Stingray Season in colder waters is in the summer but we have them here year round. There may be more in the summer or they may gather for mating season ... but don't really know. There are lots in Playa Mora at Tenacatita and also La Vena river mouth by Los Angeles Locos. Actually much of Tenacatita Bay as far south as La Manzanilla.
We were planning on going to Boca de Iguanas and the beach restaurant Las Palmas until someone reported they were stung right in that area. The last thing I wanted was to have to deal with a 2 year old or 9 year old after a sting. Boca is a long way from Melaque and I don't know where the clinic is in La Manzanilla .. or their hours. I suggested we stay in Melaque and have a much smaller chance of running into those critters.
There have been a number of conversations about what to do for a sting including using a beach vine made into a tea or poultice. Can't find any references to that plant as a cure ... so hot water and a doctor as soon as possible sound the best. They also say elevate the foot so hot water in a towel maybe.
Stingray in Playa Mora in February
For lack of a better name - Planta de Raya