Alteration of coastal productivity and artisanal fisheries interact to affect a marine food-web

Abstract

Top-down and bottom-up forces determine ecosystem function and dynamics. Fisheries as a top-down force can shorten and destabilize food-webs, while climate-change driven effects can alter the bottom-up forces of primary productivity. We assessed the response of a highly-resolved intertidal food-web to these two global-change drivers, using network analysis and bioenergetic modelling. We quantified the relative importance of artisanal fisheries as another predator species, and evaluated the independent and combined effects of fisheries and plankton-productivity changes on food-web dynamics. The food-web was robust to the loss of all harvested species but sensible to plankton-productivity decline. Interestingly, fisheries dampened the negative impacts of decreasing plankton productivity on non-harvested species, while plankton-productivity decline increased the sensitivity of harvested species to fishing. Our results show that strategies for new scenarios caused by climate change are needed to protect marine ecosystems and the wellbeing of local communities dependent on their resources.

Potential extinction cascades in a desert ecosystem: Linking food web interactions to community viability

“…Ecosystems are intricate networks of interactions in which the presence or absence of species has the potential to trigger a chain reaction of cascading secondary extinctions throughout the community (Ebenman et al, 2004). Modeling these cascades in real-world food webs can provide valuable insights for adjusting species management or harvesting strategies (Ávila-Thieme et al, 2021;de Visser et al, 2011). Indeed, the economic advantages of the ecological network-based predictive approach has led to its adoption by fisheries scientists (Yun et al, 2017), who not only have developed complex, dynamic representations of marine ecosystems (Fulton et al, 2011) but also have created bespoke software to analyze such models (Heymans et al, 2016).…”