The study conducted by Broadband Genie found that more than 74 per cent of teachers said that pupils made less progress during the first lockdown when many pupils were forced to learn from home.
More than 52 per cent said they are now very concerned about how future lockdowns will affect pupils.
In Barnsley, 17 schools have experienced student absences this week through bubble closures and pupils who are self-isolating.
Schools across the borough have been continually affected by student absence since they reopened in September following a four-month absence caused by the first national lockdown.
However, schools were allowed to remain open during the second lockdown period which ended on Wednesday.
Before the half-term break in October, more than half of the schools across Barnsley had been affected by bubble closures.
A spokesperson for Outwood Academy, Shafton, one of the schools affected this week, said: “Throughout the last few months we have worked tirelessly to ensure we have gone above and beyond the official guidance with the safety measures we have implemented across the academy, including sanitiser stations based across the site and PPE available for all staff and students.
“Despite our best efforts though, it was always inevitable that issues would arise during this unprecedented time, but we will continue with our work in the academy to ensure that we minimise risk as far as is possible for both staff and students moving forward.”
Barnsley’s infection rate has been steadily falling throughout the second lockdown period and now stands at 210.6 new cases per 100,000 people.
Coun Margaret Bruff, cabinet spokesperson for children’s services said the council wants to urge parents and carers to follow government guidance.
“It’s important that if either a child or member of staff is feeling unwell, that they stay at home and let the school know as soon as possible. If they have symptoms of Covid-19, they need to self-isolate immediately and get tested. This also applies if any members of the household are unwell.
“It’s so important that people are being more careful than ever about observing the now-familiar social distancing measures such as hand washing, social distancing, staying at home and self-isolating if symptomatic.
“Parents are also advised to wear face coverings when taking and picking up children from school to reduce opportunities for community transmission.”