The Resilience and Robustness of the Humboldt Current Large Marine Ecosystem

The Humboldt Large Marine Ecosystem (HCLME) covers an area of approximately 4 million km² – about half the size of Brazil, the world’s 5^th largest country, with 60% of the area beyond national jurisdiction. Not only is it a large area but its nearshore nutrient rich upwelling areas generate approximately 20% of the world’s fish landings with Peru being the largest global fishmeal and fish-oil product exporter: important inputs to the expanding worldwide aquaculture industry. The area is also highly biodiverse with over 10,000 species registered of which Polychaeta, Aves, and Mammalia have endemic species represented. Introduced species come from 31 taxa with Rhodophyta, Salmoniforme, and Polychaeta contributing the greatest number of exotics thereby increasing the risk of biodiversity loss and reduced ecosystem resilience though competition. The rich biodiversity supports a thriving tourism industry from Southern Chile to the Galapagos Islands in Ecuador. However increasing coastal population size with associated needs for employment, freshwater, energy and food with concomitant waste disposal problems are placing the highest stress levels on the system since the start of the industrial age. When this is coupled with climate change scenarios and high natural environmental variability caused by the ENSO (El Niño Southern Oscillation) and LNSO (La Niña Southern Oscillation), producing dramatic changes in species composition and abundance, it is evident that what has been to date a resilient and robust system could be facing a period of long term negative change. Whilst there is evidence of system cooling due to increased upwelling in the Peruvian upwelling front, there is also evidence of warming due to the ingression of equatorial surface water at the Northern extreme. Predictions suggest there could be up to three decades of increasing or equal high anchovy productivity followed by a series of decadal declines with productivity levels in 2100 at around 15% of those experienced today.  Increases in acidification and the expansion of the oxygen minimum zone (OMZ) further complicate the system’s resilience to change. Attempts to mitigate this problem involve the setting up of Marine Protected Areas (MPA) and a series of National Parks with associated buffer zones and habitat restoration.  

Key words: LME, MPA, Biodiversity, Resilience, OMZ, acidity, Climate Change, Stress, ENSO, Exotic Species.