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The global impact of offshore wind farms on ecosystem services
Get PDFUnderstanding the global impact of offshore wind farms (OWF) on biodiversity and ecosystem services (ES) is crucial in developing sustainable energy transition pathways. This study takes a holistic approach, coupling a semi-systematic review with a novel analytical methodology, to consider the consequences of construction & operation of OWF deployment on biodiversity and ES. 314 pieces of evidence taken from 132 peer-reviewed studies provide the basis to determine the ecological and ES impacts. The process showed that construction
impacts were predominantly negative across the ecological subject groups (52%), compared with positive im�pacts (8%) with several species of fish (e.g. brill, cod, dab, plaice) and some species of birds (e.g. common guillemot, northern fulmar, redhead) showing strongly negative trends. Operational phase impacts were more variable and could be either negative (32%) or positive (34%) depending on site specific conditions. More
detailed investigations into fish, shellfish, humans and air-surface studies recorded a net positive effect of wind
farm operations on these subject groups. Translation into ES outcomes identified that 14 ES are impacted by the
construction and operation of OWF. The most substantially enhanced ES included effects on commercial fisheries
and experiential recreation. Social acceptance toward new and hypothetical OWF was also strongly positive, irrespective of country location. Negative effects on ES, including existence values for culturally important groups, e.g., marine mammals and birds and the spread of non-native species, are potentially of most signifi�cance. Overall, this study finds more than 86% of possible offshore wind farm impacts on ES are still unknown.
There was also a paucity of studies on the decommissioning of OWF and the impacts of deeper-water floating structures, with a bias in studies toward northern hemisphere and developed countries
A large colonial choanoflagellate from Mono Lake harbors live bacteria
No full textAs the closest living relatives of animals, choanoflagellates offer insights into the ancestry of animal cell physiology. Here, we report the isolation and characterization of a colonial choanoflagellate from Mono Lake, California. The choanoflagellate forms large spherical colonies that are an order of magnitude larger than those formed by the closely related choanoflagellate Salpingoeca rosetta. In cultures maintained in the laboratory, the lumen of the spherical colony is filled with a branched network of extracellular matrix and colonized by bacteria, including diverse Gammaproteobacteria and Alphaproteobacteria. We propose to erect Barroeca monosierra gen. nov., sp. nov. Hake, Burkhardt, Richter, and King to accommodate this extremophile choanoflagellate. The physical association between bacteria and B. monosierra in culture presents a new experimental model for investigating interactions among bacteria and eukaryotes. Future work will investigate the nature of these interactions in wild populations and the mechanisms underpinning the colonization of B. monosierra spheres by bacteri
The genome sequence of the blonde ray, Raja brachyura Lafont, 1871
No full textWe present a genome assembly from an individual female Raja brachyura (Blonde Ray; Chordata; Chondrichthyes; Rajiformes; Rajidae). The genome sequence spans 2,700.50 megabases. Most of the assembly is scaffolded into 49 chromosomal pseudomolecules, including the X sex chromosome. The mitochondrial genome has also been assembled and is 17.12 kilobases in length. Gene annotation of this assembly on Ensembl identified 24,252 protein-coding gene
Satellite-observed SST and chlorophyll reveal contrasting dynamical-biological effects of mesoscale eddies in the North Atlantic
Get PDFThe influence of mesoscale eddies on chlorophyll (Chl) has received significant attention due to
Chl being a proxy for phytoplankton, which plays a crucial role in marine ecosystems. Solely
relying on the analysis of satellite-observed Chl poses challenges in determining the phytoplankton
response to mesoscale eddies. To address this, our study takes a collaborative approach, utilizing
satellite-derived sea surface temperature anomalies (SSTA) and chlorophyll anomalies (CHLA) to
comprehensively investigate the dynamical-biological processes associated with eddies in the
subtropical and mid-latitude North Atlantic. In the subtropics, the patterns in CHLA and SSTA
predominantly exhibit a dipole nature, with the dipole component providing more than 70% of
the explained variance (EV). This suggests that eddy stirring is the dominant mechanism driving
the observed anomaly patterns. Conversely, in the mid-latitudes, the monopole components (TM)
explain more than 60% of the EV, implying a more influential role for eddy trapping and vertical
modulations. The signs of the TM of eddy SSTA persist throughout their lifetime, being consistent
with the lowering (raising) of isopycnals within AEs (CEs). However, the subtropical CHLA
response is higher in AEs than CEs, indicating additional factors, such as eddy-induced Ekman
pumping and/or mixing to a deeper level may be important. This finding is also corroborated by
subsurface observations from Argo floats. At mid-latitudes, there is a clear inverse correspondence
between the CHLA and mixed layer depth. In contrast, no significant correlation is observed in the
subtropics, except during winter when a positive relationship emerges. These patterns suggest that
phytoplankton exhibit highly diverse responses to the physical dynamics associated with eddies.
