Improving the ecological relevance of toxicity tests on scleractinian corals: Influence of season, life stage, and seawater temperature

Environmental Pollution
Hawai‘i Institute of Marine Biology, 46-007 Lilipuna road, 96744, Hawai‘i, United States ; U.S. Fish and Wildlife Service, Pacific Islands, 300 Ala Moana Blvd, Room 3-122, Honolulu, HI 96850
By: , and 

Links

Abstract

Metal pollutants in marine systems are broadly acknowledged as deleterious: however, very little data exist for tropical scleractinian corals. We address this gap by investigating how life-history stage, season and thermal stress influence the toxicity of copper (Cu) and lead (Pb) in the coral Pocillopora damicornis. Our results show that under ambient temperature, adults and larvae appear to tolerate exposure to unusually high levels of copper (96 h-LC50 ranging from 167 to 251 μg Cu L−1) and lead (from 477 to 742 μg Pb L−1). Our work also highlights that warmer conditions (seasonal and experimentally manipulated) reduce the tolerance of adults and larvae to Cu toxicity. Despite a similar trend observed for the response of larvae to Pb toxicity to experimentally induced increase in temperature, surprisingly adults were more resistant in warmer condition to Pb toxicity. In the summer adults were less resistant to Cu toxicity (96 h-LC50 = 175 μg L−1) than in the winter (251 μg L−1). An opposite trend was observed for the Pb toxicity on adults between summer and winter (96 h-LC50 of 742 vs 471 μg L−1, respectively). Larvae displayed a slightly higher sensitivity to Cu and Pb than adults. An experimentally induced 3 °C increase in temperature above ambient decreased larval resistance to Cu and Pb toxicity by 23–30% (96 h-LC50 of 167 vs 129 μg Cu L−1 and 681 vs 462 μg Pb L−1).

Our data support the paradigm that upward excursions in temperature influence physiological processes in corals that play key roles in regulating metal toxicity. These influences are more pronounced in larva versus adult corals. These findings are important when contextualized climate change-driven warming in the oceans and highlight that predictions of ecological outcomes to metal pollutants will be improved by considering environmental context and the life stages of organism under study.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Improving the ecological relevance of toxicity tests on scleractinian corals: Influence of season, life stage, and seawater temperature
Series title Environmental Pollution
DOI 10.1016/j.envpol.2016.01.086
Volume 213
Year Published 2016
Language English
Publisher Applied Science Publishers
Publisher location Barking, Essex, England
Contributing office(s) Crustal Geophysics and Geochemistry Science Center
Description 14 p.
First page 240
Last page 253
Online Only (Y/N) N
Additional Online Files (Y/N) N