RICRMP: Ocean SAMP - Chapter 8 - Renewable Energy and Other Offshore Development (650-RICR-20-05-8)
650-RICR-20-05-8 INACTIVE RULE
8.1 Authority
A. As authorized by the federal Coastal Zone Management Act of 1972 (16 U.S.C. §§ 1451 through 1466) and R.I. Gen. Laws Chapter 46-23 the Coastal Resources Management Council may implement special area management plans.
B. The regulations herein constitute a RICR regulatory component of the Ocean Special Area Management Plan (SAMP) Chapter 8 - Renewable Energy and Other Offshore Development, and must be read in conjunction with the other RICR regulatory components and chapters of the Ocean SAMP for the full context and understanding of the CRMC’s findings and policies that form the basis and purpose of these regulations. The other RICR regulatory components and chapters of the Ocean SAMP should be employed in interpreting the regulations herein and R.I. Gen. Laws § 46-23-1, et seq.
8.2 Purpose
The purpose of these rules is to carry out the responsibilities of the Coastal Resources Management Council in establishing the Ocean Special Area Management Plan (SAMP) for the offshore waters (beyond 3 nautical mile state water boundary) within the geographic location description (GLD) and to provide the regulatory framework for promoting a balanced and comprehensive ecosystem-based management approach to the development and protection of Rhode Island’s ocean-based resources. In addition, these rules establish the regulatory standards and enforceable policies within the GLD for purposes of the federal Coastal Zone Management Act federal consistency provisions pursuant to 16 U.S.C. § 1456 and 15 C.F.R. Part 930.
8.3 Definitions
A. “Area of potential effect” or “APE” means the areas within which a project may directly or indirectly alter the character or use of historic properties as defined under the federal National Historic Preservation Act (36 C.F.R. §§ 800.1 through 800.16).
B. “Certified verification agent” or “CVA” means an independent third-party agent that shall use good engineering judgment and practices in conducting an independent assessment of the design, fabrication and installation of the facility.
C. “Construction and operations plan” or “COP” means a plan that describes the applicant’s construction, operations, and conceptual decommissioning plans for a proposed facility, including the applicant’s project easement area.
D. “Ecosystem based management” or “EMB” means an integrated approach to management that considers the entire ecosystem, including humans. The goal of EBM is to maintain an ecosystem in a healthy, productive and resilient condition that provides the services humans want and need.
E. “Enforceable policy” means State policies which are legally binding through constitutional provisions, laws, regulations, land use plans, ordinances, or judicial or administrative decisions, by which a State exerts control over private and public land and water uses and natural resources in the coastal zone.
F. “Geographic location description” or “GLD” means a geographic area in federal waters, consistent with the Ocean SAMP study area, where certain federal agency activities, licenses, and permit activities pursuant to 15 C.F.R. Part 930 Subparts D and E will be subject to Rhode Island review under the Coastal Zone Management Act (CZMA) federal consistency provisions.
G. “Large-scale offshore developments” means:
1. offshore wind facilities (5 or more turbines within 2 km of each other, or 18 MW power generation);
2. wave generation devices (2 or more devices, or 18 MW power generation);
3. instream tidal or ocean current devices (2 or more devices, or 18 MW power generation);
4. offshore LNG platforms (1 or more);
5. artificial reefs (1/2 acre footprint and at least 4 feet high); and
6. outer continental shelf (OCS) exploration, development, and production plans, except for projects of a public nature whose primary purpose is habitat enhancement.
H. “Marine spatial planning” or “MSP” means the process by which ecosystem-based management is organized to produce desired outcomes in marine environments.
I. “Site assessment plan” or “SAP” means a pre-application plan that describes the activities and studies the applicant plans to perform for the characterization of the project site.
8.4 Potential Effects on Existing Uses and Resources in the Ocean SAMP Area (formerly § 850)
A. Offshore renewable energy may potentially affect the natural resources and existing human uses of the Ocean SAMP area. Some effects may be negative, resulting in adverse impacts on these resources and uses. Alternatively, other effects may be neutral, producing no discernible impacts, while others may be positive, resulting in enhancements to the environment or to offshore human uses. The degree to which offshore renewable energy structures may affect the natural environment or human activities in the area varies in large part on the specific siting of a project. Careful consideration when planning the location of an offshore renewable energy facility, as well as the use of appropriate mitigation strategies during the construction, operation and decommissioning stages can minimize any potential negative impacts (MMS 2007a).
B. To date, most research on the potential effects of offshore renewable energy installations has been conducted in Europe, though some research has been conducted during the review of the proposed offshore wind farm project in Nantucket Sound by Cape Wind, LLC (MMS 2009a; U.S. Coast Guard 2009; Technology Service Corporation 2008). In anticipation of future offshore renewable energy development within the U.S., BOEM has identified potential impacts and enhancements of such development on marine transportation, navigation and infrastructure in the “Programmatic Environmental Impact Statement for Alternative Energy Development and Production” (PEIS) (MMS 2007a). These sources, as well as other scientific literature and relevant reports have informed this synthesis of the potential effects on existing resources and uses in the Ocean SAMP area. Where possible, research conducted as a part of the Ocean SAMP process has been incorporated to help further assess the potential for effects within the Ocean SAMP study area.
C. As presented in § 810.3, offshore wind energy currently represents the greatest potential for utility-scale offshore renewable energy in the Ocean SAMP area. For that reason, the focus of this section is mainly on the potential effects from the development of offshore wind energy facilities. However, many of the potential effects discussed may be similar across all forms of offshore renewable energy development and offshore marine construction in general.
D. While this section is meant to provide a summary of all potential effects of offshore renewable energy development, the potential effects of a particular project will be thoroughly examined as part of the review conducted under the National Environmental Policy Act (NEPA). The review process includes: an analysis of alternatives, an assessment of all environmental, social, and existing use impacts (i.e. ecological, navigational, economic, community-related, etc.), a review for regulatory consistency with other applicable federal laws and the implementation of mitigation measures. See § 820.4 and Chapter 10, Existing Statutes, Regulations, and Policies for more information on the NEPA review process, as well as other state and federal reviews and regulations relevant to offshore wind energy development.
E. This section begins with an examination of the potential effects of offshore renewable energy development on the physical environment through a discussion of the potential for avoided air emissions and the potential effects on coastal processes. Next, the potential effects of offshore renewable energy development on the ecological resources, including the benthic ecology, avian species, sea turtles, marine mammals and fish. Potential effects to human uses are then examined through a discussion of cultural and historic resources, commercial and recreational fishing activities, recreation and tourism and lastly marine transportation, navigation and infrastructure. The final section considers the potential cumulative effects of offshore renewable energy development.
8.4.1 Avoided Air Emissions (formerly § 850.1)
A. The development of an offshore wind farm or any other offshore renewable energy project would have implications for air emissions within the state. While the development of a project will produce some air emissions (especially during the construction stage), a renewable energy project, by not burning fossil fuels, will produce far fewer emissions of carbon dioxide and conventional air pollutants. This section summarizes the effects of air emissions produced and avoided by the development of an offshore renewable energy project.
