[OANNES Foro] The marine ecosystem off Peru: What are the secrets of its fishery productivity and what might its future hold?

[raul sanchez]

Progress In Oceanography
Volume 79, Issues 2-4, October-December 2008, Pages 290-299 
The Northern Humboldt Current System: Ocean Dynamics, Ecosystem Processes, and Fisheries 
doi:10.1016/j.pocean.2008.10.027    

The marine ecosystem off Peru: What are the secrets of its fishery productivity and what might its future hold? 

Andrew Bakuna, ,  and Scarla J. Weeksb

aPew Institute of Ocean Science, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL 33149, USA

bCentre for Marine Studies, University of Queensland, Brisbane, QLD 4072, Australia

Abstract
The marine ecosystem located off the coast of central and northern Peru has stood as the “world’s champion” producer, by far, of exploitable fish biomass, generally yielding more than 20 times the tonnage of fishery landings produced by other comparable regional large marine ecosystems of the world’s oceans that operate under similar dynamic contexts and are characterized by comparable, or even greater, basic primary production. Two potentially contributing aspects are discussed from a framework of interregional comparative pattern recognition: (1) the advantageous low-latitude situation that combines strong upwelling-based nutrient enrichment with low wind-induced turbulence generation and relatively extended mean “residence times” within the favorable upwelling-conditioned near-coastal habitat and (2) the cyclic “re-setting” of the system by ENSO perturbations that may tend to interrupt malignant growth of adverse self-amplifying
 feedback loops within the nonlinear biological dynamics of the ecosystem.

There is a developing scientific consensus that one of the more probable consequences of impending global climate changes will be a general slowing of the equatorial Pacific Walker Circulation and a consequent weakening of the Pacific trade wind system. Since the upwelling-favorable winds off Peru tend to flow directly into the Pacific southeast trade winds, a question arises as to the likely effect on the upwelling-producing winds that power the productivity of the regional coastal ecosystems of the Peru–Humboldt Current zone. It is argued that the effects will in fact be decoupled to the extent that upwelling-favorable winds will actually tend to increase off Peru. Data demonstrative of this decoupling are presented. A tendency for less intense El Niño episodes in the future is also suggested. These conclusions provide a framework for posing certain imponderables as to the future character of the Peruvian marine ecosystem and of the fisheries it
 supports.

Keywords: Peruvian fisheries; Ecosystem-based management; Climate change; Upwelling; Environmental conditions; El Niño


Saludos,

Raúl E. Sánchez Scaglioni