New computer-generated daily maps will help fishermen locate the most productive fishing spots in near real time while warning them where they face the greatest risk of entangling sea turtles, marine mammals, and other protected species. Scientists developed the maps, the products of a system called EcoCast, to help reduce accidental catches of protected species in fishing nets.
Funded primarily by NASA with support from NOAA, California Sea Grant, and Stanford University, Ecocast was developed by NOAA Fisheries scientists and academic partners with input from fishermen and managers.
E.L. Hazen, K.L. Scales, S.M. Maxwell, D. Briscoe, H. Welch, S.J. Bograd, H. Bailey, S.R. Benson, T. Eguchi, H. Dewar, S. Kohin, D.P. Costa, L.B. Crowder, R.L. Lewison. 2018. A dynamic ocean management tool to reduce bycatch and support sustainable fisheries. Science Advances, 4: eaar3001. PDF
Using the swordfish fishery as an example, EcoCast incorporates data from tracking of tagged animals, remote sensing satellites and fisheries observers to help predict concentrations of the target species (broadbill swordfish) and three protected species (leatherback turtle, blue shark and California sea lion).
EcoCast will help fishermen, managers, scientists, and others understand in near real time where fishing vessels have the highest probability of catching targeted species and where there is risk of catching protected species. In doing so, EcoCast aims to improve the economic and environmental sustainability of fisheries that sometimes inadvertently catch and kill sensitive species. The first peer-reviewed description of the science behind the system appears this week in Science Advances.
“We’re harnessing the field of big data so that information on ocean conditions can be of most use – so fishermen can go where they’re likely to find the swordfish they want to catch but avoid the species that they do not want to catch,” said Elliott Hazen, a research ecologist at NOAA Fisheries’ Southwest Fisheries Science Center and lead author of the new paper.
Currently NOAA Fisheries closes a large area off the West Coast to the swordfish fishery seasonally to protect leatherback turtles, which travel widely, and can be caught incidentally in the nets. Fisheries managers could use EcoCast to outline small, “dynamic closures,” that shift according to the likely locations of the species they are trying to protect. Since they concentrate protection where it’s needed most, dynamic closures for leatherback sea turtles could be two to 10 times smaller than the current static closures while still safeguarding the species that need it, the scientists found.
“EcoCast pioneers a way of evaluating both conservation objectives and economic profitability for sustainable U.S. fisheries,” said Rebecca Lewison, a senior scientist on the project from San Diego State University and a co-author of the new paper. “By meeting both conservation and economic objectives, EcoCast is an important step forward in supporting species, their ecosystems and our local and state economies.” Dynamic closures could also support more “climate-ready” fisheries management approaches that adjust to changing ocean conditions as the climate shifts and changes over time. For instance, unusually warm conditions off the West Coast in 2014 and 2015 have driven shifts in fish and marine mammal species, forcing fishermen to adjust their efforts.
“EcoCast directly addresses both scientific priorities and fisheries management needs,” said Heidi Taylor of NOAA Fisheries’ West Coast Region. “The use of real-time environmental data to support dynamic ocean management provides an innovative approach to balance viable fisheries and protecting the ecosystem.”
She noted that fishermen participated throughout the development of EcoCast, which should help boost its usefulness to the fishing fleet. .
The EcoCast system is up and running now, producing color-coded maps posted online each day hosted via NOAA’s CoastWatch West Coast Regional Node. Managers can adjust the system to support additional fisheries, but this paper focused on reducing bycatch of leatherback turtles, blue sharks, and California sea lions in the West Coast drift gillnet fishery that targets swordfish.
EcoCast maps fishing areas in a blue-to-red scale that predicts the best waters to catch swordfish with little to no bycatch in darker shades of blue, with the greatest risk of encountering sea turtles, sea lions, and sharks shown in red. As the ocean conditions change, the dynamic map also changes. Managers can adjust the weighting of each species as risks change and the fishing season progresses.
“The fishermen will be willing to try this because they’re always looking for ways to do things differently, and better,” said Gary Burke, a drift gillnet fisherman in Southern California. “It’s not going to be perfect, because it’s a prediction, but it may give us access to information we haven’t had before.”
He said that fishermen have long watched ocean conditions such as sea surface temperatures as indicators of where the best fishing might be. The added information that EcoCast provides, such as the predicted concentrations of sea turtles, sea lions, and sharks, makes it a more powerful tool to help fishermen decide where – and where not – to fish.
“EcoCast simply would not have been possible a decade ago,” Hazen said. The increasing availability of satellite ocean data, the miniaturization of satellite tags for turtles and fish combined with faster and more powerful computers helped make it happen. Researchers are working to add data on additional species such as marine mammals to best reflect bycatch concerns.
“Now we can integrate all this information through complex statistical models that turn tens of thousands of data points into something more useful,” he said. “We’re putting the information directly in the hands of the fishers and managers.”
EcoCast is supported by a partnership that includes NOAA Fisheries, The University of California Santa Cruz, San Diego State University, Stanford University, Old Dominion University, The University of Maryland, drift gillnet fishermen, fisheries managers and other stakeholders.
“EcoCast is leading the way toward more dynamic management of marine resources,” said Woody Turner, program manager for ecological forecasting in NASA’s Applied Sciences Program.
|Swordfish, Shutterstock/Joe Fish Flynn; Leatherback turtle with satellite tag, NOAA Fisheries/H. Harris (NMFS permit #1596-03); California sea lion with satellite tag, Dan Costa; Blue shark, NOAA Fisheries/Mark Conlin; Fishing vessel off the coast of southern California, NOAA Fisheries.|
For more information:
Southwest Fisheries Science Center’s Environmental Research Division (ERD)
TurtleWatch – A product produced by NOAA’s Pacific Islands Fisheries Science Center to provides up-to-date information about the thermal habitat of loggerhead sea turtles in the Pacific Ocean north of the Hawaiian Islands.
WhaleWatch – A project coordinated by NOAA Fisheries’ West Coast Region to help reduce human impacts on whales.