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Quantitative fatty acid signature analysis reveals a high level of dietary specialization in killer whales across the North Atlantic
Get PDF1. Quantifying the diet composition of apex marine predators such as killer whales
(Orcinus orca) is critical to assessing their food web impacts. Yet, with few excep-
tions, the feeding ecology of these apex predators remains poorly understood.
2. Here, we use our newly validated quantitative fatty acid signature analysis
(QFASA) approach on nearly 200 killer whales and over 900 potential prey to
model their diets across the 5000 km span of the North Atlantic.
3. Diet estimates show that killer whales mainly consume other whales in the western
North Atlantic (Canadian Arctic, Eastern Canada), seals in the mid-North Atlantic
(Greenland), and fish in the eastern North Atlantic (Iceland, Faroe Islands, Norway).
Nonetheless, diet estimates also varied widely among individuals within most re-
gions. This level of inter-individual feeding variation should be considered for fu-
ture ecological studies focusing on killer whales in the North Atlantic and other
oceans.
4. These estimates reveal remarkable population- and individual-level variation in
the trophic ecology of these killer whales, which can help to assess how their pre-
dation impacts community and ecosystem dynamics in changing North Atlantic
marine ecosystems.
5. This new approach provides researchers with an invaluable tool to study the
feeding ecology of oceanic top predators.publishedVersio
Assessing sources and fractions of metals associated with environmental plastics: a case study in Lake Como (Italy)
No full textUnderstanding plastic–metal interactions is paramount to unveil the ecological risks of plastic pollution. Besides including a (variable) amount of metal-containing additives, plastic objects can adsorb metals on their surface in the environment. This work aims at measuring and assessing the possible origin of metals in environmental plastics deposited along the shores of Lake Como (Italy). Samples were characterized through Fourier-transformed infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and water contact angle. Then, the total metal load was analysed by acid digestion. Surface extraction with nitric acid was also performed to detect labile metals and a three-step extraction scheme enabled the determination of physisorbed, carbonate-bonded and organic matter-bonded metals, respectively. Eighteen metals (Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Sr, Ag, Cd, Sn, Ba, Pb and U) were analysed in total. Newly produced plastic items were also analysed as a reference. Our findings revealed that environmental samples retained a higher concentration of metals compared to virgin ones, especially in the loosely bonded acid-extractable fractions, indicating their potential bioavailability. The source of metals on plastics was extremely variable: some metals were predominantly sorbed from the environment (e.g., Mn and Pb), and others were mainly leached from the plastic matrix (Ba, Cu and Ti) or had a mixed origin (Zn, Fe, Sn, Sr and Al). This work shed light on the changes in bioavailability of metals induced by plastic environmental ageing, set baseline values for a freshwater site, and provided insights into the potential bioavailability exerted by metals associated with plastic litter.publishedVersio
Kartlegging av vannplanter og planteplankton i vannområde Leira-Nitelva i 2023
Get PDFProsjektleder: Kirstine ThiemerHensikten med prosjektet var å få gjennomført en ny tilstandsvurdering av 13 lokaliteter i vannområde Leira-Nitelva ved kartlegging av vannplanter på 11 lokaliteter og analyse av planteplankton på 4 lokaliteter. Nedre deler av Nitelva og Svellet var omkranset av store helofyttbestander, og alle tre kroksjøer var veldig gjengrodde. De turbide vannmassene (fra leirpartikler og algevekst) påvirker utbredelsen og artssammensetningen av vannplanter, som var dominert av flytebladplanter og undervannsplanter som tåler dårlige lysforhold. Små forekomster av kortskuddarter ble registrert på grunt vann eller i områder med noe bedre lysforhold. Økologisk tilstand for vannvegetasjonen basert på TIc-indeksen var dårlig eller svært dårlig på de fleste stasjonene, med unntak av Svellet, og N8 og N11 i Nitelva, som var i moderat tilstand. Hovedårsaken til for dårlig tilstand i kroksjøene antas å være næringstilførsler fra nærområdene, kombinert med liten vannutskiftning. Planteplanktonsamfunnet var variert i alle innsjøene. Økologisk tilstand basert på planteplankton var god for lokalitetene i Langvannet og Nordbytjernet, mens tilstanden i Mylla var svært god.Vannområde Leira-NitelvapublishedVersio
Screening of Tire-Derived Chemicals and Tire Wear Particles in a Road Tunnel Wash Water Treatment Basin