B. Air emissions produced during conventional fossil fuel energy production include carbon dioxide, sulfur dioxide, nitrogen oxides, volatile organic compounds, particulate matter, and carbon monoxide. These pollutants have been demonstrated to have detrimental impacts to human health and the environment. Exposure to poor air quality is a major health risk and health cost in the United States. Smog and particle pollution are the cause of decreased lung function, respiratory illness, cardiovascular disease, increased risk of asthma, and the risk of premature death (U.S. Department of Energy 2008). The largest sources of sulfur dioxide emissions are from fossil fuel combustion at power plants; sulfur dioxide has been linked to respiratory illnesses and is a major contributor to acid rain (U.S. EPA Office of Air and Radiation 2009). Nitrogen oxides combine with volatile organic compounds (VOCs) to form ozone, a major component of smog. Ozone can cause a number of respiratory problems in humans, and can also have detrimental effects on plants and ecosystems, including acid rain. Additionally, nitrogen dioxide has also been shown to cause adverse respiratory effects (U.S. EPA Office of Air and Radiation 2009). The effects of carbon dioxide emissions, the major contributor to global climate change, are discussed in further detail in Chapter 3, Global Climate Change.
C. The process of siting, constructing, and decommissioning an offshore renewable energy project of any kind would entail some adverse impacts to air quality through the emission of carbon dioxide and conventional pollutants. Construction activity in the offshore environment would require the use of fossil fuel-powered equipment that will result in a certain level of air emissions from activities including pile installation, scour protection installation, cable laying, support structure and turbine installation, and other activities required for the development of a wind farm. During the pre-construction and installation stages, there would be some air emissions in the Ocean SAMP area from fossil fuel fired mobile sources such as ships, cranes, pile drivers and other equipment. Decommissioning would also result in some air emissions from the activities involved in the removal of the wind turbines, although emissions from decommissioning would be lower than those involved in construction (MMS 2009a). The size of an offshore renewable energy facility’s carbon footprint will vary depending on the project, as the carbon footprint of a facility depends on project specific factors (e.g. size, location, technology, installation techniques, etc.) Any calculation of carbon footprint would include the pre-construction, construction, operation, and decommissioning phases of a project.
D. When considering the benefits of wind power displacing electricity generated from fossil fuels, the carbon dioxide (CO2) emissions of manufacturing wind turbines and building wind plants need to be taken into account as well. White and Kulsinski (1998) found that when these emissions are analyzed on a life-cycle basis, wind energy’s CO2 emissions are extremely low—about 1% of those from coal and 2% of those from natural gas, per unit of electricity generated. The American Wind Energy Association has calculated that a single 1 MW wind turbine (operating at full capacity for one year) has the potential to displace up to 1,800 tons (1633 MT) of CO2 per year compared with the current U.S. average utility fuel mix (made up of oil, gas, and coal) burned to produce the same amount of energy (AWEA 2009). The generation of renewable wind energy will result in avoided future emissions of CO2 and will allow Rhode Island to meet targets set by the Regional Greenhouse Gas Initiative (RGGI) (See § 810.1).
E. Developing offshore renewable energy sources in the form of wind turbines would have a positive impact on air emissions by displacing future air emissions caused by generating electricity. The level of avoided air emissions, and the net impact from renewable energy, will be dependent upon the future demands for electricity in Rhode Island, and the proportion of this which can be met by offshore wind farms and other renewable energy sources. At the very least, an offshore wind farm would have the effect of reducing the need for adding capacity for fossil-fuel generating plants in Rhode Island and throughout New England. At present, roughly 99% of the energy generated within Rhode Island comes from combined cycle natural gas, which is considered a marginal generator, in that it provides variable output which can easily be adjusted to meet demand (ISO New England Inc. 2009c). NOx is the principal pollutant of concern for gas fired energy generation (MMS 2009a). Much of the electricity used within Rhode Island comes from the Brayton Point Power Station in Somerset, MA, the largest fossil-fueled generating facility in New England. The Brayton Point Power Station has three units that use coal and one that uses either natural gas or oil, for a combined output of over 1500 MW (Dominion 2010). The additional energy production from wind turbines would be more likely to result in avoided air emissions from natural gas plants, which are marginal and would produce less energy in the event demand was lowered because of the additional output of wind turbines. Wind energy is also a marginal source, because wind speeds and thus energy output varies. The Brayton Point Power Station, which because of its reliance on coal is mostly a baseload generator, or one that does not change short term output depending on demand (because of the difficulties in doing so), would likely continue to produce energy at the same rate. Thus air emissions from this plant would not be avoided, at least in the short term.
F. A second important benefit of switching to a zero-emission energy generation technology like wind power is impact on air quality through reduced levels of nitrogen oxides, sulfur dioxide, and mercury emitted in electrical energy generation using fossil fuels. The Cape Wind FEIS determined that a wind farm would result in the net reduction in emissions of NOx, a precursor of ozone, although only a slight reduction because of the levels of NOx still being produced by power sources elsewhere (MMS 2009a). The emissions of sulfur dioxide and nitrogen oxides have declined significantly since the early 1990s (ISO New England Inc. 2009c). However, there still may be a benefit in terms of avoided future increases in emissions of NOx and other pollutants if a project can meet increasing future energy demands. A reduction in these pollutants will have positive health effects for residents of the state of Rhode Island from the perspective of avoiding future respiratory illnesses.
8.4.2 Coastal Processes and Physical Oceanography (formerly § 850.2)
A. The following section summarizes the general potential effects of a renewable energy project on coastal processes and physical oceanography in the Ocean SAMP area. The introduction of a number of large structures into the water column may have an effect on coastal processes such as currents, waves, and sediment transport. The potential effects to coastal processes as a result of offshore renewable energy development are dependent on the size, scale and design of the facility, as well as site specific conditions (i.e., localized currents, wave regimes and sediment transport). As a result, the potential effects will vary between projects and may even vary between different parts of a project site.
B. The potential effect of offshore renewable energy structures in the water column on currents and tides have been examined using modeling techniques. Modeling of the proposed Cape Wind project found that the turbines would be spaced far enough apart to prevent any wake effect between piles; any effects would be localized around each pile (MMS 2009a). The analysis of Cape Wind demonstrated that the flow around the monopiles (which range in diameter from 3.6-5.5 m [11.8-18.0 feet] wide) would return to 99% of its original flow rate within a distance of 4 pile diameters (approximately 14.4-22 m [47.2-72.2 feet]) from the support structure (ASA 2005). Both of these studies, however, are representative of monopile wind turbine subsurface structure and may not be directly applicable to jacket-style foundations. The potential localized effects of lattice jacket structures on the hydrodynamics are likely to be even less compared to that found with monopiles as pile diameters for lattice jackets are much smaller (1.5 m [4.9 feet]) than monopiles (4-5 m [13-16.5 feet] diameter). Furthermore, the spacing between the turbines using lattice jacket support structures will be much greater than the 4 pile diameters. However, the effects of currents may be site-specific, as there could be localized currents or other conditions that could affect or be affected by the presence of wind turbines; site specific modeling may be necessary to determine impacts.
