The 36-day Del Mar summer meeting that starts Wednesday may be among the most important in the track’s history. Amidst an opening day noted for its large and festive crowds and general revelry, Del Mar opens less than a month after the conclusion of a six-month Santa Anita meeting plagued by a series of equine fatalities that led to the cancellation of three weeks of racing in March, drew national news, and led to widespread concern over horse safety. Since mid-June, new protocols have been launched at Southern California tracks, notably the creation of a five-person panel that scrutinizes the medical, racing, and veterinary records of horses entered to race. Those behind-the-scenes measures will continue at Del Mar and have been implemented to ensure the safest possible season from Wednesday’s opening day through closing day on Labor Day, Sept. 2. With fewer available racehorses in Southern California, Del Mar will follow the lead of Santa Anita and Los Alamitos and reduce the number of races during the meet. Del Mar plans to maintain a five-day racing week from Wednesdays through Sundays with six days of racing on the final week. Thursday programs will have seven races instead of the eight run in past years. Sunday programs are tentatively scheduled to have eight races instead of nine. Santa Anita canceled racing on nine Thursdays from mid-April to the conclusion of its marathon meeting on June 23 because of a shortage of race-ready horses. The Los Alamitos summer meeting, which ended Sunday, was scheduled for 12 days, but raced only nine days. Last summer, Del Mar averaged 8.69 runners per race, the most since averaging 8.79 runners at the 2015 summer meeting. Officials are hoping to complete the 36-day season with a similar average field size. “A lot of things have to fall into place for us to equal our quality and standard at Del Mar in terms of field size,” racing secretary David Jerkens said last weekend. “We’ve set the bar high. The industry is relying on us to run five days a week. That’s a challenge that’s ahead of us. “We’re optimistic given the response we’ve received from horsemen. They’re eager to hit the reset button and get started at Del Mar.” Wednesday’s opening day will have a maximum of 93 runners on a 10-race program that begins at 2 p.m. There are two six-horse fields and two seven-horse fields in the first four races before the program ends with a maximum of 12 runners in the final three races. Thursday’s seven-race program will have a maximum of 59 runners. Wednesday’s feature is the $100,000 Oceanside Stakes for 3-year-olds on turf, which could produce a few runners for the Grade 2 Del Mar Derby on Sept. 1, one of 22 graded stakes during the meeting. There are five Grade 1 races during the meet, with the $1 million Pacific Classic on Aug. 17 being the richest.