Researchers believe the shipping lane, which brings large commercial vessel traffic into Boston Harbor through the Stellwagen Bank National Marine Sanctuary, traverses an area with a lot of whale activity. This move will add 3.75 miles to the overall distance of the shipping lane and 10 to 22 minutes to overall travel time one way, according to the Coast Guard and the National Oceanic and Atmospheric Administration.
"It may not be that much of a shift spatially, but it's a huge shift ecologically," said Mason Weinrich, executive director of the Whale Center of New England on Harbor Loop in Gloucester.
Weinrich said data, which covers sightings over the last 25 years, showed the shipping lane crossed waters frequently used by whales. The lane shifted to an area in the sanctuary with a different seabed, he said, that whales tend to avoid.
The move does not eliminate the risk of vessel strikes, Weinrich said, but "it helps in a big way."
On May 14, a 2-year-old humpback whale washed up dead on Cape Hedge Beach in Rockport, the victim of a vessel strike to the head and back, researchers said after conducting a necropsy on the 25-foot, 8-ton animal. Rockport buried the remains, minus the skeleton taken by New England Aquarium officials, behind the beach parking lot.
On June 1, a sei whale was seen off Lobster Cove in Manchester and washed ashore following a storm. It weighed nearly 25 tons, was about 45 feet long and had been struck in the back by a vessel. Manchester had the animal cut apart and hauled away in a trailer for disposal, again without its skeleton.
Weinrich said it is impossible to know where each whale was struck and killed. However, the humpback whale was seen feeding off Rockport about 24 hours before it's body washed ashore. The sei whale's carcass had been at sea for quite a bit longer, and tissue samples were first taken from it near Boston Harbor two days before it appeared in Manchester.
"Whale collisions with ships pose a significant hazard that we needed to better control," said Coast Guard Capt. Liam Slein, First Coast Guard District Chief of Prevention. "We expect this small change will protect numerous whales while also reducing the damage and hazards such collisions cause."
Earlier this week, a dead whale was found in the Stellwagen sanctuary near the shipping lane. Weinrich said a necropsy was conducted Tuesday, and there are bruises on the animal, but its cause of death has not been determined.
NOAA researchers calculated the spatial density of whales in the sanctuary to determine if collision risks in the area could be reduced by moving the shipping lanes. The Coast Guard assessed safety and navigational effects of the shift on commercial ship traffic. The data on whale presence used in the analysis was collected over a 25-year period and provided by the Whale Center of New England, the Provincetown Center for Coastal Studies, as well as sightings data collected by a host of other New England researchers, according to a statement released by the Coast Guard and NOAA.
David Wiley, a research coordinator for the Stellwagen sanctuary, said he and his colleagues began compiling the data about four years ago and began pushing for policy changes about two years ago.
"We did initial research to identify that the lane goes over the most densely used area of the sanctuary," Wiley said. "We found that if the lane shifted, it would substantially reduce the risk."
Wiley said there historically have been between zero and three whale deaths recorded, but he believes that estimate may be low because researchers initially only looked for surface damage to determine if a whale had been killed by a vessel.
"Initially we thought any whale hit by a boat would have huge surface trauma, but now we know the collisions don't always leave marks on the surface," he said. "All the damage is internal."
Part of the purpose of a necropsy is to examine the skeleton to find damage that could have been caused by a vessel.
According to the Coast Guard and NOAA, there are approximately 3,500 ship transits in Stellwagen every year, with the majority of them using the shipping lanes. The shift rotated the east-west leg of the lanes by 12 degrees to the north and lengthened the north-south lane to account for the adjustment. The lanes were narrowed by a half mile, to 1.5 miles each.
Excelerate Energy, which is building a liquefied natural gas buoy 13 miles southeast of Gloucester just west of Stellwagen, has pledged to slow its vessels to 3 to 4 knots when the massive tankers carrying supercooled natural gas are traveling out of the shipping lanes.
The state also required Excelerate, and Suez Energy North America, the other company proposing an LNG buoy, to pay a $47 million mitigation package between them. Part of that package is to pay for an acoustic monitoring system designed to detect whales.