TY - JOUR
T1 - Analyzing pelagic food webs leading to top predators in the Pacific Ocean
T2 - A graph-theoretic approach
AU - Dambacher, Jeffrey M.
AU - Young, Jock W.
AU - Olson, Robert J.
AU - Allain, Valérie
AU - Galván-Magaña, Felipe
AU - Lansdell, Matthew J.
AU - Bocanegra-Castillo, Noemí
AU - Alatorre-Ramírez, Vanessa
AU - Cooper, Scott P.
AU - Duffy, Leanne M.
N1 - Funding Information:
This project was funded by Cooperative Agreement NA17RJ1230 between the Joint Institute for Marine and Atmospheric Research (JIMAR) and the National Oceanic and Atmospheric Administration (NOAA). The views expressed herein are those of the authors and do not necessarily reflect the views of NOAA or any of its subdivisions. MJL and SPC received support through research grant 2004/063 from the Australian Fisheries Research and Development Corporation. FGM was supported by the Instituto Politecnico Nacional (COFAA and EDI). NBC and VAR were supported by CONACYT and PIFI. We thank J. Sibert, former program manager of the Pelagic Fisheries Research Program (PFRP), University of Hawaii at Manoa, for his support; most of the diet data from the central-western and central-eastern regions were due to previous support by the PFRP. Stomach samples were collected from the south-western Pacific Ocean by scientists from within CSIRO, particularly T. Carter, and by the observers of the Australian Fisheries Management Authority, particularly S. Hall. Stomach samples from the eastern-central Pacific were collected by a team of observers in Ecuador and Mexico, with the valuable assistance of E. Largacha, H. Pérez, K. Loor, V. Fuentes, C. de la A.-Florenci, A. Basante, W. Paladines, F. Cruz, C. Maldonado, and the captains and crew of several purse-seine vessels. Samples of predators from the western-central Pacific were collected by observers of the national observer programs of New Caledonia, Papua New-Guinea, Federated States of Micronesia, FSM Arrangement Program, Solomon Islands, Cook Islands and Marshall Islands. Assistance with stomach content analysis was provided in Australia by S. Riddoch, in Ecuador by L. Cedeño, J. Morales and M. Loor, and in New Caledonia by Caroline Sanchez. We thank K. Hayes, P. Lehodey and two anonymous reviewers for comments that improved the clarity of this work.
PY - 2010/7
Y1 - 2010/7
N2 - This work examined diet data from studies of top pelagic predators from three large regions of the equatorial and South Pacific Ocean. Food webs of each of these three systems were found to have relatively high species diversity, but in contrast to other marine systems, relatively low connectance. Food webs were examined using graph-theoretic methods, which included aggregating species based on food-web relationships and identification of potentially influential species. Species aggregations were used to construct simplified qualitative models from each region's food web. Models from each region were then analyzed to make predictions of response to climate change for six commercially important species: mahi mahi, skipjack tuna, albacore tuna, yellowfin tuna, bigeye tuna, and swordfish. We found little commonality in the structure of the three food webs, although the two regions in the equatorial Pacific had food webs composed of four predation tiers, as defined by network levels of predation, whereas the south-western region had only three predation tiers. We also found no consistent pattern in the predicted outcomes of the perturbations, which underlines the need for detailed trophic databases to adequately describe regional pelagic ecosystems. This work demonstrates that food-web structure will be central to understanding and predicting how top pelagic predators, and the ecosystems in which they are embedded, will respond to climate change.
AB - This work examined diet data from studies of top pelagic predators from three large regions of the equatorial and South Pacific Ocean. Food webs of each of these three systems were found to have relatively high species diversity, but in contrast to other marine systems, relatively low connectance. Food webs were examined using graph-theoretic methods, which included aggregating species based on food-web relationships and identification of potentially influential species. Species aggregations were used to construct simplified qualitative models from each region's food web. Models from each region were then analyzed to make predictions of response to climate change for six commercially important species: mahi mahi, skipjack tuna, albacore tuna, yellowfin tuna, bigeye tuna, and swordfish. We found little commonality in the structure of the three food webs, although the two regions in the equatorial Pacific had food webs composed of four predation tiers, as defined by network levels of predation, whereas the south-western region had only three predation tiers. We also found no consistent pattern in the predicted outcomes of the perturbations, which underlines the need for detailed trophic databases to adequately describe regional pelagic ecosystems. This work demonstrates that food-web structure will be central to understanding and predicting how top pelagic predators, and the ecosystems in which they are embedded, will respond to climate change.
UR - http://www.scopus.com/inward/record.url?scp=77957171017&partnerID=8YFLogxK
U2 - 10.1016/j.pocean.2010.04.011
DO - 10.1016/j.pocean.2010.04.011
M3 - Artículo
SN - 0079-6611
VL - 86
SP - 152
EP - 165
JO - Progress in Oceanography
JF - Progress in Oceanography
IS - 1-2
ER -