Reducing Uncertainty through Experimental Design and ... · Reducing Uncertainty through...
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Reducing Uncertainty through Experimental Design and Appropriate Analysis: Lessons learned through post-EIA ornithological monitoring of offshore wind developments in the UK. DR FIONA CARYL, DR GILLIAN VALLEJO, DR CHRIS PENDLEBURY, & DR NANCY McLEAN Post-environmental impact assessment (EIA) ornithological monitoring at offshore wind projects is aimed at providing quantification and assessment of any associated disturbance, displacement and collision mortality. This is achieved by comparing post-construction data on bird abundance, activity, distribution and demographic rates with baseline data collected for EIA. Our experience suggests that to be effective, monitoring methods should be question-driven and yield data targeted toward answering site-specific questions that are identified during the EIA and permitting processes. These questions must fit within constraints of what can be feasibly achieved within the scope of a single wind project’s (or a group of geographically related projects) monitoring scheme, and what is a reasonable requirement on the developers. The UK currently generates more electricity from offshore wind than any other country. UK waters support over 19 GW of operational, under construction or permitted projects. Following more than two decades of offshore wind development, the UK stakeholders, environmental scientists and permitting authorities have learned a great deal about what works and, more importantly, what does not work when designing post-EIA monitoring. Introduction Lessons learned A framework moving forward Our experience has taught us that a question-driven approach to data collection and analysis for post-permit ornithological EIA is required to minimise uncertainty surrounding impacts of offshore wind. Here we propose a framework providing guidance on steps that should be taken before monitoring programs are agreed. naturalpower.com [email protected] No part of this document or translations of it may be reproduced or transmitted in any form or by any means, electronic or mechanical including photocopying, recording or any other information storage and retrieval system, without prior permission in writing from Natural Power. All facts and figures correct at time of print. All rights reserved. © Copyright 2017. Case Study 1: Asking the right questions Lesson 1: Question based approach Lesson 2: Monitoring is not a box-ticking exercise Lesson 3: Less specific conditions Case Study 2: Survey design with power to detect population change Case Study 3: Using specific approaches to answer specific questions Natural Power Ornithology Team monitored bird population densities around Robin Rigg offshore wind farm during pre-construction, construction and operation. The green areas in the plots below indicate increases and the brown areas show decreases. The hatched areas indicate where this difference is statistically significant. These plots show that the boat-based monitoring for birds has successfully collected data to answer the question, “does the density of birds change between the three phases?” Yes, it clearly does. But can those same data also answer the question, “are the changes in density due to disturbance associated with the construction of the wind farm?” no, probably not. Those changes may equally be due to wider, naturally occurring changes in sediment movement and resulting prey distribution that have not been measured and therefore not accounted for. In order to reduce uncertainty, it is vital that permit conditions set testable hypotheses and that these relate back to issues raised in the permitting process. For instance, asking whether the density of a species has changed is an answerable question. Asking whether this change can be attributed to the wind farm itself is an answerable question, albeit a harder one to answer. Asking if populations have been impacted by the wind farm is not an answerable question unless you collect data at a population level, or demographic rate data that could be used to model population level effects. Licensing authorities may not necessarily provide suitable protocols for effective monitoring schemes. Having multiple stakeholders involved in drafting monitoring plans can also lead to differences in priorities and confusion about what is an answerable question or a meaningful effect. Monitoring programs often end up repeating the baseline data collection protocols, which are often unsuitable for answering specific questions. Formation of a steering group, including the regulator, the developer and their scientific advisors, will help to define sensible permit conditions with narrowly defined and answerable questions. Permit conditions should set answerable questions, not prescriptive details about methodologies. Monitoring should be an agreed means to answer identified questions but allow flexibility for the implementation of novel techniques. Natural Power Geospatial Team were recently asked whether a proposed boat-based survey program would provide sufficient power to detect a given percentage change in the density of