title: Success in Competition for Space in Two Invasive Coral Species in the western Atlantic - Tubastraea micranthus and T. coccinea.
abstract: Invasion success by an alien species is dependent upon rate of reproduction, growth, mortality, physical characteristics of the environment, and successful competition for resources with native species. For sessile, epibenthic marine species, one critical resource is space. We examined competitive success in two invasive Indo-Pacific corals involved in competition for space in the northern Gulf of Mexico-Tubastraea coccinea and T. micranthus-on up to 13 offshore oil/gas platforms south of the Mississippi River. Still-capture photos of thousands of overgrowth interactions between the target corals and other sessile epibenthic fauna were analyzed from ROV videos collected at 8-183 m depth. T. micranthus was observed overgrowing >90% of all sessile epibenthic species which it encountered. Frequencies of competitive success varied significantly between platforms. T. coccinea was competitively superior to all competitors pooled, at the 60% level. There was little variability between T. coccinea populations. T. coccinea encountered the following species most frequently-the encrusting sponges Xestospongia sp. (with the commensal Parazoanthus catenularis), X. carbonaria, Dictyonella funicularis, Mycale carmigropila, Phorbas amaranthus, and Haliclona vansoesti-and was found to be, on average, competitively superior to them. Both T. micranthus and T. coccinea appear to be good competitors for space against these species in the northern Gulf of Mexico. Competitive success in T. micranthus was highest in the NE part of the study area, and lowest in the SW area near the Mississippi River plume. T. coccinea's competitive success peaked in the SW study area. This suggests that variation in competitive success both within and between populations of these species may be due to differences in local environmental factors.
authors.affiliation: Louisiana Universities Marine Consortium (LUMCON), 8124 Hwy. 56, Chauvin, LA 70344-2110, United States of America.|Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA 70803, United States of America.
authors.forename: Paul W
authors.initials: PW
authors.lastname: Sammarco
authors.affiliation: Louisiana Universities Marine Consortium (LUMCON), 8124 Hwy. 56, Chauvin, LA 70344-2110, United States of America.|EcoLogic Environmental, Inc., PO Box 886, Houma, LA 70361, United States of America.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Porter
authors.affiliation: Louisiana Universities Marine Consortium (LUMCON), 8124 Hwy. 56, Chauvin, LA 70344-2110, United States of America.|Center for Marine Science, University of North Carolina at Wilmington, 5600 Marvin Moss Ln., Wilmington, NC 28409, United States of America.
authors.forename: Melissa
authors.initials: M
authors.lastname: Genazzio
authors.affiliation: US Department of the Interior, Bureau of Safety and Environmental Enforcement, 1201 Elmwood Park Blvd., New Orleans, LA 70123-2394, United States of America.
authors.forename: James
authors.initials: J
authors.lastname: Sinclair
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000145:classification / Q000502:physiology*; D001267:Atlantic Ocean; D001522:Behavior, Animal; D060851:Gulf of America; D058865:Introduced Species; D061329:Oil and Gas Fields; D001468:Thoracica / Q000502:physiology*