Risk mapping of harmful algal blooms in Norwegian ocean areas. Part 1 : Coast and ocean

Referring to known harmful algal blooms, a risk mapping of the most exposed areas along the Norwegian Coast has been made. The area Svenskegrensa -Lista seems to be most exposed, the risk being reduced moving further north. Vestfjorden differs from this general pattern and is characterized as an exposed area. The inner fjords are not treated in this report. In purpose of surveillance, attention should be drawn to species previously appearing in harmful blooms along the Norwegian Coast, genera of these and other known toxic algaes common in Norwegian waters without having caused problems so far. NORSK SAMMENDRAG: På bakgrunn av kunnskap om kjente oppblomstringer av skadelige/giftige planktonalger er det foretatt en vurdering av hvilke områder langs norskekysten som synes mest utsatt for slike fenomen og hvilke potensielt giftige arter som kan forventes å blomstre. Området Svenskegrensa - Lista ansees som mest utsatt, og deretter reduseres risikoen jo lengre nord i landet en kommer. Vestfjorden skiller seg ut fra dette generelle mønsteret og karakteriseres som et utsatt område. De indre fjordstrøkene behandles ikke i denne rapporten. I overvåkingsøyemed bør en være mest oppmerksom på arter som allerede har opptrådt i skadelige blomstringer langs norskekysten, slektninger av disse og andre kjente giftproduserende arter som er vanlig forekommende i norske farvann uten hittil å ha forårsaket problemer

Increased biological production in fiords by artificial upwelling

Our investigations show that artificial upwelling of nutrient rich waters in fiords, using a submerged fresh water discharge, have a potential to increase the algae production by a factor of 3-4 after the spring bloom and probably also reduce the occurrence of toxic flagellate algae. The Samnanger fiord is suitable as a natural laboratory for testing the effects of artificial upwelling on the biological productivity and increased growth of e.g. mussels and macro algae. In general, a large nurnber of Norwegian fiords can have increased biological production because of the availability of nutrient rich deep waters and fresh water sources suitable for submerging . NORSK SAMMENDRAG: Beregninger basert på observerte miljøforhold i Samnangerfjorden viser at primærproduksjonen etter vårblomstringen potensielt kan økes 3-4 ganger ved en ferskvannsdrevet kunstig oppstrømning av næringsrikt dypvann. Kunstig oppstrømning av dypvann vil trolig redusere forekomstene av giftige flagellatalger og bedre vekstforholdene for skjell og makroalger i fjorder. I fortsettelsen av prosjektet er det planlagt å etablere et forsøksanlegg for kunstig oppstrømning i Samnangerfjorden for å etterprøve resultatene i undersøkelsen

The importance of microbiota and terrestrial inflows in controlling seston C:N:P:O:Si:Ca:Mn:Mg:Fe:K:Na:Cl:S:Cu:Zn stoichiometry of a deep coastal fjord

Comprehensive fjord-systems represent major extensions of the coastline and are therefore important transfer zones of materials from land to ocean. Despite increased terrestrial inflows to fjords due to climate changes, we know little about the effects on the ecosystem, especially biogeochemical cycling. We present novel data on spatiotemporal variations of seston multielement stoichiometry in the Sognefjord, the second longest (204 km) and deepest (1308 m) fjord in the world, relative to environmental conditions and microbiota. Concentration of major elements was highest in the upper brackish layer whereas trace metals and minor elements were highest close to the bottom. Seasonally varying microbiota was an important part of the seston in surface waters. None of the seston C:N:P (molar) annual means at specific depths corresponded to the Redfield ratio (106:16:1). At 5 m, annual means of N/P and C/N were 8.4 and 6.5, respectively, while at depth (50–1220 m) N/P were on scale 3 times higher (21–31) and C/N 3 times lower (1.6–2.6), suggesting alternative N-sequestration mechanisms. Overall, correlations between C-Ca and C-S indicate a strong influence from calcite (CaCO3) and organosulfur producing microorganisms, while correlations between particulate Si and Mg–K–Ca–O at depth are consistent with clay and sinking diatom frustules. Mn concentrations increased strongly towards the bottom, likely from resuspension of MnO2 rich sediments and clay particles. Based on seston concentrations, we arrived at the following stoichiometric relationship: C55N16P1Si3.6Ca3.4O16Fe0.74Mn0.51Zn0.33S0.21Cu0.08Cl1.7Na0.68Mg0.71K0.37, although rarely measured, such information is a prerequisite for evaluating environmental impact on coastal ecosystems, biogeochemical cycling, pollution risk analysis and monitoring guidelines.publishedVersio

