Structure, connectivity and resilience of an exploited ecosystem: towards sustainable ecosystem-based fisheries management

Shallow subtidal rocky reefs of Chile and Peru are dominated by kelps that form dense forests. In northern and central Chile this has led to one of the largest live harvest kelp fisheries in the world with ambitions to extend its spatial extent to Peru and southern Chile. Kelp harvesting leads to clearances resulting in local deforestation and habitat fragmentation with implications for the sustainable development of this fishery as well as the long-term health of kelp forest ecosystems, which support high levels of diversity and provide a wealth of goods and services worth billions of dollars to human society. Given that kelp harvesting in Chile and Peru is often undertaken by poorer members of society and that 46% of artisanal fisheries landings are of species associated with kelp forests, better management of the fishery will lead to improved economic development. Currently there are limited management strategies in place and where present, they are poorly enforced. The OECD noted that over-exploitation and illegal fishing are key fisheries challenges in the region and that ultimately a lack of governance in this area will impact the economic development of both countries. In response, the governments of Chile and Peru are committed to developing management plans for kelp resources, with the Chilean government announcing landmark plans to not only manage current stocks, but to introduce direct funding to fisherman to restock depleted areas. The Peruvian Government is on a similar path, with both countries are seeking to ensure continued biomass extraction of kelp and the maintenance of kelp associated fisheries. However, knowledge gaps exist hampering informed management and the long term sustainability of these coastal socio-ecological systems. It is unlikely that a one size fits all management approach will work in this region. The coastal oceanography is complex with areas of persistent and seasonal upwelling as well as areas with weak or no upwelling. Upwelling brings cold, nutrient-rich and CO2 saturated waters to the surface influencing population dynamics and community structure. Therefore in order to provide informed management advice there is a need to understand the impacts of harvesting intensity and environmental variability on the resilience (ability to tolerate and recover) of kelp populations. In addition, different harvesting techniques and other fisheries management devices are likely to impact the resilience of kelp forests and different restocking methods are likely to be more or less successful. We will use a multidisciplinary approach incorporating population genetics, experimental ecology, population and species distribution modelling and social-ecological approaches to deliver tools and indicators for sustainable kelp harvesting. Specifically we will address the following objectives: 1. Quantify the total stock of exploited kelp species across the region and predict how this will change with climate change. 2. Investigate the impacts of harvesting intensity and environmental variability on the population structure and connectivity of a commercially harvested kelp species as well as five important kelp-associated species using molecular techniques and traditional ecological approaches. This will enable us to identify the physical drivers and biological traits that promote resilience within kelp forests. 3. Develop tools and indicators for sustainable kelp harvesting by exploring different management options to improve kelp resilience to harvesting as well as exploring options for promoting recovery of harvested areas. 4. Explore the role of traditional ecological knowledge and bottom-up approaches to fisheries governance on management compliance. In meeting these objectives we will make significant contributions to the development of informed management plans, which will improve the sustainability and economic development of this important fishery and region.