Temporal assemblage turnovers of intertidal foraminiferal communities from tropical (SE Caribbean) and temperate (NE England and SW Spain) regions. (1st May 2018)

• Record Type: Journal Article
• Authors: Costelloe, Ashleigh; Wilson, Brent; Horton, Benjamin P.; Hayek, Lee-Ann C.
• Is Part Of: Estuarine, coastal and shelf science. Volume 204(2018)
• Page Start: 86
• Page End: 97
• Publication Date: 2018-05-01
• Subjects: Foraminifera -- Seasonal -- Turnover -- Intertidal -- Trends -- Temporal; Estuarine oceanography -- Periodicals; Coasts -- Periodicals; Estuarine biology -- Periodicals; Seashore biology -- Periodicals; Coasts; Estuarine biology; Estuarine oceanography; Seashore biology; Periodicals; 551.461805
• DOI: 10.1016/j.ecss.2018.01.028
• Languages: English
• ISSNs: 0272-7714

Abstract

Abstract: This is the first quantitative study of temporal assemblage turnovers of the relationships between intertidal foraminifera. Time series datasets collected from tropical Caroni Swamp and Claxton Bay (Trinidad, SE Caribbean) and temperate Cowpen Marsh (NE England, U.K.) and Bay of Cadiz (SW Spain) were used. The assemblage turnover index (ATI) examined species interrelationships through comparisons of monthly or biweekly species proportional abundances over one or two years. Species contributing to major assemblage turnovers (ATI > x + σ) were identified using the conditioned on-boundary index (CoBI). Foraminiferal species are heterogeneously distributed within the sediment; multiple sample stations at a study location cumulatively represent the foraminiferal metacommunity and clusters represent foraminiferal assemblages. The ATI and CoBI were applied to the proportional abundances of live specimens recorded for the metacommunity and assemblages at each location. At Caroni Swamp and Claxton Bay, major assemblage turnovers were driven by the most abundant species and the majority coincided with seasonal change or the arrival of the seasonal Orinoco plume in the Gulf of Paria. Seasonal turnovers of the foraminiferal metacommunities at temperate Cowpen Marsh and Bay of Cádiz occurred during the summer and winter. Major assemblage turnovers in the upper Cowpen Marsh occurred in the summer, and the lower marsh in the winter. Foraminiferans are useful bioindicators for monitoring the health of coastal environments. Understanding foraminiferal population dynamics will allow cyclical changes to be differentiated from abrupt and persistent changes, which are related to anthropogenic disturbances or long-term climate change. The ATI and CoBI are useful indices for quantitatively exploring relationships of foraminiferal populations over time. Highlights: Tropical and temperate foraminiferal species interrelationships over time were examined. The assemblage turnover index (ATI) identified periods of major assemblage turnover. The conditioned on-boundary index (CoBI) identified those species which contributed the most to major assemblage turnovers. Turnovers coincided with peak Orinoco River outflow or summer and winter transitions at the temperate locations. Species fluctuations during seasonal turnovers were suggestive of competitive interactions.