Seaborne flows of Russian crude oil declined by a quarter in the seven days to April 15. Volumes heading to Asia from ports on the Black Sea, Baltic and Arctic coasts plunged to the lowest in two months.

A total of 30 tankers loaded about 21.8 million barrels from Russian export terminals, according to vessel-tracking data monitored by Bloomberg and port agent reports. That put average seaborne crude flows at 3.12 million barrels a day, down by 25% against the week ended April 8.

The decline in oil exports means reduced revenue for Moscow as the costs mount of Vladimir Putin’s war in Ukraine and consequent sanctions on the Russian economy. At current rates of crude oil export duty, the week’s shipments will have earned the Kremlin about $181 million; that’s $60 million less than the previous week.

To be sure, while the week-on-week drop in export flows is dramatic, it only takes them back to the level seen in the week to April 1. The figures can swing depending on the timing of when tankers leave, which is also heavily influenced by the weather at ports.

The week saw lower volumes from all four export regions. Flows of Urals and Siberian Light crude from terminals in the Baltic and Black Sea fell by 770,000 barrels a day, or 30%, with the volume of crude leaving the Black Sea port of Novorossiysk down by almost 60%.

Meanwhile, shipments from the country’s three eastern terminals on its Pacific Ocean coast were down by 205,000 barrels a day, or 17%. Cargoes from Murmansk, which handles crude produced along Russia’s Arctic coastline were also down, dropping by 57,000 barrels a day, or 15%.

Pressure is mounting within the European Union for an embargo on Russian oil and the world’s biggest traders say they will stop handling the country’s supplies, which should reduce future flows. Russia’s production in the first week of April was down by about 500,000 barrels a day from March.

Even as things are, the tumble in crude flows from Russia’s export terminals in the seventh week after the invasion cut the Kremlin’s export duty revenues by 25% week-on-week.

Crude oil export duty is set at $61.20 a ton in April, equivalent to about $8.30 a barrel. That’s up from $58.30 a ton, $7.95 a barrel, in March and is calculated from an average Urals price over the period from Feb. 15 to March 14. Export duty will fall to $49.60 a ton, $6.81 a barrel, in May.

The number of tankers that completed loading cargoes of Russian crude in the week to April 15 was down by 10, or 25%, from the previous week, with the biggest fall seen at Novorossiysk in the Black Sea.

A gale warning for the Novorossiysk area issued on April 12 appears to have halted flows from the terminal for the latter part of the week, with no tankers mooring at the crude oil jetty between April 12 and April 15.

The following four charts show the destinations of crude cargoes from each of the four export regions. Destinations are based on where vessels signal they are heading at the time of writing and may change as voyages progress.

There was a rebound in shipments from the Baltic terminals at Primorsk and Ust-Luga to ports in Northwest Europe, with flows at their highest in four weeks. At the same time, the number of tankers leaving the Baltic for destinations in Asia fell sharply, dropping to a four-week low.

Two cargoes that were scheduled to load at Primorsk during the week to April 15 appear to have slipped from the program, but most others are loading on schedule. Shipments from Ust-Luga ran to plan.

Of the three vessels loading at Novorossiysk in the Black Sea, one is signaling India, one remained in the Black Sea and the third is showing its destination as St Lucia in the Caribbean, although it remains to be seen if it will actually make the journey, or do a ship-to-ship transfer in the Mediterranean.

Of the three ships that loaded from floating storage facilities at Murmansk, one has discharged in the U.K.—the first delivery of Russian crude to the country since before Russia’s invasion of Ukraine. One is heading to Rotterdam and the third is signaling Santa Panagia in Italy, where Lukoil owns a refinery.

Crude shipments from Russia’s three eastern oil terminals during the week to April 15 showed a greater variety of destinations than in either of the two previous weeks. While more crude again went to China than anywhere else, more was shipped to Japan than at any time this year, with two cargoes of ESPO crude and one of Sokol heading to Japanese ports.

The Sokol cargo is probably equity crude from a Japanese consortium’s stake in the Sakhalin 1 project, while the ESPO cargoes are likely to have been purchased before Russia’s invasion of Ukraine.

The number of ships heading to Asia from Russia’s western ports fell sharply in the week to April 15. Just four tankers loading that week showed their destinations as India, or a destination that’s unlikely to be their final port of discharge. That’s down from 10 ships in the previous week.

Two vessels loading in the week to April 15 are showing destinations in India, while two more are signaling Gibraltar. That’s a common signal for ships heading into the Mediterranean and there are several possibilities once they arrive there. They may deliver to a Mediterranean terminal, they may pass through the Suez Canal and on to Asia, or they may transfer their cargoes to other vessels.

The area off the port of Ceuta, just south of Gibraltar, has become a popular site for ship-to-ship transfers of Russian crude. There are two very large crude carriers, or VLCCs, owned by Vitol Group, the world’s largest independent oil trader, in the area at present.

The Elandra Denali took on cargoes from two smaller ships in the week to April 15 and is expected to take one more before heading to Asia. The Elandra Everest arrived in the area on April 18, though it is showing its destination as Rotterdam.

Vitol has said that is will stop trading Russian crude and refined products by the end of the year, with volumes set to “diminish significantly in the second quarter as current term contractual obligations decline.”

The VLCC Searacer completed its third transfer on April 10 and is now heading around the west coast of Africa carrying about 2 million barrels of crude. It is signaling a destination of Saldanha Bay in South Africa, though it is not expected to discharge its cargo there.

Note: This story forms part of a regular weekly series tracking shipments of crude from Russian export terminals and the export duty revenues earned from them by the Russian government.

Note: Bloomberg uses commercial ship-tracking data to monitor the movement of vessels. Ships can avoid detection by turning off on-board transponders, as has been done widely by the Iranian tanker fleet. There is no evidence yet that this is being done by crude oil tankers calling at Russian ports.

Note: Destinations are those signaled by the vessel and are monitored until the cargo is discharged. Destinations may change during a voyage, even under normal circumstances, and the final discharge point for the cargo may not be known until that port is reached.

Note: Cargo volumes are based on loading programs, where those are available, and on a combination of the ship’s capacity and its depth in the water where we have no other information.