Connectivity of marine populations and ecosystems is crucial to maintaining and enhancing their structure, distribution, persistence, resilience and productivity. Artificial hard substrate, such as that associated with oil and gas platforms, provides settlement opportunities for species adapted to hard substrates in areas of soft sediment. The contribution of artificial hard substrate and the consequences of its removal (e.g. through decommissioning) to marine connectivity is not clear, yet such information is vital to inform marine spatial planning and future policy decisions on the use and protection of marine resources. This study demonstrates the application of a social network analysis approach to quantify and describe the ecological connectivity, informed by particle tracking model outputs, of hard substrate marine communities in the North Sea. Through comparison of networks with and without artificial hard substrate, and based on hypothetical decommissioning scenarios, this study provides insight into the contribution of artificial hard substrate, and the consequence of decommissioning, to the structure and function of marine community connectivity. This study highlights that artificial hard substrate, despite providing only a small proportion of the total area of hard substrate, increases the geographic extent and connectivity of the hard substrate network, bridging gaps, thereby providing ‘stepping stones’ between otherwise disconnected areas of natural hard substrate. Compared to the baseline scenario, a decommissioning scenario with full removal of oil and gas platforms results in a nearly 60% reduction in connectivity. Such reduction in connectivity may have negative implications for species’ distribution, gene flow and resilience following disturbance or exploitation of marine hard substrate communities. Synthesis and applications. Social network analysis can provide valuable insight into connectivity between marine communities and enable the evaluation of impacts associated with changes to the marine environment. Providing standardized, transparent and robust outputs, such a tool is useful to facilitate understanding across different disciplines, including marine science, marine spatial planning and marine policy. Social network analysis therefore has great potential to address current knowledge gaps with respect to marine connectivity and crucially facilitate assessment of the impacts of changes in offshore substrate as part of the marine spatial planning process, thereby informing policy and marine management decisions.

Artificial structures in the marine environment may have direct and/or indirect impact on the behaviour and space use of mobile foragers. This study explores whether environmental and physical features in the North Sea—including artificial structures (wrecks, wind turbines, cables, and oil and gas structures) were associated with local abundance of three fish species: cod (Gadus morhua), plaice (Pleuronectes platessa), and thornback ray (Raja clavata). Generalized additive models (GAMs) were used to compare distributions between data collected by fisheries surveys and electronic tags. Distributions of cod, plaice, and ray were correlated with environmental variables including temperature, depth, and substrate, matching findings from previous studies. All species showed seasonal increases in their abundance in areas with high densities of artificial structures, including oil and gas platforms and wrecks. Independent of whether fish purposefully associate with these features or whether structures happen to coincide with locations frequented by these populations, the strong association suggests that greater consideration needs to be given to regulation of habitat alterations, including decommissioning.

Results from a 1D setup of the European Regional Seas Ecosystem Model (ERSEM) biogeochemical model were compared with new observations collected under the UK Shelf Seas Biogeochemistry (SSB) programme to assess model performance and clarify elements of shelf-sea benthic biogeochemistry and carbon cycling. Observations from two contrasting sites (muddy and sandy) in the Celtic Sea in otherwise comparable hydrographic conditions were considered, with the focus on the benthic system. A standard model parameterisation with site-specific light and nutrient adjustments was used, along with modifications to the within-seabed diffusivity to accommodate the modelling of permeable (sandy) sediments. Differences between modelled and observed quantities of organic carbon in the bed were interpreted to suggest that a large part ([90%) of the observed benthic organic carbon is biologically relatively inactive. Evidence on the rate at which this inactive fraction is produced will constitute important information to quantify offshore carbon sequestration. Total oxygen uptake and oxic layer depths were within the range of the measured values. Modelled depth average pore water concentrations of ammonium, phosphate and silicate were typically

El presente artículo de investigación tiene como objetivo realizar una lectura etnográfica de las estrategias comunitarias que los cabildos indígenas quillacingas del municipio de Pasto han implementado para adaptarse y mitigar los efectos nocivos generados por el cambio climático sobre el paisaje cultural (geografía sagrada). El texto se enfoca en los efectos de este fenómeno sobre el buen vivir y el etnodesarrollo. La investigación adelantada corresponde al enfoque cualitativo de carácter hermenéutico, en donde se aplicó el método etnográfico, utilizándose las siguientes técnicas de recolección de la información: la entrevista, el taller y la observación participante. La unidad de trabajo estuvo conformada por doce integrantes de los cuatro cabildos quillacingas, para un total de cuarenta y ocho participantes entre miembros, líderes y personas mayores de 40 años que por su conocimiento del medio ambiente local se consideraron como informantes clave. El estudio permitió establecer que el cambio climático está generando efectos adversos sobre el buen vivir en la etnia de los quillacingas, especialmente debido a las alteraciones en la concepción del tiempo y en el manejo del territorio respecto a los ciclos de producción agrícola, los ritos estacionales, las labores tradicionales y las prácticas comunitarias, así como el consecuente desplazamiento de algunos miembros de la familia hacia las ciudades en búsqueda de oportunidades de vida que son esquivas para ellos. Todo esto ha contribuido a aumentar la pobreza y la miseria, la desprotección, la inseguridad y la violencia, el desarraigo hacia sus territorios y la pérdida de identidad cultural. PALABRAS CLAVE Cultura, territorio, cambio climático, etnografía y medio ambiente.

The University of Manizales, through the Center for Research on Environment and Development (CIMAD) and the Masters in Sustainable Development and Environment,