LONG BEACH — At the Pacific County Marine Resource Council’s April 27 science conference, attendees had breakfast, lunch and dinner and heard hours of talks on fish-related science.
Sessions included McKenzie Gavery of the National Oceanic and Atmospheric Administration presenting on epigenetics in fish, and the possible effects of a hatchery environment of the epigenome of a fish and its offspring. Kathleen Sayce, a Peninsula biologist, spoke on the importance of the bottom of a water body to the entire food chain and associated ecology.
Customized gene responses
Epigenetics is the study of how the environment affects how genes express themselves. We usually treat DNA and the environment as two distinct causes of behaviors or traits, McGavery noted. But epigenetics is where that distinction breaks down; creatures with the same genetic code can have different genetic expression, giving them traits suitable to their environments. The same process by which a person’s eye cells “know” to behave differently from the person’s skin cells, even though all share identical DNA, is the process by which genes express differently in different environments. These changes are in some cases heritable despite not involving any genetic mutation.
Epigenetics can be a problem for hatchery operators. Epigenetic changes resulting from a hatchery environment that benefit a fish in the environment in which it spends its first months may be harmful to it when it leaves for the ocean. And there is currently little scientific knowledge of what environmental factors are causing what epigenetic changes. The hope is that scientific progress in the field can lead to hatchery fish that are better able to survive in the wild.
“We need to know the mechanism of change [in fish] to tell people how to improve their hatchery,” Gavery said.
Gavery presented on her group’s genetic analysis comparing hatchery fish with fish in artificial streams, conducted in the Methow River in north-central Washington. She discussed methodology, findings, and possibilities for future research.
Water bottoms matter
Sayce believes the importance of the bottom of a body of water in the food chain and ecology of that water body is neglected, with the water column mistakenly treated as the source of all food. She presented on a study conducted with Dr. Richard Wilson, a scientist and Bay Center oysterman, who removed burrowing shrimp from oyster-growing ground and observed the results. Sayce detailed the observed changes to the environment, beginning with the sand itself and continuing with responses by creatures all the way up the food chain.
The final link in the chain was the one that packed by far the most punch with the audience: the reestablishment of oyster crops.
Sayce’s talk was science-focused, but had obvious implications for the intense political battle over state regulations of ghost shrimp control efforts. Those implications were the focus of many of the audience questions. Why, one questioner asked, does the state ban shrimp eradication chemicals if the case in favor of them is so strong?
“Urban voters,” was Sayce’s rueful reply, recognizing that the Seattle area drives opposition to the use of pesticides in places like Willapa Bay.
Her conclusions are in line with local sympathies, and opposed to those of the state regulators that urban voters have helped empower. But Sayce grounds these views solidly in the environmentalist values those voters tend to share. When a questioner asked why, if ghost shrimp are native to the region, they are only now becoming a problem, Sayce said their numbers have exploded because of human actions. Humans drove their natural predators near extinction and dammed the Columbia River, which altered the water flow, affecting salinity levels in Willapa Bay. Sayce said she would like to restore the ghost shrimp’s natural predators, but isn’t sure how much can be done at this point, though she cited the gray whale’s comeback as an encouraging sign.
As a result of this line of questioning, Kevin Decker of Washington Sea Grant was asked to give a brief impromptu explanation of his organization’s role in finding ways to provide relief for ghost shrimp-plagued oyster growers. Decker discussed Sea Grant, a joint University of Washington and NOAA project, and encouraged people to connect with the organization and provide input. Decker’s Sea Grant biography says he joined the group “as a Coastal Outreach Specialist, primarily focused on communicating and engaging with communities,” currently serves as a coastal economist, and is “founder and Board Chair” of “a networking group based out of Aberdeen that seeks to increase social capital through a more networked community.” His brief presentation sparked interest; during a break that followed, numerous attendees sought him out to discuss ideas with him.
Other presentations included information on the Chinook hatchery revival, reports on burrowing shrimp and the Willapa Refuge, a talk on ocean conditions and salmon, one on orcas and salmon, and another on salmonid use of tidal estuarine channels.