Nonlinear ecological processes driving the distribution of marine decapod larvae

• Published in: Deep-sea research. Part I, Oceanographic research papers Oceanographic research papers, 2015-03, Vol.97, p.92-106
• Main Authors: Peña, M., Carbonell, A., Tor, A., Alvarez-Berastegui, D., Balbín, R., dos Santos, A., Alemany, F.
• Format: Article
• Language: English
• Subjects: Adults; Balearic Sea; Communities; Crustaceans; Data analysis; Decapod larvae; Deep sea; Dispersion; Dispersions; Dynamic height; Ecology; Larvae; Marine; Marine ecology; Neural networks; Nonlinear processes; Nonlinearity; Plankton; Self-Organising Maps; Survival analysis; Unsupervised neural networks; Variables
• ISSN: 0967-0637; 1879-0119
• DOI: 10.1016/j.dsr.2014.11.017

The complexity of the natural processes lead to many nonlinear interacting factors that influence the distribution and survival of marine pelagic species, particularly in their larval phase. The management of these ecosystems requires techniques that unveil those interactions by studying the system globally, including all relevant variables and combining both community and environmental data in a single step. Specifically, we apply an unsupervised neural network, the Self-Organising Map (SOM), to a combined dataset of environmental and decapod larvae community data from the Balearic sea, obtained in two years with contrasting environmental scenarios, as an Exploratory Data Analysis (EDA) technique that provides a global and more detailed view of both the environmental processes and their influence on the distribution of such planktonic community. We examine the parental influence on the initial larval distribution by aggregating data by adult habitat, which also increments the signal to noise ratio (mean data patterns over noise due to outliers or measurement errors), and consider the distribution of larvae by development stage (as a proxy of age and hence of potential dispersion). The joined study of parental effect, drifting or concentration events determined by dynamical processes in the whole water column, and lifespan, draws the possible paths followed by larvae, and highlights the more influencing variables in their distribution. Investigation of the different aspects of dynamic height (absolute values, gradients or edges and correlations) clarified the effect of the oceanographic processes on decapods׳ larvae. •The Self-Organising Map unveils nonlinear relations in the ecosystem.•Dynamics in the entire water column regulate larvae distribution.•Adult habitat influences the spawning area and thus the initial and the final larvae distribution.•Larvae of different adult habitats were segregated at different regions of mesoscale processes.•Larvae stage informs on lifespan path, according to water dynamics.