Scoping document

With the increasing number and size of offshore Wind farm construction, there has been an increased rate of consequences and impacts of these constructions on the lives of the marine species (Zhang, Fowai and Sun 2016). Besides the natural stochastic process, certain other anthropogenic activities like operation, construction and maintenance can affect the abundance and behavior of marine mammals. Researchers have found out that the loud sounds that are emitted during the pile driving have severe impacts on the marine species (Dai et al. 2015). These can potentially damage the hearing organs of the animals. There lies further risk of the animals in the ocean getting injured by the ships, the movements of the vessels and activities associated with survey and installation of the construction buildings in the sea. Marine animals are sensitive species and they are sensitive to sound (Premalatha,Abbasiand Abbasi2014). Studies have focused on the increasing influence of offshore wind farm construction on marine mammals recently for understanding how to facilitate planning in the ocean area (“Hornsea Offshore Wind Farm Project-Environmental Statement.” 2015). The assignment reviewed the potential threats to the marine mammal species namely, grey seals, minke whales, harbour porpoise, harbour seals and more.

The purpose and scope of this assignment are to provide a baseline characterization of the ecology of the marine mammals. The objective of the assignment is to characterize the area of study of the marine mammals with respect to their presence, distribution, and seasonality. Further, the assignment aims to produce density maps for each of the key species for indicating the targeted areas and the potential usage across the area (Bergström et al. 2014). The scope of the report is to compare the mammal study area with the North Sea region for assessing the importance of the report regarding the safety of the marine mammals in a broader context. While writing the report, the number of marine mammals valued ecological report has been considered. Some of the reports are from Marine Management Organization and Joint Nature Conservation Committee. The report highlights the adverse effect of the establishment of Hornsea 3 offshore Wind farm on the lives of the species living in the ocean (Premalatha, Abbasi and Abbasi 2014). The scope of this report is to find out the areas where development is required for the safety of the marine population and how these species can be preserved and protected in the coming days.

Assessment of potential impacts

The growth of offshore wind firms plays a major role in meeting the carbon reduction targets which have been expanded to mitigate the potential effects of the change in the climate.

The Hornsea 3 offshore Wind farm is situated approximately at 31km off the coast of Yorkshire in the southern hemisphere of the North Sea. The Hornsea 3 offshore zone covers an area of approximately 5000 km² and falls under the survey Block U of the Small Cetaceans in the North Sea (“Hornsea Offshore Wind Farm Project-Environmental Statement.” 2015). The construction of The Hornsea 3 offshore Wind farm is having a negative impact on the lives of the mammals in the ocean both during the construction and in the operation stage (Nehls et al. 2016). The turbines, the noise of construction, the noise in the underwater and the traffic of the boat and helicopter disturbs the mammals (Zhang, Fowai and Sun 2016).

Research has found out that mammals are very dependent and sensitive of their hearing systems (Verfuss et al. 2016). They use their hearing system for several purposes like communicating among fellow species or team members, orientation and echolocation. The consequences caused due to the formation of wind farms and its noises cause problems of viability, increased chances of diseases, damage to any organs and even death.

Some of the possible impacts of the development of offshore wind farm on marine mammal population are:

•    Anthropogenic Sound
•    Wind Firm construction noise
•    Wind Firm operation noise
•    Decommissioning
•    Pollution (Ward 2014)
•    Ship strikes
•    Cabling

According to certain reports, the noise range measured by the German Federal Ministry of Environment, the noise level caused due to the construction of farms or the movement of any other transport in or near the ocean does not seem to damage the hearing ability or the hearing organs of the marine mammals (Dongenergy.co.uk. 2018). It is still a huge debate whether the noise affects the behavior of the species in the area surrounding the Hornsea 3 turbines. Different reactions between the different species in the ocean give a clear analysis of the adverse effect of the offshore wind farm on the livelihood of the species underwater (Russell 2016).

