Traits associated with food web structure in lagoon and reef ecosystems

Abstract

The oceans are currently facing multiple anthropogenic threats, such as overexploitation, pollution, habitat destruction, and climate change. To address these challenges, ecological indicators are needed to monitor the impact of human activities and assess the effectiveness of conservation measures. Food web topology captures the entire community structure, providing systems-based indicators of ecological status rather than monitoring single species and their composition. In this study, the association between functional organismic traits and topological indices describing the food web structure was tested by using network analysis in 4 reef and 15 lagoon Ecopath with Ecosim models. We aimed to understand if traits and conservation status can be linked with specific network position of a node. We analyzed 3 traits (diet, fertilization type, substratum), conservation status, and 18 topological indices. The results showed at least two significant associations for each trait. Conservation status, fertilization type, and diet displayed more distinct aggregations, being relevant in explaining food web structure. Conservation status aggregated top predators in a risk position (endangered or vulnerable) and also those with fewer network connections. Fertilization type (external, internal, or asexual) could be considered a good grouping trait. Diet has the highest coverage and revealed expected patterns, which can be very helpful for environmental predictions under disturbances, using the trait-based approach. Substratum is the least useful trait for this approach. The associations of ecological traits and topological indices in lagoon and reef food webs might help in conservation “ecosystem-based” management decision-making and prioritization.