and store carbon, thus mitigating climate change. But marine forests also serve in climate change adaptation through three important functions:

  • Providing natural coastal protection against storms.
  • Elevating the seafloor to protect against sea level rise.
  • Creating high pH oases in an acidified ocean.

Both seagrass meadows and kelp forests deliver coastal protection by attenuating waves along the coast. Seagrasses provide further protection by trapping particles and building up sediment at the seafloor, which are then stabilised by their underground structures of roots and rhizomes.  The formation of such Blue Carbon sediments gradually elevates the seafloor, thereby counteracting sea level rise.

Seagrasses, as well as forests of kelps and other macroalgae, also have the capacity to create oases of high pH during the productive summer period, offering protection to organisms with carbonate shells, including mussels, snails and shrimps, from increasingly acidic oceans.

Marine forests: a refuge in an acidic ocean

Ocean acidification is a well-known side effect of climate change, whereby the oceans become more acidic (lower pH) as they soak up CO2 from the atmosphere. Our research shows that intense photosynthesis of marine forests extracts CO2 from the water and thereby form refuges from the general increase in CO2 that leads to ocean acidification. During the night, the opposite happens as the forests respire CO2 and thereby reduce pH. However, some calcifying organisms are able to benefit from the fluctuations in pH created by marine forests by producing their carbonate shells during the daytime.

In our research, we observed these high-pH oases in Nordic marine forests in the Disko Bay, Greenland, where the long summer days make this effect prevalent during spring and summer, which is the most critical period for calcifying organisms in terms of growth and reproduction.

So what now?

All of this goes to show that there are many reasons to protect and expand marine forests. And it is clear that they represent a vast, though as yet, poorly quantified resource in the Nordic countries, with significant hot spots of eelgrass in Denmark and extensive kelp forests along rocky shorelines that extend into the Arctic. These forests most likely store large amounts of carbon, but the question is, how much? And how can they help us combat climate change in practice?

 

Originally posted at: https://sciencenordic.com/climate-change-climate-solutions-denmark/marine-forests—natures-own-carbon-capture-and-storage/1458305 

 

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Workshop on the status of Nordic carbon cycling in Blue Forests https://nordicbluecarbon.no/index.php/2018/04/20/workshop-on-the-status-of-nordic-carbon-cycling-in-blue-forests/ Fri, 20 Apr 2018 10:00:09 +0000 http://totaltheme.wpengine.com/boxed-folio/?p=40  

The Nordic Blue Carbon project aims to make an updated overview of carbon cycles of kelp, eelgrass and rockweed in Nordic marine waters. 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.

Blått-karbon prosjektet har til hensikt å lage en oppdatert oversikt over karbonkretsløp i blå skog (her: tare, ålegras og tang) i de nordiske landene. Rapporten presenterer foreløpige resultater og fremdrift i prosjektet Blått-karbon som startet opp høsten 2017. Rapporten gir i tillegg et sammendrag av presentasjoner og diskusjoner på workshopen «Status of knowledge for Nordic carbon cycling in blue forest» 16. – 17. November 2017.

Permanent link
http://hdl.handle.net/11250/2478099

Issue date: 2017, Publisher: Norsk institutt for vannforskning, Series: NIVA-rapport;7213, Miljødirektoratet-rapport;M-904/2017, Copyright: Norsk institutt for vannforskning / Norwegian Institute for Water Research

 

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Et surere hav får denne taren til å vokse https://nordicbluecarbon.no/index.php/2018/04/10/et-surere-hav-far-denne-taren-til-a-vokse/ Tue, 10 Apr 2018 16:36:16 +0000 http://nordicbluecarbon.no/?p=332 Havforsuring påvirker planter og dyr i sjøen på ulike måter. Nå viser det seg at vår vanligste tare faktisk vil kunne trives godt i et surere hav.

I det moderne samfunnet vårt slipper vi ut store mengder CO2 til atmosfæren. Utslippene fører til at nivåene øker både i atmosfæren og sjøen, og høyere nivåer av CO2 i havvann betyr lavere pH i sjøen. Det er dette som gjør at vannet langs kysten blir surere, og prosessen kalles havforsuring. Så langt har de fleste studier vist at havforsuring påvirker marine arter og økosystemer i negativ retning, spesielt for organismer som koraller og skalldyr. Nå har forskere ved Norsk institutt for vannforskning (NIVA) testet effekten av høyere CO2-nivåer på en av Norges vanligste tarearter, sukkertaren (Saccharina latissima). Og det viser seg at havsuringen faktisk får taren til å vokse.

