The United Nations needs to keep a closer watch on Iran as the Persian country is not only underreporting its Uranium reserves but is also hiding its fish catch. Iran is accounted for more than 12,000 tonnes in fishes every year from 728 large weirs.

Studying Google Earth images from 2005-10, scientists at the University of British Columbia in Vancouver found that 31,433 tonnes of fish was caught by Persian Gulf nations in 2005, which is six times more than what it officially reported to the United Nation's Food and Agriculture Organization (FAO). The seven countries of the region reported catching 5,260 tonnes of fish in 2005 to the FAO.

Dalal Al-Abdulrazzak and Daniel Pauly also found 1,900 fishing weirs in 2005 along the Persian Gulf coast.

"Our results document the unreliability of catch data from the Persian Gulf, a small part of a global misreporting problem," the authors wrote in the study.

"Underreporting fish catches can jeopardize a country's food security, economy, not to mention impact entire marine ecosystems," Al-Abdulrazzak of the UBC Fisheries Centre's Sea Around Us Project and the study's lead author told Quartz. "This is particularly important in the case of the Persian Gulf, where fisheries are the second most important natural resource after oil."

For the study, the scientists used a Google ruler tool to measure the size of each weir's traps. They also calculated daily fish catch based on historical records, the length of the fishing season and composition of fish species, such as mackerel, crab, lobster and sardines, at each location.

They found that 50 percent of the weirs were found in Bahrain followed by Iran with 37 percent and Kuwait, 5 percent. Bahrain was also the leading country in terms of estimated catch with 54 percent followed by Iran (39 percent). Bahrain's estimated catch was 142 percent greater than the total catch reported to the FAO.

Only one nation was found to have reported the correct fish catch. Kuwait's 300 tonnes of fish catch was close to the figures it reported to the UN.

"Time and again we've seen that global fisheries catch data don't add up," Pauly, principal investigator with the Sea Around Us Project and the study's co-author, said. "Because countries don't provide reliable information on their fisheries' catches, we need to expand our thinking and look at other sources of information and new technologies to tell us about what's happening in our oceans."

Fishing weirs are semi-permanent traps that are used to catch marine species with the help of tidal differences. This technique is predominantly used in Southeast Asia, Africa and parts of North America.

"This ancient fishing technique has been around for thousands of years," Al-Abdulrazzak said in a statement. "But we haven't been able to truly grasp their impact on our marine resources until now, with the help of modern technology."

The study has been published Monday in the ICES Journal of Marine Science.