Diversidad, Abundancia Y Amenazas De Los Octocorales De La Isla Malpelo, Pacífico Oriental Tropical, Colombia

Abstract

During three expeditions to the island (2009 and 2010), the diversity, abundance and status of octocorals were explored. Seven species of octocorals were recorded: Leptogorgia alba, Pacifigorgia cf. lacerata, Pacifigorgia sp.1 y Pacifigorgia sp.2, Muricea cf. fruticosa, Muricea sp., and the invasive species Carijoa riisei. Octocorals form dense aggregations in rocky walls and cliffs, with higher abundances between 10 and 20 m, reaching up to 20 colonies m-2. The most abundant species was Pacifigorgia cf. lacerata with a dominance of more than 60 % and a frequency of occurrence of 100 % for all visited sites. According to depth, three well-defined zones were determined for most sites. A deep zone between 25 and 40 m with an exclusive dominance of L. alba, a shallow assemblage between 7 and 20 m dominated by Pacifigorgia spp., and a transition zone between 18 and 25 m with a mixture of L. alba and P. cf. lacerata. Surprisingly, during November 2009, diseases of possible fungal origin visibly affected populations of Leptogorgia and Pacifigorgia. Subsequently, during February 2010 the same populations of octocorals were monitored and up to 66 % of the colonies were already dead in some locations. Leptogorgia had a significant reduction at El Arrecife site, while Pacifigorgia cf. lacerata had high mortality at La Nevera and El Freezer sites, and a recovery in El Arrecife. There was a notable improvement in disease prevalence by July 2010 with less than 10 % of diseased colonies. The invasive species C. riisei was observed in La Catedral and El Monstruo bank. Thus, this information increases considerably the knowledge of octocorals on Malpelo Island and is the first warning of possible threats against local octocoral populations, such as fungal diseases and the invasive octocoral C. riisei.

Responses of the tropical gorgonian coral Eunicea fusca to ocean acidification conditions

“…In some shallow reefs, octocorals are becoming extremely abundant, which would probably lead to a shift in the reef communities from scleractinian coral dominated to octocoral/soft coral dominated habitat (Inoue et al 2013;Ruzicka et al 2013). Interestingly, in rocky reefs of the Eastern Pacific gorgonian corals are the most conspicuous invertebrates (Sánchez et al 2011). These areas are habitats with low pH in tropical shallow waters, serving as possible natural examples of the outcome of ocean acidification (Manzello 2010).…”

Dynamic Interplay of ENSO Events and Local Hydrodynamic Parameters Drives Demography and Health Status of Gorgonian Sea Fan Populations on a Remote Tropical Eastern Pacific Island

“…Being long-lived and slow-growing species, they are particularly sensitive to natural disturbances (Linares et al, 2008). Moreover, gorgonian corals are increasingly affected by disease outbreaks and abundances of many species have declined worldwide (Bourne et al, 2009;Sánchez et al, 2011. This is of great concern given that these organisms play a key ecological role in benthic communities and are considered "engineering species, " shaping the habitat and increasing its complexity by forming three-dimensional structures (Jones et al, 1994;Ballesteros, 2006;Sánchez et al, 2016).…”

“…This uninhabited island is considered to be under pristine conditions (Zapata and Vargas-Ángel, 2003;Quimbayo et al, 2016). While gorgonians are typically diverse in the TEP (Bayer, 1953;Van Oppen et al, 2005;Sánchez, 2016), rocky reef environments of Malpelo Island are mainly dominated by species of the genera Leptogorgia and Pacifigorgia (Sánchez et al, 2011;Sánchez, 2016). Of these, Pacifigorgia cairnsi, which is endemic to the TEP, is considered a keystone species in Malpelo.…”

Community structure of shallow water Alcyonacea (Anthozoa: Octocorallia) from the southern Tropical Eastern Pacific

“…In the TEP, delineated as the region between southern California and Northern Peru, studies on Alcyonacea began in the mid nineteenth century with Valenciennes (1846;review in Breedy and Guzman 2002), and have revolved around taxonomy and species inventories (Hickson 1928;Bielschowsky 1929;Stiasny 1941Stiasny , 1943Prahl et al 1986;Sinsel-Duarte 1991;Reyes-Bonilla et al 1997;Breedy and Guzman 2002, 2005a, b, 2007, 2011, 2015Guzman et al 2004;Williams and Breedy 2004;Breedy andCorte´s 2008, 2014;Breedy 2008, 2011;Breedy 2009;Vargas et al 2008Vargas et al , 2010Breedy et al 2009a, b;Sa´nchez et al 2011Soler-Hurtado and Lo´pez-Gonza´lez 2012;Soler-Hurtado et al 2016). Van Oppen et al (2005) presented initial ecological insights after examining 27 Eastern Pacific species for endosymbiotic zooxanthellae, finding none.…”

“…Van Oppen et al (2005) presented initial ecological insights after examining 27 Eastern Pacific species for endosymbiotic zooxanthellae, finding none. Mortality due to epizooics and thermal anomalies (Sa´nchez et al 2011, as well as the impact of the invasive Carijoa riisei on other Alcyonacea were monitored in Colombia. Species composition and bathymetric distribution were first quantified by Abeytia et al (2013) in southern Mexico, and by Gomez et al (2014) in Panama.…”