Description: Ocean Acidification (OA) has become one of the most studied global stressors in marine science during the last fifteen years. Despite the variety of studies on the biological effects of OA with marine commercial species, estimations of these impacts over consumers' preferences have not been studied in detail, compromising our ability to undertake an assessment of market and economic impacts resulting from OA at local scales. Here, we use a novel and interdisciplinary approach to fill this gap. We experimentally test the impact of OA on commercially relevant physical and nutritional attributes of mussels, and then we use economic discrete choice models to assess the marginal effects of these impacts over consumers' preferences and wellbeing. Results showed that attributes, which were significantly affected by OA, are also those preferred by consumers. Consumers are willing to pay on average 52% less for mussels with evidences of OA and are willing to increase the price they pay to avoid negative changes in attributes due to OA. The interdisciplinary approach developed here, complements research conducted on OA by effectively informing how OA economic impacts can be analyzed under the lens of marginal changes in market price and consumer' welfare. Thereby, linking global phenomena to consumers' wellbeing, and shifting the focus of OA impacts to assess the effects of local vulnerabilities in a wider context of people and businesses.

Description: Global environmental change is increasing hypoxia in aquatic ecosystems. During hypoxic events, bacterial respiration causes an increase in carbon dioxide (CO2) while oxygen (O2) declines. This is rarely accounted for when assessing hypoxia tolerances of aquatic organisms. We investigated the impact of environmentally realistic increases in CO2 on responses to hypoxia in European sea bass (Dicentrarchus labrax). We conducted a critical oxygen (O2crit) test, a common measure of hypoxia tolerance, using two treatments in which O2 levels were reduced with constant ambient CO2 levels (~530 µatm), or with reciprocal increases in CO2 (rising to ~2,500 µatm). We also assessed blood acid-base chemistry and haemoglobin-O2 binding affinity of sea bass in hypoxic conditions with ambient (~650 μatm) or raised CO2 (~1770 μatm) levels. Sea bass exhibited greater hypoxia tolerance (~20% reduced O2crit), associated with increased haemoglobin-O2 affinity (~32% fall in P50) of red blood cells, when exposed to reciprocal changes in O2 and CO2. This indicates that rising CO2 which accompanies environmental hypoxia facilitates increased O2 uptake by the blood in low O2 conditions, enhancing hypoxia tolerance. We recommend that when impacts of hypoxia on aquatic organisms are assessed, due consideration is given to associated environmental increases in CO2.

Description: Benthic habitat condition assessments are a requirement under various environmental directives. The Marine Strategy Framework Directive (MSFD),for example, challenges member states in a European sea region to perform comparable assessments of good environmental status and improve coherence of their monitoring programmes by 2020. Currently, North Sea countries operate independent monitoring programmes using nationally defined assessment areas. Lack of an agreed OSPAR or EU scale monitoring method and programme has been identified as a priority science need. This paper proposes a method for the development of a coherent and efficient spatial sampling design for benthic habitats on regional level and gives advice on optimal monitoring effort to get more accurate assessments. We use ecologically relevant assessment areas (strata) across national borders and test spatial sample allocation methods.

Description: The sustainable development of the marine environment has resulted in the introduction of man-made structures (MMS) in the North Sea. These structures range from oil and gas platforms, buoys, wrecks to wind turbines, offering additional artificial habitat over predominantly soft-sediment areas. The expected effects from MMS in shallow shelf seas will modify benthic communities over various spatial and temporal scales with repercussions for overall ecosystem functioning. Research on large offshore structures have identified a suite of unique effects ranging from biodiversity changes with repercussions on local ecosystem functioning to the provision of habitat for fouling communities, acting as stepping stones and many other ecological modifications. Consequently, MMS might induce structural, functional and process-driven changes, which are different from those expected in natural soft bottom benthic systems. This study considers soft-sediment and introduced hard-substrate epifouling communities. The combination of these systems provides a unique ecological opportunity to ascertain biodiversity changes triggered by loss and gain of species provided by the addition of MMS. To date, our current understanding of how ecological functioning might be modified by the addition of these MMSs is still in its infancy. Our current analysis aimed at evaluating functional changes with a combination of biological traits analysis and energy flow changes calculated via modelled secondary production. Further, our study compared the different types of introduced MMS among the natural soft sediment communities, disentangling how the ecological functioning of the macrobenthos may be altered by the introduction of these structures, which provides improved concepts for current monitoring assessments.

