Morphological and community changes of turf algae in competition with corals

Abstract

The morphological plasticity and community responses of algae competing with corals have not been assessed. We evaluated eight morphological characters of four species of stoloniferous clonal filamentous turf algae (FTA), including Lophosiphonia cristata (Lc) and Polysiphonia scopulorum var. villum (Psv), and the composition and number of turf algae (TA) in competition for space with the coral Orbicella spp. under experimental and non-manipulated conditions. All FTA exhibited morphological responses, such as increasing the formation of new ramets (except for Psv when competing with O. faveolata). Opposite responses in the space between erect axes were found when Psv competed with O. faveolata and when Lc competed with O. annularis. The characters modified by each FTA species, and the number and composition of TA species growing next to coral tissue differed from that of the TA growing at ≥3 cm. The specific and community responses indicate that some species of TA can actively colonise coral tissue and that fundamental competitive interactions between the two types of organisms occur within the first millimetres of the coral−algal boundary. These findings suggest that the morphological plasticity, high number, and functional redundancy of stoloniferous TA species favour their colonisation of coral tissue and resistance against coral invasion.

Resolving coral photoacclimation dynamics through coupled photophysiological and metabolomic profiling

“…Characterizing the effects of changes in light availability on coral metabolism is critical to understanding not only how corals respond to natural changes in light but also how corals fundamentally cope with light-altering stressors attributed to human activity, such as enhanced sedimentation (Bessell-Browne et al, 2017) and algal shading (Cetz-Navarro et al, 2015). Rapidly altered light conditions are also induced via increasingly popular interventional reef management strategies involving coral transplantation (e.g.…”

Length and Biomass Data for Atlantic and Pacific Seaweeds From Both Hemispheres

“…A unitary seaweed only produces one frond from its holdfast (Scrosati, 2005). While demographic studies are done at the level of the individual for unitary seaweeds, they are typically done at the level of the frond for clonal seaweeds, as fronds are easy to count and, ultimately, are the structures that develop reproductive tissues and provide biomass readily available for consumers (Rivera and Scrosati, 2008;Cetz-Navarro et al, 2015;Pereira et al, 2017). Therefore, in this paper, length and biomass are reported for fronds for clonal species and for individuals for unitary species.…”

Estructura de la comunidad de céspedes algales en interacciones con corales masivos en arrecifes del Parque Nacional Natural Tayrona, Caribe colombiano

“…Los céspedes son ensamblajes mixtos de algas, densamente agregados, con altura de dosel no mayor a 2 cm y compuestos por una gran variedad de grupos que incluyen cianobacterias y algas rojas, verdes y pardas (Bender-Champ et al, 2014;Connell et al, 2014;Harris, 2015). Dependiendo del hábitat donde se desarrollan, exhiben gran variedad de morfologías, siendo las formas filamentosas (corticadas y no corticadas), las pequeñas foliáceas y las calcáreas articuladas las más frecuentes (Connell et al, 2014;Cetz-Navarro et al, 2015). En comparación con otras formas funcionales como las algas carnosas (calcáreas y no calcáreas) y algas costrosas, los céspedes poseen ventajas competitivas que les permiten colonizar el espacio disponible más rápidamente (Díaz-Pulido y McCook, 2002), al tener altas tasas de crecimiento (Littler et al, 2006), ser menos vulnerables a perturbaciones (Hay, 1981) y desarrollarse en ambientes con sobrecarga de nutrientes y alta sedimentación (Airoldi y Virgilio, 1998;Gorgula y Connell, 2004).…”