The rapid development of in-stream tidal energy conversion (TISEC) presents a mix of challenges for environmental scientists and regulators. Like the metaphor in the title, options and threats are dichotomous: large scale grid contributions favour installation in the highest flows, whereas smaller-scale applications increase both the number of potential locations, and the unit output costs; large scale extraction involves multiple conflicts (e.g. endangered species, other resource uses) and larger scales of environmental assessment, while smaller developments generate cumulative effects and emphasise the paucity of background information available. The Bay of Fundy illustrates all of these challenges. It has numerous potential TISEC sites, including extremely energy intense ones. It is an evolving ecosystem of global significance through biological connections. Because of resonance its responses to energy extraction may occur over great distances and several political boundaries. While TISEC technologies may be developing adequately to handle extreme flows, monitoring technologies are less well developed, presenting challenges for environmental assessment. Regulators in Canada are considering an adaptive management approach, using Pathways of Effects (PoE) and Risk Management models, and promoting coordinated environmental research. This presentation will outline progress, present thinking, and remaining uncertainties regarding Fundy Tidal Power – now in its 100th year of consideration.