Description: Marine renewable energy projects (MREs) are supported by mandatory environmental monitoring programmes due to assumed environmental impacts. These programmes concentrate on the resultant effects of single industrial projects onto biological and physical components contributing to the local ecosystem structure. To date, impact assessments at the ecosystem functioning level (e.g. trophic interactions, nutrient cycling) are largely lacking. This critical knowledge gap hampers our ability to answering the “so what” question when assessing environmental impacts, i.e. whether the observed impacts are classified as good, bad or neutral, and/or acceptable or unacceptable. When assessing MREs, there is a fundamental need to focus on ecosystem functioning at relevant spatial and temporal scales to properly understand ecological impacts and its consequences. Here, we make a science-based plea for an increased investment in large scale impact assessment of MREs focused on ecosystem functioning. This presentation will cover a selection of examples from MRE monitoring programmes, where the current knowledge has limited conclusions on the “so what” question. Further, applications will demonstrate how a proposed ecosystem functioning approach at an appropriate spatial and temporal scale could advance our current assessment. These examples will illustrate the need to expand the current level of MRE monitoring beyond that of community structure and of individual industrial projects. This work will advance and strengthen collaborative MRE monitoring strategies, facilitating scientists, developers and regulators to answer the much needed “so what” question when undertaking environmental assessments, and reassuring stakeholders with high confidence over these assessments.

Description: Offshore marine renewables energy developments (MREDs), particularly in the light of extensive offshore wind farm development in shallow shelf seas, are expected to affect the structure and functioning of marine ecosystems. Several activities linked to the installation and operation of MREDs each have their differential impacts onto the ecosystem. The benthos plays key roles in the ecosystem, supporting numerous ecosystem goods and services such as long-term carbon storage and food resources for higher trophic groups (e.g. fish, birds, mammals and including humans). Development of MREDs will initiate processes which are expected to affect benthic assemblages over various, currently unknown, spatial and temporal scales. This work provides a structured overview of ecological cause-effect relationships related to MREDs, based on a set of hypothesis-driven pathways supported by literature (〉230 publications reviewed). Furthermore, this work evaluated the sensitivity of benthic causeeffect relationships to potential effects of MREDs on different spatial and temporal scales and weighted the assessment by confidence in existing knowledge and the consistency of effects among habitats. The outcomes allowed identification of knowledge gaps about ecological processes, in order to prioritize the ‘known-unknowns’ and highlight priority research areas. Our results suggest that the sensitivity of the benthos to MREDs is much higher than previously indicated, particularly where cascading effects lead to changes in ecological functioning. Filling existing knowledge gaps and understanding ecological processes and patterns occurring at low-trophic levels, including those within the benthos, are essential to maintain ecological integrity key to the ecosystem and to society even under MREDs developments.

Description: Over the last decade, the installation and operation of extensive offshore wind farms led to a substantial increase in artificial substrates in the North Sea. Man-made structures (MMS) such as wind turbines represent additional hard-substrate habitats in the areas of the North Sea that are predominantly characterized by soft sediments. Man-made structures, colonised by fouling populations, may have potential effects by additional biomass discharge from MMS on the benthic soft bottom systems. At the same time, many ecosystem goods and services of the North Sea such as long-term carbon storage and natural resources (e.g. for fish, birds, mammals and finally humans) are intimately linked to the benthic system. Benthic invertebrates form the major food source for many commercially exploited fish species and thus the production (i.e. species energy that is turned into biomass) of benthic communities is of direct relevance for the food provisioning ecosystem service. In this study, production was calculated based on species populations as a quantification of energy flow and trophic interactions. The obtained results may thus provide clear signals for status and possible responses of populations and entire ecosystems to the introduction of MMS. The analysis included different datasets from various monitoring programs of offshore wind farms (i.e. the production and biomass of fouling communities and of natural soft-bottom community) from the Southern North Sea over several years. We analysed production changes due to environmental parameters and the presence of the structures in a meta-analysis. The analysis revealed clear modifications in the upper parts of MMSs, where the highest production values and potential biomass export to soft bottoms were detected. The outcome may thus represent a first step to disentangle the potential effects of additional biomass discharge from MMS on the ecological functioning of benthic systems. Future monitoring should therefore focus on specific targeted monitoring, i.e. investigate the cause-effect relationships to understand changes in energy flow and how this might affect (positive-neutral-negative) the food provisioning in marine ecosystems.

