A marine science grad student at the Scripps Institution of Oceanography has designed a new fish trap that reduces the number of low-value fish being caught.
“Coral reef fishing constitutes the majority of fishermen’s incomes, yet these traps reduce the waste associated with fishing, and without effecting their revenue,” creator Ayana Johnson said. “It’s a win-win situation.”
To do this, Johnson surveyed reef traps across the Caribbean island of Curacao. According to Johnson, up to 80 percent of smaller fish irrelevant to commercial fishermen could be saved by her proposed alteration. These juvenile and smaller species of fish are undesirable for food and are often disposed of when found in fishing traps.
Johnson studied these traps for approximately four months in 2008 in Curacao, a country off the coast of Venezuela. The government there had proposed regulation that required local fishermen to use escape gaps (exit slots that allow smaller fish to escape) in their traps.
This proposal was based on a law from Bermuda. But neither Curacao nor Bermuda had conducted research on how this might affect the fish population.
Johnson constructed replicas with the suggested dimensions — 20-by-2.5 centimeters, as proposed by Curacao’s regulation. A local welder created these escape gaps out of cheap steel rebar, which could be added to the mesh traps fishermen currently use.
Johnson placed eight traps at three different locations on the island to soak for three days.
Some traps had exit slots and others did not, in order to analyze the variety of species caught.
“It is important to test the traps in multiple locations to make sure that the results are generalizable and not specific to one part of the reef,” she said. “I chose the locations after consulting with Curacao’s fishery manger to find places where trap fishing has traditionally occurred, and that also represent different types of coral reef habitat.”
The fish caught were then weighed and multiplied at pound per value to calculate the revenue that would be lost. Johnson found that fishermen using her new traps would be catching half the amount of fish, with no relative change in their profit.
According to the Coral Reef Alliance, 36 percent of the world’s reefs are exploited by overfishing, and in some areas this has led to the extinction of highly valued species. Johnson said she sees her research as a way of improving this process.
“About 500 million people in developing countries around the world depend on coral reefs for their nutrition and livelihoods, and trap fishing accounts for the majority of reef fish caught in many locations,” she said. “That’s what makes it so important to figure out a way to conduct trap fishing in a more sustainable manner.”
Johnson would like to see her improved fish traps enforced by new laws from the Curacao government. She is working alongside fisheries and other interested researchers to get her traps implemented.
“I have provided my results to the fishery management department and hope that this data will help to encourage the politicians there to pass the proposed law that would require the gaps to be used,” she said.
Readers can contact Kirsten Mauro at [email protected].
