Mathematician uses big data to save tiny smelt

Ken Newman, a mathematician and statistician with the U.S Fish and Wildlife Service in Sacramento, Calif., is exploring new statistical methods to help save the endangered Delta smelt. Credit: Steve Martarano/USFWS

With a passion for statistics, a Service scientist studies the numbers surrounding the Delta smelt in the hope of ensuring its survival

By Steve Martarano
June 23, 2016

Editor’s note: the Delta Smelt, only found in California’s Sacramento-San Joaquin Bay-Delta Estuary, are on the brink of extinction, and scientists in the San Francisco Bay-Delta and Lodi Fish and Wildlife offices are battling to save the indicator species on several fronts. These are their stories. First in a series:

For more than 30 years, Ken Newman has used his statistical methods to help endangered fish and wildlife species in some of the most complex ecosystems across the U.S. and Scotland. Yet, his work with the Delta smelt may be his most daunting task.

The U.S. Fish and Wildlife Service (USFWS) statistician is working in California’s Bay-Delta to determine population numbers and trends, and ultimately help reverse the decline of a struggling, much-maligned Delta smelt.

“I get a lot of satisfaction understanding existing technical statistical theory and methods, and enjoy the creativity of coming up with something that hasn’t been done before,” Newman said.

It’s not a coincidence that when Delta Smelt numbers started to plunge in the early 2000s, so did just about every other native fish in that estuary. Unlike most other species Newman has worked on, however, the elusive nature of the Delta smelt has always made it a challenge to study.

“There are definitely challenges to working with, capturing and studying Delta smelt,” Newman said, citing their 2-to 3-inch size as too small and fragile for acoustic tags to be applied that would allow real-time information on individual fish location and movement.

Captive Delta Smelt at the Livingston Stone National Fish Hatchery below Shasta Dam. Credit: Steve Martarano/USFWS

There’s also a lack of large scale mark and release studies of the wild fish, which would provide information on individual fish survival, in contrast to existing technology available to study salmon. Improvements in technology, however, may eventually make that possible, Newman said.

”As a result,” he said, “we don’t have that much solid info on how smelt move and die. They’re short-lived at about a year, and are rare and getting rarer, which makes them even harder to catch and find out where they are.”

In a career filled with complicated projects that apply statistics to problems in natural resources and ecology, Newman currently works quietly out of cubicles at both the Lodi and the Bay-Delta Fish and Wildlife offices.

Newman has been interested in applications of statistics to natural resource problems since his undergrad days at Ohio State University. After five years working as a biometrician for tribal fisheries programs in western Washington, he went back to school, receiving a PhD in statistics at the University of Washington. Newman was a professor of statistics at the University of Idaho for 10 years, and then a Senior Lecturer in statistics at the University of St. Andrews, Scotland, before USFWS hired him in 2006.

USFWS Biologists monitor for Delta Smelt near Rio Vista on the Sacramento River. Credit: Steve Martarano/USFWS

With smelt numbers at their lowest levels in history, Newman heads a small group developing models that can estimate population numbers using existing data from several of the California Department of Fish and Wildlife’s (CDFW) long-running spring trawling surveys that track adult Delta smelt. It is a major development that, beginning in January and February 2016, scientists were able to estimate how many adults were alive at the start of the spawning season. The estimates are not exact numbers, rather a range, but it’s a start in the right direction.

“We’re trying to bring in not just fish data but also other measurements, like water temperature, or salinity, and we’re using data from several different long-term surveys to build these models,” Newman said.

The calculations on Delta Smelt developed by Newman’s team have been striking, showing the dire situation of the Delta smelt. USFWS estimates that the current population of adult Delta smelt is about 13,000 fish, compared to January and February 2015 when there was an estimated all-time low of 112,000 fish.

USFWS Biologist William E. Smith, (left to right) Ken Newman, Newton Parks and Monica Umeda, co-founders of Akabotics, a micro-dredging technology company, and USFWS Biologist Armin Halson on the Sacramento River near downtown Sacramento. Credit: Steve Martarano/USFWS

As an integral part of these estimates, Newman’s group is also working with the CDFW on a study to help determine if current ways data are collected by existing gear or equipment, are effective.

“It’s been a great collaboration; Ken’s interest in and desire for gear efficiency data has pushed us to do more than we might have done otherwise on answering some important questions on how our gear works,” said Randy Baxter, CDFW’s supervising Senior Fisheries Biologist, who has worked with Newman and USFWS since 2011, most of that time on the gear study.

The state operates numerous key fish surveys on the Delta throughout the year for several species like Delta smelt, Longfin smelt and Sacramento Splittail. Those data are used by USFWS’ Bay-Delta office to help manage programs including developing limits on the number of Delta smelt that can be taken at Delta pumping operations, as well as to develop the ground-breaking population estimates.

Home of the Delta smelt, along the Sacramento River near downtown Sacramento. Credit: Steve Martarano/USFWS

“We always knew that some of our gear is more effective than others for catching certain Delta smelt life stages: the Kodiak trawl is good at catching older Delta smelt, or that many of the Delta smelt in the Fall Midwater Trawl were slipping through the mesh early in the sampling season, for example,” Baxter said.

Newman reiterated that studying gear efficiency with CDFW “has never been done on this scale before.” The data generated by CDFW and studied by Newman are also assisting in efforts towards another key project – a lifecycle model for Delta Smelt that promotes a better understanding of the species that could ultimately help recover it.

“We’re trying to use the survey data that’s been in place to come up with absolute abundance numbers in a scientific and sound way,” Newman said. He added that all data collected looking at environmental factors that affect survival rates and reproduction can be bundled together “to build a lifecycle house and tools that will help us evaluate various management actions.”

A frequent author, in April 2010 Newman was an expert witness for the defense in the Federal District Court hearings for the Delta Smelt Consolidated Cases. He was the lead author on a book titled “Modelling Population Dynamics,” published in 2014, which is centered on a statistical procedure called state-space modeling that underlies much of the lifecycle modeling work.

Since 2009, he has annually co-taught a week-long course on developing a long-term Biological Monitoring Program for USFWS personnel across the country.

From that course came a “Road Map for Developing a Biological Monitoring Program,” a report that will appear in the journal Environmental Monitoring and Assessment. It continues the work Newman has pursued throughout his career, which is especially pertinent now as he tackles the challenges by Delta smelt.

“I’m very excited that the “Road Map” will be a way to help ensure that resource agencies collect data in a scientifically sound manner,” Newman said, “and am looking forward to it being a tool readily used by resource manager decision makers.”

 

Steve Martarano is the public affairs officer for the San Francisco Bay-Delta Fish and Wildlife Office located in Sacramento, Calif.