Liu, Zhen (Jiangsu University of Science and Technology) | Zhu, Renqing (Jiangsu University of Science and Technology) | Ji, Chunyan (Jiangsu University of Science and Technology) | Chen, Minglu (Jiangsu University of Science and Technology) | Teng, Bin (Dalian University of Technology) | Li, Liangbi (Jiangsu Modern Shipbuilding Technology Co. Ltd, Jiangsu University of Science and Technology)
Streever, Bill (BP) | Ellison, William T. (Marine Acoustics, Inc.) | Frankel, Adam S. (Marine Acoustics, Inc.) | Racca, Roberto (Jasco Applied Sciences) | Angliss, Robyn (Alaska Fisheries Science Center, NMFS/NOAA) | Clark, Christopher (Cornell University) | Fleishman, Erica (University of California) | Guerra, Melania (Cornell University) | Leu, Matthias (The College of William and Mary) | Oliveira, Shirley (North Slope Borough) | Sformo, Todd (SEA, Inc.) | Southall, Brandon (North Slope Borough) | Suydam, Robert
Most assessments of multiple, interacting, and/or repeated anthropogenic underwater sounds (sometimes considered to be an aspect of cumulative effects assessment) rely on narrative descriptions rather than systematic evaluations. In 2010, recognizing the need to better understand the potential effects of multiple sound sources (such as vessels, drilling rigs, pile drivers and seismic operations), British Petroleum (BP) sponsored the University of California to convene an expert committee tasked with advancing a method of systematic evaluation. The method developed by the committee (1) identifies the species, region, and period to be assessed, (2) compiles data on relevant sound sources for that region and period, (3) models the acoustic footprint of those sources, (4) models the movement of simulated marine mammals (animats) through the acoustic footprint, and (5) aggregates data on sound exposure and movements for each of the simulated animals. The method was applied to a test case or trial loosely based on data from the Alaskan Beaufort Sea during a period of seismic exploration and other activities. Substantial additional work is needed to better define output metrics related to degradation of acoustic habitat and to understand the potential effects of multiple sound sources on individuals and populations. Nevertheless, the method provides a starting point that will lead to improved understanding of the implications of multiple underwater sound sources associated with industrial activities.
We present results of monitoring studies on emergent coral reefs and submerged shoals, two potentially sensitive seabed habitats found within range of the modeled hydrocarbon plume from the 2009 Montara uncontrolled release in the Timor Sea.
Divers conducted reef surveys 6 and 16 months after the release was stopped. Hydrocarbons were detected in surface carbonate sediments at very low levels and declined between the two surveys in both frequency of occurrence and concentration. While hydrocarbon degradation precluded source matching, some samples were consistent with a Montara type oil, but there was also evidence for multiple sources of hydrocarbons in the region. Coral and fish communities were in good condition and potential indicators of disturbance in some elements, for example moderate levels of coral bleaching observed in 2010, were related to unusually warm sea surface temperatures rather than distance from the well head platform or plume.
The submerged shoals component targeted a series of nine discrete shoals ~30-150 km from Montara well head platform. The shoals have abrupt bathymetric profiles rising from 100-200 m depths to within 15-36 m of the sea surface. Sufficient light reaches these plateau environments to support benthic habitats for primary producers, including algae, corals and seagrass. Sampling used remotely deployed cameras and grabs.Benthic and fish communities were diverse and shared many species with shallow coral reefs. Hydrocarbon contamination was measured around the base of the shoals. While there was no conclusive evidence of a impact from the spill, spatial patterns in a subset of the fish data showed a reduction in abundance and diversity at shoals closest to the well head. Similarly a marked reduction in seagrass was noted on one shoal closest to the well head platform in the period between surveys, 6-16 months after the release was stopped. These observations may reflect an influence from the hydrocarbon release but could equally be the result of natural spatial patterns and disturbance events in the region.
Overall, the lack of sufficient prior data characterizing the region, especially for the shoals, constrained insights into any effect or otherwise of the spill and reinforces the need for regional scale baseline data. These surveys make a significant contribution and an excellent starting point for baseline characterization of the broader suite of emergent reefs and submerged shoal habitats in the Browse Basin.
In May 2011 Shell announced its commitment to the development of a Floating Liquefied Natural Gas (FLNG) concept by taking the Financial Investment Decision on the Prelude FLNG Project. Prelude is located in Australian offshore waters, approximately 475 km north-northeast of Broome and 825 km west of Darwin, and will be Shell's and possibly the world's first FLNG development. FLNG offers a number of environmental advantages over traditional onshore LNG developments. This paper describes some of these and the associated environmental permitting/approval conditions for the project.
As part of the Devil Creek Development Project, Apache successfully used horizontal directional drilling (HDD) with a delayed break out as the installation method for the shoreline crossing of a new gas pipeline at Gnoorea Point, 45 km southwest of Dampier, Western Australia to achieve excellent environmental and social outcomes.
Technical, environmental and community engagement challenges included an HDD reach distance of 1.85 km, a delayed break out technique, hard complex and variable geological strata, the HDD exit point in shallow water (6 m) and surrounded by benthic habitats consisting of corals, seagrass and macroalgae within a Marine Conservation Reserve, stringent regulatory requirements and the onshore drilling location directly adjacent to a heavily used camping area and a public boat ramp with adjacent beach.
To achieve minimal disturbance to the marine environment and social amenity of the surroundings, an extensive and innovative marine monitoring programme was used in combination with an intensive community engagement programme. The techniques used for this project have application to oil and gas activities involving stringent regulatory requirements, sensitive marine environments and proximity to public amenities.
Results, Observations and Conclusions
Mapping of the drilling fluid showed a small area of the seabed that was affected. Some small, unplanned areas of leakage of drilling fluid onto the seabed were also identified and the leaks remediated: these leakages occupied only a very small area of the seabed. Apache were required to demonstrate that HDD activities resulted in no more than 0.5% loss of seagrass, macroalgae and coral based upon losses predicted from mapping, modeling suspended sediment concentrations in the water column and sedimentation rates on the seabed based on drilling fluid discharge rates and applying conservative coral health threshold criteria to discharge model outputs to predict zones of impact to benthic habitats. An extensive marine monitoring programme, sampling before and after HDD, using high definition video camera to capture photoquadrats conclusively demonstrated that losses were significantly less than predicted and permitted.
Drilling operations were a 24 hour activity and located directly adjacent to a popular camp site and boat ramp. Apache engaged with the community before and during the HDD activity and no complaints were received from the users of the area during operations.
Significance of the Subject Matter
Provides an example of industry's ability to operate successfully in sensitive marine environments and close proximity to communities.
This paper describes a novel instrumental technique using astronomical cameras modified to monitor the whole-of-sky light emissions visible to marine turtles nesting near industrial developments in Western Australia. The results provide quantitative and qualitative data on specific light sources including sky glow which cannot be otherwise be measured in a field setting. The quantitative and qualitative results provide environmental practitioners and managers with the first reliable tool with which to monitor light emissions. This instrumental method has application well beyond marine turtles and can be used to measure and monitor light in any setting and for any receptor (wildlife or human) exposed to light, either astral or artificial.
Conference review - No abstract available.