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NRC committee hears testimony on impacts of North Slope oil and gas development Gravel placed to date is 12,000 acres; Corps of Engineers working with companies this past year to get them to reuse gravel versus capping or grind and inject Kristen Nelson PNA Editor-in-Chief
The volume of gravel on the North Slope is fairly well known, but the impact of oil and gas development on tundra and wildlife is not as well understood. That was some of what the National Research Council committee heard at an open meeting April 2 in Fairbanks. The committee is preparing a report on cumulative oil and gas impacts on the North Slope.
David Hobby of the Corps of Engineers said the Corps’ latest estimate of gravel placed for oil and gas activities is 12,000 acres, although that may not include early exploration pads. He said the Corps has been working with the companies over the last year to get them to reuse gravel — there are three options now for gravel at sites being remediated: capping; grind and inject; treatment and reuse. (See related news item on page B1 of this issue.)
Plants at little risk Torre Jorgenson of ABR Environmental Research and Service told the committee that plant populations were not at much risk on the North Slope, but also said there was very poor data for indirect impacts. An assessment of seismic trails and ice roads and ice pads shows the overall impacts are small and recovery occurs over a few years, but, he said, there are some areas where “green trails” exist from compression damage in winter.
Anne Morkill, assistant refuge manager at the Arctic National Wildlife Refuge, said that in spite of onsite monitors, the 1984-85 seismic program on the coastal plain damaged the tundra. The snow cover was fairly poor in that winter, she said, and damage was also related to the type of equipment used. About one-quarter of the seismic trails in ANWR received some damage, she said, and there is still scenic impact. Caribou displacement Two researchers, wildlife biologist Stephen Murphy of the University of Alaska Fairbanks and Brad Griffith, U.S. Geological Service, Alaska Cooperative Fish and Wildlife Research Unit at UAF, told the committee that there is good information on displacement of caribou by human activity, but less complete information on how displacement and population are related to weather and what happens to caribou in other parts of their range.
Murphy said studies have found displacement from facilities during calving, as much as 4 kilometers for two to three weeks.
“Most of the data that this is based on are 20 years old,” he said, “and we might have a different situation now with animals that were born and raised in oil fields. But we’re going to look at this localized displacement again.”
The other issue with calving is regional displacement from traditional calving grounds, he said, and noted that calving for the central Arctic herd has shifted south from Kuparuk-Milne as infrastructure as been built .
Both the central Arctic herd and the Teshekpuk Lake herd in the undeveloped area to the west have grown in recent years and Murphy said temperatures are favorable now compared weather over the past 100 years.
“If you think of the Arctic herd and the central Arctic herd as being an experiment, what happens when we introduce an oil field into the range of a caribou herd, if that’s a good analogy, we haven’t finished the experiment. We have not seen a series of hard winters, we have not seen very difficult environmental conditions …” Coastal plain different Brad Griffith said that over 20 years the porcupine herd has calved about two-thirds of the time on the coastal plain and about one-third of the time in the foothills.
“The porcupine herd is on a narrow coastal plain with very little room to maneuver,” he said. “If they start redistributing much they’re going to be into the foothills and the mountains where predator density is reportedly higher. Whereas the central Arctic herd can move an equivalent distance and remain on a flat plain and not be redistributed into the foothills and mountains.”
Griffith said that across the Arctic the 13 North American barren ground caribou herds have been displaced by activities such as railroads, hydroelectric development and power lines. Cows during calving are particularly sensitive to development, he said.
Griffith said modeling results of calving ground displacement for the porcupine herd predict that calf survival would change as a result of displacement. But, he said, there are unknowns. For instance, he said, we “don’t know if winter calf mortality is additive or compensatory to what happens in the summer… “
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