As ENSO forecasting has improved, so has Pacific albacore fishing

NMFS-Sea Grant Fellow uncovers how weather forecasting helps fishermen, policy makers
April 27, 2015
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The following is a guest article from Deanna Dang.

Before the introduction of El Nino Southern Oscillation (ENSO) forecasting, fishermen often had trouble locating their catch. A natural phenomenon that disrupts temperature patterns in the ocean-atmosphere system, ENSO made it difficult for fishermen to predict where Pacific albacore would move and when. In the past few decades, weather forecasting has been highly successful in helping fisheries adjust their habits to minimize the harmful impacts of ENSO. Recent work by Jeff Shrader shows that forecasting could also have potential to reduce environmental consequences associated with fishing.

A NOAA researcher and Economics graduate student at the University of California, San Diego, Shrader observes ENSO’s effects on Pacific albacore tuna fisheries and studies how releasing monthly forecast bulletins to fishermen can help them better respond to ENSO conditions.

“What I’m trying to investigate is not whether El Nino has impacts, but whether or not weather forecasts issued by NOAA can mitigate those impacts,” said Shrader. “This is really cool in terms of economics literature because where the government doesn’t implement public policy to address El Nino, the only way we can mitigate impacts will be through individual actions—and that’s exactly what we’re doing here.”

The outstanding question then is, how much can individual actions alleviate effects of ENSO? Shrader’s study, “Forecasts and Adaptation of Tuna Fisheries in Response to El Nino Southern Oscillation,” focuses on the ability of fishermen to consume his forecasts, update their beliefs about whether El Nino will soon occur, and act on that shift in mindset by changing their behavior.

According to Shrader, “It just so happens that these weather forecasts are extremely useful for fishermen so however they are assimilating the forecasts in their minds, it seems to be working pretty well.” His research shows that Pacific tuna fishery outcomes have improved in three significant ways as result of the forecast bulletins.

First, fishermen seem to be timing their fishing for tuna much better so that they will cast their nets before or after El Nino hits instead of during. Without the bulletins, they were unable to predict when El Nino would hit and therefore persisted with their normal, irregular patterns throughout the year. With the bulletins, fishermen changed the timing of their fishing to avoid El Nino.

Second, fishermen are choosing their fishing grounds with improved accuracy. With El Nino warming some parts of the ocean and cooling others, awareness of its arrival has helped them better predict which areas would have ideal temperatures for fishing.

Additionally, fishermen are able to enter and exit tuna fisheries more efficiently. Since most albacore tuna fishermen also crab and fish other species during the tuna off-season, knowing when El Nino will hit provides them with clues as to when they should switch gears in order to mitigate losses.

Given the same information and seeming to also interpret it similarly, Shrader has observed a convergence in the behavior of Pacific albacore tuna fishermen. “They’ve begun to fish together more closely both geographically and temporally,” he said.

Despite this pattern, Shrader thinks a risk of overfishing the tuna is unlikely.

Because locating albacore tuna was more difficult for fishermen during El Nino periods, it is unclear whether El Nino reduces the population or creates conditions that stimulate tuna to move around. In the latter case, El Nino actually serves as a period of recovery for the tuna where they are not being fished as heavily because vessels are unable to locate them.

“Albacore tuna are a pretty healthy and well-managed species that remain abundant among US vessels. There hasn’t been too much competition going on in that sense,” Shrader says.

"I would say ENSO forecasts represent an opportunity as well as a possible challenge to fisheries management. I would hope that my paper can help fishery managers understand the effects that forecasts have on overall fish harvest so that they can use that information to make informed policy decisions in the future.”

If albacore tuna fishery managers can use Shrader’s forecasts and observations to advance active fishery policy, they will be able to construct a win-win situation where increased efficiency and effectiveness in albacore tuna fisheries are counterbalanced by regulations to avoid potential negative impacts on supply. Overall, fishermen can benefit from better catch outcomes and the environment can benefit from intentionally sustained albacore tuna populations.

Essentially, Jeff Shrader’s study demonstrates two things: that forecasts can lead to clear individual behavioral shifts and that these shifts have impacts that should be monitored.

In the case of Pacific albacore tuna, knowing that forecast bulletins can improve fishery outcomes prompts us to pay closer attention to how this could affect tuna populations in the near future and respond with appropriate policy if necessary.

Shrader aims to apply the methodology he used to observe and influence outcomes in other environmental areas. For instance, he hopes to make a connection between weather forecasting and farmer behavior in the instance of drought.

“If you are issuing farmers a drought forecast and it exacerbates their water use, you can make things worse. If we can characterize conditions under which this occurs, we can avoid them,” said Shrader. “You can really use forecasts to either help or hurt certain circumstances.”

About California Sea Grant

NOAA’s California Sea Grant College Program funds marine research, education and outreach throughout California. Our headquarters is at Scripps Institution of Oceanography, University of California, San Diego; we are one of 33 Sea Grant programs in the National Oceanic and Atmospheric Administration (NOAA), U.S. Department of Commerce.