Evidence of climate‐driven ecosystem reorganization in the Gulf of Mexico

Abstract

The Gulf of Mexico is one of the most ecologically and economically valuable marine ecosystems in the world and is affected by a variety of natural and anthropogenic phenomena including climate, hurricanes, coastal development, agricultural runoff, oil spills, and fishing. These complex and interacting stressors, together with the highly dynamic nature of this ecosystem, present challenges for the effective management of its resources. We analyze a compilation of over 100 indicators representing physical, biological, and economic aspects of the Gulf of Mexico and find that an ecosystem-wide reorganization occurred in the mid-1990s. Further analysis of fishery landings composition data indicates a major shift in the late 1970s coincident with the advent of US national fisheries management policy, as well as significant shifts in the mid-1960s and the mid-1990s. These latter shifts are aligned temporally with changes in a major climate mode in the Atlantic Ocean: the Atlantic Multidecadal Oscillation (AMO). We provide an explanation for how the AMO may drive physical changes in the Gulf of Mexico, thus altering higher-level ecosystem dynamics. The hypotheses presented here should provide focus for further targeted studies, particularly in regard to whether and how management should adjust to different climate regimes or states of nature. Our study highlights the challenges in understanding the effects of climatic drivers against a background of multiple anthropogenic pressures, particularly in a system where these forces interact in complex and nonlinear ways.

Persistence of coral assemblages at East and West Flower Garden Banks, Gulf of Mexico

“…Climate change, invasive species, storms, and water quality degradation are potential threats (ONMS 2008;Nuttall et al 2014). As the Gulf of Mexico ecosystem continues to change (Karnauskas et al 2015), ongoing monitoring will be critical to document ecosystem variation. The relatively high coral cover since the beginning of the monitoring program make EFGB and WGB ideal for protection and conservation.…”

Preliminary recovery of coastal sharks in the south‐east United States

“…Rather, effects of climatic drivers within the optimal DFA models were survey specific and likely indicative of localized distributional reorganization, while the estimated DFA trends reflect underlying patterns in relative abundance over broad geographic scales. These regional distributional changes due to climatic forcing may be the mechanism underlying local ecosystem reorganization noted by several studies (Stenseth et al ., and references therein; Collie et al ., ; Nye et al ., , ; Karnauskas et al ., ).…”

“…The NAO, which is a measure of pressure difference over the North Atlantic Ocean, and AMO, which encompasses basin‐wide sea surface temperature, circulation patterns and sea level pressure, were selected as environmental drivers because they directly impact climate patterns and have been shown to affect fish survival and ecosystem organization through bottom‐up control in the south‐east United States. Atlantic coast and Gulf of Mexico (Stenseth et al ., and references therein; Collie, Wood, & Jeffries, ; Nye, Link, Hare, & Overholtz, ; Nye et al ., ; Karnauskas et al ., ). Annually averaged SST was included because several studies have shown that shark movement is influenced by temperature patterns (e.g.…”

Fishes in a changing world: learning from the past to promote sustainability of fish populations

“…Multi‐disciplinary, ecosystem‐based approaches have emerged as particularly promising novel frameworks, resulting in significant advances in both research and management applications. For instance, local societal and ecological changes have been linked to global climate change (Karnauskas et al, ), biophysical modelling has been integrated with population genetics (Selkoe et al, ), ecosystem service ideas have been expanded to include relational values (Chan et al, ), and fisheries sustainability has been added to biodiversity in considering the effectiveness of marine protected areas (Krueck et al, ). Furthermore, recent ideas promote decision‐making based upon expected future ecosystem states, as opposed to past baselines, to increase the efficacy of future management strategies (Rogers et al, ).…”