Effects of Karenia brevis on clearance rates and bioaccumulation of brevetoxins in benthic suspension feeding invertebrates

• Published in: Aquatic toxicology 2012-01, Vol.106 (15), p.85-94
• Main Authors: Echevarria, Michael, Naar, Jerome P., Tomas, Carmelo, Pawlik, Joseph R.
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Animals; Applied ecology; Aquatic Organisms - metabolism; Aquatic Organisms - physiology; Autoecology; Benthic suspension feeder; bioaccumulation; Biological and medical sciences; Bivalvia; Bivalvia - metabolism; Bivalvia - physiology; Brevetoxin; brevetoxins; Bryozoa - metabolism; Bryozoa - physiology; Bugula neritina; Clearance rate; coasts; Ecotoxicology, biological effects of pollution; enzyme-linked immunosorbent assay; Feeding Behavior; Fundamental and applied biological sciences. Psychology; General aspects; Haliclona tubifera; Invertebrata; invertebrates; Invertebrates - metabolism; Invertebrates - physiology; Karenia brevis; Marine; Marine Toxins - metabolism; Mercenaria mercenaria; Mitigation; Oxocins - metabolism; Porifera - metabolism; Porifera - physiology; Rhodomonas; seawater; Stress, Physiological; Styela plicata; Trophic transfer; Tubifera; Urochordata - metabolism; Urochordata - physiology; Water Pollutants, Chemical - metabolism
• ISSN: 0166-445X; 1879-1514
• DOI: 10.1016/j.aquatox.2011.10.011

► Effect of Karenia brevis on clearance rates of benthic suspension feeders. ► Bioaccumulation of brevetoxins in tissue of benthic suspension feeders. ► All species studied cleared significant quantities of K. brevis from seawater. ► Clearance rates of bryozoan and tunicate reduced by >50% due to K. Brevis. ► High concentrations of brevetoxins were retained in tissue. Blooms of the toxic alga Karenia brevis occur along coastlines where sessile suspension feeding invertebrates are common components of benthic communities. We studied the effects of K. brevis on four benthic suspension feeding invertebrates common to the coast of the SE United States: the sponge Haliclona tubifera, the bryozoan Bugula neritina, the bivalve Mercenaria mercenaria, and the tunicate Styela plicata. In controlled laboratory experiments, we determined the rate at which K. brevis was cleared from the seawater by these invertebrates, the effect of K. brevis on clearance rates of a non-toxic phytoplankton species, Rhodomonas sp., and the extent to which brevetoxins bioaccumulated in tissues of invertebrates using an enzyme-linked immunosorbent assay (ELISA). All four invertebrate species cleared significant quantities of K. brevis from seawater, with mean clearance rates ranging from 2.27 to 6.71 L g h −1 for H. tubifera and S. plicata, respectively. In the presence of K. brevis, clearance rates of Rhodomonas sp. by B. neritina and S. plicata were depressed by 75% and 69%, respectively, while clearance rates by H. tubifera and M. mercenaria were unaffected. Negative effects of K. brevis were impermanent; after a recovery period of 13 h, B. neritina and S. plicata regained normal clearance rates. All four invertebrates accumulated high concentrations of brevetoxin after a 4 h exposure to K. brevis, but when animals were transferred to filtered seawater for 15 h after exposure, brevetoxin concentrations in the tissues of H. tubifera and B. neritina decreased by ∼80%, while there was no change in toxin concentration in the tissues of S. plicata and M. mercenaria. High cell concentrations of K. brevis may cause a suppression of clearance rates in benthic suspension feeding invertebrates, resulting in a positive feedback for bloom formation. Also, high concentrations of toxin may accumulate in the tissues of benthic suspension feeding invertebrates that may be transferred to higher-level consumers.