Please select your home edition
Edition
Henri-Lloyd Dynamic Range

Autonomous vehicles help scientists estimate fish abundance while protecting human health and safety

by NOAA Fisheries 5 Jun 2020 16:56 UTC
NOAA Fisheries plans to use autonomous surface vehicles © Saildrone

Scientists are capitalizing on existing technological capabilities and partnerships to collect fisheries data. This will help fill the information gap resulting from the cancellation of FY20 ship-based surveys due to the COVID-19 pandemic.

NOAA Fisheries plans to use autonomous surface vehicles to collect some critically needed data to support management of the nation's largest commercial fishery for Alaska pollock.

"Extraordinary times require extraordinary measures," said Alex De Robertis, NOAA Fisheries fisheries biologist and project lead for the Alaska Fisheries Science Center. "We knew there was a possibility that surveys may be cancelled this year, so we worked on a contingency plan to collect some data just in case. We were able to capitalize on our previous experience working closely with Saildrone and NOAA Research's Pacific Marine Environmental Laboratory to get things off the ground quickly."

This effort supports NOAA's broader strategy to expand the use of emerging science and technologies including unmanned systems, artificial intelligence, and 'omics to advance ocean research. NOAA released its strategy in February.

"The Alaska Fisheries Science Center has been engaged in research and development efforts to test new technologies to both improve our operating efficiencies and enable us to quickly respond when situations like this arise," said Robert Foy, Alaska Fisheries Science Center Director. "Providing the best available science to support management decisions is at the heart of our mission to ensure the health of marine ecosystems while supporting sustainable commercial and recreational fisheries and strong local economies."

Measuring fish abundance acoustically

Three saildrones, unmanned wind-powered surface vehicles, are en route. They are sailing autonomously, from Alameda, California on a six-week journey to the eastern Bering Sea. They are expected to reach Alaska in early July to begin a 60-day survey. The ocean-going robots will cover roughly the same area normally covered by standard research vessels to estimate pollock abundance.

Scientists and engineers integrated newly designed low-power sonar instruments, known as echosounders, into the saildrones. This fishfinder technology detects the presence of fish using sound. Echosounders send sound pulses into the water and measure how much of this energy echoes back from fish. From this, scientists are able to make an estimate of the population of fish below. Scientists from the Alaska Fisheries Science Center worked with Saildrone, the Pacific Marine Environmental Laboratory, and Kongsberg to develop this technology.

The technology is great at detecting fish. But, it is less effective at differentiating among species and fish sizes. That is why during standard acoustic-trawl surveys on research vessels, scientists also use a net to collect a sample of fish. From this, they are able to confirm the species, as well as the weight, length, and sex of individual fish.

Stock assessment scientists use these data together with other data collected from commercial fishing vessels to estimate fish population size each year.

De Robertis and colleagues have spent the past several years testing and validating this technology. They conducted side-by-side comparisons with a NOAA research vessel. They found that the saildrone-mounted echosounders produced equivalent acoustic measurements of pollock to NOAA's fisheries survey vessels.

"In this part of the Bering Sea, pollock are by far the dominant midwater fish species. So, we are confident of getting a useful measure of pollock abundance from the echosounder, even if we can't directly sample fish. Acoustic-only measurements from ships are already used to inform fisheries management, and we plan to do the same thing with the saildrones," said De Robertis.

The saildrones are also equipped with solar-powered instruments to measure oceanographic and meteorological conditions. Wind, solar radiation, surface temperature, and salinity measurements will be made along the way.

Real-time data to inform management decisions

Throughout the survey, compressed summaries of the echosounder data and environmental conditions, and photos will be transmitted to shore via the saildrone's satellite modem four times per hour.

With the real-time information, De Robertis and colleagues can monitor progress. Using the satellite link, they will be able to adjust the course of the saildrones, if necessary.

Scientists at the Pacific Marine Environmental Laboratory will process the oceanographic and meteorological data in real time.

"We will make data available to weather forecast centers worldwide via the World Meteorological Organization's Global Telecommunication System so that the observations can be incorporated into weather predictions," said Eugene Burger, associate director for Information Technology, Pacific Marine Environmental Laboratory.

According to De Robertis what he once perceived as science fiction has become an operational reality. A lot of progress has been made in just a few short years using unmanned surface vehicles and associated technologies for studying the marine environment.

"If you had asked me six years ago, when I first heard about this, I wouldn't have thought it possible. Now, I see it as a valuable tool for augmenting our standard research surveys."

This is especially relevant this year. Unmanned vessel surveys are helping scientists provide some key scientific data at a time when it will be difficult to collect the data any other way.

Related Articles

Monk seal & sea turtle research & recovery review
As we prepare for our 2025 field camps, we look back on the important work done in 2024 Monitoring and population assessment field camps are the foundation of NOAA's research and recovery efforts for Hawaiian monk seals and Hawaiian green sea turtles (honu) in the Papahanaumokuakea Marine National Monument. Posted on 18 May
Conserving long-lived species
The importance of monitoring decades-old individuals Conservation and recovery of long-lived species requires continued monitoring of individuals. Meet some of the animals that have been known to scientists for decades. Posted on 17 May
Gray whales on the rebound
Signs of hope despite challenges California's gray whales are an iconic, beloved species. Our scientists have been concerned about the Eastern North Pacific gray whale after a recent increase in strandings and deaths. Posted on 21 Feb
Top must-read Pacific Islands stories of 2024
Take a look at some of the most important and inspiring stories We've shared many great stories throughout 2024. Among these stories are our staff favorite reads of 2024. Posted on 8 Feb
Hawai‘i Coral Reef assessments complete for 2024
3-month mission assessing coral reef health and ocean conditions Kanaka Oiwi knowledge systems, values, and practices inform a 3-month mission assessing coral reef health and ocean conditions in Hawai'i as part of the National Coral Reef Monitoring Program. Posted on 10 Dec 2024
Ocean gliders listen for whales off Oregon
Passive acoustic monitoring by “gliders” may better detect some species Three small autonomous underwater gliders called Seagliders crisscrossed the ocean off the Oregon Coast in recent months. Posted on 8 Dec 2024
Monitoring endangered North Atlantic right whales
NOAA Fisheries uses the latest technologies such as passive acoustic monitoring The annual North Atlantic right whale calving season, which begins in mid-November and runs through mid-April, is almost here once again. Posted on 15 Nov 2024
Gray Whale Calf count remains low in 2024
As population slowly emerges from multi-year decline The number of gray whale calves migrating with their mothers along the California Coast this year was one of the lowest on record. Posted on 2 Nov 2024
Tagging Humpbacks
Where Biology, Conservation, and Engineering meet "Alright, this is gonna be the one!" The 22-foot inflatable research vessel Balena speeds up and approaches a group of four humpback whales along the edge of Stellwagen Bank National Marine Sanctuary offshore Provincetown, Massachusetts. Posted on 29 Sep 2024
From past patients to new moms
Two Hawaiian monk seals who were previously rescued are now new mothers! Two Hawaiian monk seals who were previously rescued and rehabilitated are now new mothers! Posted on 27 Sep 2024
Crewsaver 2021 Safetyline FOOTERHyde Sails 2024 - One DesignPantaenius 2022 - SAIL & POWER 1 FOOTER ROW