Get PDFRoad tunnels play a crucial role in modern road networks, in both urban and non-urban areas, and necessitate frequent cleaning and washing due to the harsh tunnel environment. As a result, road tunnels are considered hot spots for the emission of road-related pollutants into the environment. In this study, we conducted extensive measurements of tire wear particles (TWPs) and 18 tire-derived chemicals (TDCs) during the washing process, throughout a 21-day treatment period in a rectangular sedimentation basin in concrete, and during the discharge of treated wash water. Our key findings indicate that TWPs are effectively retained in the sedimentation basin, demonstrating that simple mitigation measures can prevent their release near the source. However, several TDCs displayed high concentrations, mobility, and leachability, leading to inadequate retention in the basin. Moreover, some TDCs exhibited negative treatment performance, resulting in higher concentrations in the treated wash water than in the untreated wash water. Importantly, our findings can be applied to not only tunnel wash water but also normal road runoff, as sedimentation basins are widely used in many countries. This study provides a novel and significant contribution to the evolving understanding of the presence and fate of TWPs and TDCs in the environment.publishedVersio
Temperature and prey density drive growth and otolith formation of the world's most valuable fish stock
Get PDFPeruvian anchovy (Engraulis ringens) represents the largest single-species fishery worldwide. Knowledge on how temperature and prey availability influences growth and age estimation during marine fish early life stages is critical for predicting bottom-up processes impacting stock productivity under changing environmental conditions. We reared Peruvian anchovy larvae at two temperatures (14.5 and 18.5 °C) and prey concentrations [high (HF), and low (LF)] from 6 to 30 days post-hatch (dph) to measure growth rate and examine daily deposition of otolith increments. Peruvian anchovy larvae grew faster at 18.5 °C compared to 14.5 °C. Larvae reared at low prey concentration (18.5-LF) and low temperature (14.5-HF) grew 61 and 35% slower, respectively, than those at high prey and warm temperature (18.5-HF). Age and growth rates of larvae were well depicted in the otolith microstructure of well-fed larvae at 18.5 °C. However, larvae reared at 18.5-LF or 14.5-HF, had only 55 and 49% of the expected number of daily otolith increments. Our results suggest caution when attempting to explore how ocean processes regulate small pelagic stocks, the productivity of which are largely driven by changes in the survival and growth of young larvae.publishedVersio
Monitoring of microplastics in the Norwegian environment (MIKRONOR)
Get PDFProsjektleder Vanja AllingIn 2021 The Norwegian Environment Agency (Miljødirektoratet) assigned the first analyses of microplastics within a national monitoring program “Microplastics in Norwegian coastal areas, rivers, lakes and air (MIKRONOR)” to NIVA. The aim of the program was to build knowledge about the background levels of microplastics in Norwegian environment, as well as identify potential sources and sinks. This is the second annual report, which presents the results from samples of 1) marine and lake/river sediments, biota and water, 2) air and deposition at two sites, including one at Svalbard, and 3) potential sources: urban runoff and effluent of wastewater treatment plants (WWTP) in two cities (Oslo and Hamar). The samples were analysed for microplastics, including tyre wear particles (TWP) from cars. The concentrations of plastic particles (mass of polymers per volume/weight unit) were calculated, using a novel formula for estimating volume of particles from the numerical analysis by spectroscopic (FTIR) analysis. The air samples were analysed for mass concentrations by mass spectrometric analysis. The main findings were the large number and concentrations of particles found in the inner Oslofjord. This included large numbers of microplastic particles resulting in high mass concentrations (μg/g dw) of plastic polymers. Particularly high mass concentrations of TWP were found in the sediments of the inner Oslofjord. TWP were also found at considerably high concentrations in blue mussels from the same area (Akershuskaia). Additionally, the urban runoff samples from both Oslo and Hamar showed high concentrations of TWP. High concentrations of TWP were also found in freshwater sediments near Hamar.Norwegian Environment AgencypublishedVersio
A global assessment of lake restoration in practice: New insights and future perspectives
