Seagrass production around artificial reefs is resistant to human stressors

Primary production underpins most ecosystem services, including carbon sequestration and fisheries. Artificial reefs (ARs) are widely used for fisheries management. Research has shown that a mechanism by which AR in seagrass beds can support fisheries and carbon sequestration is through increasing primary production via fertilization from aggregating fish excretion. Seagrass beds are heavily affected by anthropogenic nutrient input and fishing that reduces nutrient input by consumers. The effect of these stressors is difficult to predict because impacts of simultaneous stressors are typically non-additive. We used a long-term experiment to identify the mechanisms by which simultaneous impacts of sewage enrichment and fishing alter seagrass production around ARs across non-orthogonal gradients in human-dominated and relatively unimpacted regions in Haiti and The Bahamas. Merging trait-based measures of seagrass and seagrass ecosystem processes, we found that ARs consistently enhanced per..., The study aimed to examine the effect of fishing pressure and anthropogenic nutrient pollution on the nutrient supply in artificial reefs (ARs).The study involved the construction and deployment of ARs in seagrass habitats dominated by turtle grass in two locations in The Bahamas and one in Haiti in 2014. The ARs were constructed from cinder blocks and were deployed at similar depths. 
In May and June 2018, measurements were taken at two levels - at the AR level and on a plot level (within each AR) - in order to quantify seagrass and sediment nutrient content, fish biomass and nutrient supply, and seagrass variables. AR level measurements were taken 1 meter from the AR and plot-level measurements were taken using three transects oriented ~120° apart with eight distances (0.5, 1, 2, 3, 4, 6, 12, and 20 m from the AR) resulting in 24 sampling “plots” per AR.
Samples of seagrass and sediment were processed at the Department of Ecology and Evolutionary Biology, University of Michigan, USA. ...,