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Thousands of offshore oil and gas platforms have been installed throughout the world's oceans and more structures are being installed as part of the transition to renewable energy. These structures increase the availability of ecological niches by providing hard substrate in midwater and complex 3D habitat on the seafloor. This can lead to 'hotspots' of biodiversity, or increased densities of flora and fauna, which potentially spill over into the local area. However, the distances over which these higher densities extend (the 'range of influence') can be highly variable. Fish aggregate at such structures, but the range of influence and any implications for wider fish populations, are unclear. We investigated the relationship between fish and platform areal densities using high resolution fisheries acoustic data. Data were collected in the waters surrounding the vessel exclusions zones around 16 oil and gas platforms in the North Sea, and throughout the wider area. We estimated densities of schooling fish using echo-integration, and densities of non-schooling fish using echo-counting. At 10 platforms, non-schooling fish densities were elevated near the platform relative to background levels in the equivalent wider area. The range of influence, defined here as the range to which fish densities were elevated above background, varied from 0.8 to 23 km. In areas of high platform density, fish schools were encountered more often, and non-schooling fish densities were higher, when controlling for other sources of environmental variation. This is the first time such long-range effects have been identified; previously, ranges of influence have been reported in the order of just 10s-100s of metres. These findings suggest that the environmental impact of these structures may extend further than previously thought, which may be relevant in the context of upcoming management decisions around the decommissioning of these structures. [ABSTRACT FROM AUTHOR]

Seabed sediment maps underpin a variety of marine research endeavours. Seabed mapping data are available for many regions, but these usually provide discrete classifications which obscure underlying continuous properties of the sediments. Other areas are poorly surveyed, e.g., polar regions which are inaccessible due to ice cover. Here, we focus on the inaccessible North East Greenland shelf for which there are almost no seabed sediment data. We trained a random forest model to predict sediment classes from an existing map of the well‐surveyed neighbouring Barents Sea, using data on bathymetry, currents and waves. We then used our model to predict the unknown sediment distributions off East Greenland. In the process, we generated some new spatial data on previously un‐mapped properties of the Barents Sea, such as mean grain size, organic carbon and nitrogen content, porosity and permeability. The maps of both regions are available to support future research activities in the Arctic, e.g., the parameterization of benthic biogeochemistry in ecosystem models, or mapping species distributions. [ABSTRACT FROM AUTHOR]

We present StrathE2E2, an r package for modelling the whole ecosystem, or 'big‐picture' effects of hydrodynamics, temperature, nutrient additions and fishing on continental shelf marine food webs.StrathE2E2 has two linked parts—a fishing fleet model and an ecology model. The fishing model combines harvesting, discarding and seabed disturbance rates across a range of gears and passes the results into the ecology model.The ecology model is a network of coupled ordinary differential equations representing the rates of change in nitrogen mass of organic detritus, dissolved inorganic nutrient and coarse guilds of living biomass spanning microbes to megafauna. The equations include representations of feeding, metabolism, reproduction, active migrations, advection and mixing. Environmental driving data include temperature, irradiance, hydrodynamics and nutrient inputs from rivers, atmosphere and ocean boundaries.The package includes functions for parameter optimization, global sensitivity analysis and Monte Carlo estimation of credible intervals for model outputs.A fully developed and documented implementation for the North Sea is included with the package. [ABSTRACT FROM AUTHOR]

Seabed sediment mapping is important for a wide range of marine policy, planning and scientific issues, and there has been considerable national and international investment around the world in the collation and synthesis of sediment data sets. However, in Europe at least, much of this effort has been directed towards seabed classification and mapping of discrete habitats. Scientific users often have to resort to reverse-engineering these classifications to recover continuous variables such as mud content and median grain size that are required for many ecological and biophysical studies. Here we present a new set of 0.125 by 0.125° resolution synthetic maps of continuous properties of the northwest European sedimentary environment, extending from the Bay of Biscay to the northern limits of the North Sea and the Faroe Islands. The maps are a blend of gridded survey data, and statistically modelled values based on distributions of bed shear stress due to tidal currents and waves, and bathymetric properties. Recent work has shown that statistical models can predict sediment composition in British waters and the North Sea with high accuracy, and here we extend this to the entire shelf and to the mapping of other key seabed parameters. The maps include percentage compositions of mud, sand and gravel; porosity and permeability; median grain size of the whole-sediment and of the sand and the gravel fractions; carbon and nitrogen content of sediments; percentage of seabed area covered by rock; mean and maximum depth-averaged tidal velocity and wave-orbital velocity at the seabed; and mean monthly natural disturbance rates. A number of applications for these maps exist, including species distribution modelling and the more accurate representation of seafloor biogeochemistry in ecosystem models. The data products are available from doi:10.15129/07bc686e-a354-40de-8c08-372ced7aad64. [ABSTRACT FROM AUTHOR]

In recent years, historical ecologists have turned their attention to the long-term impact of fishing on coastal marine ecosystems in the North Atlantic. Through the examination of non-traditional sources, scientists and scholars are beginning to piece together a clearer picture of ecosystem change over centuries of anthropogenic influence. One aspect of this long-term approach is that data are being recovered from some surprising sources, and, when placed alongside other evidence, are being used to create models of change through time where previously none would have been thought possible. Taking its lead from this work, our research takes a mixed approach to the history of Scotland's regional fisheries in the 19th century, combining the anecdotal evidence of fishers to parliamentary commissions of enquiry with data relating to landings and fishing effort which were gathered by the United Kingdom Fishery Board from 1809 onwards. As a result, it has been possible to calculate catch per unit effort (cpue) for the period between 1845 and the mid-1880s which, when placed alongside the direct evidence of fishers, lead to some unexpected conclusions. In particular, we demonstrate that inshore stocks of commercial whitefish appear to have been in decline by the mid-1850s in some areas, many years before the widespread adoption of beam trawling in Scotland; and we conclude that the most likely reason for this decline is the rapid intensification of fishing from open boats using the traditional techniques of handlines and longlines. [ABSTRACT FROM AUTHOR]