Comparing EPA production and fatty acid profiles of three Phaeodactylum tricornutum strains under western Norwegian climate conditions

Microalgae could provide a sustainable alternative to fish oil as a source for the omega-3 polyunsaturated fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). However, growing microalgae on a large-scale is still more cost-intensive than fish oil production, and outdoor productivities vary greatly with reactor type, geographic location, climate conditions and microalgae species or even strains. The diatom Phaeodactylum tricornutum has been intensively investigated for its potential in large-scale production, due to its robustness and comparatively high growth rates and EPA content. Yet, most research have been performed in southern countries and with a single commercial P. tricornutum strain, while information about productivities at higher latitudes and of local strains is scarce. We examined the potential of the climate conditions in Bergen, western Norway for outdoor cultivation of P. tricornutum in flat panel photobioreactors and cultivated three different strains simultaneously, one commercial strain from Spain (Fito) and two local isolates (M28 and B58), to assess and compare their biomass and EPA productivities, and fatty acid (FA) profiles. The three strains possessed similar biomass productivities (average volumetric productivities of 0.20, 0.18, and 0.21 g L− 1 d− 1), that were lower compared to productivities reported from southern latitudes. However, EPA productivities differed between the strains (average volumetric productivities of 9.8, 5.7 and 6.9 mg L− 1 d− 1), due to differing EPA contents (average of 4.4, 3.2 and 3.1% of dry weight), and were comparable to results from Italy. The EPA content of strain Fito of 4.4% is higher than earlier reported for P. tricornutum (2.6–3.1%) and was only apparent under outdoor conditions. A principal component analysis (PCA) of the relative FA composition revealed strain-specific profiles. However, including data from laboratory experiments, revealed more significant differences between outdoor and laboratory-grown cultures than between the strains, and higher EPA contents in outdoor grown cultures.publishedVersio

Linking bacterial community structure to advection and environmental impact along a coast-fjord gradient of the Sognefjord, western Norway

publishedVersio

Measurement and modeling of volume scattering functions for phytoplankton from Norwegian coastal waters

The volume scattering function (VSF) describes the angular distribution of scattered light, and the VSF of phytoplankton is one of the most important inherent optical properties of oceanic water. Despite its importance, relatively few measurements of the VSF have been carried out in aquatic environments, and we present here data and analyses of measured VSFs at 442, 490, and 550 nm for 15 representative phytoplankton species from Norwegian coastal waters. In addition, the analytic scattering phase functions Henyey-Greenstein (HG) and Fournier-Forand, as well as Mie theory, were fitted and compared to the measured VSFs. The measured VSFs for all the species were strongly, but unequally forward peaked with HG-fitted asymmetry factors in the range 0.897–0.988. The VSF of Synechococcus sp., Phaeodactylum tricornutum, and Emiliania huxleyi (naked) had shoulders in the forward direction, whereas the VSF of the cylindrically shaped Chaetoceros calcitrans and Chaetoceros wighamii had minima in the backward direction. Results from this work indicate that internal structures influence the angular and spectral shape of the VSF more significantly than the morphology and size of the phytoplankton cells

CDOM absorption properties of natural water bodies along extreme environmental gradients

