Forslag til metode for kartlegging av korall og svamp ved nye akvakulturanlegg - Kunnskapsleveranse til Fiskeridirektoratet

Denne rapporten er en del-leveranse av bestilling på «Kunnskapsstøtte til forvaltning av svamper og koraller» der Fiskeridirektoratet er oppdragsgiver (Bestilling 18/3675). Rapporten anbefaler prosedyrer for kartlegging av bunndyrsamfunn i et område eller ved en lokalitet som ønskes tatt i bruk til ulike akvakulturformål og der det er aktuelt å pålegge søker en bestemt kartlegging fordi det er sannsynlig at man vil finne sårbare naturtyper bygget av korall og svamp.publishedVersio

Forslag til metode for kartlegging av sårbare arter og naturtyper på grunt vann (0-50 meters dyp) til søknader om akvakultur i sjø - Kunnskapsleveranse til Fiskeridirektoratet

Denne rapporten er en del-leveranse på bestilling 20/16132 «Kunnskapsstøtte: forslag til metodikk for kartlegging av sårbart naturmangfold». Denne rapporten komplementerer rapporten: Forslag til metode for kartlegging av sårbare arter og naturtyper på dypt vann til søknader om akvakultur i sjø (https://imr.brage.unit.no/imr-xmlui/handle/11250/2825884). Fiskeridirektoratet er oppdragsgiver på begge rapportene. Rapporten anbefaler prosedyrer for kartlegging av bunnsamfunn i et område eller ved en lokalitet som ønskes tatt i bruk til ulike akvakulturformål. Hensikten med en slik undersøkelse er å kartfeste forekomst og tetthet, samt å estimere omfang av arter som bidrar til å danne grunne naturtyper som står på Norsk rødliste for naturtyper (Artsdatabanken 2018) eller på OSPARS liste over truede og/eller minkende habitat (OSPAR, Reference Number: 2008-6). Spesielle grunne naturtyper jfr. Håndbok for kartlegging av marint mangfold (DN- 2007) og forvaltningsrelevante marine naturenheter (Bekkby mfl. 2021) kan også omfattes av en slik undersøkelser. En slik kartlegging kan også avdekke spredte forekomster av arter med rødlistestatus som ikke danner en naturtype.publishedVersio

Forslag til metode for kartlegging av sårbare arter og naturtyper på dypt vann til søknader om akvakultur i sjø - Kunnskapsleveranse til Fiskeridirektoratet

Denne rapporten er en del-leveranse på bestilling 20/16132 «Kunnskapsstøtte: forslag til metodikk for kartlegging av sårbart naturmangfold». Rapporten bygger på og erstatter Forslag til metode for kartlegging av korall og svamp ved nye akvakulturanlegg som ble publisert i 2020 som del-leveranse på bestilling 18/3675 «Kunnskapsstøtte til forvaltning av svamper og koraller». Fiskeridirektoratet er oppdragsgiver på begge rapportene. Rapporten anbefaler prosedyrer for kartlegging av bunndyrsamfunn i et område eller ved en lokalitet som ønskes tatt i bruk til ulike akvakulturformål og der det er aktuelt å pålegge søker en bestemt kartlegging fordi det er sannsynlig at man vil finne sårbare dype naturtyper (>50 meters dyp) (jfr. forundersøkelse i NS 9410:2016). Hensikten med en slik undersøkelse er å kartfeste forekomst og tetthet, og å estimere omfang av arter som bidrar til å danne dype naturtyper som står på Norsk rødliste for naturtyper (Artsdatabanken 2018) eller på OSPARS liste over truede og/eller minkende habitat (OSPAR, Reference Number: 2008-6). Det er i dag kun naturtyper som er bygget av korall/sjøfjær eller svamp som er definert som sårbare eller truede i områder som er dypere enn 50 meter langs kysten av Norge. OSPAR definerer «Sjøfjærbunn og gravende megafauna» som en egen naturtype (truet og /eller minkende habitat). En slik kartlegging kan også avdekke spredte forekomster av arter med rødlistestatus som ikke danner en naturtype. En egen rapport med forslag til metodikk for kartlegging av sårbare naturtyper på grunnere vann vil publiseres høsten 2021.publishedVersio

Broad Thermal Tolerance in the Cold-Water Coral Lophelia pertusa From Arctic and Boreal Reefs

