For more than two decades, Mona Khalil protected the endangered sea turtles that laid their eggs on a beach near her bed-and-breakfast in Lebanon and kept predators away from the vulnerable hatchlings running to the Mediterranean Sea.

Her efforts to spotlight the plight of the turtles, bringing together often opposing interests, earned her respect among conservationists. She remained unflinching in her mission even as periodic war erupted around her in southern Lebanon.

On June 4, the fighting between Israel and Hezbollah that has taken so many civilian lives in recent months caught up to her. She was wounded in an Israeli airstrike in southern Lebanon, and on Friday, she died of her injuries at the American University of Beirut Medical Center, a close friend, Fadia Jomaa, said.

Her sister, Amal Khalil, remembered Mona Khalil, who was 76, as “a well-rounded person — extremely tough, extremely kind.”

“Inside, I am angry,” Amal Khalil said.

More than 4,000 people have been killed in the most recent round of fighting between the Israeli military and Hezbollah, the Iran-backed armed group and political party that controls much of southern Lebanon. The fighting has threatened to upend a fragile peace agreement between the United States and Iran.

Ms. Khalil was born to Lebanese parents in Lagos, Nigeria. She later moved to the Netherlands, where she lived for more than a decade, working for a time as a porcelain restorer.

In the 1990s, Ms. Khalil returned to Lebanon to visit her family’s seaside home between Tyre and Naqoura, which had been built by her grandfather in the 1970s but abandoned during the civil war in the 1980s. It was dangerously close to a zone the Israelis occupied at the time. One night, she was walking on the Hima Qoleileh–Mansouri beach when she spotted a turtle squirming across sand.

“The first time I saw them, it was completely by accident,” Ms. Khalil said to a reporter for a 2006 Times article. “I suddenly heard a noise. It was a turtle creeping through the sand, coming to lay her eggs.”

Ms. Khalil learned that two species of sea turtle who nested there — the loggerhead and the green turtle — had been declared critically endangered by the World Conservation Union.

Her plans shifted. She moved to Lebanon in 2000.