Conservações e áreas afins - Comunicações orais

Islands and coastal mainland areas are hotspots of invasions and although boundaries of protected areas provide some resistance to invasions, even the most isolated and well-managed reserves are experiencing pressure from invasive alien species. Established invasions need to be managed as the example of sun coral invasion in the Brazilian coastline. Few MPAs has controlling actions program but it occurs in the no-take Alcatrazes MPA since 2013. Approximately 1.2 million colonies ≈ 92 % of T. tagusensis) were removed, resulting in more than 12.3 tonnes in 267 days in the field. We evaluated sun coral population dynamics and observed a decrease in the relative abundance of sun coral after management actions, decreasing the dominance and increasing the absence frequencies in some parts of the MPA. However, an annual evaluation showed a minor increase in the abundance of the pest and sun coral cover ranged between 4 and 28 %. Our results show that management actions keep a populational structure formed mainly by small colonies (up to 5 polyps), but it increased fast between annual field campaigns. In some places, sun coral cover returns to the same value in less than a year. Considering that benthic composition has a high cover of turf algae, a change in ecosystem functioning is expected since a primary producer is changed by a heterothrophic habitat modifier. Many groups were negatively affected by sun coral presence, such as ascidians, bryozoans, CCA, hydrozoans and cnidarians. In one site, a positive correlation was observed with macroalgae since its tridimensionality growth is seasonal. Data analyses keep in practice, but we can conclude that the management plan in Alcatrazes is maintaining sun coral populational structure and consequently decreasing propagule pressure. Then, currently it is controlling sun coral spread but it is far to think about its eradication in Alcatrazes MPA.