Our work offers a method to estimate eddy dynamical-biological impacts on phytoplankton using
satellite products, compensating for the limitations of in-situ observations. It also reveals potential
contributions to marine primary production, global carbon cycles, and the development of
biogeochemical models
Methane Emissions From Seabed to Atmosphere in Polar Oceans Revealed by Direct Methane Flux Measurements
Get PDFSea-air methane flux was measured directly by the eddy-covariance method across approximately 60,000 km of Arctic and Antarctic cruises during a number of summers. The Arctic Ocean (north of 60°N, between 20°W and 50°E) and Southern Ocean (south of 50°S, between 70°W and 30°E) are found to be on-shelf sources of atmospheric methane with mean sea-air fluxes of 9.17 ± 2.91 (SEM (standard error of the mean)) μmol m−2 d−1 and 8.98 ± 0.91 μmol m−2 d−1, respectively. Off-shelf, this region of the Arctic Ocean is found to be a source of methane (mean flux of 2.39 ± 0.68 μmol m−2 d−1), while this region of the Southern Ocean is found to be a methane sink (mean flux of −0.77 ± 0.37 μmol m−2 d−1). The highest fluxes observed are found around west Svalbard, South Georgia, and South Shetland Islands and Bransfield Strait; areas with evidence of the presence of methane flares emanating from the seabed. Hence, this study may provide evidence of direct emission of seabed methane to the atmosphere in both the Arctic and Antarctic. Comparing with previous studies, the results of this study may indicate an increase in sea-air flux of methane in areas with seafloor seepage over timescales of several decades. As climate change exacerbates rising water temperatures, continued monitoring of methane release from polar oceans into the future is crucial
Editorial: The Atlantic Meridional Transect programme (1995-2023)
Get PDFSince 1995 the Atlantic Meridional Transect (AMT) has undertaken measurements of oceanographic and atmospheric variables during 30 research cruises on a passage between
the UK and destinations in the South Atlantic (Aiken and Bale, 2000; Robinson et al., 2006; Robinson et al., 2009; Rees et al., 2017). The transect spans more than 100° of latitude, samples to ocean depths of up to 1000 m and crosses a range of ecosystems from sub-polar to tropical, from eutrophic shelf seas and upwelling systems, to oligotrophic mid-ocean gyres. AMT has enabled the acquisition of repeat measurements of several Essential Ocean Variables and other ecosystem parameters and rate processes at a resolution of ~160 km (over ~13000 km). In delivering these activities AMT has facilitated long-term collaborations with NASA and ESA for the calibration and validation of satellite ocean colour sensors; with the UK Met-Office, NOC, NOAA, SOCCOM and University of Washington for ARGO and Bio-ARGO float deployment; and has maintained a long-term mooring in the South Atlantic Gyre (2009 to 2023). AMT data is archived and managed by the British Oceanographic Data Centre (BODC), whilst key data are also directed to other focus specific databases (e.g. NASA SeaBASS, ESA OC-CCI, SOCAT, CDIAC, SeaDataNet).
