School District 71 has told all Comox Valley schools to cancel all overnight camping trips.The announcement — written by assistant superintendent Sheila Shanahan and posted on SD71's website Monday — directs all schools to cancel overnight camping trips scheduled to take place between now and the end of the school year."Principals and vice-principals are required to be available in the schools and are unable to provide supervision for students on overnight trips or events," wrote Shanahan in the letter. "As these are school-sanctioned events, without school district staff in attendance, they cannot occur."Teachers recently voted to withdraw from extracurricular activities as a way to legally protest Bill 22, the Education Improvement Act.Shanahan added there could be opportunities for schools to organize alternate activities during the day when teachers are available to supervise students, but she expects some disappointment."We do not expect that this news will be taken easily; it is of course disappointing for our students," said Shanahan.Graduation ceremonies are typically supervised by secondary school administrators and they will continue to do so, according to the letter. Parents have helped with the ceremonies in the past.Schools will provide specific information to parents and students about individual school events that may be affected. Parents can contact their child's school with questions.