Stanford graduate students create ice bag to keep fish fresh

Yasmin Arquiza

Posted at Nov 21 2018 02:13 AM

It’s tuna season in Lubang, and fisher Edgar Monteleyola is excited to test something new on his next fishing expedition. 

In the past, tuna fishers would often catch smaller juveniles that could fit in the Styrofoam ice boxes where they store their catch.

This time, he will be one of the first to see if a newly designed expandable bag could keep bigger and mature tuna on a bed of ice packs fresh for a longer period.

Lubang island sits on the western edge of the Verde Island Passage, described in the landmark 2005 study of marine biologist Kent Carpenter as the “center of the center of marine shore fish biodiversity” in the world. 

Despite the abundance, however, coastal fishers remain poor. In the community of Tagbac, where Edgar lives, the income of fishers is dependent on the monsoon seasons and transportation facilities.

With the main trading centers located in mainland Batangas, 2 to 3 hours away by boat on calm seas, keeping the fish catch fresh until it reaches the buyers is a daily struggle.

Finding solutions to the cold chain problem in fisheries was highlighted in the latest report of the Food and Agricultural Organization, released last July, which noted that 1 in 3 fish caught at sea do not make it to the dining table. 

Commercial trawlers that discard unwanted fish are partly to blame, but the bigger culprit in wasted fish catch is lack of proper cold storage, the report said.

Graduate students from Stanford University’s design school took up the challenge when they visited the municipalities of Lubang and Libertad together with Rare, an international conservation organization. 

Rare is working with the local governments of both towns, which have thriving tuna fisheries, in promoting sustainable fisheries in coastal waters through the Fish Forever campaign.

After an intensive immersion in the fishing communities, the students came up with two ideas: an ice bag that can maintain the freshness of fish at sea, which they called Fortuna, and a storage box for surplus ice they named Frost.D that would be cheaper to maintain instead of keeping all the ice in the freezer.

“Together, the two solutions will help solve our cold chain challenges – retaining the freshness of the fish catch and hopefully getting more premium prices for the fishers,” said Cris Lomboy, markets director for Rare Philippines.

Compared to the fishers’ current Styrofoam ice box that costs P500 and needs to be replaced every three months, the Fortuna ice bag is estimated to cost P5,000 and has a projected lifetime of up to five years. 

By catching bigger fish and putting them in higher quality storage, the fishers could access new markets and increase their income from an average of P80 to P300 per kilogram of fish, according to the design team.

Meanwhile, the Frost.D unit is expected to result in substantial savings for a fishing community, as it uses 80 percent less energy in keeping ice packs from the freezer cool while in storage. 

The projected impact for an ice-selling business could be as much as 100 percent more revenues over a 9-month period, while increasing the quantity of ice available to fishers during peak seasons. 


Tamara Mekler and Michelle Huang, who monitored the pilot testing of the bag in Lubang, spent several weeks refining the design after getting feedback from volunteer fishers.

“We've made eight different prototypes, each a different design, and we've tested different materials – sourced locally in the Philippines as well as brought back from the US – to compare the quality, cost, and insulating ability,” said Tamara.

The early prototypes were made of tarpaulin because of its heat-sealing qualities, with 2 layers of double reflective foam as filling. A temperature logger on the inner wall collects data while the fish is in storage.

During the first test run, Edgar placed 15 ice packs inside the bag and was satisfied to see the fish remaining fresh even when he spends many hours at sea. 

When not in use, the bag can be stowed in the corner easily, although he noted that sewing of the zipper closure in the first model he tested needed to be improved to avoid heat seeping through the seams.

In September, after 3 months of testing, Tamara reported that the temperature inside their latest prototype cooler stayed below 40 degrees Fahrenheit for 48 hours. This is good news for Lubang fishers, who often have to wait for a break in the weather during habagat (southwest monsoon) – which coincides with peak tuna season – before they can sell their catch in the mainland.

The newest design can hold 3 to 5 fish weighing up to 40 kilograms each and measuring up to 5.5 feet in length. It is also extra collapsible and portable, no more than a 5-kilo backpack when folded.

With the initial success, the Stanford team is busy looking for the best materials and design. “We’ll be spending the next couple of months finalizing these details, and will start our first manufacturing run in early 2019,” said Tamara.

The author is a senior communications manager of the international conservation organization Rare, which promotes responsible fishing behavior in Philippine coastal areas.