C. One predicted potential effect of wind turbines has been changes to the wave field from diffraction caused by the monopiles, and resulting changes to longshore sediment transport (CEFAS 2005). A study of the wave effects at Scroby Bank, located in the North Sea off the U.K., found no significant effects to the wave regime (CEFAS 2005). Modeling of the effects of wind farms on waves found a reduction in wave height on average of 1.5% in the region, and maximum localized amplification of wave heights at the site of the wind farm of about 0.0158 m (0.6 inches). As the modeled wind farm was moved further from shore, the wave height amplification decreased (ABP Marine Environmental Research Ltd 2002). Modeling for the Cape Wind project found that the largest wave diffraction occurred for small waves with low bottom velocities that did not cause significant sediment transport; larger waves were not affected by the presence of the turbines. Overall, the models found that the presence of turbines would have a negligible impact on wave conditions in the area (MMS 2009a). Because there are no significant changes predicted for tides and waves, there are not expected to be significant effects to sediment movement or deposition along the coastline (ABP Marine Environmental Research Ltd 2002).
D. Preliminary scaling estimates for the cumulative generation of water column turbulence due to wakes behind subsurface pilings, using parameters applicable to Ocean SAMP waters and a 100-turbine wind power generation field, suggests their influence on vertical mixing could be comparable to that due to bottom friction (Codiga and Ullman 2010c). The known persistence of stratification in much of the Ocean SAMP region during summertime suggests that bottom friction is relatively weak, and thus the effects of platform pilings are not expected to produce major, large scale changes in water column stratification. However, additional research is needed to address the extent to which the spatial patterns and seasonal cycle of stratification in Ocean SAMP waters could potentially be altered by the presence of arrays of various types (pilings, lattice jackets, etc.) of subsurface structures as infrastructure for renewable energy generation devices.
E. The turbine foundations may increase turbulence and disrupt flow around the structures, potentially causing local erosion around the structures, or “scour”. This process is caused by the orbital motion of water produced by waves and currents, and the vortices that result as the water flows around the pile of a wind turbine or another structure (MMS 2009a). Scour often results in the erosion of the sediments supporting the structure as they are transported elsewhere, forming a hole at the base. Scour can also affect sediments in areas between structures where multiple structures are present, also known as “global scour”. However, because of the distances required between turbines, it has often been assumed that global scour will be limited (MMS 2007b). In addition, the use of scour protection such as boulders, grout bags or grass mattresses may be used to minimize the effects if scouring on the seafloor (MMS 2007a).
F. The seabed disturbance during construction and from scour may result in changes to sediment grain size. Smaller grains may be transported if suspended during disturbance, leaving only grains too large to be transported to remain. This could affect the structure of the benthic habitat and its associated community (MMS 2007b).
G. The placement of submarine cables will have limited and localized effects on seafloor sediments. Jet plowing, the method most likely to be used in the Ocean SAMP area, will likely result in the resuspension of bottom sediments into the water column. Heavier particles will settle in the immediate area of the activity, but finer particles are likely to travel from the disturbed area. These effects will be relatively small and short-term, however. Modeling of sedimentation during the cable laying process for the Cape Wind project found that sediment would settle within a few hundred yards of the cable route (MMS 2009a). In some cases, where suspended sediment levels are already high in the vicinity because of storms, areas of mobile surface sediment, or fishing activities such as trawling, the additional increase in sediments from cable-laying will probably not be significant. Once it is buried, the cable will not likely have any significant effect on sediments as long as it remains buried (ABP Marine Environmental Research Ltd 2002). If the cable becomes exposed, increased flow could occur above the cable, resulting in localized sediment scour (MMS 2009a).
H. The cable laying process would form a seabed scar from where the jet plow passed over. In some areas the scar may recover naturally, over a period of days to months or years depending on local tidal, current, and sediment conditions at various points along the cable route (MMS 2009a). However, depending on extent and depth of scars and the site specific conditions, areas which may not recover naturally may require the bathymetry to be restored to minimize impacts.
I. Studies on the effects of radiated heat from buried cables have found a rise in temperature directly above the cables of 0.19ºC [0.342 ºF] and an increase in the temperature of seawater of 0.000006ºC [0.0000108 ºF]. This is not believed to be significant enough to be detectable against natural fluctuations (MMS 2009a).
J. Overall, it is unlikely that wind farms will have a significant effect on wave, current, and sediment processes overall, with only small effects within the areas of the wind farms. The further to sea the wind farm is located, and the deeper water it is in, the lesser the effects to coastal processes are likely to be (ABP Marine Environmental Research Ltd 2002).
8.4.3 Benthic Ecology (formerly § 850.3)
A. Offshore renewable energy development in the Ocean SAMP area, especially offshore wind energy development, may potentially affect the benthic ecology of a project site by: disturbing benthic habitat during construction activities; introducing hard substrate that may be colonized and produce reef effects, or alter community composition; generate noise or electromagnetic fields that may affect benthic species; or impacting the water quality of an area during the installation or operation of a facility. This section summarizes the general potential effects of a renewable energy project on the Ocean SAMP area’s benthic ecosystem; potential effects of these phenomena on species groups (e.g., birds, marine mammals, and finfish) are detailed below in separate sections.
B. Undoubtedly, the construction of large, offshore structures will result in effects to coastal processes and to benthic habitats and species, at least in the immediate vicinity of the turbine installation. However, it may be a challenge to accurately assess changes in the benthic ecology of the Ocean SAMP area unless a good baseline is established. Studies of European offshore renewable energy projects, the PEIS (MMS 2007a) and the Cape Wind FEIS (MMS 2009a) provide some insight into the range of potential ecological effects offshore wind energy development, though the specific effects produced within the Ocean SAMP area will vary depending on site specific conditions and the size and design of the proposed project.
C. Benthic habitat disturbance (formerly § 850.3.1)
1. The PEIS indicates that habitat disturbance may result through the construction of offshore renewable energy infrastructure (MMS 2007a). Here, habitat disturbance is used broadly to refer to sediment disturbance and settling; increased turbidity of the waters in the construction area; and the alteration or loss of habitat from installation of infrastructure including piles, anti-scour devices, and other structures.
