Open AccessChanges in soft coral <em>Sarcophyton</em> sp. abundance and cytotoxicity at volcanic CO<sub>2</sub> seeps in Indonesia
Author(s) -
Hedi Indra Januar,
Neviaty Putri Zamani,
Dedi Soedarma,
Ekowati Chasanah
Publication year - 2016
Publication title -
aims environmental science
Language(s) - English
Resource type - Journals
eISSN - 2372-0352
pISSN - 2372-0344
DOI - 10.3934/environsci.2016.2.239
Subject(s) - coral , ocean acidification , coral reef , benthic zone , cytotoxicity , volcano , environmental chemistry , chemistry , oceanography , ecology , biology , geology , seawater , biochemistry , in vitro , paleontology
This study presents the relationship between benthic cover of Sarcophyton sp. living on coral reefs and their cytotoxicity (an assumption of soft coral allelochemical levels) along acidification gradients caused by shallow water volcanic vent systems. Stations with moderate acidification (pH 7.87 ± 0.04), low acidification (pH 8.01 ± 0.04), and reference conditions (pH 8.2 ± 0.02) were selected near an Indonesian CO2 seep (Minahasa, Gunung Api Island, and Mahengetang Island). Cover of the dominant soft coral species (Sarcophyton sp.) was assessed and tissue samples were collected at each site. The cytotoxicity tissue extracts were analyzed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolinon bromide (MTT) method. Levels of cytotoxicity were strongly correlated with Sarcophyton sp. cover (p < 0.05; R2 = 0.60 at 30 ppm and 0.56 at 100 ppm), being highest at mean pH 8.01 where the soft corals were most abundant. This finding suggests that Sarcophyton sp. can be expected to survive ocean acidification near Indonesia in the coming decades. How the species might be adversely affected by further ocean acidification later in the century unless CO2 emissions are reduced remains a concern