One of the major potential risks associated with the evolution and growth of the offshore wind energy is the ship collisions with the turbines (Goodale and Milman 2016). The collision with the turbine leads to a possible destruction and breakdown of a ship (Areas 2014). The spillage of oil or chemicals from the ship in the ocean water results in damage to the health of the mammals in the ocean. The oil and the waste materials that spill into the ocean water tremendously affect the mammals. It results in chronic diseases among the mammals and often leads to death (Dahl, de Jong and Popper 2015).

Possible mitigation

Besides the radars and radio signals also have an adverse impact on the lives of the marine mammal population. The radar waves and the pulses of high-frequency electromagnetic fields have a severe impact on mammals of the ocean. It affects their behavior, culture and the nature of their livelihoods (Karlõševa et al. 2016).

Table: 1       

The table shows the number of species observed who are residing in the North Sea. From the above table it is clear that the number of Harbour porpoise in the Southern central North Sea is

the highest. The White-beaked dolphin and the Bottlenose dolphin population are very low.

Source: (“Hornsea Offshore Wind Farm Project-Environmental Statement.” 2015)

Chart: 1

The chart explains the number of species sighted in the North Sea. The number of White Beaked Dolphin observed in the sea is the highest, followed by the Gray seal and the Harbour seal. The number of porpoise sighted in the sea is very negligible.

Source: (“Hornsea Offshore Wind Farm Project-Environmental Statement.” 2015)

Table: 2       

Table explains the summary of the potential interest of rMCZs to marine mammals living in the central and southern part of North Sea.

Source: (“Hornsea Offshore Wind Farm Project-Environmental Statement.” 2015)

Chart 2  Source: (“Hornsea Offshore Wind Farm Project-Environmental Statement.” 2015)

The Figure explains the patterns in the seasonal variation of harbor porpoise across the subzones. The harbor porpoise is the only resident cetacean marine species in the North Sea. Throughout the last decades, the stock of harbor porpoise has been declining drastically.

Chart 3       

The Table shows the number of grey seals counted on the east coast of the North Sea throughout the span of years.

Source: (“Hornsea Offshore Wind Farm Project-Environmental Statement.” 2015)

Sections 101(a)(5)(A) and (D) of the Marine Mammals Protection Act authorizes incidental but un-intentional movements only on the assurance that they would be less in number, have negligible or zero impact on marine mammals and have no un-mitigable adverse effect on the marine mammals’ habitats (Sparling, Lonergan and McConnell 2018). Mitigation measures for the reduction of potential effects to marine population from noise coming from the construction and wind farm activities include the formation of site-specific exclusion and zones of harassments (May et al. 2015).

Mitigation measures for impact pile driving may also include a system for the reduction of pile driving power in case if the mammals in the ocean approach close enough and has the chance of getting injured. Additional measures may also include sound attenuation systems like dual walled shields/piles, cofferdams, bubble curtains in the initial stage of pile installation (Bergström et al. 2014).

Monitoring plan to allow for assessment of any long term possible impacts and your objective opinion on the development

Further surveys could be carried out to investigate the distribution of species in relation to the impacts of construction and operational sounds, electromagnetic fields, and artificial reefs.

The basic factor of a marine mammal monitoring plan is to observe the mammals in the targeted area where the effects of sound and noise are maximum. The monitoring plan is essential during the pile driving to help prevent acoustic effects on ESA-listed marine mammals (Dahl, de Jong and Popper 2015).