2. Sediment disturbance caused by the installation of foundations or underwater transmission cables may result in the smothering of some benthic organisms as suspended sediments resettle onto the seafloor (MMS 2007a). Smothering would primarily affect benthic invertebrates as most finfish and mobile shellfish would move to nearby areas to avoid the construction site (MMS 2007a). The eggs and larvae of fish and other species may be particularly susceptible to burying (Gill 2005). Smaller organisms are more likely to be affected than larger ones, as larger organisms can extend feeding and respiratory organs above the sediment (BERR 2008). Sediment also has the potential to affect the filtering mechanisms of certain species through clogging of gills or damaging feeding structures; however, most species in the marine environment likely have some degree of tolerance to sediment and this effect is likely to be minimal (BERR 2008). In the Ocean SAMP area, species that may be impacted by the settling of sediments include eastern oysters (Crassostrea virginica) and northern quahogs (Mercenaria mercenaria), among others, resulting in mortality or impacts to reproduction and growth (MMS 2009a).
3. In addition to the disturbance of sediments, construction of the foundation substructure and the installation of cables may result in increased turbidity in the water column. This may in turn affect primary production of phytoplankton and the food chain; however, these effects are likely to be short-term and localized, as sediments will likely settle out after a few hours or be flushed away by tidal processes (MMS 2009a). Increased turbidity in a project area is generally temporary and will subside once construction has been completed (Johnson et al. 2008). Sediment suspension times will vary according to particle size and currents. In Nantucket Sound, sediments were predicted to remain suspended for two to eighteen hours, and the amount of sediment suspended would be minimal compared with normal sediment transport within the region due to typical tidal and current conditions (MMS 2009a). This may impact the abundance of planktonic species by decreasing the availability of light in the water column. Sediment suspended during the construction or decommissioning activities and transported by local currents may result in impacts to neighboring habitats, perhaps posing a temporary risk of smothering to nearby benthic species. Sediment transport in the Ocean SAMP area will need to be further modeled to predict the potential effects to turbidity from construction of offshore wind turbines.
4. Habitat conversion and loss may result from the physical occupation of the substrate by foundation structures or scour protection devices. Steel foundations and scour protection devices, which may be made up of rock or concrete mattresses, may modify existing habitat, or create of new habitat for colonization (Johnson et al. 2008). The direct effects of these hard structures to the seabed are likely to be limited to within one or two hundred meters of the turbine (OSPAR 2006). Additionally, cables will need to be installed between turbines, and this will require temporarily disturbing the sediment between the turbines. The total area of seabed disturbed by wind turbine foundations is relatively small compared to the total facility footprint. The scour protection suggested for the Cape Wind project around each monopile vary depending on the pile and the location, though the total scour protection area of 47.82 acres (0.19 square kilometers). Compared to the total footprint of the Cape Wind project (64 km2 or 15,800 acres), the area affected by scour protection equals only 0.3% (MMS 2009a).
5. In addition to physically changing benthic habitat, the placement of wind turbines, especially in large arrays, may alter tidal current patterns around the structures (see § 8.4.2 of this Part, Coastal Processes and Physical Oceanography), which may affect the distribution of eggs and larvae (Johnson et al. 2008). However, a study of turbines in Danish waters found little to no impact on native benthic communities and sediment structure from a change in hydrodynamic regimes (DONG Energy et al. 2006). Studies conducted at wind farms in the North Sea did not find significant changes in the benthic community structure that could be related to changes in the hydrodynamics as a result of the placement of in-water wind turbine structures (DONG Energy et al. 2006). See Chapter 2, Ecology of the SAMP Region for more information on physical oceanography and primary production in the Ocean SAMP area.
6. The installation and burial of submarine cables can cause temporary habitat destruction through plowing trenches for cable placement, and may cause permanent habitat alteration if the top layers of sediment are replaced with new material during the cable-laying process, or if the cables are not sufficiently buried within the substrate. Likewise, cable repair or decommissioning can impact benthic habitats. The effect of the cables will depend on the grain size of sediments, hydrodynamics and turbidity of the area, and on the species and habitats present where the cable is being laid. Cables are usually buried in trenches 2 m (6.6 feet) wide and up to 3 m (9.8 feet) in depth (OSPAR 2008). Disturbance to the seabed during cable-laying may also result from anchor and chain damage from the installation barge, as the barge will have to repeatedly anchor along the length of the cable route (MMS 2007b). In addition, sediments disturbed in the cable-laying process may contain contaminants, and these may be dispersed in the process. However, most contaminated sediments are likely to be found close to the coast, unless the cable route passes close to a disposal site (BERR 2008).
7. In many cases, the seabed is expected to return to its pre-disturbance state after cable installation. The extent of the impacts from cable laying may depend on the amount of time it takes for the natural bathymetry to recover. Post-construction monitoring may be used to track the recovery of a project site. On rock or other hard substrates where the seabed may not recover easily, backfilling may be required, or else permanent scarring of the seabed may result. Scars along the bottom may impact migration for benthic animals. Species found in rock habitats tend to be sessile (permanently attached to a substrate), either encrusting or otherwise attached to the rock, and are therefore more susceptible to disturbance (BERR 2008). Clay, sand, and gravel habitats are typically less affected. Undersea cables can also cause damage to benthic habitat if allowed to “sweep” along the bottom while being placed in the correct location (Johnson et al. 2008). Initial re-colonization of the site by benthic invertebrates takes place rapidly, sometimes within a couple of months (BERR 2008). In deeper waters, where disturbance of the seabed occurs with less frequency, recovery to a stable benthic community can take longer than in shallow waters, sometimes years. Generally, the effect on the benthic ecology will not be significant if the cabling is done in areas where the habitat is homogenous. However, if the cabling activity takes place in areas of habitat that are rare or particularly subject to disturbance, the effects could be greater (BERR 2008). The most serious threats are to submerged aquatic vegetation, which serves as an important habitat for a wide variety of marine species. Shellfish beds and hard-bottom habitats are also especially at risk (Johnson et al. 2008). Shellfish in particular are usually not highly mobile, and cannot relocate during the cable-laying process. Biogenic reefs made up of mussels or other shellfish may become destabilized if plowing for cable-laying damages the reefs (BERR 2008).
8. The magnitude of the habitat disturbance effects depends on the duration and intensity of the disturbance, and on the resilience of species living within the sediment (Gill 2005). The expected effects are a local loss of sedentary fauna living in the substrate, with mobile bottom-dwellers being displaced from the area (Gill 2005). During the construction and decommissioning phases of a project, the eggs and larvae of many fish species may be vulnerable to being buried or removed. After the activity has ceased, recolonization may take months or years (Gill 2005). Studies conducted on Danish wind farms found the effects on benthic communities from burial by sediment were minimal when monopiles were used, and the effects were both temporary and had limited spatial distribution. Effects to the benthic community were limited primarily to the area immediately surrounding the pile driving activity (DONG Energy et al. 2006). Studies of the effects of sediment displacement from cable laying found macro algae and benthic infauna were still recovering two years after the activity had ceased (DONG Energy et al. 2006).