a specific receptor within the wind farm footprint. Distributions of a hypothetical bird population were simulated using biological parameters from the species of interest. By reducing densities within the wind farm footprint by given amounts, uncertainties regarding the efficacy of boat transects of different spatial and temporal configurations to detect these hypothetical density reductions could then be resolved. Natural Power Consultants Benthic Team recently tackled the question of whether there had been reef effects from the Robin Rigg offshore wind farm. A novel technique using a relatively simple drop down video answered the question: the turbines and sub-stations had clearly become reefs. Repeating baseline surveys, by trawling within the OWF footprint, would not have given these results. This illustrates the need to bring forward novel techniques to answer specific questions. Identify key species and populations During the permitting process, key species and populations should have been identified along with associated risks from potential impacts. Not all species, or populations of species, will be impacted by development. In addition, of those that are, some have more importance than others. Monitoring should target key species of high importance. While further information on less important species may be of value if obtained incidentally, monitoring methods should not aim to capture data on all species present. Identify specific answerable questions It is important to make the distinction between an effect and an impact. An EIA makes predictions about the effects of a wind farm (e.g. the number of birds displaced), but the impacts are largely assumed. An effect does not equal a impact. It’s only an impact if the rate of growth of the population being affected changes as a result. Monitoring should aim to determine whether effects occur. Identify appropriate survey methodology What constitutes the appropriate methodology will be species-, site- and question-specific. Depending on the questions being asked, a monitoring technique used for a given species at one site may not be suitable at another site. Using a “one-size-fits-all” approach to monitoring risks monitoring becoming a box- ticking exercise. To increase our understanding, the methods chosen must be appropriate to collect data with which to answer specific questions at that site. Identify appropriate analytical techniques Before any resources are spent collecting monitoring data, time should be spent identifying appropriate analysis techniques. It is also necessary to identify where additional covariate data may be needed to control for extraneous effects that may confound perceived effects on species of interest. Ideally, a power analysis should be conducted to determine whether or not a given level of impact could be detected with a given monitoring protocol.
Transcript of Reducing Uncertainty through Experimental Design and ... · Reducing Uncertainty through...
Reducing Uncertainty through Experimental Design and Appropriate Analysis: Lessons learned through post-EIA ornithological monitoring of offshore wind developments in the UK.
DR FIONA CARYL, DR GILLIAN VALLEJO, DR CHRIS PENDLEBURY, & DR NANCY McLEAN
Post-environmental impact assessment (EIA) ornithological monitoring at offshore wind projects is aimed at providing quantification and assessment of any associated disturbance, displacement and collision mortality. This is achieved by comparing post-construction data on bird abundance, activity, distribution and demographic rates with baseline data collected for EIA. Our experience suggests that to be effective, monitoring methods should be question-driven and yield data targeted toward answering site-specific questions that are identified during the EIA and permitting processes. These questions must fit within constraints of what can be feasibly achieved within the scope of a
single wind project’s (or a group of geographically related projects) monitoring scheme, and what is a reasonable requirement on the developers.
The UK currently generates more electricity from offshore wind than any other country. UK waters support over 19 GW of operational, under construction or permitted projects. Following more than two decades of offshore wind development, the UK stakeholders, environmental scientists and permitting authorities have learned a great deal about what works and, more importantly, what does not work when designing post-EIA monitoring.
Introduction
Lessons learned
A framework moving forwardOur experience has taught us that a question-driven approach to data collection and analysis for post-permit ornithological EIA is required to minimise uncertainty surrounding impacts of offshore wind. Here we propose a framework providing guidance on steps that should be taken before monitoring programs are agreed.
No part of this document or translations of it may be reproduced or transmitted in any form or by any means, electronic or mechanical including photocopying, recording or any other information storage and retrieval system,
without prior permission in writing from Natural Power. All facts and figures correct at time of print.All rights reserved. © Copyright 2017.
