Applying Ecological Risk Assessment Methodology for Outlining Ecosystem Effects of Ocean Energy Technologies

With the increasing utilization of marine space and resources, ecosystem-based approaches to environmental assessments are requested. In this study the Ecological Risk Assessment (EcoRA) framework was used to outline risks from three ocean energy technologies; wave power, tidal current power, and ocean thermal energy conversion (OTEC). Our findings show that the potential risks from these new technologies include a multitude of ecosystem components and biological processes, which stretch over large spatiotemporal scales and motivate, the use of ecosystem-level assessment endpoints. In order to structure environmental assessments with such complex scope, assessment endpoints may preferably be associated with resilience in terms of maintaining ecosystem services. Moreover, cumulative effects from multiple stressors should be included. The systematic EcoRA methodology seems an appropriate tool for proactively assessing the risks from new technologies, such a

Imaging-sonar observations of salmonid interactions with a vertical axis instream turbine

Anthropogenic activities and their influences on aquatic systems is an important topic, especially considering the growing interest in using the earth\u27s resources in a sustainable way. One of those anthropogenic activities is the introduction of renewable technologies into the aquatic environment such as instream turbines. Environmental studies around those technologies are often still ongoing due to their novelty. During the spring of 2018, juvenile individuals of two salmonid species, Atlantic salmon and brown trout were released upstream a vertical axis instream turbine in the river Dal (Dal\ue4lven) in eastern Sweden. The aim of this study was to investigate the swimming behavior of the salmonids around a small-scale prototype vertical axis instream turbine. The swimming pattern and the possible response of avoiding the vertical axis instream turbine were documented with a multi beam sonar. A control area, next to the turbine, was used as reference. No consistent results were shown for trout as they were passing the control area with a statistically high variation, and specimens were rarely observed in proximity of the turbine, neither if the turbine was operating nor at stand still. Salmon clearly avoided the operating turbine, but did not avoid the turbine when it was at stand still, and was often observed swimming straight through the turbine area. These findings indicate that operating this type of instream turbine in a river affects the swimming behavior of Atlantic salmon but is unlikely to affect its migration paths. For brown trout, the statistical results are inconclusive, although data indicate a response of avoiding the turbine. The species are in little risk to suffer physical harm as no fish entered the rotating turbine, despite very turbid water conditions

Temperate fish community variation over seasons in relation to large-scale geographic seascape variables

In shallow-water marine environments, ecosystem functioning is a complex interworking of fine-scale characteristics and region-wide factors, and the importance of these variables can vary on multiple temporal and spatial scales. This underwater video study targeted seasonal changes in the fish community of seagrass habitats along the Swedish west coast and the influence of offshore seascape variables (latitudinal position, wave exposure, open ocean, and deep water). Results showed that fish assemblage structure exhibited seasonal changes between summer and autumn and strong spatiotemporal variations in the importance of offshore factors affecting shallow-water fish communities. In summer, abundance from the Gobiidae family responded to wave exposure, whereas the Gadidae family and juvenile migrant habitat preference guild responded to latitudinal position and proximity to deep water. In autumn, deep water was related to abundance of Gadidae and juvenile migrants, whereas latitudinal position influenced Gasterosteidae. These findings underscore the importance of understanding the influence of offshore factors on facets of coastal fish assemblages to address large-scale geographic connectivity along nearshore– offshore gradients

Cumulative impact assessment for ecosystem-based marine spatial planning

Claims for ocean space are growing while marine ecosystems suffer from centuries of insufficient care. Human pressures from runoff, atmospheric emissions, marine pollution, fishing, shipping, military operations and other activities wear on habitats and populations. Ecosystem-based marine spatial planning (MSP) has emerged worldwide as a strategic instrument for handling conflicting spatial claims among competing sectors and the environment. The twofold objective of both boosting the blue economy and protecting the environment is challenging in practice and marine planners need decision support. Cumulative Impact Assessment (CIA) was originally developed to provide an overview of the human imprint on the world\u27s ocean ecosystems. We have now added a scenario component to the CIA model and used it within Swedish ecosystem-based MSP. This has allowed us to project environmental impacts for different planning alternatives throughout the planning process, strengthening the integration of environmental considerations into strategic decision-making. Every MSP decision may entail a local shift of environmental impact, causing positive or negative consequences for ecosystem components. The results from Swedish MSP in the North Sea and Baltic Sea illustrate that MSP certainly has the potential to lower net cumulative environmental impact, both locally and across sea basins, as long as environmental values are rated high and prevailing pressures derive from activities that are part of MSP. By synthesizing innumerous data into comprehensible decision support that informs marine planners of the likely environmental consequences of different options, CIA enables ecosystem-based MSP in practice

