13-09-2014, 12:44 PM
Potential Impacts of Ocean Energy Development
on Marine Mammals in Oregon
Potential Impacts.pdf (Size: 801.78 KB / Downloads: 17)
Abstract:
The demand for clean renewable energy sources is increasing worldwide and the state
of Oregon hopes to establish itself as a leader in ocean wave energy research and development.
Seven coastal counties have been selected as potential offshore sites for wave energy parks, and
Tillamook County has been identified for a potential wind-float park. The state of Oregon works
in partnership with several federal, state, and non-profit agencies to oversee the responsible
development of ocean energy. The technology used for wave energy development is relatively
new and little is known about the environmental impacts it will have on our coastal ecosystems.
In an effort to identify potential environmental impacts of wave energy development, a workshop
was held at the Hatfield Marine Science Center in Newport, Oregon, to assess uncertainties and
identify research projects that could aid in minimizing the impact. Of concern regarding marine
mammals was potential collision and entanglement in mooring cables and behavioral reactions to
the acoustic output of wave energy buoys during installation and operation. There is available
research on the impacts of marine wind energy on marine mammals, however, it is limited and
more baseline studies are needed. This review is focused on the development of ocean energy in
Oregon, potential impacts to marine mammals, and reviewing current and future research that
could aid in mitigating those impacts. Specific interest is placed on the Eastern Gray whale
(Eschrichtius robustus), Harbor porpoise (Phocoena phocoena), and local pinniped populations.
While clean renewable energy development in Oregon is beneficial for the economy, it may
come with ecological costs, including impacts on Oregon’s marine mammals.
. Introduction
As we move into the 21st century, the demand for clean and sustainable renewable energy is
increasing worldwide. The threat of global climate change due to increasing carbon emissions in
the atmosphere and reliance on fossil fuels has led to the search for clean renewable energy
sources as well as development of technology to harness that energy (Cada et al. 2007; Pelc and
Fujita 2002). In 2005, President George W. Bush signed the Energy Policy Act which
encouraged the development of renewable energy sources in the United States and provided
various tax incentives to those who increased energy efficiency (United States 2005). The act
also stated the federal government was required to purchase a minimum of 7.5% of its electricity
from renewable energy sources by 2013 (United States 2005). Since then, renewable energy in
the United States has skyrocketed and in 2009 over half of newly installed power capacity was
from clean renewable energy (REN21 2010).
Wave Energy Background
While the development of wave energy conversion devices (WECs) to harness the power of the
ocean is relatively new, the concept dates back to 1799 when the earliest patent known for
converting wave energy was filed (Falcão 2010). In the 1940’s, Yoshio Masuda, a researcher in
Japan, developed the first oscillating water column and has since been regarded as a pioneer in
wave energy technology (Falcão 2010). Later on, the oil crisis in 1973 spurred the scientific
community to look deeper into the possibility of converting wave energy (Falcão 2010; Patrício
et al. 2009). Today, a wide variety of WECs are in development. For more information on
specific WEC devices, please see (Lavrakas and Smith 2009).
Gray Whale
The Eastern North Pacific stock of gray whales (Eschrichtius robustus) live on the west coast of
North America, spending their summers feeding up in the Bering and Chukchi Seas and
migrating south to Baja California, Mexico in the winter to breeding and calving lagoons
(Ortega-Ortiz and Mate 2008). Some of the population remains in the Pacific Northwest from
May-October and are referred to as “resident” gray whales (Ortega-Ortiz and Mate 2008). Gray
whales are mysticetes, baleen whales, and spend the majority of their time in coastal waters.
They have poor sight and rely heavily on underwater sound for communication, foraging, and
navigation purposes (Perrin et. al. 2002). The gray whale emits low frequency broadband signals
ranging from around 100 Hz to 4 kHz (Perrin et. al. 2002). Human induced anthropogenic noise
often occurs in this low frequency range with high intensity outputs and as a result gray whales
have been documented increasing their call types, rates, and frequency in order to overcome the
disturbance (Perrin et. al. 2002).
Pile Driving in Newport Harbor
This research is still in the development stage. Dr. Dave Mellinger and colleagues will conduct
research on the pile driving operation at the new NOAA headquarters in Newport, Oregon. The
project will be approximately four months long, continuously monitoring the underwater
acoustic sound fields produced before, during, and after pile driving activities occur (Mellinger
et al. 2010). Their research will evaluate the potential effects of pile driving on nearby marine
mammal species, particularly the California sea lion (Zalophus californianus) (Mellinger et al.
2010). Two underwater hydrophones will be placed somewhere within Newport Harbor, outside
the vessel traffic lane. The Port of Newport and United States Coast Guard will be consulted on
the placement. This project will also be accompanied with a visual survey by the Oregon State
Marine Mammal Institute.
Conclusion
With increasing demand worldwide for sustainable clean renewable energy sources, the
responsible development of ocean energy technologies is critical. The state of Oregon is
dedicated to the responsible development of ocean energy, overseen by OWET. While the state
of Oregon would like to become the North American leader in ocean energy research and
development, it is crucial to assess the environmental costs our coastline will endure. The idea of
“clean” renewable energy may in fact have significant environmental costs. The workshops held
in Oregon on the potential impacts of wave energy have identified current knowledge and areas
of research to focus on. In the future, similar workshops should be held regarding the
development of offshore wind energy in Oregon. With the state of Oregon, development
companies, and scientists working together, the responsible development of ocean energy is
achievable.