“Mother of Jesus, a redhead!” That’s how loner marine biologist Siobhán (Hermione Corfield) is greeted by a tight-knit sea crew when she hops onboard a ragged fishing trawler in director Neasa Hardima’s sci-fi horror “Sea Fever.” The superstitious fishermen and women see redheads as bad luck, doctoral student Siobhán shrugs it off as mere folklore. She joins this sea expedition to study faunal behavior, planning on photographing the catches made on this expedition for scientific anomalies.