Hydrokinetic Turbine Effects on Fish Swimming Behaviour

Hydrokinetic turbines, targeting the kinetic energy of fast-flowing currents, are under development with some turbines already deployed at ocean sites around the world. It remains virtually unknown as to how these technologies affect fish, and rotor collisions have been postulated as a major concern. In this study the effects of a vertical axis hydrokinetic rotor with rotational speeds up to 70 rpm were tested on the swimming patterns of naturally occurring fish in a subtropical tidal channel. Fish movements were recorded with and without the rotor in place. Results showed that no fish collided with the rotor and only a few specimens passed through rotor blades. Overall, fish reduced their movements through the area when the rotor was present. This deterrent effect on fish increased with current speed. Fish that passed the rotor avoided the near-field, about 0.3 m from the rotor for benthic reef fish. Large predatory fish were particularly cautious of the rotor and never moved closer than 1.7 m in current speeds above 0.6 ms-1. The effects of the rotor differed among taxa and feeding guilds and it is suggested that fish boldness and body shape influenced responses. In conclusion, the tested hydrokinetic turbine rotor proved non-hazardous to fish during the investigated conditions. However, the results indicate that arrays comprising multiple turbines may restrict fish movements, particularly for large species, with possible effects on habitat connectivity if migration routes are exploited. Arrays of the investigated turbine type and comparable systems should therefore be designed with gaps of several metres width to allow large fish to pass through. In combination with further research the insights from this study can be used for guiding the design of hydrokinetic turbine arrays where needed, so preventing ecological impacts

Power from the Brave New Ocean Marine Renewable Energy and Ecological Risks

This thesis address ecological risks associated with the possible growth of marine renewable energy. Tidal power, wave power, ocean thermal energy conversion (OTEC) and currently expanding offshore wind power are likely to become common components of future seascapes. The world ocean is strongly affected by other marine activities and it is essential that the possible expansion of marine renewables takes place without causing further detriment to the ecosystem. Identifying possible ecological risks at an early stage of technical development facilitates adaptation and supports apposite regulation. The five studies of this thesis address: (I) stressors from marine renewables in comparison with other human activities that can cause cumulative effects to marine ecosystems; (II) ecological risks of an offshore wind power project in Kattegat; (III) effects of a small tidal turbine on fish movements; and (IV-V) modeling of collision risks of large tidal turbines. Methodological contributions include procedures for handling assessment uncertainties, introduction of fish behavior in collision ris

Power from the Brave New Ocean - Marine Renewable Energy and Ecological Risks

This thesis address ecological risks associated with the possible growth of marine renewable energy. Tidal power, wave power, ocean thermal energy conversion (OTEC) and currently expanding offshore wind power are likely to become common components of future seascapes. The world ocean is strongly affected by other marine activities and it is essential that the possible expansion of marine renewables takes place without causing further detriment to the ecosystem. Identifying possible ecological risks at an early stage of technical development facilitates adaptation and supports apposite regulation. The five studies of this thesis address: (I) stressors from marine renewables in comparison with other human activities that can cause cumulative effects to marine ecosystems; (II)ecological risks of an offshore wind power project in Kattegat; (III) effects of a small tidal turbine on fish movements; and (IV-V) modeling of collision risks of large tidal turbines.Methodological contributions include procedures for handling assessment uncertainties,introduction of fish behavior in collision risk modeling, and stereo-video based in situ measurements of current speed and fish swimming speed.The results indicate that marine renewables are associated with comparatively many different stressors with potential effects on marine ecosystems. The stressors from offshore wind power, wave power and tidal turbines are quite similar. Most stressors from marine renewables are already common as a cause of existing human activities; however, some are different and may have unprecedented effects. Particular uncertainties regard the ecologicaleffects of OTEC. It was further shown that ecological risks from offshore wind power on cod can be effectively reduced by planning harmful installation procedures so as not to coincide with biologically sensitive periods and that risks for cod are insignificant during the wind power operation phase. For tidal turbines particular uncertainty regards underwater collisions. Here it was found that small turbines are unlikely to pose significant risk to fish. For large turbines the findings indicate that small fish are unlikely to be harmed while large animals may be at risk for collision under poor visibility conditions, such as at night.Apparent ecological risks of marine renewables vary among the many technical designs and are not known to detail. Positive effects are possible and have not been studied here. By further reducing uncertainties and mitigating risks through technical adaptation, regulationand planning negative effects of expanding marine renewables can be alleviated. This thesis provides some recommendations for research, development and management

