Sea turtles are some of the oldest, slowest growing creatures in the ocean; some species take up to 30 years to reach maturity. A researcher studying these ancient beasts might get the chance to observe just one generation. Selina Heppell, who has devoted much of her career to sea turtle conservation planning, doesn't want to wait that long.
Heppell is a marine ecologist at Oregon State University. She has worked with sharks, sea turtles, and West Coast rockfish, studying how populations of these long-lived species respond when conditions are disrupted in their deep ocean world. When such slow-growing creatures are harvested directly or accidentally killed in fishing operations, it can be hard for the population to recover. It is Heppell’s job to figure out how many creatures need to be left alone— and where—in order for that population to survive.
“In the old days, these fish and turtles had refuges away from human impacts—isolated beaches, big ocean currents, the deep sea—where populations had a chance to replenish themselves,” Heppell said. “Now, with modern technology, we can intensively harvest fish anywhere, anytime—far offshore, in deep submarine canyons, and continuously in any weather for months at a time.” As refuges are lost, populations become more vulnerable and they lose their natural resilience.
But finding the right balance between adequate protection for sea life and sustainable fisheries for people is a tricky business. The ocean is vast and it’s hard to count things that you can’t actually see. Increasingly, Heppell is called on to navigate the murky waters of ocean management and policy, applying what she knows as a scientist to help craft recovery plans for endangered species such as sea turtles and overfished species such as the yelloweye rockfish.
Heppell moves gracefully past old conflicts to help the fishing industry and conservation groups find common ground. As a result, she’s been asked to advise the National Marine Fisheries Service and to serve on the Pacific Fisheries Management Council. Heppell connects the virtual world of mathematical models with the nuts-and-bolts management of harvest rates and conservation policies. She uses biological information about the animals she studies—their population size, distribution, behavior, habitat requirements—to simulate populations in “virtual space.” Then she tests what might happen with various management strategies without putting at risk a population or an industry. “If the policy is too lax, we risk losing a population; if the policy is too conservative, we risk shutting down an industry unnecessarily. Testing models lets us get closer to the right measures to protect both the species and the industry.”
As a panel member for a National Research Council review, Heppell recently evaluated data collection and modeling of sea turtle populations. At the time, she strongly recommended that government monitoring should shift from simply counting turtle nests on beaches to measuring survival and growth rates of turtles at sea. Such a shift of monitoring would have made it more possible to understand the effects of the BP oil spill on highly sensitive species, such as the Kemp’s ridley sea turtle in the Gulf of Mexico.
“The Kemp’s ridley has made a terrific comeback, thanks to intensive conservation efforts by Mexican and U.S. scientists, volunteers, conservation groups, and recovery support from the shrimping industry,” Heppell said. “The oil spill has put their recovery in jeopardy; but we don’t know how bad things really are. Our model simulations will be uncertain because we lack basic information about the turtles’ life at sea.”
In the highly charged world of fisheries management, Heppell insists on solid evidence to improve the mathematical models used to determine sustainable catch levels.
“Models can be dangerous tools,” she said. “It’s easy to pull the wool over someone’s eyes with pages of complicated equations. Science need not be unfathomable. It requires explaining our assumptions and laying out the tools we use to reach our conclusions.”
Heppell has been explaining the complexities of marine life and science since she was 12, when she began volunteering as a guide and interpreter at the Seattle Aquarium. She works hard to keep messages simple, but accurate. “People need to know about the seafood they eat, and how fishing can be modified to reduce negative impacts on the environment,” she said. “I particularly love to talk to kids about the sea, and to combine math and biology. As a student, I loved science butreally didn’t like math. Then I learned about models and their application to sea turtle conservation and I was hooked—math can help save endangered species. I try to convey that excitement to the undergraduate math-phobes that I teach now.”
Science communication is central to the work of students in Heppell’s lab, which she shares with her husband, Scott, a fisheries ecologist and physiologist who is also on the faculty of OSU’s Department of Fisheries and Wildlife. Their students partner with people in the field, such as fishermen in Port Orford working with rockfish; Oregon coast communities working to develop marine reserves; and agency scientists working on grouper conservation in the Cayman Islands. In each case, they help build conservation plans based on rigorous science and evidence based methods.
Conservation biology is a relatively young science, and the Heppells are introducing these evidence-based methods to students around the world. In 2004, the Heppells started the International School of Conservation Biology in Croatia, an intensive short course that has engaged graduate students from 19 countries, primarily from eastern Europe where conservation biology is a new discipline and a new priority.
“If we scientists speak only among ourselves, we won’t be effective,” Heppell said. “We must work with fishermen, biologists, conservation groups, governments, and managers so that we understand the challenges that we each face and the populations we want to both protect and harvest. We all want long-term sustainability of ocean ecosystems. Combining good science with local knowledge is the key.”