<p>According to Brazil's environment department official, the cause of sudden, massive extermination of fish has not yet been ascertained, but it could have been caused by the unusual proliferation of algae, which have reduced the oxygen content of the water.<br /><br />Friday, thousands of fish appeared floating on the waters of Rodrigo de Freitas Lagoon, a tourist attraction near the beaches of Copacabana, Ipanema and Leblon, the Urban Cleaning Company of Rio de Janeiro said.</p>
<p>According to Brazil's environment department official, the cause of sudden, massive extermination of fish has not yet been ascertained, but it could have been caused by the unusual proliferation of algae, which have reduced the oxygen content of the water.<br /><br />Friday, thousands of fish appeared floating on the waters of Rodrigo de Freitas Lagoon, a tourist attraction near the beaches of Copacabana, Ipanema and Leblon, the Urban Cleaning Company of Rio de Janeiro said.</p>