We present absorption properties of colored dissolved organic matter (CDOM) sampled in six different water bodies along extreme altitudinal, latitudinal, and trophic state gradients. Three sites are in Norway: the mesotrophic Lysefjord (LF), Samnangerfjord (SF), and Røst Coastal Water (RCW); two sites are in China: the oligotrophic Lake Namtso (LN) and the eutrophic Bohai Sea (BS); and one site is in Uganda: the eutrophic Lake Victoria (LV). The site locations ranged from equatorial to subarctic regions, and they included water types from oligotrophic to eutrophic and altitudes from 0 m to 4700 m. The mean CDOM absorption coefficients at 440 nm [ a CDOM (440) aCDOM(440) ] and 320 nm [ a CDOM (320) aCDOM(320) ] varied in the ranges 0.063–0.35 m −1 −1 and 0.34–2.28 m −1 −1 , respectively, with highest values in LV, Uganda and the lowest in the high-altitude LN, Tibet. The mean spectral slopes S 280−500 S280−500 and S 350−500 S350−500 were found to vary in the ranges of 0.017–0.032 nm −1 −1 and 0.013–0.015 nm −1 −1 , respectively. The highest mean value for S 280−500 S280−500 as well as the lowest mean value for S 350−500 S350−500 were found in LN. Scatter plots of S 280−500 S280−500 versus a CDOM (440) aCDOM(440) and a CDOM (320) aCDOM(320) values ranges revealed a close connection between RCW, LF, and SF on one side, and BS and LV on the other side. CDOM seems to originate from terrestrial sources in LF, SF, BS, and LV, while RCW is characterized by autochthonous-oceanic CDOM, and LN by autochthonous CDOM. Photobleaching of CDOM is prominent in LN, demonstrated by absorption towards lower wavelengths in the UV spectrum. We conclude that high altitudes, implying high levels of UV radiation and oligotrophic water conditions are most important for making a significant change in CDOM absorption properties.publishedVersio

Kartlegging av potensielle områder for skadelige planktonalger i norske farvann, Del 1, Kyst og hav

Referring to known harmful algal blooms, a risk mapping of the most exposed areas along the Norwegian Coast has been made. The area Svenskegrensa -Lista seems to be most exposed, the risk being reduced moving further north. Vestfjorden differs from this general pattern and is characterized as an exposed area. The inner fjords are not treated in this report. In purpose of surveillance, attention should be drawn to species previously appearing in harmful blooms along the Norwegian Coast, genera of these and other known toxic algaes common in Norwegian waters without having caused problems so far. NORSK SAMMENDRAG: På bakgrunn av kunnskap om kjente oppblomstringer av skadelige/giftige planktonalger er det foretatt en vurdering av hvilke områder langs norskekysten som synes mest utsatt for slike fenomen og hvilke potensielt giftige arter som kan forventes å blomstre. Området Svenskegrensa - Lista ansees som mest utsatt, og deretter reduseres risikoen jo lengre nord i landet en kommer. Vestfjorden skiller seg ut fra dette generelle mønsteret og karakteriseres som et utsatt område. De indre fjordstrøkene behandles ikke i denne rapporten. I overvåkingsøyemed bør en være mest oppmerksom på arter som allerede har opptrådt i skadelige blomstringer langs norskekysten, slektninger av disse og andre kjente giftproduserende arter som er vanlig forekommende i norske farvann uten hittil å ha forårsaket problemer

Restoration of carrying capacity of mussel farming in fjords by use of artificial upwelling

Presented at International symposium on integrated coastal zone management, Arendal, Norway, 11-14 June 200

Primærproduksjonsforholdene i Ytre Oslofjord

Med bakgrunn i klorofyll og lysdata og ved hjelp av en enkelt algoritme, har den årlige primærproduksjonen i Ytre Oslofjord blitt beregnet til ca. 100 gC m-2. En sammeligning av årsproduksjoner basert på beregnede og målte dagsproduksjoner. viste at bruk av algoritmen førte til en underestimering av årsproduksjonen på mellom 10-30% i forhold til målt produksjon fra andre tilsvarende kystområder. Denne usikkerhet tatt i betrakning, ligger årsproduksjonen ved Ytre Oslofjord i samme størrelsorden som målte årsproduksjoner i andre upåvirkede fjord/pollsystemer langs norskekysten og litt under halvparten av produksjonen gitt for områder med lokale næringssalt tilførseler. Det ble også funnet høye bakgrunnsverdier for partikulært organisk karbon (POC) sammelignet med lite påvirkede områder. Disse høye POC verdier kunne ikke direkte knyttes til primærproduksjonen i området