9. The recovery period, or the time required for an area disturbed by construction related activities to return to its pre-construction state, will vary between sites. For example, research on the effects of trawling on the seabed have found that benthic communities in habitats already subject to high levels of natural disturbance will be less affected by trawling disturbance than more stable communities (Hiddink et al. 2006). Typically, habitats such as coarse sands are in general more dynamic in nature and therefore recover more rapidly after disturbance than more stable habitat types where physical and biological recovery is slow (Dernie et al. 2003). Disturbance from the construction of wind turbine towers and laying cable is likely to produce similar results. A few studies of dredging found that recovery times are roughly six to eight months for estuarine muds, two to three years for sand and gravel bottoms, and up to five to ten years for coarser substrates (e.g. Newell et al. 1998).
10. See below for the potential effects of benthic habitat disturbance on Ocean SAMP area species including birds, sea turtles, marine mammals, and fisheries resources.
D. Reef effects (formerly § 850.3.2)
1. Offshore renewable energy development, especially offshore wind development, will result in the presence of man-made structures in the water column and on the seafloor. These hard structures, such as the foundation structures and scour protection devices, will introduce new habitat into the area that did not previously exist. In this way, wind turbine structures may serve as artificial reefs, in providing surfaces for non-mobile species to grow on and shelter for small fish (Wilhelmsson et al., 2006). Any man-made structure in the marine environment is usually rapidly colonized by marine organisms (Linley et al., 2007). Fouling communities will colonize the hard structure and will create new pathways for nutrients to be moved from the water column to the benthos (Gill and Kimber 2005). Once a structure such as a wind turbine has been erected, it increases the heterogeneity of the habitat. The physical structure represents more colonization opportunities for invertebrates, as they have more surface area. This in turn increases the number of food patches available, as food resources generally are not uniformly distributed in coastal waters (Gill and Kimber 2005). This will cause a fundamental shift in the overall food web dynamics of the ecosystem, and may result in further shifts in benthic community diversity, biomass and organic matter recycling (Gill and Kimber 2005). Because some European offshore renewable energy facilities have been closed to fishing activity (see § 8.4.8 of this Part, Commercial and Recreational Fishing), the ecological effects observed in these facilities may be in part due to decreased fishing disturbances. Researchers in the North Sea (DONG Energy et al., 2006) found that a reduction in fishing activity complicates their ability to assess ecological change from wind farm development; there is no good information for ecosystem functioning prior to or without fishing activity impacts and therefore difficult to establish any cause-and-effect.
2. In places where the wind turbines are under threat from erosion, large boulders are often used as scour protection; these also serve as an artificial reef of their own (Petersen and Malm 2006). Scour protection also provides hard surfaces for colonization by fouling communities, as well as providing crevices and structural complexity likely to attract fish and invertebrate species seeking shelter (MMS 2007b).
3. It has been found that although colonizing communities on offshore structures may vary depending on geographic location and a number of other factors after initial colonization, the differences are likely to decrease over the years as more stable communities develop (Linley et al. 2007). Colonizing communities will develop through the process of succession, where early colonizing species are subsumed by secondary colonizers, leading to what is known as the climax community, or the stable end point in the colonization process. It may take five to six years for the climax community to develop at a given site (Whomersley and Picken 2003, in Linley et al. 2007).
4. The changes likely to be brought about by the reef effect of the turbines are not universally considered to be beneficial. The changes in abundance and species composition could degrade other components of the system, potentially pushing out other species found in the particular habitat where construction is taking place. In particular, this could affect vulnerable or endangered species through factors such as loss of habitat, increased predation, or increased competition for prey as the composition of the benthic community shifts to that of a hard bottom community (Linley et al., 2007).
5. The diversity and biomass of the colonized structures will depend in part on the choice of material, its roughness (rugosity), and overall complexity. Concrete attracts benthic organisms; however, when used in sub-marine construction, it is often coated with silane or silicone, which deters the settling of organisms. Smooth steel monopiles, which are often painted, tend to attract barnacles (Balanus improvisus) and filamentous algae (Petersen and Malm 2006). The scaffolding used for oil and gas rigs provides more structural complexity than monopile foundations; the same is likely to be true for a jacketed structure for a wind turbine. These rougher, complex structures offer more protection from predators and from high velocities and scour (MMS 2009a).
6. Another factor influencing the colonization of wind turbine structures will be the orientation of the structures to the prevailing currents. Current speed and direction can influence food availability, oxygen levels and the supply of larval recruits to an area. As a result, structures more exposed to local currents may be more colonized than other installations within the facility. Furthermore, structures with more complex shapes will offer a greater range of localized hydrographic conditions, offering more potential for colonization and greater biodiversity (Linley et al. 2007). Colonization of structures will be dependent on sufficient numbers of larvae present in the area, and on suitable environmental conditions (Linley et al. 2007).
7. Often barnacles are the first colonizers of the intertidal zone, while algae such as red seaweeds and kelp, along with mussels, will dominate colonization starting at 1 to 2 meters below the surface. Colonies based on mussels will also attract scavengers such as starfish and flounder. In addition to mussels, some structures may instead be colonized by a grouping of species including anemones, hydroids, and sea squirts. The larvae present in the water column will vary depending on the time of year, so colonization may be dependent on the time of year in which the structures are erected. Community structure will also be dependent on the presence of predators and on secondary colonizers (Linley et al. 2007). Other species found within the Ocean SAMP area that are likely to be early colonizers include algae, sponges, and bryozoans, and other secondary colonizers are likely to include polychaetes, oligochaetes, nematodes, nudibranchs, gastropods, and crabs (MMS 2009a). These substantial colonies of invertebrates will attract fish to the structures, resulting in a reef effect around the support structures. For more on reef effects and the attraction of fish, see § 8.4.7(G) of this Part below.
8. Studies conducted in Denmark (Dong Energy et al. 2006) at two wind farms sites (Nysted, 76 turbines; Horns Rev, 80 turbines) has shown major changes in community structure of the offshore ecosystem from one based on infauna, or invertebrates that live within the substrate, to that of a hard bottom marine community and a commensurate increase in biomass by 50 to 150 times greater.
9. Wind turbines in the Baltic Sea built on monopiles are almost entirely encrusted with a monoculture of blue mussels (Mytilus edulis), which may be the result of a lack of predation and competition from other species (Petersen and Malm 2006), as well as from low salinity in the area where the turbines have been constructed. Mussels provide a hard substratum used by macroalgae and epifauna, and therefore have the potential to induce further change in the ecosystem by providing more surface area for colonization. Colonization of wind farms will be determined partly through zonation, the distribution of various communities of organisms at different depths in the water column. A study of the Nysted offshore wind farm found high concentrations of blue mussels on the wind turbine foundations, with mussel biomass increasing closer to the surface, although in the highest zonation, in the upper one meter of depth, the foundation was instead colonized by barnacles. The biomass of barnacles was determined, through modeling techniques, to be seven to eighteen times higher on the foundation close to the surface than on the scour protection. The extent to which these mussels serve as an artificial reef and increase productivity and biomass will depend on the ecosystem feedback between the mussel colonies and the pelagic and benthic environments around them, such as whether other invertebrates colonize the mussels, and whether fish and other animals utilize these colonies for food and shelter (Maar et al. 2009). On oil and gas platforms in California, the structures are encrusted with mussels, at least at depths above 100 feet (30.5 m); as mussels are knocked off the platforms and accumulate at the bottom, they create shell mounds on the seafloor which provide a secondary habitat for fish and other species (Love et al. 2003).