The generation of sustained observations of ocean biogeochemical variables is invaluable in monitoring ecosystem function and health during this period of rapid
climate and environmental change. Globally there are a number of initiatives which aim to make repeated observations which include ship transects such as GO-SHIP and GEOTRACES and deployment of hydrodynamical and biogeochemical sensors as part of the ARGO programme. Examples of fixed point observations in the Atlantic include: The European Station for Time-Series in the Ocean (ESTOC) which has provided observations of the eastern sub-tropical Atlantic for more than twenty five years (González-Dávila and Santana-Casiano, 2023), the Bermuda Atlantic Time Series (BATS) in the western sub�tropical Atlantic, which, since 1988 has documented increases in temperature, ocean
acidification and decreasing oxygen (Bates and Johnson, 2021); In the north-east Atlantic,the Western Channel Observatory (WCO) has records dating to the
early 20th century and in recent decades has further evidenced
climate related shifts in plankton communities alongside increases in temperature and ocean acidification (McEvoy et al., 2023); the Estación Permanente de Estudios Ambientale (EPEA) in the western South Atlantic has evidenced increases in chlorophyll associated with an increased proportion of small celled phytoplankton (Lutz et al., 2023). The AMT offers a unique and alternative approach by making repeat measurements along a transect which incorporates the latitudinal range of all these fixed-point stations.
AMT provides an inclusive platform for multi-disciplinary
ocean research with cruise berths open to the international
community upon request. The thirty research expeditions to date have involved 310 sea-going scientists from 81 institutes representing 31 countries, resulting in 400 refereed papers which are available here
Multilayer biological networks to upscale marine research to global change-smart management and sustainable resource use
Get PDFHuman activities are having a massive negative impact on biodiversity and ecological processes worldwide. The rate and magnitude of ecological transformations induced by climate change, habitat destruction, overexploitation and pollution are now so substantial that a sixth mass extinction event is currently underway. The biodiversity crisis of the Anthropocene urges scientists to put forward a transformative vision to promote the conservation of biodiversity, and thus indirectly the preservation of ecosystem functions. Here, we identify pressing issues in global change biology research and propose an integrative framework based on multilayer biological networks as a tool to support conservation actions and marine risk assessments in multi-stressor scenarios. Multilayer networks can integrate different levels of environmental and biotic complexity, enabling us to combine information on molecular, physiological and behaviour responses, species interactions and biotic communities. The ultimate aim of this framework is to link human-induced environmental changes to species physiology, fitness, biogeography and ecosystem impacts across vast seascapes and time frames, to help guide solutions to address biodiversity loss and ecological tipping points. Further, we also define our current ability to adopt a widespread use of multilayer networks within ecology, evolution and conservation by providing examples of case-studies. We also assess which approaches are ready to be transferred and which ones require further development before use. We conclude that multilayer biological networks will be crucial to inform (using reliable multi-levels integrative indicators) stakeholders and support their decision-making concerning the sustainable use of resources and marine conservation
Georectifying drone image data over water surfaces without fixed ground control: Methodology, uncertainty assessment and application over an estuarine environment
Get PDFLight-weight consumer-grade drones have the potential to provide geospatial image data to study a broad range of oceanic processes. However, rigorously tested
methodologies to effectively and accurately geolocate and rectify these image data over mobile and dynamic water surfaces, where temporally fixed points of
reference are unlikely to exist, are limited. We present a simple to use automated workflow for georectifying individual aerial images using position and orientation
data from the drone’s on-board sensor (i.e. direct-georectification). The presented methodology includes correcting for camera lens distortion and viewing angle and
exploits standard mathematics and camera data processing techniques. The method is used to georectify image datasets from test flights with different combinations
of altitude and camera angle. Using a test site over land, directly-georectified images, as well as the same images georectified using standard photogrammetry