Bra for fotosyntesen

– Den stadige økningen av CO2 i atmosfæren, med påfølgende pH-reduksjon i havene, er påfallende. Havforsuringen har blitt pekt på som den nest mest dramatiske faktoren som påvirker livet i havet, etter stigende vanntemperatur, sier Kasper Hancke, marinbiolog og seniorforsker ved NIVA.

– Imidlertid tar tare og andre alger opp CO2 i forbindelse med fotosyntesen og bruker karbonet i kombinasjon med sollys og næringsstoffer, til å vokse – akkurat som planter på land. Dette indikerer at en økning av CO2 i havet teoretisk sett kunne stimulere vekst til tare og andre alger, forklarer Hancke.

Forskernes foreløpige funn støtter denne hypotesen: Da forskerne reduserte pH-nivåene like mye som IPCCs (Intergovernmental Panel on Climate Change) har varslet at nivåene vil være i 2030, vokste taren fortere.

– Dette betyr at taren ser ut til å vokse fortere med høyere nivåer av CO2 i kystvannet. Den samlede effekten av klimaendringer på tareskogen vil imidlertid være en blanding av positive og negative påvirkninger. Dette gjør det vanskelig å forutse nettoendringen, men sannsynligvis vil havene både se annerledes ut og fungere på en annen måte i fremtiden, legger NIVA-forskeren til.

Råtnende planter gir mørkere hav

Høyere CO2-nivåer er imidlertid ikke den eneste effekten på havet vi kan forvente å se av endringer i klimaet. Klimaendringene vil sannsynligvis også føre til mer regn i tempererte områder, og kombinert med andre faktorer, kan dette føre til at mer organisk materiale finner veien til havet via bekker og elver.

– Avrenning fra elver til norske kystvann har doblet seg i løpet av de siste tretti årene enkelte steder, og nyere forskning tilsier at denne mengden vil fortsette å øke med mer enn én prosent i året, sier Hancke.

Han forklarer at elveavrenning inneholder mye organisk materiale, dels fra råtnende planter, som kan stamme fra for eksempel jordbruk eller gammelt løv. En fraksjon av dette materialet kaller forskerne CDOM, eller Coloured Dissolved Organic Matter på engelsk, og den fører til at elvevann blir gulere.

– Når det gule vannet når havet, blir vannet i kystområdene mørkere. Da vil mindre sollys slippe ned til taren og andre alger som står på bunnen og av avhengige av sollys til fotosyntesen for å vokse.

Både lys og surhet vil påvirke taren

Siden tare er avhengig av både sollys og CO2 for å vokse, understreker Hancke og forskergruppen hans hvor viktig det er at begge disse faktorene tas med i beregningene av hvordan tare kan påvirkes av klimaendringer. Forskerne undersøkte derfor den samlede effekten av surere vann og dårligere lysforhold på tare ved å dyrke dem ved ulike nivåer av surhet og organisk materiale. Resultatet viste at mindre lys alene ikke forårsaket noen vesentlig reduksjon i veksten ved dagens pH-nivå, men forskerne fant en nevneverdig gjensidig påvirkning mellom de to stressfaktorene.

– I testtankene hvor vi kombinerte surere vann med mindre lys på grunn av tilsatt organisk materiale, så vi at taren vokste mindre, forteller Hancke.

– Dette betyr at en positiv effekt av havforsuring på tarevekst kan bli motvirket av mørkere vann, hvis det mest sannsynlige fremtidsscenariet for klimaendringer slår til i kystområdene våre.

 

Originally posted at https://forskning.no/2018/04/vil-klimaendringene-positivt-pa-norske-tareskoger/produsert-og-finansiert-av/norsk-institutt-for-vannforskning

 

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Will climate change affect Norwegian kelp forests in a positive way? https://nordicbluecarbon.no/index.php/2018/02/24/will-climate-change-affect-norwegian-kelp-forests-in-a-positive-way/ Sat, 24 Feb 2018 16:35:59 +0000 http://nordicbluecarbon.no/?p=331 Climate change, including acidification of the oceans, will likely affect many of the plants and animals in our sea and oceans. Fresh research results indicate that kelp could be favoured by some of the changes.