10. A study of the effects of the Horns Rev wind farm in Denmark found a shift in the benthic community from the indigenous infaunal community to an epifouling community associated with hard bottom habitats as both the monopiles and the scour protection were colonized by algae and invertebrates. Two species of amphipods (Jassa marmorata and Caprella linearis) were the most abundant species found on the turbines, and a total of seven species of invertebrates, including the two amphipods, the common mussel (Mytilus edulis), a barnacle species (Balanus cretanus), the common starfish (Asteria rubens), the bristle worm (Pomatoceros triqueter), and the edible crab (Cancer pagurus) made up 94% of the total biomass on the structures. There were also eleven taxa of seaweeds found on the monopiles and the scour protection. The monopiles and scour protection were found to be hatchery or nursery grounds for a number of invertebrates, including crabs. The wind turbine substructure and scour protection were found to house two species of worms new to this area, and considered threatened elsewhere in the region. The result of this new community has been an estimated 60-fold increase in the availability of food for fish and other organisms in the area compared with the original benthic community (Leonhard and Pedersen 2005). For information on the potential future uses associated with the epifouling communities formed on offshore wind energy turbines see Chapter 9, Other Future Uses.
11. Conversely, one study conducted at the Nysted offshore wind farm in Denmark, found an overall decline in biomass measured over three years. The encrusting community at this site had evolved to become almost a monoculture of mussels. This particular area is brackish; the lack of sea stars, an important mussel predator, was attributed to the low salinity. Similar changes were observed at a test site; it was concluded that these were the result of natural variations rather than an effect of the wind turbines (MMS 2007b).
12. If scour holes form in the sea bed adjacent to the turbines, these holes may be attractive habitat to species such as crab and lobster, and to some fish species, furthering the reef effect of the structures (Rodmell and Johnson 2002). For more on effects on scour and the physical oceanography of the Ocean SAMP area from wind turbines, see § 8.4.2(E) of this Part.
13. If periodic cleaning of the encrusting organisms on the structure base occurs, the community will be more or less permanently in the early-colonization phase, and will not develop through succession into a more mature climax community with greater biodiversity. Instead, after each cleaning a new community will redevelop on the structure, with the species composition varying based on the season, depending on which larval species are present in the water column at the time. Moreover, if shells are periodically removed, the discarded debris may attract scavenging animals, and may serve to create new habitat on the seafloor where they accumulate (Linley et al. 2007).
14. The reef effect is particularly relevant to fisheries resources as well as other species groups; see sections on marine mammals, fish, and sea turtles below for further discussion.
E. Changes in community composition (formerly § 850.3.3)
1. Wind energy and other offshore renewable energy projects could have indirect ecological effects that could affect the benthic community. A change in the type and abundance of benthic species can be expected at the turbine sites, which will change food availability for higher trophic levels. Studies of habitat disturbance resulting from fishing or dredging activity have shown effects on local species diversity and population density; the effects of offshore renewable energy projects are likely to be similar (as suggested by Gill 2005). The magnitude of these effects depends on the duration and intensity of the disturbance, and on the resistance and resilience of species living within the sediment. The expected effects are a local loss of sedentary fauna living in the substrate, with non-sedentary bottom-dwellers being displaced from the area.
2. Because the placement of wind turbines will increase habitat for benthic species, the structures will have the effect of increasing local food availability, which may bring some fish and other mobile species into the area. This may increase use of the area by immigrant fauna. More adaptable species will probably dominate the area under these new ecological conditions. The change in prey size, type, and abundance in the vicinity of the structures may also affect predators. Predators moving into the area may result in prey depletion (Gill 2005).
3. The PEIS (MMS 2007a) indicates that the removal and deposition of benthic sediments associated with construction may result in the smothering of some benthic organisms within the footprint of the towers or along the cable route. Smothering would be a problem primarily for sedentary invertebrates as most finfish and mobile shellfish would be expected to move out of the way of incoming sediment (MMS 2007a). Studies conducted on Danish wind farms found the impacts on benthic communities from burial by sediment were minimal when monopile substructures were installed, and the impacts were both temporary and had limited spatial impact (DONG Energy et al. 2006). The recolonization of an area disturbed during the construction process may take months or years (Gill 2005). Studies of the impacts of sediment displacement from cable laying found macro algae and benthic infauna were still recovering two years after the activity had ceased (DONG Energy et al. 2006).
4. If fishing pressure is reduced in the areas around the turbines as a result of fewer fishing vessels in the vicinity of the turbines, this could have impacts on the community as a whole, both from a reduction on fishing mortality of some species and a resulting increase in predation by these species on others (MMS 2007b). For example, in the Horns Rev wind farm, an increase in bivalves and worms inside of the park was attributed to a decline in predation from scoters (a waterfowl species), who were avoiding the wind turbines (Leonhard and Pedersen 2005). At the Nysted wind farm in Denmark, densities of sand eels were found to increase by 300 percent between 2002 and 2004. The increase was likely attributable to either a decrease in sand eel predation, or a decrease in fishing mortality (Jensen et al. 2004, in MMS 2007b).
5. There is also a possibility that invasive species may colonize the structures (MMS 2007a). The disturbances caused by the placement of new structures may make the area more susceptible to invasion by non-native species (Petersen and Malm 2006). Monitoring at Denmark’s Horns Rev wind farm in 2004 found an invasive species of tube amphipod, Jassa marmorata, not previously seen in Denmark, to be the most abundant invertebrate found on hard bottom substrate in the area (DONG Energy and Vattenfall 2006).
6. Didemnum spp., a particularly aggressive invasive tunicate (sea squirt) of unknown origin, arrived in the New England region in the late 1980s and has become firmly embedded in the aquatic community from Eastport, ME to Shinnecock, NY (Bullard et al. 2007). There are no known, consistent predators of this species, which grows rapidly on hard structure to depths of 80 m (262.5 feet). This sea squirt could be problematic on new subsurface structures placed in the Ocean SAMP area, potentially colonizing the structure and competing with native species for planktonic food resources. Furthermore, this species is known to be able to regenerate entire individuals from fragments (Bullard et al. 2007), such as might be formed during maintenance procedures to control biofouling on wind turbine support structures, for instance. Didemnum is known to grow particularly well in areas that are well-mixed (Valentine et al. 2007); it is unknown if the turbulence created downstream of subsurface structure, wind turbine pilings for instance, would further promote conditions that favor this organism. See Chapter 2, Ecology of the SAMP Region for more information on invasive species in the Ocean SAMP area.
