|Two Humpback Whales; Atlantic Ocean: Texas Horizon 08.2007|
Location of Northeast Gateway Pipeline Project:
My first offshore assignment was the construction and implementation of the Northeast Gateway Pipeline Project (NEG). Northeast Gateway Energy Bridge, L.L.C. acquired a license to construct, own, and operate the Northeast Gateway Deepwater Port (NEG Port or Port). This NEG was located approximately 13 miles southeast of Gloucester, Massachusetts. The Port, which will be located in Massachusetts Bay, will consist of a submerged buoy system to moor specially designed Liquefied Natural Gas (LNG) carriers approximately 13 miles offshore of Massachusetts in Federal waters approximately 270 to 290 feet in depth. The facility will deliver regasified LNG to onshore markets via new and existing pipeline facilities owned and operated by Algonquin Gas Transmission, LLC (Algonquin).
|Two Humpback Whales Blowing and Tail Slapping; Atlantic Ocean: Texas Horizon 09.2007|
Main Objective of Northeast Gateway Pipeline Project:
During this time, Marine Mammal Scientists or also recognized as Marine Mammal Observers (MMOs) were placed on the project to document all marine mammal sightings, correspond with Cornell University and Woods Hole Oceanographic Institution, and enforce specific guidelines into the project’s structure. The guidelines applied by the Marine Mammal Scientists were to shut down operations in severe environmental conditions (thick fog), a Humpback whale within 100 meters of the ship (within exclusion zone), and if there was a sighting of the North Atlantic right whale (NARW) close to the ship. In accordance with enforcing these guidelines, the United States Coast Guard (USCG), the National Oceanographic and Atmospheric Administration (NOAA), the Commonwealth of Massachusetts and other Federal and State agencies has established a program for preventing, monitoring, and mitigating environmental impacts (Prevention, Monitoring, and Mitigation Plan [PMMP]). The PMMP integrated environmental permits, certificates, licenses, and approved monitoring and mitigation plans obtained by the NEG and Algonquin – this supported the collective pre-construction, construction, post-construction, and operation of the NEG Port and Pipeline Lateral (an extended piece of the pipeline). Without getting to technical, the PMMP served as a purpose to support the requirements that helped minimize adverse impacts to marine mammals. This objective mixes into the overall composition of working with the Endangered Species Act (ESA) Biological Opinion (BO), the Marine Mammal Protection Act (MMPA), Incidental Harassment Authorization (IHA), and Incidental Take Statement (ITS) as amended, and the National Marine Sanctuary Act (NMSA) Section.
|Close-up of Humpback Whale; Atlantic Ocean: Texas Horizon 09.2007|
In other words, this project had to be executed with careful consideration towards the marine mammals, especially the critically endangered North Atlantic right whale (Eubalaena glacialis) (NARW) that were subjected to the operation of NEG. The NARW was a rare occurrence in these waters, but the fact of the matter, was that they did exist – this created an effective approach in the NEG project to help conserve them and their environment. NOAA/National Marine Fisheries Service (NMFS), has determined that serious injury or mortality of even a single individual of the critically endangered North Atlantic right whale could jeopardize this species’ continued existence.
|Humpback Fluke in Strong Sun Glare; Atlantic Ocean: Texas Horizon 09.2007|
In addition, serious injury or mortality to other large whale species that frequent greater Massachusetts Bay waters, including North Atlantic fin whale (Balaenoptera physalus), Humpback whale (Megaptera novaeangliae), Sei whale (Balaenoptera borealis), and Blue whale (Balaenoptera musculus), is also prohibited due to their endangered status. In addition, the Minke whale (Balaenoptera acutorostrata), Common dolphin (Delphinus delphis), Long-finned pilot whale (Globicephala melas) Harbor porpoise, (Phocoena phocoena), Harbor seal (Phocac vitulina), and Gray seal (Halichoerus grypus) also were taken in account for. Therefore, Federal actions that could lead to even a very small increased risk of serious injury or mortality must contain plans to mitigate the potential impact of those actions to these species. Specifically, Federal agencies whose actions may affect endangered and/or threatened species must consult with NMFS as specified under the implementing regulations for the ESA. Any harassment to any marine mammal species due to the licensed activity must also be permitted by NMFS as specified under the MMPA.