Along the Norwegian coasts and margins, extensive reefs of the stony coral Lophelia pertusa act as hotspots for local biodiversity. Climate models project that the temperature of Atlantic deep waters could rise by 1–3°C by 2100. In this context, understanding the effects of temperature on the physiology of cold-water species will help in evaluating their resilience to future oceanic changes. We investigated the response of L. pertusa to stepwise short-term increases in temperature. We sampled corals from four reefs, two located north of the Arctic circle and two at the mid-Norwegian shelf (boreal). In on-board experiments (one per reef), the sampled fragments were exposed to increasing temperatures from 5 to 15°C over 58 h. Respiration increased linearly by threefold for a 10°C increase. The short-term temperature increase did not induce mortality, cellular (neutral red assay for lysosome membrane stability; but one exception) or oxidative stress (lipid peroxidation assay) – to a few exceptions. However, the variability of the respiration responses depended on the experiment (i.e., reef location), possibly linked to the genetic structure of the individuals that we sampled (e.g., clones or siblings). The corals from the Arctic and boreal regions appear to have a high tolerance to the rapid temperature fluctuations they experience in the field. Over extended periods of time however, an increased metabolism could deplete the energy stored by the corals, if not met by an increased food availability and/or uptake. Empirical data on organisms’ thermal performance curves, such as the one presented in this study for L. pertusa, will be useful to implement predictive models on the responses of species and populations to climate change

Effekter av utslipp av oppdrettsfôr på svamp

Studie utført på oppdrag fra Fiskeridirektoratet, november 2013-201

Cold-Water Coral Reefs in the Langenuen Fjord, Southwestern Norway — A Window into Future Environmental Change

Ocean warming and acidification pose serious threats to cold-water corals (CWCs) and the surrounding habitat. Yet, little is known about the role of natural short-term and seasonal environmental variability, which could be pivotal to determine the resilience of CWCs in a changing environment. Here, we provide continuous observational data of the hydrodynamic regime (recorded using two benthic landers) and point measurements of the carbonate and nutrient systems from five Lophelia pertusa reefs in the Langenuen Fjord, southwestern Norway, from 2016 to 2017. In this fjord setting, we found that over a tidal (12 °C) than the mean conditions and high CT concentrations of 20 µmol kg−1 over the suggested threshold for healthy CWC reefs (i.e., >2170 µmol kg−1). Combined with hindcast measurements, our findings indicate that these shallow fjord reefs may act as an early hotspot for ocean warming and acidification. We predict that corals in Langenuen will face seasonally high temperatures (>18 °C) and hypoxic and corrosive conditions within this century. Therefore, these fjord coral communities could forewarn us of the coming consequences of climate change on CWC diversity and function

Regional impact from fin-fish farming in an intensive production area (Hardangerfjord, Norway)

The Hardangerfjord is one of the largest salmon-farming areas in Norway, with an annual production of approximately 70,000 metric tonnes. The regional impact of fin-fish farming in a fjord environment was studied during 2008–2010. Ecological conditions in intertidal macroalgal and benthic deep basin communities were studied in addition to measurements of nutrients and chlorophyll-a values. Macroalgal communities in the intertidal zone and the deep water fauna communities showed a high ecological status in the intermediate part of the fjord and a good status in the inner part of the fjord. Faunal communities in the outermost basin indicate that the assimilative capacity for farm waste of this deep basin could be limited. Nutrients and chlorophyll-a values were within national thresholds defined as high water quality. The good ecological conditions of the parameters studied in the fjord show little evidence of a regional impact from the fish farming industry despite the intensive production level.publishedVersio

Reduced physiological performance in a free-living coralline alga induced by salmon faeces deposition

Maerl beds are formed by the accumulation of free-living coralline algae and have considerable ecological significance due to the high diversity of associated fauna and flora. The rapid expansion of the Atlantic salmon Salmo salar aquaculture industry in Norway may have major impacts on surrounding maerl beds through the release of effluents, including fish faeces. This study is the first to test the effects of salmon faeces and inorganic sediment deposition on the photosynthesis, respiration, calcification and pigment content of the coralline alga Lithothamnion soriferum. In a 6 wk laboratory experiment, inorganic sediment and salmon faeces deposition significantly reduced the amount of light reaching the surface of coralline algae. No impact of inorganic sediment deposition was detected on L. soriferum physiology, while salmon faeces deposition increased respiration rate and reduced net primary production and calcification. The accumulation of salmon faeces stimulates proliferation of bacteria, with adverse consequences on L. soriferum physiology due to the potential release of toxic compounds. Burial by salmon faeces deposition also affects the physiology of coralline algae due to the flocculation of sticky faeces particles, which may limit nutrient and gas exchanges in the vicinity of thalli. Carbon dioxide accumulation in the vicinity of L. soriferum may lead to a decline in pH and alter the calcification process in cell walls. In natural maerl beds, the negative effect of faeces deposition may be exacerbated by longer-term exposure and the presence of other chemicals released by fish farms.publishedVersio