software, are evaluated using a network of known ground control points. The novel methodology performs well with the camera at nadir (both 10 m and 25 m above
ground level) and exhibits a mean spatial accuracy of ±1 m. The same accuracy is achieved when the camera angle is 30◦ at 10 m above ground level but decreases to
±2.9 m at 30◦ and 25 m. The accuracy changes because the uncertainties are a function of the altitude and angle of the camera versus the ground. Drone in-flight
positioning errors can reduce the accuracy further to ±5 m with the camera at 30◦ and 25 m. An ensemble approach is used to map the uncertainties within the
camera field-of-view to show how they change with viewing distance and drone position and orientation. The complete approach is demonstrated over an estuarine
environment that includes the shoreline and open water, producing results consistent with the land-based field-tests of accuracy. Overall, the workflow presented
here provides a low cost and agile solution for direct-georectification of drone-captured image data over water surfaces. This approach could be used for collecting
and processing image data from drones or ship-mounted cameras to provide observations of ocean colour, sea-ice, ocean glitter, sea surface roughness, white-cap
coverage, coastal water quality, and river plumes. The Python scripts for the complete image georectification workflow, including uncertainty map generation,
are available from https://github.com/JamieLab/SArONG
EAT v0.9.6: a 1D testbed for physical-biogeochemical data assimilation in natural waters
No full textData assimilation (DA) in marine and freshwater systems combines numerical models and observations to deliver the best possible characterisation of a water body’s physical and biogeochemical state. This underpins the widely used 3D ocean state reanalyses and forecasts produced operationally by e.g. the Copernicus Marine Service. The use of DA in natural waters is an active field of research, but testing new developments in realistic setting can be challenging, as operational DA systems are demanding in terms of computational resources and technical skill. There is a need for testbeds that sufficiently realistic but also efficient to run and easy to operate. Here, we present the Ensemble and Assimilation Tool (EAT): a flexible and extensible software package that enables data assimilation of physical and biogeochemical variables in a one-dimensional water column. EAT builds on established open-source components for hydrodynamics (GOTM), biogeochemistry (FABM) and data assimilation (PDAF). It is easy to install and operate, and flexible through support for user-written plugins. EAT is well suited to explore and advance the state-of-the-art in DA in natural waters thanks to its support for (1) strongly and weakly coupled data assimilation, (2) observations describing any prognostic and diagnostic element of the physical-biogeochemical model, and (3) estimation of biogeochemical parameters. Its range of capabilities is demonstrated with three applications: ensemble-based coupled physical-biogeochemical assimilation, the use of variational methods (3D-Var) to assimilate sea surface chlorophyll, and the estimation of biogeochemical parameters
Eddy detection inverted from Argo profiles to surface altimetry
Get PDFArgo floats are widely used to characterize vertical structures of ocean eddies, yet their capability to invert sea-surface features of eddies, especially those overlooked by available
altimeters, has not been explored. In this paper, we propose an “interior-to-surface” inversion algorithm to effectively expand the capacity of eddy detection by estimating altimeter-missed
eddies’ surface attributes from their Argo-derived potential density anomaly profiles, given that interior property and surface signature of eddies are highly correlated. An altimeter- calibrated machine learning ensemble is employed for the inversion training based on the joint altimeter-Argo eddy data and shows promising performance with mean absolute errors
of 5.4 km, 0.5 cm, and 14.3 cm2/s2 for eddy radius, amplitude, and kinetic energy. Then, the trained ensemble model is applied to independently invert the properties of eddies captured
by an Argo-alone detection scheme, which yields a high spatiotemporal consistency with their altimeter-captured counterparts. In particular, a portion of Argo-alone eddies is ~25% smaller than altimeter-derived ones, indicating Argo’s unique capability of profiling weaker submesoscale eddies. Sea surface temperature and chlorophyll data are further applied to validate the reliability of eddies identified and characterized by the Argo-only algorithm. This new methodology effectively complements that of altimetry in eddy detecting and can be expanded to estimate other physical/biochemical eddy variables from a variety of in-situ observations