CR 62:189-198 (2015)  -  DOI: https://doi.org/10.3354/cr01275

ABSTRACT: Estuarine and coastal ecosystems are strongly affected by variations in climate through alterations in freshwater input, which result in changes in water temperature and salinity. Predicting the response of estuarine systems to future scenarios of climate change requires knowledge of the present relationships between estuarine and coastal communities and variations in local weather patterns. Synoptic climatology is a method that identifies recurrent weather patterns at a regional scale (1000s of km) and is valuable for predicting estuarine ecosystem responses to environmental variability. This method was applied for a region of southwest Europe, and the effects of weather patterns on the zooplankton community of the Mondego Estuary (Portugal) were investigated. We identified 9 weather patterns for the region during the last 61 yr. A regression analysis related these weather patterns with freshwater flow in the estuary during the winter, and subsequently years between 2003 and 2011 were classified as average, dry or wet by a percentile approach. The abundance and spatial distribution of the zooplankton community responded to weather pattern variability during the winter. For example, years that featured lower precipitation, freshwater flow and higher salinity were characterized by marine planktonic groups. Salinity appeared to be the main factor related to zooplankton community changes. This study shows that the synoptic climatology approach is effective at capturing regional-scale dynamics of estuaries and at providing baseline climate relationships with estuarine zooplankton communities, which can be used to predict future response to climate change.

KEY WORDS: Plankton communities · Synoptic climatology · Mondego Estuary · Climate variability