An offshore wind developer is using satellite technology to determine whether an endangered shorebird species would risk colliding with planned wind turbines when it migrates from New Jersey beaches to South America.
The company, Atlantic Shores, has hired Larry Niles, a wildlife biologist, to attach satellite tags to 30 red knots to collect data on their flight path and altitude that can be used to judge whether a proposed wind farm off Atlantic City would conflict with the migration.
Niles, who has been monitoring the bird’s migration through New Jersey for the last 24 years, will begin the project this week by trapping some of the birds on a beach at Brigantine using a net fired with small cannons, allowing them to be captured, weighed and measured before having the satellite tags attached.
Niles will use the weight of individual birds to judge when they are likely to resume their southbound migration, based on research showing that they need to reach a certain weight in order to have the energy to fly to wintering grounds as far away as Tierra del Fuego at the southernmost tip of South America. Based on the expected departure date, he will program the satellite tags to send data on the birds’ movements in 60 “pings” over a specified period.
The data will allow the company, the conservation community and federal regulators to determine for the first time whether the wind farm would represent a new threat to the birds, whose depleted population has already led New Jersey to classify them as endangered, and for the U.S. Fish & Wildlife Service to designate them a threatened species.
Red knots, rusty-red or gray birds about the size of a robin, and weighing less than 5 ounces, are mostly known in New Jersey for their annual visits each May to the Delaware Bay beaches where they feast on the eggs of horseshoe crabs and put on enough weight to complete migrations of up to 9,000 miles – one of the longest in the avian world – to their Canadian breeding grounds.
The mysteries of their journey southward
While their northbound migration has been closely studied and widely reported in the media, less is known about their return trip and whether the species faces additional threats to its survival – such as collisions with offshore wind turbines – on the southbound journey.
New Jersey’s fledgling offshore wind industry is getting big support from Gov. Phil Murphy, who has pushed green energy and backed a plan to make the state home to a facility that would build and assemble massive wind turbines. The data gathered by Niles and his team will show whether wind farms are another threat to a vulnerable species, and will give the industry a chance to show a sometimes skeptical public that it’s concerned about its relationship to the natural world.
“The industry is still trying to figure out how it does these reviews,” said Paul Phifer, permitting manager for Atlantic Shores, which holds a lease on 183,000 acres of ocean about 15 miles off Atlantic City. “Red knots probably fly through our area, and we’re not quite sure of the degree to which they fly through our area, and if they do, they do it at night. Fortunately, red knots are big enough, and the satellite technology is getting good enough, that we can put satellite tags on them.”
Whatever results are obtained from the red knot project will be reviewed by the U.S. Fish & Wildlife Service, which is responsible for protecting listed species like the knot.
Offshore wind is an important component of Murphy’s plan to switch the state to 100% clean energy by mid-century. Last year, he set a goal of generating 7.5 gigawatts of offshore wind by 2035. About a third of that, or enough to power almost 1 million homes, would come from the Atlantic Shores project if fully developed, said Jennifer Daniels, development director for the company, which is a 50-50 partnership between Shell New Energies US and EDF Renewables North America.
The experience in Europe, where the offshore wind industry is much more developed than that in the U.S., is that the risk of birds colliding with turbines is low, said Phifer, a former official with the U.S. Fish & Wildlife Service who led its designation of the red knot as threatened in 2014. One European study in 2018 found only six bird strikes out of 3,375 migratory trips, a rate of 0.017%, he said.
Managing the risk
But when the risk is multiplied across the potential 20 gigawatts of wind power that the federal government projects eventually for the Eastern Seaboard, the question is how to manage it, Phifer said.
“None of this is risk-free, so how do you manage the risk?” he said. “Birding issues in Europe are significant, and I imagine they will be in New Jersey as well.”
Still, the state’s leading bird conservation group, NJ Audubon, is comforted that the proposed wind farm will be about 15 miles offshore, where it will present less of a threat to birds than closer in, simply because fewer birds migrate that far out, said David Mizrahi, vice president for research and monitoring at the nonprofit.
“There’s a lot of data to suggest that as you go further offshore, the encounter rates of wildlife diminish,” he said. “We are certainly supportive of a project that is further out, and we are certainly supportive of the work to identify the possible issues related to red knots.”
He said NJ Audubon fully supports the development of offshore wind as a source of clean energy and encourages the satellite-tagging project.
Even though other shorebirds like semipalmated sandpipers are also in decline, it’s doubtful that they could be studied in the same way as the knot because they are about one-fifth its size, and so would be incapable of flying with a satellite tag, Mizrahi said.
Calculating the threat
If Niles catches 30 birds at Brigantine and attaches a 60-“ping” satellite transmitter to each of them, researchers will have data from a total of 1,800 “pings” on which to decide whether a wind farm would be a threat to the birds.
But trapping enough birds won’t be easy because southbound flocks are a lot smaller than those going through Delaware Bay in the spring, and because Niles and his team are seeking the so-called long-distance birds – those that fly all the way to Tierra del Fuego. Distinguishing them from others that winter in Brazil or the southeastern U.S. is an inexact science. “It’s going to be tricky,” he said.
Even if the data shows that the knots are flying higher than the 300 feet of a typical offshore wind turbine, they will still be influenced by winds that lead them to fly at different altitudes in search of lower wind resistance, Niles said. The satellite data is also intended to show whether the birds get close to turbine height under different weather conditions.
Niles, who is working on the project with New Jersey’s Division of Fish & Wildlife, hopes the project will also draw attention to the need to protect the only two New Jersey sites – Brigantine and Stone Harbor – where the birds pause on their southbound migration each year.
Although the Brigantine site has been fenced off this year to protect another shorebird, the piping plover, there is no such protection at Stone Harbor where human disturbance by boaters, swimmers and beachgoers makes it difficult for the knots to feed and put on enough weight to fuel their onward flights. “It’s pandemonium,” he said.
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