Martina McBride, Trisha Yearwood Among Latest Cancellations at SeaWorld

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Justin Moore, Scotty McCreery and .38 Special among the only artists left on the bill.

SeaWorld continues to come under scrutiny as more and more musicians back out of its Brews, Bands and BBQ concert series amid petitions and protests stemming from the documentary film Blackfish.

Now, Martina McBride, Cheap Trick, REO Speedwagon and Trisha Yearwood are among those canceling their scheduled performances at the Orlando marine theme park after pressure from animal rights groups and petitions on citing SeaWorld's alleged track record in terms of treating its marine life. McBride is the latest artist to back out of the show, revealing in a Facebook post on Dec. 14 that "given all the issues that have aired recently," it wasn't in her best interest to play the show.

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McBride follows REO Speedwagon, which announced the cancellation on Twitter on Dec. 13, while Yearwood confirmed her departure from the series on Dec. 12 and Cheap Trick made its announcement on Dec. 11. A petition for McBride to cancel her show had reached more than 20,000 signatures before meeting its goal.

Heart, Barenaked Ladies and Willie Nelson originally agreed to perform during the concert series but have since withdrawn amid public pressure. As it stands, only Justin Moore, Scotty McCreery and .38 Special remain on the bill, though all have corresponding petitions asking them to cancel as well.

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Many of the cancellations stem from Blackfish, which was released earlier this year. Discussing the captivity of killer whale Tilikum and its role in the deaths of three individuals, while decrying SeaWorld's alleged practices with many of its marine animals held at its parks, the film was included on the shortlist for best documentary at the Oscars last week.

SeaWorld has dismissed the allegations in Blackfish, calling the film inaccurate.