Mr Berrios ran his seafront tent camp with strict discipline, allowing no alcohol and ensuring the beach was combed daily.
BBC: Vieques protesters: 'We'll be back'
2.
Researchers such as Lopez and his wife, Ana Longo Berrios, have been fanning out across the Caribbean and returning with new and troubling evidence of the decline.
NPR: Alarm Over Vanishing Frogs In The Caribbean
3.
Despite his popularity, Mr Berrios and his party generally receive only around 5% of the vote at most - a reflection of Puerto Ricans' hesitation to sever their ties to the United States.