Marine Biology Research ISSN: 1745-1000 (Print) 1745-1019 (Online) Journal homepage: http://www.tandfonline.com/loi/smar20 Spatial and short-term variability of larval, post- larval and macrobenthic assemblages associated with subtidal kelp forest ecosystems in Central Chile Sergio A. Carrasco, Loes Vandecasteele, Marcelo M. Rivadeneira, Miriam Fernández & Alejandro Pérez-Matus To cite this article: Sergio A. Carrasco, Loes Vandecasteele, Marcelo M. Rivadeneira, Miriam Fernández & Alejandro Pérez-Matus (2017): Spatial and short-term variability of larval, post-larval and macrobenthic assemblages associated with subtidal kelp forest ecosystems in Central Chile, Marine Biology Research, DOI: 10.1080/17451000.2017.1322704 To link to this article: http://dx.doi.org/10.1080/17451000.2017.1322704 Published online: 18 Jul 2017. Submit your article to this journal View related articles View Crossmark data Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=smar20 Download by: [Australian Catholic University] Date: 19 July 2017, At: 12:46 MARINE BIOLOGY RESEARCH, 2017 https://doi.org/10.1080/17451000.2017.1322704 ORIGINAL ARTICLE Spatial and short-term variability of larval, post-larval and macrobenthic assemblages associated with subtidal kelp forest ecosystems in Central Chile Sergio A. Carrascoa, Loes Vandecasteeleb, Marcelo M. Rivadeneirac, Miriam Fernándezd and Alejandro Pérez-Matusa aSubtidal Ecology Laboratory & Center for Marine Conservation, Estación Costera de Investigaciones Marinas, Pontificia Universidad Católica de Chile, Santiago, Chile; bFaculty of Sciences, Ghent University, Ghent, Belgium; cCentro de Estudios Avanzados en Zonas Aridas (CEAZA), Facultad de Ciencias del Mar, Universidad Católica del Norte, Coquimbo, Chile; dEstación Costera de Investigaciones Marinas & Center for Marine Conservation, Pontificia Universidad Católica de Chile, Santiago, Chile ABSTRACT ARTICLE HISTORY Identifying patterns of spatial and temporal variability in the composition of communities Received 5 October 2016 associated with kelp forests is critical to understand the functioning of this productive, yet Accepted 20 April 2017 vulnerable ecosystem. We used a suite of sampling methods (light attraction and airlift RESPONSIBLE EDITOR devices) to evaluate the variability of larval, post-larval and macrobenthic assemblages Eric Hilton associated with kelp forests (Lessonia trabeculata) in Central Chile (30° to 33°S). Pelagic collections identified two assemblages: early-life stages and emerging macrobenthos, with KEYWORDS the later contributing three quarters to the total abundance regardless of the source of Larval supply; emerging illumination (permanent or flashing). Field experiments showed that moon phases affected macrobenthos; invertebrate; the structure and composition of the samples. Surveys carried out during new moon showed fish; recruitment; upwelling the highest abundances and taxonomic richness of emergent assemblages. However, species composition varied in both assemblages depending on the moon phase. Although the pelagic assemblages collected at sites with contrasting upwelling intensity did not show differences in community structure, differences in composition were evident for early-life stages. The relationship between pelagic and benthic collections indicated that four decapod crustaceans were represented at both larval and early juvenile stages; however, only the high abundances and densities of Paraxanthus barbiger allowed for estimations of benthic-pelagic coupling. For this species, larval abundances and benthic juvenile densities demonstrated contrasting local and regional patterns, suggesting a decoupling between pelagic and benthic environments. These findings highlight the differential variability in smaller components of kelp forests, but also suggest that post-settlement processes may be driving biological interactions through these highly productive and complex environments. Introduction drive larvae offshore, whereas events of upwelling Abiotic (e.g. climate, ocean circulation patterns) and relaxation can generate larval aggregations driving biotic factors (e.g. biogenic habitat availability, individ- them towards the shore (Wieters 2005; Narváez et al. uals’ physiological performance, inter- and intraspecific 2006). Similarly, gyres formed in bay systems will also interactions) are critical components determining the drive larval transport and settlement patterns (Palma magnitude of variation of wild populations across a et al. 2006). These meso-scale oceanographic and topo- wide range of spatial and temporal scales (reviewed graphic conditions may not only affect larval distri- by Bell et al. 2015). The complex life-history traits of bution, but also the