A coalition of environmental organizations will hold a concert Friday night in San José to call attention to the decline of shark populations in Costa Rica and pressure authorities to strengthen protection for threatened marine species. The event, scheduled for Friday, May 8, at 7:30 p.m. at Amón Solar, is organized by the UCR Kiosks Program, the Paul Watson Foundation, Operation Rich Coast, Costa Rica por el Océano, Green Wolf and Bloque Verde,…