The next WREN Environmental Webinar will be held on December 2, 2015 (16:00-17:30 UTC) about wildlife monitoring and wind energy. More info here.
The next Annex IV Environmental Webinar will be held on December 10, 2015 (16:30-18:00 UTC) about adaptive management in the MRE industry. More info here.
BRI hosted a webinar on November 17 about a report detailing wildlife distribution in the Mid-Atlantic coast of the U.S. A video will soon be available.
Several upcoming conferences to be aware of: Ocean Sciences 2016 on Feb 21-26 in New Orleans and ICOE 2016 on Feb 23-25 in Edinburgh.
Are you new to Tethys? Check out the Tips for Tethys page to get started.
Tethys Blasts are bi-weekly newsletters alerting you to recent news and new information available on Tethys. Sign up now!

Welcome to Tethys

Environmental Effects of Renewable Energy from the Sea

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Tethys is a knowledge management system that actively gathers, organizes, and provides access to information on the environmental effects of marine energy, offshore wind energy, and land-based wind energy development. This information is constantly growing through collaboration at local, national, and international levels. Tethys, named after the mythical Greek titaness of the seas, supports programs at the U.S. Department of Energy's Wind and Water Power Technologies Office.


Tethys Home: Users of the marine environment

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Marine and Hydrokinetic (MHK) or marine energy development in U.S. and international waters includes projects using the following devices:

Waves Harnessed for Marine Energy

Common environmental concerns associated with marine energy developments include:

  • The risk of marine mammals and fish being struck by tidal turbine blades;
  • The effects of EMF and underwater noise emitted from operating marine energy devices;
  • The physical presence of marine energy projects and their potential to alter the behavior of marine mammals, fish, and seabirds with attraction or avoidance;
  • The potential effect on nearfield and farfield marine environment and processes such as sediment transport and water quality.

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Tethys is also a clearinghouse for information and metadata associated with the Annex IV project, an international collaborative project among member nations of the International Energy Association’s Ocean Energy Systems (OES). The goal of Annex IV is to examine the environmental effects of marine energy devices and environmental research studies from around the world and disseminate information to marine energy researchers, regulators, developers, and stakeholders.

13 Countries Involved in Annex IV

The 13 OES member nations involved in Annex IV are highlighted on the map above.

Led by the U.S. Department of Energy, the Annex IV project concluded its first phase in 2013 with a Final Annex IV Report that uses the best available science and information to examine three case studies of specific interactions of marine energy devices with the marine environment. The Annex IV project has also developed a widespread community of international experts focused on aggregating and disseminating information related to the potential environmental effects of marine energy developments.

For more information on Annex IV, please visit the About Annex IV page.

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The expansion of wind energy into marine areas is accompanied by uncertainty associated with the effects of offshore wind devices on the marine and coastal environments. Common environmental concerns associated with offshore wind developments include:

  • Seabird strike by blades and/or displacement from critical habitat;
  • Underwater noise generated from installation of certain foundation types;
  • Alteration to the behavior of marine organisms resulting from attraction or avoidance to the structure;
  • Potential disturbance of the benthic habitats and communities.

Offshore Wind Turbines

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WREN HUB supports the dissemination of information on environmental effects of wind development. WREN Hub is facilitated by the Tethys platform and has been created to support the work of IEA Wind Task 34, made up of 6 nations involved in the development of land-based and/or offshore wind.

Map of Potential Wind Power Across the World

WREN will become an international forum for the exchange and dissemination of current knowledge on scientific research results, as well as methods for assessing, monitoring, and mitigating the environmental effects of wind energy development on habitats and the wildlife they support.

For more information on WREN, please visit the About WREN page.

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