• The observer of the marine mammals needs to be on site throughout, during the pile driving.
• The observers must monitor the area of potential noise effects for the marine mammals during the process of pile driving (Dai et al. 2015).
• The observers must carry a hand-held or boat-mounted GPS device for verifying the monitoring distance needed from the site of the project(Dongenergy.co.uk. 2018).
• The observers must use binoculars to scan the waters within the targeted area.
• The observers must cease the pile installation process if the sea or the weather condition is bad.
• The observer must ensure scanning of the water for more than 20 mins before and during all the process of pile driving. They must report to their supervisor in case any marine mammals enter the area (Sparling, Lonergan and McConnell 2018).
• The pile driving process should be done only in broad day light when the observers can visually monitor the marine mammals.
• The observers must use “The Marine Mammal Observation Sheet” for recording species category, date, time of sighting and the nature or behavior of the marine mammals during the pile driving(Bergström et al. 2014).

Since the marine mammals are highly mobile creatures, designing and developing some feasible and appropriate monitoring programme is a challenge. The formation of a monitoring and mitigation plan for the marine mammal population should be site specific. The plan should consider the account of sound propagation and the presence of marine species in the place of the target (Culloch et al. 2016). Monitoring and mitigation regulations should be adapted to suit the animals residing within the radius of the space that is affected by the sound levels which can cause harm to them. Throughout these years, many mitigation measures have been advised for the development of the construction phase of offshore wind farms (May et al. 2015). Various monitoring plans are required depending on the risks involved and the requirements of development in different areas. Some of the measures that can be used during the construction of the firm are:

• Assignation of an exclusion zone
• Usage of acoustic deterrents
• Seasonal/area restrictions
• Engineering designs ( Premalatha, Abbasi and Abbasi 2014)
• Passive and visual acoustic monitoring within the range of exclusion zone.

Source: (Sparling, Lonerganand McConnell2018)

The construction and operation of the wind farms have been adversely affecting the lives of the marine species through the decades. Loud noise, transportation of heavy vessels in the ocean has been disrupting the ecology and livelihood of the marine mammals. This is because there lies an adverse or a negative relationship between the sound levels and the sensitivity of the marine animals. The sound or the noises that are produced due to the construction or the transportation or while offshore wind farm operations affect the hearing paradox and result in various diseases among the marine mammals.

Showing consideration while constructing near the dwelling areas and during the time of reproductive periods can be one of the measures to reduce the impacts on marine mammals from operation and construction of offshore wind turbines of Hornsea 3 firm (“Hornsea Offshore Wind Farm Project-Environmental Statement.” 2015). Major and special consideration should be done for the harbor seals, porpoise and some of the few grey seals residing in the North Sea. The gradual increase in the power of blows during piling may give the species in the ocean some time to move or flee from the area before their hearing levels are hurt. Acoustic scars can also be used to warn the seals and the porpoises (Bergström et al. 2014). Besides, screening off pile sound with the use of air bubbles can also be an efficient way to alert the animals in the ocean (Hermannsen et al. 2015).

Your objective opinion on the aspect of the development you have explored

Though it is difficult to reduce the continuous noise of the construction and operating phase of the Hornsea 3 wind farm, future generators should be developed so that they emit less sound and less noise get spread into the water levels (Premalatha, Abbasiand Abbasi 2014).

Another possible solution that has been proposed by the researchers explains the introduction of newer devices to cover the foundations with noise absorbing materials (Premalatha, Abbasiand Abbasi 2014). The effect of the electromagnetic waves has considerably reduced throughout these years and hence no action is needed to reduce its impact (Sparling, Lonerganand McConnell 2018).The construction and operation plan for the offshore wind farms needs to go through an environmental impact procedure by the Department of Marine. This should be done to make sure that little or no harm is made to the marine mammals living in the ocean.

Conclusion

Attempts to extend approach for analyzing the potential effects of the disturbance to the livelihood of the marine mammal population face a number of challenges. There is very less data on the response of mammals to the anthropogenic sound. Besides, the identification of vital rates which are the most sensitive to the effects of disturbance of the marine species is a big challenge. Though there is a need for the development of realistic stochastic models of population dynamics of the marine mammals, the method of formation of the model is a big confusion. This is because there is no relevant information for the most of the marine mammals till date and it is unlikely to be available in the near future.

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