Reports of wildlife crimes surged in the pandemic-hit year of 2020, including badger setts being bulldozed by builders and birds of prey being killed near grouse moors, according to a new report by wildlife charities.

The illegal taking of fish such as salmon from rivers and disturbance of seals and dolphins by people in boats also rose, the report found. Plants and fungi were also the targets of criminals, who snatched large numbers of mushrooms and bluebells to sell. At the same time, convictions for wildlife crime fell significantly.

The wildlife groups acknowledge the data they collect is incomplete and represents just “the tip of the iceberg”. This is because police are not required to officially record wildlife crimes – most are listed as “miscellaneous”. The groups said wildlife crimes must become notifiable so resources can be better assessed and repeat offenders targeted.

The lockdowns and restrictions of 2020, with the police busy monitoring social distancing rules, may have emboldened offenders, the report said, while greater use of the countryside by the public could have increased the witnessing of wildlife crimes. It said Covid-19 restrictions and staff absences also appeared to have reduced the capacity of police and prosecutors.

”Wildlife crime is something that should concern everyone,” said Martin Sims, the chair of Wildlife and Countryside Link’s (WCL) wildlife crime working group. “It inflicts pain, harm and loss for much-loved wildlife and fuels wider criminality against people and property. It is high time the government steps in to treat wildlife crime with the seriousness it deserves.”

The report was produced by WCL, the biggest coalition of wildlife and environment charities in England, and Wales Environment Link. It found reports of suspected crimes against badgers rose by 36% to 614 reports in 2020, compared with 2019. About half were referred to the police.

Reports of potential fishing crimes went up by more than a third in 2020 and disturbances of marine mammals in Cornwall jumped by 90%, according to data gathered by the NGOs.

The number of confirmed birds of prey crimes in England and Wales almost doubled in 2020 to 104 – the worst year for bird crime since recording began in 1990, according to the RSPB. Buzzards, red kites, peregrine falcons and sparrowhawks were the most common victims.

There were few known convictions for wildlife crime in 2020: one related to birds of prey, two to bats and four for trading in illegal wildlife. The exception was in fishing, where the sale of fishing licences to anglers provides funds for the Environment Agency to enforce its duty of protection. But even here, fishing crime convictions fell by almost two-thirds, from 2037 in 2019 to 679 in 2020.

Dawn Varley, of the Badger Trust, said: “Badger crime has been a UK wildlife crime priority for more than a decade, but sadly this persecution shows no sign of letting up. The 2020 rise [was] driven in large part by a shocking 220% increase in reports of developers interfering with badger setts. A small minority seem to see badger habitat protections as an inconvenience to be quietly bulldozed over, rather than a legal requirement to conserve an iconic British mammal.”

Nearly half of the UK’s biodiversity has been lost since the Industrial Revolution, making the UK one of the most nature-depleting countries in the world. Mark Thomas, at the RSPB, said: “Wildlife declines are already being felt, and species can ill afford to face the additional pressure of being brutally shot, trapped or poisoned.”

David Bunt, at the Institute of Fisheries Management, said: “It is hugely worrying that fisheries crimes have been on the rise in the pandemic, but convictions are down by two-thirds. Our biggest concern is whether inland enforcement agencies, the Environment Agency and Natural Resources Wales have the resources and staff to detect and deter crime on our rivers and lakes.”

The National Wildlife Crime Unit only receives funding year to year and the wildlife groups said it should be put on a permanent footing. The NWCU has produced a shortlist of wildlife offences that is being considered by the Home Office for official recording. The groups are also calling for sentencing guidelines; currently there are none on wildlife crimes.

A government spokesperson said: “We recognise the importance of tackling wildlife crime, which is why we directly fund the NCWU who provide intelligence and support to police forces protecting our precious wildlife. Those found guilty of harming animals should be subject to the full force of the law. Significant sanctions are available to judges to hand down to those convicted of wildlife crimes.”