Mine waste and acute warming induce energetic stress in the deep-sea sponge Geodia atlantica and coral Primnoa resedeaformis; results from a mesocosm study

There is the potential for climate change to interact with pollution in all of the Earth's oceans. In the fjords of Norway, mine tailings are released into fjords generating suspended sediment plumes that impact deep-sea ecosystems. These same deep-sea ecosystems are expected to undergo periodic warming as climate change increases the frequency of down-welling events in fjords. It remains unknown how a polluted deep-sea ecosystem would respond to down-welling because multiple stressors will often interact in unpredictable ways. Here, we exposed two deep-sea foundation species; the gorgonian coral Primnoa resedaeformis and the demosponge Geodia atlantica to suspended sediment (10 mg L−1) and acute warming (+5°C) in a factorial mesocosm experiment for 40 days. Physiology (respiration, nutrient flux) and cellular responses (lysosomal cell stability) were measured for both the coral and sponge. Exposure to elevated suspended sediment reduced metabolism, supressed silicate uptake and induced cellular instability of the sponge G. atlantica. However, combining sediment with warming caused G. atlantica to respire and excrete nitrogen at a greater rate. For the coral P. resedaeformis, suspended sediments reduced O:N ratios after 40 days, however, warming had a greater effect on P. resedaeformis physiology compared to sediment. Warming increased respiration, nitrogen excretion, and cellular instability which resulted in lower O:N ratios. We argue that suspended sediment and warming can act alone and also interact to cause significant harm to deep-sea biota, however responses are likely to be species-specific. Warming and pollution could interact in the deep-sea to cause mortality to the coral P. resedaeformis and to a lesser extent, the sponge G. atlantica. As foundation species, reducing the abundance of deep sea corals and sponges would likely impact the ecosystems they support.publishedVersio

Quantification of eDNA to map the distribution of cold-water coral reefs

An effective management of vulnerable marine ecosystems is dependent on thorough knowledge of their location. Multibeam bathymetric mapping and targeted remotely operated vehicle (ROV) surveys are currently used to map areas impacted by industrial activities when vulnerable species are expected. However, multibeam bathymetric mapping is not always a possibility and surveying large areas using ROVs is expensive. Here, we developed a species-specific eDNA assay targeting a 178 bp fragment in the control region of the mitochondrial DNA of the cold-water coral (CWC) Lophelia pertusa. The aim was to test if concentrations of L. pertusa eDNA in seawater, determined using droplet digital PCR (ddPCR) technology, could be used to assess the broad scale distribution of CWCs in a region, to supplement multibeam mapping and direct targeted ROV surveys. Our assay successfully amplified L. pertusa DNA from seawater. In laboratory we documented an exponential decay rate of the targeted DNA fragment and a linear correlation between coral biomass and eDNA concentrations in flow through microcosms. The ability of the method to detect CWC reefs in situ was tested in the fjords south of Bergen, Norway, where such reefs are common. We tested five sites with, and five sites without, known reefs. Lophelia pertusa eDNA was detected in all 10 sites. However, concentrations were elevated by 5 to 10 times in water sampled off the two large reefs growing on vertical surfaces. Water sampled 10 m above CWC reefs growing on the flat seabed did not produce an equally clear eDNA signal, nor did single CWC colonies growing on vertical surfaces. Treating the eDNA as a passive particle with no active vertical or horizontal movement, we successfully modeled the dispersal of eDNA from the known CWC reefs in the region and achieved a good fit with measured eDNA concentrations. In all, our study demonstrated a great potential for eDNA measurements as a cost-efficient tool for a rapid screening of the broad scale distribution of CWC reefs growing on vertical surfaces (so called wall reefs) that cannot be imaged using traditional ship mounted downward looking multibeam echo-sounders and difficult to detect using ROVs alone.publishedVersio