Determinants of Tubastraea coccinea invasion and likelihood of further expansion in the northern Gulf of Mexico

Abstract

Invasive species have large economic and ecological impacts and are the leading driver of extinction for both plants and animals worldwide. In the USA, coral reefs, which provide $3.4 billion per year in ecosystem services, are impacted by invasive marine species. One such species is Tubastraea coccinea, which was the first scleractinia to invade the western Atlantic and recently has spread to natural reefs within the northern Gulf of Mexico (GoM). We document this recent invasion by compiling occurrence records, develop a species distribution model identifying important determinants of invasion, and project potential range expansion. Our results indicate T. coccinea currently is distributed along the GoM coast from the Florida Keys to southern Texas, with documented localities clustered ≈ 100 km off the Louisiana coast and ≈ 200 km off the Texas coast, and sparsely distributed elsewhere. Our species distribution model identified five environmental factors that together contribute > 99% to the overall model. These factors include two surface variables (mean pH and mean calcite, contributing ≈ 40%) and three benthic variables (maximum current velocity, minimum iron, and minimum dissolved oxygen, contributing ≈ 60%). Our model suggests potential habitat for range expansion is distributed mainly within the western portion of the northern GoM, with the highest probabilities of occurrence (0.8 < P < 1.0) clustered along the Texas and Louisiana coasts between 88 and 97°W (near the border between states).

Importance of Anthropogenic Determinants of Tubastraea coccinea Invasion in the Northern Gulf of Mexico

“…Colonies are composed of a spongy calcareous base with protruding calcareous cups known as corallites [17]. Each corallite contains a single polyp [14], which can be up to 11 mm in diameter and can extend up to 4 cm from the spongy calcareous base [8]. In the GoM, T. coccinea rarely occurs at depths >78 m [19].…”

“…We obtained T. coccinea occurrence data from Derouen et al [14] (Figure 1b). Derouen et al [14] collected data from the Ocean Biogeographic Information System [23], the Global Biodiversity Information Facility [24], and the Web of Science [25].…”

“…We obtained T. coccinea occurrence data from Derouen et al [14] (Figure 1b). Derouen et al [14] collected data from the Ocean Biogeographic Information System [23], the Global Biodiversity Information Facility [24], and the Web of Science [25]. They identified nine environmental variables as being physiologically and/or ecologically relevant for marine organisms in general [15,26] and for T. coccinea in particular [14].…”

“…Tubastraea coccinea, whose occurrence in its nonnative range is mainly associated with artificial structures such as oil/gas platforms and shipwrecks, is considered a major threat to marine biodiversity [6,[11][12][13]. A recently developed species distribution model identified important determinants of T. coccinea invasion in the northern GoM and projected its potential range expansion [14]. Five environmental factors, including two variables from the top surface layer of the ocean (mean pH and mean calcite) and three variables from benthic layers adjacent to the seabed (maximum current velocity, minimum iron, and minimum dissolved oxygen), contributed >99% to the overall model [14,15].…”

“…A recently developed species distribution model identified important determinants of T. coccinea invasion in the northern GoM and projected its potential range expansion [14]. Five environmental factors, including two variables from the top surface layer of the ocean (mean pH and mean calcite) and three variables from benthic layers adjacent to the seabed (maximum current velocity, minimum iron, and minimum dissolved oxygen), contributed >99% to the overall model [14,15]. However, the potential effects of anthropogenic factors were not considered.…”