DURHAM, N.C. – A new $411,000 grant from the U.S. Department of Defense’s Strategic Environmental Research and Development Program (SERDP) is funding a four-year study by Duke University researchers to better understand the cumulative effects of human and natural stresses on critically endangered North Atlantic right whales.
Fewer than 330 of the whales are thought to still exist. Findings from the new study will help scientists develop more effective conservation tools and strategies to protect the whales that remain and help reverse the species’ decline.
“Despite decades of post-whaling protection, the number of North Atlantic right whales is still shrinking due to deaths and injuries linked to vessel strikes, entanglements in fishing gear, food limitations and increasing underwater noise levels, which can elevate the whales’ stress hormones and limit their ability to navigate safely, avoid predators, find food, and locate and communicate with each another,” said Robert Schick, a research scientist at Duke’s Nicholas School of the Environment, who will co-lead the study.
“Since doing hands-on physical exams of the whales isn’t really an option, we need alternative ways to measure the adverse cumulative health effects these stressors may be having over time,” he said. “That’s what we’ll be working toward in this study.”
A key part of the research will be seeing if tools and models borrowed from epigenetics – the study of how changes in behaviors and environment affect the way genes work – can be used to project how one stress can compound the effects of the others on the whales.
“We hypothesize, based upon bioenergetics, that prey limitation will amplify the consequences of poor health induced by other stressors such as entanglement,” said Douglas Nowacek, Repass-Rodgers University Distinguished Professor of Conservation Technology in Environment and Engineering, who is co-leading the study with Schick.
“We also hypothesize that chronic stress induced by constant exposure to stressors such as anthropogenic noise may alter endocrine or neural responses in the whales and increase the normal wear and tear on their bodies, amplifying declines in health associated with stressors such as entanglement,” Nowacek said. “Time and data will tell if we’re right.”
Schick and Nowacek’s right whale case study focuses on Cape Cod Bay in Massachusetts where researchers from the Center for Coastal Studies (CCS) have been documenting the occurrence of right whales and their prey since 1984. The Duke team will collaborate with CCS, the New England Aquarium and Woods Hole Oceanographic Institution to relate information about changes in the prey populations and the distribution and abundance of right whales in the bay along with changes in stressors like ocean noise and entanglement.
“The information is out there and this project gives us a unique opportunity to develop a single authoritative dataset and build models to help understand how these multiple stressors are impacting right whales,” Schick says.
The grant supporting Schick and Nowacek is part of a larger SERDP-funded initiative, led by the University of St. Andrews, that aims to shed light on the effects of multiple stressors on many species of marine mammals including northern elephant seals, bottlenose dolphins and North Atlantic right whales.