Get PDFA global survey of 179 restoration practitioners spanning 65 countries identified the extent of stakeholder engagement as a key factor determining the success or failure of restoration projects. Lack of support across sectors and for funding, policy, monitoring, governance and knowledge assessment of pressures and their effects were most frequently cited as factors contributing to restoration failure. The responses indicate that, although nutrient enrichment is perceived to be the primary issue for lakes globally, the impacts of climate change, hydrological modifications and invasive species are widely recognized as pervasive anthropogenic pressures of global importance. Practitioners recognized that the ecosystem services most impacted by these pressures were recreation and tourism, although in low income countries the provisioning service, aquaculture, was considered most impacted. Ecology-based and/or pressure-related restoration targets had been set for most restoration programs in our survey. However, the strength of the evidence underpinning these targets was often weak and the effects of climate change were rarely considered when setting targets. The most effective and widely used restoration measures target nutrient loading (both catchment and in-lake) while hydrological modifications and the implementation of nature-based solutions are used to a lesser extent. Measures for the control of non-native invasive species are rarely applied and are viewed as being largely ineffective. The results of the survey provide direction for future work. New and emerging pressures, singly and in combination, may require new approaches to lake restoration: for both setting restoration targets and devising restoration strategies. The future of lake restoration depends on joined-up thinking that better integrates science into policy and practice and, most importantly, ensures strong and inclusive stakeholder engagement and collaboration across multiple sectors.publishedVersio
Handling of wild Atlantic salmon smolts reduced marine survival more than hydropower turbine passage
Get PDFAtlantic salmon smolts are sensitive to disturbance during their migration and negative effects experienced in freshwater may carry over into the marine environment. In this study, smolts were PIT-tagged and detected during their subsequent spawning migration. A generalized linear model fitted to the return data predicted a return probability of 0.091 ± 0.0061 (±SE) for smolt that was released downstream of a hydropower dam. The additional effect of migrating through a Kaplan turbine associated with hydroelectric generation did not significantly reduce return rates, while the additional effect of being handled twice in a trap was significant and lowered the predicted return probability to 0.057 ± 0.0079 (±SE; model predictions from logistic regression). Catch-mark-recapture methods such as those using physical recapture of fish should be applied with great care to avoid multiple handling stress that may lead to reduced marine survival and biasing estimates intended to help monitor population statuses. Moreover, similar return rates in turbine and bypass migrating smolts emphasize that more knowledge is needed when evaluating mitigation actions for migratory fish at hydropower plants.Handling of wild Atlantic salmon smolts reduced marine survival more than hydropower turbine passageacceptedVersio
Beslutningsmatrise for effektiv og skånsom rydding av ulike miljøer - Rapport fra forprosjekt
Get PDFProsjektleder: Jannike Falk-AnderssonProsjektet «Beslutningsmatrise for effektiv og skånsom rydding av ulike miljøer» har som mål å utvikle et kartbasert verktøy for å støtte beslutninger rundt rydding av makrosøppel i strandsonen. I dette forprosjektet har vi gjennomført en litteraturstudie for å identifisere relevante risikomatriser som beslutningsverktøyet kan bygge på, identifisert tilgjengelighet, kvalitet og relevans av kartdata i Norge, samt gjort en litteraturstudie for å kartlegge kunnskapsstatus på konsekvens av søppelgjenstander på organismer og habitat og negativ miljøpåvirkning av rydding. Vi har også vurdert hvordan verktøyet kan ta hensyn til mobile arter, samt hvordan det kan oppdateres med nye data, for eksempel tidligere ryddeaksjoner. I tillegg har vi beskrevet målgrupper og eksempler på bruk.Handelens MiljøfondpublishedVersio
Utredning om parametere for suspendert stoff og organisk materiale kan inkluderes i klassifiseringssystemet for vann
Get PDFProsjektleder: Øyvind KasteDet mangler per i dag vannkjemiske grenseverdier for suspenderte partikler og organisk materiale i klassifiseringssystemet for vann. Begge elementene var inkludert i klassifiseringsveilederen fra 1997, men i dag brukes parameterne kun til å bestemme vanntype. Forvaltningen ønsker derfor en ny vurdering av om parametere for partikler og organisk materiale igjen kan innarbeides i systemet slik at en får et nytt verktøy for å vurdere effektene av antropogene utslipp. Rapporten utreder mulighetene for dette basert på analyser av eksisterende data, hovedsakelig hentet fra vannforvaltningens database Vannmiljø. Det er også gitt en omtale av de viktigste effektene av partikler og organisk stoff på biota, samt noen anbefalinger knyttet til metodikk for overvåking av partikler og organisk materiale i vann.MiljødirektoratetpublishedVersio