Seasonal and spatial heterogeneity of recent sea surface temperature trends in the Caribbean Sea and southeast Gulf of Mexico Iliana Chollett a,b,⇑ , Frank E. Müller-Karger c , Scott F. Heron d,e , William Skirving d , Peter J. Mumby b,a a Marine Spatial Ecology Lab, College of Life and Environmental Sciences, University of Exeter, Exeter, UK b Marine Spatial Ecology Lab, School of Biological Sciences, University of Queensland, Brisbane, Australia c Institute for Marine Remote Sensing, College of Marine Science, University of South Florida, FL, USA d NOAA Coral Reef Watch, Townsville, Australia e Marine Geophysical Laboratory, Physics Department, School of Engineering and Physical Sciences, James Cook University, Townsville, Australia article info Keywords: Remote sensing AVHRR pathfinder Trend detection Spatial variability abstract Recent changes in ocean temperature have impacted marine ecosystem function globally. Nevertheless, the responses have depended upon the rate of change of temperature and the season when the changes occur, which are spatially variable. A rigorous statistical analysis of sea surface temperature observations over 25 years was used to examine spatial variability in overall and seasonal temperature trends within the wider Caribbean. The basin has experienced high spatial variability in rates of change of temperature. Most of the warming has been due to increases in summer rather than winter temperatures. However, warming was faster in winter in the Loop Current area and the south-eastern Caribbean, where the annual temperature ranges have contracted. Waters off Florida, Cuba and the Bahamas had a tendency towards cooling in winter, increasing the amplitude of annual temperature ranges. These detailed pat- terns can be used to elucidate ecological responses to climatic change in the region. Ó 2012 Elsevier Ltd. All rights reserved. 1. Introduction Global sea surface temperatures (SSTs) are rising. Over the past 150 years global mean SSTs have increased at an average of 0.04 °C decade 1 (Trenberth et al., 2007). Recent temperatures are changing at a much faster rate than in the past: since 1979, the global rate of warming has increased to 0.13 °C decade 1 , and is projected to continue to rise (Trenberth et al., 2007). Changes in temperature are a general public concern (Patz et al., 2005; Solomon et al., 2007), but, from a biological perspective, con- sequences on the dynamics of marine organisms, brought about through changes to their physiology and phenology are of main significance. Increased temperatures can have either a positive or negative effect on physiological processes, depending on whether or not organisms are currently close to their thermal optimum for that particular function (Huey and Stevenson, 1979). Tempera- ture regulates a large number of physiological functions in all organisms (Brown et al., 2004; Gillooly et al., 2001, 2002). Effects of increased temperatures on the physiology of marine organisms include increased developmental and growth rates (e.g., Gillooly et al., 2002; Lough and Barnes, 2000), decreased reproductive out- put (e.g., Philippart et al., 2003; Ruttenberg et al., 2005), increased prevalence of disease (e.g., Harvell et al., 2002; Sato et al., 2009), reduced planktonic life (e.g., Munday et al., 2009; O’Connor et al., 2007), and increased mortality (e.g., Gagliano et al., 2007; Rankin and Sponaugle, 2011). The rate of warming determines the response of the organisms and their ability to acclimatize (Peck et al., 2009; Rezende et al., 2011). Although warming is occurring at a global scale, rates of warming differ according to the location, with some places even showing long-term cooling (Trenberth et al., 2007). Spatial hetero- geneity in temperature trends has been observed at basin scales (Andersen et al., 2002; Demarcq, 2009; Good et al., 2007; Rayner et al., 2006; Strong et al., 2008) and also at regional scales (Peñaflor et al., 2009; Saulquin and Gohin, 2010). This variability implies that temperature-induced changes in marine organisms will likely vary dramatically, and sometimes in contrasting directions, within a gi- ven study area. Changing temperatures can also affect the phenology of marine organisms, that is, the timing of life-history events. Seasonal changes in the temperature of the water affect the migration of many species (e.g., MacLeod et al., 2006; Solow et al., 2002) as well as the timing of gametogenesis and therefore spawning or nesting time (e.g., Baird et al., 2009; Colin, 1992; Olive, 1995). Changes in phenology of marine species in response to recent changes in tem- perature have already been reported in different parts of the globe (e.g., Philippart et al., 2003; Weishampel et al., 2004). Global and regional analyses of SST data have found considerable spatial 0025-326X/$ - see front matter Ó 2012 Elsevier Ltd. All rights reserved. doi:10.1016/j.marpolbul.2012.02.016 ⇑ Corresponding author at: Marine Spatial Ecology Lab, College of Life and Environmental Sciences, University of Exeter, Exeter, UK. Tel.: +41 (0)7 33651671. E-mail address: i.c.chollett-ordaz@ex.ac.uk (I. Chollett). Marine Pollution Bulletin 64 (2012) 956–965 Contents lists available at SciVerse ScienceDirect Marine Pollution Bulletin journal homepage: www.elsevier.com/locate/marpolbul