Large amounts of carbon dioxide (CO2) are being released into the atmosphere by the modern world. The emissions cause the atmosphere and oceans’ CO2 levels to increase, and since higher levels of CO2 means lower pH in water, coastal waters turn more acidic. This process is called ocean acidification. So far, most studies show negative impacts of ocean acidification on marine species and ecosystems, particularly on calcifying organisms such as corals and shellfish. In a new study, researchers at the Norwegian Institute for Water Research (NIVA) have tested the effect of increased CO2 levels on one of Norway’s most common kelp species, the sugar kelp (Saccharina latissima). “The on-going increase in CO2 in the atmosphere, and the following reduction of pH in seas and oceans, are pronounced and have been pointed out as the second most dramatic factor influencing ocean life after increasing water temperature,” says Kasper Hancke, marine biologist and senior researcher at NIVA. “However, kelp and seaweeds take up CO2 as part of their photosynthesis and use the carbon, in combination with sunlight and nutrients, to grow – just like plants on land. This implies that an increase of CO2 in the ocean theoretically could stimulate higher growth of kelp and seaweeds,” Hancke explains. The researchers’ preliminary findings support this hypothesis, as the results showed that reduced pH levels relative to the IPCC (Intergovernmental Panel on Climate Change) forecast for year 2050 significantly increased the growth rate of sugar kelp.  “This means that with elevated CO2 in the atmosphere and coastal water, kelp will likely grow faster. The overall response of climate change on kelp forests however, will be a combination of positive and negative responses. This makes the net change difficult to forecast, but likely will the oceans look and function differently in the future,” Hancke adds.

Darker oceans counteract the positive effect

Increasing levels of CO2 is however not the only expected effect on the ocean brought by climate change. The changing climate is also predicted to increase rainfall in temperate regions. Combined with other factors, this could result in more organic matter finding its way to the coastal ocean via streams and rivers. “The input of river runoff into the Norwegian coastal waters has doubled during the last 30 years in some regions and predictions are that this amount will keep increasing with more than 1% per year,” says Hancke. He explains that river-runoff contains a lot of organic matter, partly from decomposed plants, which can come from agriculture or leaf deposits. This matter is called Coloured Dissolved Organic Matter (CDOM) and makes the colour of river water turn yellow.  When the yellow water reaches the ocean, it darkens the water in coastal areas and attenuates the available sunlight that is used for photosynthesis by kelp and other algae”. Seeing that kelp is dependent on both sunlight and CO2 to grow, Hancke and his research team emphasises the necessity to take both these factors into account to understand how kelp might be affected by the changing climate. The researchers therefore investigated the combined effect of more acidic water and reduced light conditions on kelp by growing them at different levels of pH and CDOM. Although reduced light levels alone did not cause any significant reduction in the growth at present day pH level, they found a significant interaction between the two stressors. “In the test tanks where more acidic water and lower light from increased levels of organic matter were combined, we saw that the kelp grew less,” says Hancke. “This means that a positive impact of ocean acidification on kelp growth could be counteracted by coastal darkening, if the most likely future scenario of climate change impact on our coastal waters occurs.”

The study

For this study, small sugar kelp plants were sampled from the Oslofjord (Norway) and put into nine different treatment tanks. To study the effect of ocean acidification, the researchers tested three different levels of CO2: present day levels and predicted levels of CO2 to be found 50 and 100 years into the future according to leading climate prediction models (IPCC). In a similar manner, three levels of CDOM were mimicked in mesocosms incubation tanks by reducing the level and quality of light that would be caused by increased CDOM. The researchers measured growth and photosynthetic activity in six to nine kelp plants within each tank, every four days for two months, to analyse for any differences between the plants exposed to the various water qualities.

Originally posted at http://sciencenordic.com/will-climate-change-affect-norwegian-kelp-forests-positive-way

 

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Interview at NRK Radio- Ekko https://nordicbluecarbon.no/index.php/2017/09/12/interview-at-nrk-radio-ekko/ Tue, 12 Sep 2017 17:17:02 +0000 http://nordicbluecarbon.no/?p=349 On Wednesday 11th September, Hartvig Christie and Hege Gundersen were interviewed at NRK Ekko about the status of kelp forests in Norway and the role of blue forests in carbon uptake.

Kelp forests along the Norwegian coast are slowly growing back after more than forty years of absence due to sea urchin grazing. This is good news for the thousands of species living in these forests, but also for the global climate, since kelp forests are assumed to be major carbon sinks. Recent research predicts that kelp forests store even more carbon than other green forests, like tropical rainforests, and blue forests, like mangroves and seagrasses.

The interview can be found here.

 

Originally posted at https://nbfn.no/2017/09/interview-nrk-radio-ekko/

 

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