Teekay Tankers Ltd. report an adjusted net loss of $6.3 million, or $0.08 per share, for the quarter ended June 30, 2013, compared to adjusted net income attributable to shareholders of Teekay Tankers of $0.9 million, or $0.01 per share, for the same period in the prior year. Teekay explain that the increase in adjusted net loss attributable to shareholders of Teekay Tankers is primarily the result of the change in employment of certain of the Company's vessels from fixed rates…