Case Study 1: Asking the right questions
Lesson 1: Question based approach Lesson 2: Monitoring is not a box-ticking exercise Lesson 3: Less specific conditions
Case Study 2: Survey design with power to detect population change
Case Study 3: Using specific approaches to answer specific questions
Natural Power Ornithology Team monitored bird population densities around Robin Rigg offshore wind farm during pre-construction, construction and operation. The green areas in the plots below indicate increases and the brown areas show decreases. The hatched areas indicate where this difference is statistically significant.
These plots show that the boat-based monitoring for birds has successfully collected data to answer the question, “does the density of birds change between the three phases?” Yes, it clearly does. But can those same data also answer the question, “are the changes in density due to disturbance associated with the construction of the wind farm?” no, probably not. Those changes may equally be due to wider, naturally occurring changes in sediment movement and resulting prey distribution that have not been measured and therefore not accounted for.
In order to reduce uncertainty, it is vital that permit conditions set testable hypotheses and that these relate back to issues raised in the permitting process. For instance, asking whether the density of a species has changed is an answerable question. Asking whether this change can be attributed to the wind farm itself is an answerable question, albeit a harder one to answer. Asking if populations have been impacted by the wind farm is not an answerable question unless you collect data at a population level, or demographic rate data that could be used to model population level effects.
Licensing authorities may not necessarily provide suitable protocols for effective monitoring schemes. Having multiple stakeholders involved in drafting monitoring plans can also lead to differences in priorities and confusion about what is an answerable question or a meaningful effect. Monitoring programs often end up repeating the baseline data collection protocols, which are often unsuitable for answering specific questions. Formation of a steering group, including the regulator, the developer and their scientific advisors, will help to define sensible permit conditions with narrowly defined and answerable questions.
Permit conditions should set answerable questions, not prescriptive details about methodologies. Monitoring should be an agreed means to answer identified questions but allow flexibility for the implementation of novel techniques.
Natural Power Geospatial Team were recently asked whether a proposed boat-based survey program would provide sufficient power to detect a given percentage change in the density of a specific receptor within the wind farm footprint. Distributions of a hypothetical bird population were simulated using biological parameters from the species of interest. By reducing densities within the wind farm footprint by given amounts, uncertainties regarding the efficacy of boat transects of different spatial and temporal configurations to detect these hypothetical density reductions could then be resolved.
Natural Power Consultants Benthic Team recently tackled the question of whether there had been reef effects from the Robin Rigg offshore wind farm. A novel technique using a relatively simple drop down video answered the question: the turbines and sub-stations had clearly become reefs. Repeating baseline surveys, by trawling within the OWF footprint, would not have given these results. This illustrates the need to bring forward novel techniques to answer specific questions.
Identify key species and populations
During the permitting process, key species and populations should have been identified along with associated risks from potential impacts. Not all species, or populations of species, will be impacted by development. In addition, of those that are, some have more importance than others. Monitoring should target key species of high importance. While further information on less important species may be of value if obtained incidentally, monitoring methods should not aim to capture data on all species present.
Identify specific answerable questions
It is important to make the distinction between an effect and an impact. An EIA makes predictions about the effects of a wind farm (e.g. the number of birds displaced), but the impacts are largely assumed. An effect does not equal a impact. It’s only an impact if the rate of growth of the population being affected changes as a result. Monitoring should aim to determine whether effects occur.
Identify appropriate survey methodology
What constitutes the appropriate methodology will be species-, site- and question-specific. Depending on the questions being asked, a monitoring technique used for a given species at one site may not be suitable at another site. Using a “one-size-fits-all” approach to monitoring risks monitoring becoming a box-ticking exercise. To increase our understanding, the methods chosen must be appropriate to collect data with which to answer specific questions at that site.
Identify appropriate analytical techniques
Before any resources are spent collecting monitoring data, time should be spent identifying appropriate analysis techniques. It is also necessary to identify where additional covariate data may be needed to control for extraneous effects that may confound perceived effects on species of interest. Ideally, a power analysis should be conducted to determine whether or not a given level of impact could be detected with a given monitoring protocol.
