Abstract
The Massachusetts Clean Energy Center (MassCEC), the Massachusetts Executive Office of Energy and Environmental Affairs, the Bureau of Ocean Energy Management (BOEM), and the New England Aquarium (NEAq) convened a workshop on 30 and 31 May 2018 that included marine scientists, NGO representatives, regulators, public stakeholders, and offshore wind leaseholders to inform the development of a scientific research framework (the “Framework”) to guide studies of potential impacts to endangered whales and sea turtles associated with offshore wind facility construction and operation in the U.S. Northeast.
Baleen whales and sea turtles are migratory species that rely on North Atlantic waters for all aspects of their life history. Recent surveys of wind energy areas offshore of Massachusetts and Rhode Island have documented their presence in the area at various times of the year. In order to assess the ecological impacts of offshore wind facility construction and operation on marine mammals and sea turtles in U.S. waters, a carefully designed research plan is needed. Because of multiple variables, changing oceanic conditions, and inter‐annual variability, any such research to determine effects will require careful experimental design, appropriate statistical methods, and data collection methods designed to collect adequate sample sizes.
The workshop informed this marine mammal and wind research framework. The framework identifies options to assess potential population‐level impacts to marine mammals and sea turtles associated with offshore wind facility construction and operation. This includes both the immediate effects of short‐term construction activities at the project‐specific scale, and the long term effects of and potential population‐level impacts of windfarm placement and operations on distribution, abundance, behavior, or demography of endangered marine mammals and sea turtles. The framework was developed with a focus on assessing potential impacts to baleen whales and sea turtles associated with offshore wind facility construction and operation within the Massachusetts and Rhode/Island Massachusetts Wind Energy Areas (MA and RIMA WEAs). This is because adequate baseline marine mammal and sea turtle data exist, and wind facility construction is anticipated to begin in the next two years. However, the framework approach should be applicable in other offshore wind developments along the Atlantic coast.
The generic research question was “Do wind farms cause a change in some parameter of interest for species of concern?” To generate more specific questions, researchers will need to define the spatial and temporal scope and the parameters of interest. In terms of scope, one can measure temporal change (short‐term or long‐term, i.e., trend) over some defined area, or spatial change over some defined time, or both spatial and temporal change simultaneously. The potential parameters of interest include population size (stock abundance), relative population abundance (indices), occupancy, local spatial density/abundance, local spatial indices of abundance, movement (e.g., avoidance behavior of individuals), demographic parameters (e.g., birth, immigration, mortality), body condition/health, and/ or physiological/behavioral measures (e.g., stress hormones or changes in calling rates).
The hypotheses generated during the workshop fell into three categories. One, animals could be displaced from the wind energy area (by noise, construction, towers, etc), two, animal behavior and or physiological parameters could change (e.g. calling rates, feeding, breathing, movements, stress hormone levels), and three, wind farms could alter habitat in a way that disrupts prey species availability for relevant whales or sea turtles (Table 1). In all cases, it will be important to differentiate minor effects from those that will impact particular species at the population level.
Recent efforts to develop tools for detecting and measuring the population‐level consequences of disturbance (PCoD) include a set of mathematical methods to quantitatively assess the magnitude of these effects. Incorporating the concept of animal “health” (often quantified in terms of energy stores), was a way to link short‐term effects of disturbance with long‐term demographic outcomes on individuals. A number of case studies have been created, and work is ongoing to transition the methods to an operational context. In 2017, a National Academies report reviewed the wider context of the cumulative impact of multiple stressors. An expanded conceptual framework was developed, but implementing it in practice will be very difficult due to lack of knowledge on cumulative effects. This body of work is relevant to the marine renewable energy situation because installation and operation of wind farms may cause behavioral disturbance, potentially leading to population‐level effects. Research studies should, therefore, be designed in such a way that they can help parameterize a PCoD model.
There are several potential data‐collection methods available for testing hypotheses. These include aerial surveys, remote sensors (e.g., infrared, radar, LIDAR), passive acoustic monitoring including both archival and real‐time acoustic methods, tagging, drones, hormones in scat and blow, and habitat monitoring/oceanographic sampling. It is likely that the well‐known data collection methods (aerial surveys, passive acoustics, DTAGs) are best suited for answering most questions. However, the chosen monitoring program should be flexible, and be able to incorporate new technologies that may enhance data collection. Additional data considerations for every method includes species identification capacity, acoustic and behavioral characteristics of the species of interest, cost, data turnaround time, data‐processing time, technology development stage, geographic scale, detection range, limitations due to ocean and weather conditions, ease of implementation, suitability for short‐term or long‐term studies, durability, and reliability of detections.
Workshop participants made several recommendations with regard to the links between data collection and managing wind farm development. One, data must be collected in a manner that can inform regulatory and management decisions on individual project review and long‐term cumulative impacts. Two, the framework should be adaptable to new lease areas as they come online and other stressors emerge (e.g., fishing, climate change), so that each wind project can be informed by the data collected from previous projects. Three, the framework should be designed to provide usable information about cumulative effects in order to respond to managers and regulators. Finally, the data collected following the research framework should help regulators and developers determine the best timing for construction.
Finally, there is still much to learn about whale and sea turtle behavior and physiology; these gaps in knowledge will be a challenge when designing a long‐term study. There are outstanding questions about how whales find food, how they navigate, migration routes, and the scope of their sensory capabilities. Regulators and industry should proceed with caution because these unknowns may be important for designing monitoring and research programs to determine the effects of wind energy facilities, and could have implications for the timing and magnitude of both construction and operations.