|Humpback Whale in Exclusion Zone; Atlantic Ocean: Texas Horizon 08.2007|
In other words, these federal agencies were taken effective measures and implementing procedures into the design of the NEG project to protect the environment and its inhabitants. Honestly, this is why I was presently there – to help oversee our guidelines enforced and carefully monitor the area for marine mammals. Our project consisted of a dive bell, which concealed commercial divers who were constructing the pipeline below the ocean’s surface – the guidelines were also established to reassure their safety while they were working at critical depths.
|North Atlantic White-Sided Dolphin; Atlantic Ocean: Texas Horizon 10.2007|
The project plan emphasized that NMFS did not expect any whales to be injured or killed by these activities. However, planned monitoring and mitigation measures were designed to avoid sudden onsets of potentially disturbing noise, detection of marine mammals occurring near the activities, and avoided exposing them to sound sources that may have caused hearing impairment. NMFS had established guidelines for what constituted harassment and acoustic takes on marine mammals under the Marine Mammal Protection Act (MMPA) and the Endangered Species Act (ESA). Two levels of harassment had been defined in the MMPA: Level A harassment with the potential to injure a marine mammal in the wild, and Level B harassment with the potential to disturb a marine mammal in the wild by causing disruption to behavioral patterns such as migration, breeding, feeding, and sheltering. The current thresholds were 180 dBL for Level A harassment, and 160 dBL (impulse) and 120 dBL (continuous) for Level B harassment. If you are interested in learning about Cornell University’s and Woods Hole Oceanographic Institution acoustic concepts, additional information is listed below.
My First Sighting of Megaptera novaeangliae:
I will never forget my first “sighting” of a Humpback whale (Megaptera novaeangliae); I waited patiently observing the water for 3 days until I had my first encounter with a Humpback whale. Of course, my lead Meghan seemed to sight the marine mammals right away without any hesitation or uncertainty in the identification of the marine mammal. I had confidence that I would also develop the trained eye to easily spot marine mammals within the close proximity of the ship; however, I was praying that I would begin spotting marine mammals very soon! That particular afternoon as I stood looking at the sun, I started skimming the horizon for any visible blows. To my surprise, I discovered 4 bushy blows that were gliding along the horizon.
|Humpback Fluke Lowers in Water; Atlantic Ocean: Texas Horizon 09.2007|
As I darted across to the port side of the ship to get Meghan’s attention, I almost slipped on some water dripping off the bridge deck. I was literally out of breath and all I could gesture was to grab her binoculars and follow me to the starboard side, where the sighting had taken place. Meghan looked into her binoculars in the direction that I had pointed out and immediately noticed them as well. I remember her telling me that I did a fantastic job observing the marine mammals from such a far distance away. I walked into the bridge grabbed the necessary information for our logs and enjoyed the rest of the sighting with Meghan. Would you believe that the Humpback whales remained in the same area as sunset quickly approached? What a great sighting! I love sunsets and observing Humpback whales blowing and breaching as the sun set was an incredible moment that I will never forget!
“Getting my Feet Wet”:
Once I was able to “get my feet wet” (literally), then I was finally able to understand the project and its primarily mission. I was happy to see that many precautions were taken in the overall design of this pipeline. The marine mammals were being observed by me and several other colleagues. Our working hours were increments of 12 to 12; meaning, 2 people would work midnight to noon, while the other group would work noon to midnight. There was always someone on watch, regardless of the time. Fortunately, Meghan and I were able to work noon to midnight and left the boys observing midnight to noon.
|Minke Whale Detected on IR Scanner; Atlantic Ocean: Texas Horizon 10.2007|
During the night time monitoring we had to introduce an Infra Red (IR) scanner into our daily routine, which detected the marine mammals’ presence on a tiny screen. The idea of the IR scanner was to identify main differences in water temperatures. Most of the time the screen displayed blue, which was a representation of cold water; however, only a few times there was a red color shown - this was evidence that a marine mammal was under the surface at that exact spot where you have your IR scanner pointed. I had only one nighttime sighting with the IR scanner, but it was still a pretty cool method to effectively and efficiently detect marine mammals in nighttime conditions.
|Single Fin Whale; Atlantic Ocean: Texas Horizon 09.2007|
After this initial sighting, I gained a great deal of confidence and was ready to play, “Where’s the cetaceans (whales and dolphins)?” I seemed to catch on to the identification of species pretty quickly; I soon was detecting marine mammals quite often. For my second week on the NEG project, we had noted 50 Humpback whales, 20 Fin whales, and 2 North Atlantic white-sided dolphins (Lagenorhynchus acutus). Needless to say, I was able to photograph many marine mammals, sunrises, sunsets, and any other wildlife in the immediate area. What I really enjoyed on the NEG project was the enthusiasm for marine mammals and their conservation status. I had the opportunity to chat with some biologists from Cornell University’s Bioacoustics Research Program and the Woods Hole Ocean Institution about the buoy-system that they had placed next to our ship for the sole detection of the NARW. The buoy coordinates were as followed - NEG Port was located at 42º 23’ 38.46” N/70º 35’ 31.02” W for Buoy A and 42º 23’ 56.40 N/70º 37’0.36” W for Buoy B in Massachusetts Bay.