Towards Technology Assessment of Ocean Energy in a Developing Country Context

New technologies for the extraction of valuable ocean resources are emerging: renewable ocean energy. Ocean energy technologies have so far primarily been developed in industrialized countries but will be deployed in both industrialized and developing countries. Ocean energy technologies promise benefits to people and the global environment on the one hand, and carry risks to marine ecosystems on the other. Simultaneously, the world’s oceans are under severe pressure from human activities, mainly due to a history of high technical development in combination with low regulation. Much could be gained by proactively examining both benefits and hazards at early stages of development. In this thesis, the Technology Assessment framework has been used to outline prerequisites for, benefits from, and adverse consequences of ocean energy technologies in developing countries. The case-study is the Western Indian Ocean (eastern Africa), a region experiencing increasing energy demand, both in fossil fuel-dependent small islands and in mainland countries with very low rural electrification levels and diesel-fuelled off-grid systems. This thesis combines technical, social, and environmental aspects.Firstly, resource overviews were performed, indicating that potentially useful ocean energy sources exist in the region. Wave power resources are abundant in southern parts of the case-study region and conditions are good for ocean thermal energy conversion (OTEC) at several locations. Secondly, the socio-technical prerequisites for the use of ocean energy technologies were examined, considering both small-scale (off-grid) and large-scale (main-grid) applications. Numerous barriers to small-scale use were identified; these should be addressed both by adapting technology and by improving institutional quality. Thirdly, the benefits of different ocean energy technologies were discussed based on the regional context of local demand and existing power systems. In rural areas, electricity demand is low and introduced power sources for off-grid electrification need to be used for productive purposes and should be accompanied by other rural development services, if economic development is to be improved. Connected to main-grids, ocean energy can provide significant amounts of fuel-independent electricity, of particular value to the small island states. Finally, environmental consequences were examined, concluding that very little is yet known.The outcomes of this thesis indicate that large-scale developments of wave power and OTEC can become important contributors to small island states in the Western Indian Ocean, while implementation of small-scale ocean energy in the region would encounter many socio-technical challenges. Due to its higher robustness, higher power output, and by-product of desalinated water, OTEC may provide the highest benefits of the two. In both cases, uncertainties regarding ecological risks remain important constraints to thorough assessment. Mitigation of ecological risks requires more research, emphasis on key ecological processes and cumulative effects in risk assessments, and efficient monitoring of impacts. At the resource-level, risks can be reduced by having a wide range of technical options to choose from (many different technologies for extracting the same resource), and by using technologies that can be further adapted, even after they have become widely used. From this perspective, wave power is the more promising ocean energy technology for the region. The thesis provides a first step towards a policy-supporting proactive Technology Assessment of ocean energy in a developing country context

Will ocean energy harm marine ecosystems?

Human activity tends to excavate the natural capital and degrade the ecosystemservices on which civilization depends. For long-term sustainability a more proactiveresource management is needed.1 Since natural and social systems are complex,environmental impacts of new technologies can be very difficult to predictbeforehand, but once technical systems have spread and have become widelyaccepted they tend to be hard to control. Will ocean energy development be asafe path towards sustainable power production, or will it inflict additional burdenon already deprived marine life? In this chapter it will be argued that the answer ismuch dependent on adaptive engineering and prospective planning