Description: Over the last decades, the rapid expansion of man-made structures (MMS) in the marine environment has generated increased attention by industry, scientists and legislators. In the North Sea, these hard substrates host fauna that is different from the naturally occurring widespread soft sediment communities. These new areas are expected to have an ecological footprint on the environment. To investigate the potential trophic changes through carbon flows caused by MMS, we built an Ecopath with Ecosim (EwE) model focusing on the benthic community. The challenge here was to combine meaningful ecological compartments that are both representative of the benthic functional biodiversity and can detect potential changes in energy flow patterns due to MMS. We adapted a framework developed in terrestrial systems for our analysis whereby the selection of categories was based on functional traits representative of the North Sea fauna, with emphasis on their trophic behaviour, the preferred sediment and environmental position. This method yields a simple, yet effective conceptual trophic network that was then tested under various scenarios. A ‘typical soft bottom’ reference was used to compare the effect of three hard structure scenarios (e.g. ‘offshore wind farm’, ‘oil and gas’ and ‘wrecks’). Temporal assessments of each of these scenarios were also considered (i.e. immediately after construction vs 5 years old structures). The results of these simulations can aid further understanding of the wider effects of man-made structure across the marine food-web, improving the limited knowledge available to date with regards to MMS in these systems.

Description: Over the last decade, the installation and operation of extensive offshore wind farms led to a substantial increase in artificial substrates in the North Sea. Man-made structures (MMS) such as wind turbines, oil and gas rigs represent additional hard-substrate habitats in the areas of the North Sea that are predominantly characterized by soft sediments. Research on large offshore structures has identified a suite of unique effects ranging from biodiversity changes with repercussions on local ecosystem functioning to the provision of habitat for fouling communities, acting as stepping stones also for non-native species. Consequently, MMS might induce structural, functional and process-driven changes over various spatial and temporal scales, that are different from those expected for natural soft-bottom benthic systems. However, our current understanding of how ecological functioning might be modified by the addition of these MMSs is still scarce. Many ecosystem goods and services of the North Sea such as long-term carbon storage and natural resources (e.g. for fish, birds, mammals and finally humans) are intimately linked to the benthic system. Benthic invertebrates form the major food source for many commercially exploited fish species and thus the production (i.e. species energy that is turned into biomass) of benthic communities is of direct relevance for the food provisioning ecosystem service. In this study, production was calculated based on species populations as a quantification of energy flow and trophic interactions. The obtained results may thus provide clear signals for status and possible responses of populations and entire ecosystems to the introduction of MMS. The analysis included different datasets from various monitoring programmes of offshore wind farms and oil and gas rigs (i.e. the production and biomass of fouling communities and of natural soft-bottom community) from the Southern North Sea over several years. We analysed production changes due to environmental parameters and the presence of the structures in a meta-analysis. The analysis revealed clear modifications in the upper parts of MMSs, where the highest production values and potential biomass export to soft bottoms were detected. The outcome may thus represent a first step to disentangle the potential effects of additional biomass discharge from MMS on the ecological functioning of benthic systems.

Description: Maritime industries routinely collect critical environmental data needed for sustainable management of marine ecosystems, supporting both the blue economy and future growth. Collating this information would provide a valuable resource for all stakeholders. For the North Sea, the oil and gas industry has been a dominant presence for over 50 years that has contributed to a wealth of knowledge about the environment. As the industry begins to decommission its offshore structures, this information will be critical for avoiding duplication of effort in data collection and ensuring best environmental management of offshore activities. This paper summarises the outcomes of a Blue Growth Data Challenge Workshop held in 2017 with participants from: the oil and gas industry; the key UK regulatory and management bodies for oil and gas decommissioning; open access data facilitators; and academic and research institutes. Here, environmental data collection and archiving by oil and gas operators in the North Sea are described, alongside how this compares to other offshore industries; what the barriers and opportunities surrounding environmental data sharing are; and how wider data sharing from offshore industries could be achieved. Five primary barriers to data sharing were identified: 1) Incentives, 2) Risk Perception, 3) Working Cultures, 4) Financial Models, and 5) Data Ownership. Active and transparent communication and collaboration between stakeholders including industry, regulatory bodies, data portals and academic institutions will be key to unlocking the data that will be critical to informing responsible decommissioning decisions for offshore oil and gas structures in the North Sea.