7. One study of the North Hoyle wind farm in the UK found that variability in benthic organisms taken from surveys around the wind farm pre- and post-construction was more likely related to natural variability, such as localized sediment composition, than to any effects caused by the construction or operation of the wind farm (NWP Offshore Ltd. 2007).
8. The decommissioning of wind turbines would also have significant ecological effects, as the new habitat and accompanying species are removed. Habitat heterogeneity would be immediately reduced, removing a large component of the benthic community (Gill 2005).
9. In summary, the significant human activity resulting from the wind turbines would be likely to have significant effects upon the food web, but just what those effects are is unknown.
10. See § 8.4.7(G) of this Part below for the potential effects of changes in community composition on fisheries and fishery resources.
F. Noise (formerly § 850.3.4)
1. Underwater noise may be generated during all stages of an offshore renewable energy facility, including during pre-construction, construction, operation and decommissioning. The potential effects of noise from offshore renewable energy are especially a concern for marine mammals and fish species (see §§ 8.4.5 and 8.4.7 of this Part) It is not understood whether the noise generated in the construction, operation, and decommissioning of a wind turbine array would have an effect on invertebrate species in the benthic environment. Few marine invertebrates have the sensory organs to perceive sound pressure, although many can perceive sound waves (Vella et al. 2001 in MMS 2007b). Studies on the potential impact of air guns on squid have found few behavioral or psychological effects unless the organisms are within a few meters of the source (MMS 2007b). If there is any effect to these species, it is likely to be much less than any potential effects to fish or marine mammals (Linley et al. 2007).
G. Electromagnetic fields (EMF) (formerly § 850.3.5)
1. Underwater transmission cables used to carry the electricity from an offshore renewable energy facility back to shore produce magnetic fields around the cables, both perpendicularly and in a lateral direction around the cable. While the design of industry standard AC cables prevents electric field emissions, magnetic field emissions are not prevented. These magnetic emissions induce localized electric fields in the marine environment as sea water moves through them. Furthermore, in AC cables the magnetic fields oscillate, and thereby also create an induced electric field in the environment around the cables, regardless of whether the cable is buried. Thus the term electromagnetic field, or EMF, refers to both of these fields (Petersen and Malm 2006). While EMF is primarily an issue for fish, sharks and rays (see § 8.4.7 of this Part), some invertebrate species, such as a variety of crustacean species, have demonstrated magnetic sensitivity and could be affected by EMF. These animals may become disoriented; it is not known whether this will have a small or a significant impact on these animals, although the likely impact is believed to be small (BERR 2008). For more information on the effects of electromagnetic fields, see § 8.4.8 of this Part, Fish and Fisheries Resources.
2. If electromagnetic fields affect the presence or behavior of species likely to colonize wind turbine structures, this could have an effect on the potential reef effects of the structures. However, the interaction between most invertebrates and EMF is not known, and the existence of healthy communities of colonizing species on turbine structures in Europe indicates EMF will not have a significant impact on at least these species assemblages (Linley et al. 2007).
H. Water quality impacts (formerly § 850.3.6)
1. Offshore renewable energy facilities would result in increased vessel traffic through the site characterization, construction, operation, and decommissioning phases. The PEIS indicates that such an increase in traffic could increase the likelihood of fuel spills as a result of vessel accidents or mechanical problems, though it indicates that the likelihood of such spills is relatively small (MMS 2007a). In addition, wastewater, trash, and other debris may be generated at offshore energy sites by human activities associated with the facility during construction and maintenance activities (MMS 2007a, Johnson et al. 2008). The platforms may hold hazardous materials such as fuel, oils, greases, and coolants. The accidental discharge of these contaminants into the water column could affect the water quality around the facility; however these contaminants would likely remain at the surface and not impact benthic ecosystems (MMS 2007a). In the PEIS, BOEM indicates that the potential risk to water quality from offshore renewable energy development is negligible to minor (MMS 2007a).
2. Water quality may also be impacted during the construction process by re-suspending bottom sediments, increasing the turbidity within the water column. For the potential effects of water quality impacts on birds, marine mammals, and fish, see sections below.
8.4.4 Birds (formerly § 850.4)
A. Offshore renewable energy may have a variety of potential effects on avian species in the Ocean SAMP area. Some effects may be negative, resulting in adverse impacts, other effects may be neutral, producing no discernible impacts, while others may be positive, resulting in enhancements. The purpose of this section is to provide an overview of all the potential effects of offshore renewable energy development on birds, including the potential for habitat displacement or modification; disturbances associated with construction activities and/or vessel traffic; avoidance behavior or changes in flight patterns; risk of collision with installed structures; the risk of exposure to pollutants accidentally discharged during construction, operation or decommissioning. Potential affects to birds in the Ocean SAMP area will vary based on the species, as well as on the particular site, and size of the project. The timing of construction or decommissioning of an offshore renewable energy facility, along with the cumulative impacts of other offshore developments will also have an effect on the degree of impact.
B. Key to measuring and understanding the effects of offshore renewable energy development on avian species requires first sufficient baseline data on the abundance, distribution, habitat use and flight patterns in the project area. Baseline studies provide an important comparison point for assessing the effects of pre-construction, construction, operation or decommissioning activities. The duration of baseline studies may vary between project areas to account for ‘natural variability’ observed in avian use of an area. Locations that experience large fluctuations in avian densities over time may require additional baseline monitoring to accurately assess pre-construction conditions (Fox et al. 2006).
C. Research conducted by Paton et al. (2010) for the Ocean SAMP has collected baseline data on species occurrence and distribution in the Ocean SAMP area through land-based, ship-based and aerial surveys, as well as through radar surveys from 2009 to 2010, although the exact time period of surveys varied by survey technique. The goal of this research is to assess current spatial and temporal patterns of avian abundance and movement ecology within the Ocean SAMP boundary. Preliminary analysis of the surveys conducted in nearshore habitats during land-based point counts from January 2009 to February 2010 recorded 121 species and over 460,000 detections in the nearshore portion of the Ocean SAMP area (Figure 8.37 in § 8.4.4(C)(1) of this Part; Paton et al. 2010). Observations during these nearshore surveys have demonstrated that a wide range of birds use the Ocean SAMP area, including seaducks (e.g., eiders and scoters), other seabirds (e.g., loons, cormorants, alcids and gannets), pelagic seabirds (e.g., storm petrel and shearwaters), terns and gulls, shorebirds, passerines and other land birds (e.g., migrating species and swallows). The most abundant bird species observed in nearshore habitats in the Ocean SAMP area during land-based surveys were Common Eider (Somateria mollissima), Herring Gull (Larus argentatus), Surf Scoter (Melanitta perspicillata), Black Scoter (Melanitta nigra), Double crested Cormorant (Phalacrocorax auritus), Tree Swallow (Tachycineta bicolor), Great Black-backed Gull (Larus marinus), Laughing Gull (Leucophaeus atricilla), and the Northern Gannet (Morus bassanus) (see Figure 8.37 in § 8.4.4(C)(1) of this Part) (Paton et al. 2010). Farther offshore, more pelagic species were detected during boat-based surveys conducted from June 2009 to March 2010. During boat-based surveys, which sampled eight 4 by 5 nm grids, 55 species were detected from 10,422 detections (see Figure 8.38 in § 8.4.4(C)(2) of this Part). In offshore areas, Herring Gulls, Wilson’s Storm-Petrels (Oceanites oceanicus), Northern Gannets, Great Black-backed Gulls, White-winged Scoters (Melanitta fusca) were among the most commonly detected species.