|Two Humpback Whales Fluke and Tail Slapping; Atlantic Ocean: Texas Horizon 09.2007|
If the Marine Mammal Scientists spotted the NARW, then immediate attention would be given to the situation and the two research teams would be called. During this call the coordinates of our position, environmental conditions, observations, and any other relevant information would be provided. Those two research teams were the main consultants for developing, implementing, collecting, and analyzing the acoustic data; reporting; and maintaining the acoustic monitoring system. It was nice to work together with a bunch of individuals that could talk about marine mammals all day to you. I could not have asked for a better project, especially for my first one.
Underwater Acoustic Concepts:
The loudness of sound is dependent on the radiated sound power of the source and the propagation and attenuation characteristics of the medium through which the sound passes (sea water). The standard unit of sound is the decibel (dB), a logarithmic scale formed by taking 20 times the logarithm (base 10) of the ratio of two pressures: the measured sound pressure divided by a reference sound pressure. For underwater sound, this reference sound pressure is 1 micro-Pascal (μPa). The hearing capabilities and frequency (Hz) responses of marine mammals vary significantly. Therefore, underwater sound levels are typically expressed using unweighted or linear broadband levels (dBL) spanning the entire frequency spectrum under consideration. (For this study, the frequencies analyzed span 10 Hz to 20k Hz). The National Marine Fisheries Service (NMFS) criteria used to assess impact and determine the potential of acoustic take or harassment are also presented in dBL sound levels.
Sound sources are typically presented as sound pressure levels at a distance of 1 meter from an idealized point source, i.e. dB re 1 μPa at 1 meter. This standardized reference distance was developed to allow for direct comparison of different sound source levels. Received sound levels include the effects of propagation and attenuation that occurred between the source and receptor. Under standard propagation conditions and in non-shallow water environments, received underwater sound levels lower at a horizontal distance 100 meters away from a source will be approximately 40 dBL lower than the source level at a reference of 1 meter. However, because many man-made underwater sound sources have dimensions that are much larger than an idealized point source, the relationship between near-field and far-field sound levels is more complicated than this simple rule and must therefore be determined through field measurements. In the acoustic near field, propagation losses will be generally lower than expected. Conversely, received source levels extrapolated from far-field measurements will be higher when the acoustic energy from a large area source is back-calculated to characterize an idealized point source. To account for sound propagation resulting from a large area source such as the Energy Bridge Regasification Vessel (EBRV), the transition from the acoustic near to far field, as well as the site- specific characteristics, must be well understood.
The propagation and attenuation of sound waves under water is a complex phenomena influenced by gradients of temperature, water column depth, salinity, currents, sea surface turbulence and wake bubbles, scattering by seafloor and surface, etc. Within close range of the sound source, attenuation and propagation losses are primarily driven by geometric spreading, i.e. sound levels decreasing with increased distance from the sound source as the sound energy is gradually spread across increasingly larger and larger surfaces. In unbounded sea water, free field spherical wave spreading will occur at a decay rate of TL = 20 log R, where R is the horizontal propagation path between the source and receptor in meters and TL symbolizes sound energy transmission loss.
Extensive research has demonstrated that spherical wave spreading, together with seawater absorption rates, provides a reasonable fit to measured underwater sound levels under a wide variety of conditions. Because the ocean is bounded by the surface above and the seafloor below, additional adjustments must be made. When the propagation path becomes greater than the water depth, free field spherical spreading can no longer continue. If perfectly reflective boundaries were assumed, the spherical wave spreading would transition to cylindrical spreading, represented by the decay rate of TL = 10 log R. However, to account for the fact that neither the surface or seabed floor are perfectly reflective, modified or transitional cylindrical spreading represented by decay rate of TL = 15 log R has been shown to have the best fit when compared to actual TL measurements made at sea. At horizontal propagation distances much greater than the depth, standard cylindrical spreading combined with a linear (dB per km) absorption and scattering rate provides conservative modeling results.