Marine conservation: towards a multi-layered network approach

Abstract

Valuing, managing and conserving marine biodiversity and a full range of ecosystem services is at the forefront of research and policy agendas. However, biodiversity is being lost at up to a thousand times the average background rate. Traditional disciplinary and siloed conservation approaches are not able to tackle this massive loss of biodiversity because they generally ignore or overlook the interactive and dynamic nature of ecosystems processes, limiting their predictability. To conserve marine biodiversity, we must assess the interactions and impacts among biodiversity and ecosystem services (BD-ES). The scaling up in complexity from single species to entire communities is necessary, albeit challenging, for a deeper understanding of how ecosystem services relate to biodiversity and the roles species have in ecosystem service provision. These interactions are challenging to map, let alone fully assess, but network and system-based approaches provide a powerful way to progress beyond those limitations. Here, we introduce a conceptual multi-layered network approach to understanding how ecosystem services supported by biodiversity drive the total service provision, how different stressors impact BD-ES and where conservation efforts should be placed to optimize the delivery of ecosystem services and protection of biodiversity. This article is part of the theme issue 'Integrative research perspectives on marine conservation'.

Keywords: ecosystem services; marine biodiversity; multi-layer networks.

Figure 1.

The workflow of the five layers of multi-layered network approach: (a) the ecological network, (b) the ecosystem service network, (c) the socio-ecological network, (d) the threat network and (e) the conservation strategy network, illustrating the connections within the network, the direct and indirect links between neighbouring and across multiple networks.

Figure 2.

Illustration of the conceptual workflow of the multi-layered network approach using cod and its role in multiple networks as an example, including the identification of the networks as well as the interactions between them. Cod play an essential role in marine ecosystems. As the top predator, cod is of major importance to marine plant and animal life. This means that threatening impacts on the cod stock have consequences throughout the entire ecological network layer, impacting the services cod provides and thereby influencing the socio-ecological network. The cod's crucial role illuminates the importance of fisheries management and conservation strategies that views the multi-layered network as a whole.