dynamics and structure of most marine species, including both pelagic and planktonic communities. In fact, macrozooplankton, benthic or demersal phases, add another level of com- nekton, as well as emerging species (i.e. demersal zoo- plexity to advance our understanding of the dynamics plankton), are integral parts of the pelagic food web of marine populations (see Rodriguez et al. 1993; Caley (Pacheco et al. 2013a; Webster et al. 2015), playing et al. 1996). The processes affecting the transport and important roles in benthic-pelagic coupling by return- larval availability are highly variable on both spatial ing nutrients from the water column to the benthos, and temporal scales. For example, events of upwelling where they in turn may also be consumed by pelagic concentrated around headlands may consequently predators (Vallet & Dauvin 2001; Pacheco et al. 2013a, CONTACT Sergio A. Carrasco [email protected] Subtidal Ecology Laboratory & Center for Marine Conservation, Estación Costera de Investi- gaciones Marinas, Pontificia Universidad Católica de Chile, Santiago 6513677, Chile © 2017 Informa UK Limited, trading as Taylor & Francis Group 2 S. A. CARRASCO ET AL. 2013b). Therefore, strong spatial variability in abun- Besides structural traits, the kelp canopy may also dance of larval and post-larval dispersal stages can be exert some influence on other attractants, including predicted based on the topography of the coast, chemical signals (e.g. presence of conspecifics) or phys- coupled to coastal oceanographic conditions, expect- ical habitat modifications (e.g. light regimes) as a con- ing lower abundance in upwelling sites, explained by sequence of an extensive cover of fronds (Almanza the persistent offshore larval transport. et al. 2012). In fact, several studies have highlighted In addition to meso-scale patterns of variation in the importance of specific light-mediated mechanisms oceanographic conditions affecting larval transport, that cue movements and migrations through the water small-scale variation in the structure of habitats may column, suggesting that timings for species’ migrations influence changes in hydrodynamic conditions and may be significantly governed by light levels, particu- supply to adult habitats (Eckman et al. 1989; Duggins larly moonlight (see Alldredge & King 1980; Abello et al. 1990; Gaylord et al. 2007). For example, kelp et al. 2005; Vopel & Thistle et al. 2011; Pacheco et al. forest ecosystems have been described as strongly 2014; Webster et al. 2015). Although patterns and affecting larval supply, acting as a physical barrier rhythms of these movements may vary substantially that modifies water current velocity and flow among different habitats (intertidal, subtidal, estuaries), (Almanza et al. 2012). Coastal rocky environments other factors such as seasonal changes in sun angle, along the Humboldt Current Ecosystem are character- water column optical properties (e.g. turbidity) and ized by the dominance of large brown macroalgae, food sources may also be important in modulating i.e. Macrocystis pyrifera (Linnaeus) C. Agardh and Lesso- species-specific responses (Abello et al. 2005). nia trabeculata Villouta & Santelices (Laminariales), However, the association between larval supply, which are the main habitat-forming species in recruitment and adult abundance has been poorly ana- shallow subtidal ecosystems (up to 30 m depth) lysed in kelp forest environments, and the influence of between 12° and 56° latitude south (Stenek et al. other meso-scale processes, such as day/night, moon 2008; Villegas et al. 2008). In Central Chile cycles and illumination, remain largely unexplored. L. trabeculata is the main foundation species, being Based on these assumptions, we can predict benthic- replaced by M. pyrifera towards the south (Thiel et al. pelagic coupling in all kelp-dominated sites if kelp 2007). trap larvae and provide shelter to juveniles; nonethe- Given their three-dimensional structure, these kelp less, significantly higher abundances of larval, post- beds not only supply food, but also provide a bio- larval and macrobenthic communities are expected in genic habitat for the species that feed, breed and less intense upwelling sites if transport offshore domi- live on it, playing an important role in shaping the nates larval supply. structure and dynamics of associated communities The coast of central Chile offers a good system to (Morton & Anderson 2013). Many reef fish live in test alternative methods to study species with association with kelp, as they use the forest as a complex life-history strategies in general and in struc- primary habitat for settlement (Morton & Anderson turally complex environments (e.g. kelp forests) in par-