Universal says it now expects the economic impact of the COVID-19 pandemic to stretch into 2021.
Comcast CEO Brian Roberts said some guests may not return to theme parks until a COVID-19 vaccine is available.
"SeaWorld has determined that it must transition certain park and corporate personnel from a furloughed status to a permanent layoff," the company said in a statement.
Additional notices filed with the state of Florida bring the total number of affected workers to 2,306.
The layoffs affected Loews Portofino Bay Resort, Cabana Bay Beach Resort, and Universal's Hard Rock.
This is the second round of layoffs at the resort since it reopened in June.
The Winter Haven resort declined to specify the number of layoffs or which departments were affected.
143 workers at the Paddlefish and Terralina Crafted Italian restaurants at Disney Springs will be laid off.
The layoffs at Universal Orlando affected multiple business units, though the resort did not say how many workers were being let go.