What is the impact of kelp forest density and/or area on fisheries?

Background: Kelp forests are highly productive ecosystem engineers of rocky cold-water marine coastlines, providing shelter, habitat and food for a variety of associated organisms. Several factors have been related with an observed trend of kelp deforestation in some regions of the globe. The effect of this trend on fisheries has been poorly studied. The European directives addressing the conservation of marine habitats highlight the need to increase the knowledge about the relationship between kelp forests and fisheries, which will also be very valuable for the definition of fisheries management measures. This protocol describes the methods that will be used to conduct a systematic review to answer the following question: What is the impact of changes in kelp forest density and/or area on the abundance and diversity of fisheries? Methods/design: This systematic review will be focused primary in studies that report on positive, negative or no quantitative relationships between kelp forests (abundance and/or presence) and the health of fisheries (including adults and young life stages). The measurement of fisheries health will include abundance, presence and diversity of fisheries, mortality, fertility and recruitment rates and feeding behavior.