An interesting controversy is brewing in Guyana over suspicions that expanding offshore oil operations might be to blame for declining catches.

Industry experts say that declines became noticeable, especially for shrimp, as far back as 2013. However, the major local companies think that the noise from exploratory drilling, chemicals used in the process, and increased activities from three oil fields currently in operation are the main reasons for declining returns. Commercial quantities of oil were discovered in 2015, two years after authorities said they noticed that returns were declining.

American supermajor ExxonMobil, which is leading a consortium producing around 650,000 barrels of oil daily, this week declined to comment on allegations that its operations are to blame but says it is “bolstering available data on local fisheries through a “Participatory Fish Study which is the first of its kind in Guyana.”

In consortium with Hess Corp and CNOOC of China, the company says in an available company fact sheet to industry players that its operations are way beyond the normal areas where local boats operate. “These activities take place at least 160 kilometers from the shore, and few fishing vessels travel to this area. For most vessels, fishing occurs in water depths of 30 meters or less, except for industrial drift seine vessels, which may fish up to 60 meters in water depth. In comparison, oil and gas activities in the Stabroek Block occur in much deeper, between 750 and 2,000 meters deep,” the sheet argues.

Large operators like PSI Investments argue that they have undoubtedly noticed a decline over the past five years, with catches now only filling two instead of 20 containers, as was the case two years ago, when the company complained to the local Stabroek News newspaper.

Fishing companies, meanwhile, say they want the local Environmental Protection Agency (EPA) to conduct a definitive study that would put their suspicions to rest. They are convinced there is a link to operations in three oil fields and preparations for up to five more by the end of the decade. Most of the oil fields are located near the border with Suriname.

As lamentations about declines continue, the state’s fisheries division contends that, in addition to chemicals and noise from drills and support ships, there could be a number of reasons for the state of play. These include El Nino weather conditions, overfishing by local vessels and unmonitored boats working illegally in the exclusive economic zone, increased salinity in ocean waters, and natural cycles.

Smaller vessels that spend four days to a week nearshore say it costs them around $1,000 per trip, and many boat owners are now in debt because of poor catches, especially for shrimp.