1. Figure 8.37: Most abundant species observed in nearshore habitats of the Ocean SAMP study area based on land-based point counts from January 2009 to January 2010 (Paton et al. 2010). (Note: Total detections = 465,039)
2. Figure 8.38: Most abundant species observed in offshore habitats based on ship-based point counts in the Ocean SAMP study area from Mar 2009-Jan 2010 (Paton et al. 2010).
D. Species distribution and abundance varied both spatially and seasonally in the Ocean SAMP area. Most birds that use the Ocean SAMP area are migratory, so that their occurrence is highly seasonal. Paton et al. (2010) have found high inter-annual variability in the abundance and distribution of avian species in the Ocean SAMP area, suggesting that the collection of long-term baseline data prior to construction and operation of an offshore renewable energy facility will be important in examining any potential effects to avian species. For further discussion of the findings of Paton et al. (2010) see Chapter 2, Ecology of the SAMP Region.
E. In addition to recording occurrence and abundance in the Ocean SAMP area, Paton et al. (2010) have also identified potential foraging habitat for avian species. Based on a literature review performed by Paton et al. (2010) nearshore habitats, with water depths of less than 20 m [66 ft], are believed to be the primary foraging habitat for seaducks (see Table 8.13 in § 8.4.4(E)(1) of this Part). Figure 8.39 in § 8.4.4(F)(1) of this Part illustrates the areas within the Ocean SAMP boundary with water depths less than 20 m (66 feet) and therefore is thought to represent the primary foraging habitat for the thousands of seaducks that winter in the Ocean SAMP waters. Preferred sea duck foraging areas are strongly correlated with environmental variables such as water depth, bottom substrate, bivalve community, and bivalve density (Vaitkus and Bubinas 2001). Currently, bathymetric data (water depth, bottom substrate) of the Ocean SAMP area is well known, but relatively little is known about bivalve community and bivalve density, especially further offshore. Foraging depths of seaducks differ among species and are a function of preferred diet, but average depths tend to be less than 20 meters (66 feet) for most species. Common eiders forage in water less than 10 m (33 feet) during the winter when diving over rocky substrate and kelp beds (Goudie et al. 2000; Guillemette et al., 1993). Preferred diet of common eider changes with season and foraging location, but mainly consists of mollusks and crustaceans (Goudie et al. 2000; Palmer 1949; Cottam 1939). Maximum diving depths of scoters are about 25 m (82 feet), although most birds probably forage in water less than 20 meters (66 feet) deep, particularly during the winter months (Vaitkus and Bubinas 2001; Bordage and Savard 1995). Scoter diet in marine environments predominantly consists of mollusks (Bordage & Savard 1995; Durinck et al. 1993; Madsen 1954; Cottam 1939). Paton et al. (2010) did detect seaducks in waters up to 25 meters (82 feet) deep during aerial surveys, although it was unclear from the aerial surveys if the seaducks were foraging or engaging in other behaviors such as roosting. Paton et al. (2010) suggest more detailed research be conducted to better understand the depths used for foraging by scoters or eiders in the Ocean SAMP area.
1. Table 8.13: Foraging depths of seaducks based on a literature review (Paton et al. 2010).
Species |
Dive depth |
Source |
Common eider |
0-15 m (0-49 feet). |
Ydenberg and Guillemetter 1991 |
Surf Scoter - day |
90% of dives <20 m (66 feet) depth during diurnal period - used deeper waters at night - but rarely dived at night. |
Lewis et al. 2005 |
White-winged Scoter-day |
~90% of diver <20 m (66 feet) depth - used deeper waters at night - but rarely dived at night. |
Lewis et al. 2005 |
Black Scoter |
>95% of observations were in waters <20m (66 feet) deep. |
Kaiser et al. 2006 |
Common Eider |
100% <16 m (52.5 feet) deep. |
NERI Report 2006 |
Black Scoter |
100% <20 m (66 feet) deep. |
NERI Report 2006 |
F. Land-based surveys conducted by Paton et al. (2010) support the findings of the literature review, as large concentrations of seaducks (e.g. scoters and eiders) have been recorded in these nearshore areas, particularly off Brenton Point (see Figure 8.39 in § 8.4.4(F)(1) of this Part). Because one potential effect of offshore renewable energy development may include permanent habitat loss, identifying and avoiding potentially important foraging habitat prior to siting future projects may help to minimize any adverse impacts.
1. Figure 8.39: Potential foraging areas for seaducks within and adjacent to the Ocean SAMP boundary (based on a literature review by Paton et al. 2010)
2. Figure 8.40: Total number of detections for the most abundant guilds observed in nearshore habitats during land-based point counts, Jan 2009-Feb 2010 (Paton et al., 2010). (Note: Total Number of detections = 465,039; Total Number of Species Recorded= 121)
G. When assessing the potential effects of offshore renewable energy development, the impact on endangered or threatened species are of particular concern, mainly because the magnitude of the potential impact may be much more severe to these species due to their low population numbers (MMS 2007a). The one federally-listed endangered bird using the Ocean SAMP area is Roseate Tern (Sterna dougalli dougalli). This species is a long-distance migrant that spends the summer months in New England, including within the Ocean SAMP area (Paton et al. 2010). Although this species does not nest in Rhode Island, there are nesting colonies in Connecticut, New York, and Massachusetts that are close enough that foraging adults from nesting colonies may use Ocean SAMP waters (see Figure 8.41 in § 1.4.4(G)(1) of this Part). Terns may travel substantial distances, 25.8 to 30.6 km [16 to 19 miles] from their breeding locations to access foraging habitat, and therefore Roseate Terns may use portions of the Ocean SAMP area (Paton et al. 2010). As of 2007, about 85% of the population was concentrated at Great Gull Island, NY (1,227 pairs); Bird Island, Marion, MA (1,111 pairs); and Ram Island, Mattapoisett, MA (463 pairs). There was a small colony (48 pairs) on Penikese Island and 26 pairs nesting on Monomoy National Wildlife Refuge (Mostello 2007). Areas located in the northeast and northwest of the Ocean SAMP area lie within the foraging range of the Roseate Tern, and may potentially be used by for foraging adults.
1. Figure 8.41: Roseate tern nesting locations in Southern New England (Paton et al. 2010).