A new report has raised concerns over the growing conversion of ageing and deteriorating cargo ships, which should have been scrapped several years ago, into livestock carriers currently operating in the global shipping industry.

The report found that many of these vessels, which are over 50 years old, sail under low-performing and blacklisted flags identified by Port State Control, had a history of recurring deficiencies and detentions for failing to comply with international pollution-prevention standards, lack classification by the International Association of Classification Societies (IACS), operate under complex ownership structures, and exhibit limited transparency in the global livestock trade.

The report, jointly produced by Robin des Bois, a French organisation, the German Animal Welfare Foundation (AWF) and the Swiss Tierschutzbund Zürich, analysed the global livestock carrier fleet and painted a troubling picture of an industry dominated by ageing converted vessels, recurring safety deficiencies, inadequate regulatory oversight and poor compliance with international maritime standards.

Of the 159 livestock fleet identified in the report made available to The Guardian, only 25 vessels (16 per cent) were purpose-built for livestock transport, while the remaining 134 vessels (84 per cent) were originally constructed as merchant ships before being converted.

These merchant vessels included 68 general cargo ships, 17 container ships, 16 roll-on/roll-off (Ro-Ro) vessels, 15 vehicle carriers, 12 refrigerated cargo vessels (reefers), two palletised cargo ships, two bulk carriers, one fishing vessel and one crude oil tanker.

According to the report, the conversion of ageing merchant vessels into livestock carriers has become increasingly common and is supervised by non-IACS classification societies.

The report further revealed that 54.6 per cent of the converted livestock carriers sail under flags listed on the Paris Memorandum of Understanding (MoU) Black List, compared with just eight per cent of purpose-built livestock carriers.

The report noted that the consequences of the ageing fleet extend far beyond animal welfare, with nearly one-third of the ships inspected between 2024 and 2025 found to be in violation of international environmental regulations.

According to the report, the 159 vessels had accumulated a total of 565 known detentions throughout their operational lives, including periods before their conversion into livestock carriers.

The report also found that violations of international labour standards were recorded on the vessels, with deficiencies ranging from inadequate crew accommodation and poor working conditions to wage-related issues and insufficient social protection.

A representative of the German Animal Welfare Foundation, Maria Boada Saña, said the case of the 53-year-old livestock carrier Spiridon II, which was currently before the courts, exemplified a poorly regulated shipping industry that had , over the years, relied on ageing and substandard vessels.

Boada Saña said in 2024, deficiencies were identified during 88 per cent of all inspections of livestock carriers, adding that a total of 15 per cent of the vessels were detained – almost four times the average detention rate for all ship types.

“Despite transporting sentient animals, livestock carriers have been the world’s most dangerous fleet for six consecutive years. Our report shows that many of these vessels should have been retired long ago,” she said.

Director of Robin des Bois, Jacky Bonnemains, stressed that the converted livestock carriers are, on average, over 45 years old, have accumulated 242 technical deficiencies and have each been detained by port authorities an average of four times.

Bonnemains added that the report clearly demonstrated that the problems associated with ageing livestock carriers extended far beyond animal welfare, affecting maritime safety, marine environmental protection and the working conditions of seafarers.

The organisations, however, urged governments of all countries involved in the live animal export trade by sea to take decisive action by enforcing stricter standards and closing existing regulatory loopholes.

They also called for measures to protect animals, seafarers, and the marine environment, while advocating a complete ban on live animal exports by sea to end what they described as a cruel practice.