Biogeography of dinoflagellate cysts in northwest Atlantic estuaries

Abstract

Few biogeographic studies of dinoflagellate cysts include the near‐shore estuarine environment. We determine the effect of estuary type, biogeography, and water quality on the spatial distribution of organic‐walled dinoflagellate cysts from the Northeast USA (Maine to Delaware) and Canada (Prince Edward Island). A total of 69 surface sediment samples were collected from 27 estuaries, from sites with surface salinities >20. Dinoflagellate cysts were examined microscopically and compared to environmental parameters using multivariate ordination techniques. The spatial distribution of cyst taxa reflects biogeographic provinces established by other marine organisms, with Cape Cod separating the northern Acadian Province from the southern Virginian Province. Species such as Lingulodinium machaerophorum and Polysphaeridinium zoharyi were found almost exclusively in the Virginian Province, while others such as Dubridinium spp. and Islandinium? cezare were more abundant in the Acadian Province. Tidal range, sea surface temperature (SST), and sea surface salinity (SSS) are statistically significant parameters influencing cyst assemblages. Samples from the same type of estuary cluster together in canonical correspondence analysis when the estuaries are within the same biogeographic province. The large geographic extent of this study, encompassing four main estuary types (riverine, lagoon, coastal embayment, and fjord), allowed us to determine that the type of estuary has an important influence on cyst assemblages. Due to greater seasonal variations in SSTs and SSSs in estuaries compared to the open ocean, cyst assemblages show distinct latitudinal trends. The estuarine context is important for understanding present‐day species distribution, the factors controlling them, and to better predict how they may change in the future.

Dinoflagellate fossils: Geological and biological applications

“…The modern distribution and the taxonomy inventory of modern dinocyst species have been well documented through regional in situ studies of sediment traps and/or surface sediment samples since the 1960-70s (e.g., Wall, 1965;Wall et al, 1977;Williams, 1971;Harland, 1983, Turon, 1984Dodge and Harland, 1991;Marret, 1994;Marret and de Vernal, 1997;Rochon et al, 1999;Zonneveld et al, 2001;Radi and de Vernal, 2004;Pospelova et al, 2005;Holzwarth et al, 2007;Bouimetarhan et al, 2009;Price and Pospelova, 2011;Limoges et al, 2013;Price et al, 2016;Mudie et al, 2017). Several of these studies constituted the basis for the first global Atlas of Recent dinoflagellate cyst distribution (835 modern assemblages), depicting worldwide distribution of 61 species (Marret and Zonneveld, 2003).…”

Effect of nutrient pollution on dinoflagellate cyst assemblages across estuaries of the NW Atlantic

“…Sediment collection and measurements of sea-surface parameters are described fully by Price et al (2016). Sediment samples from PEI were collected using an Ekman dredge the summer of 2013, and 18 samples with surface salinities >20 psu were chosen for this study (Fig.…”

“…Sediments were treated using a standard palynological method (Pospelova et al, 2005;Price et al, 2016). In brief, a known volume of sediment was rinsed, oven dried, and weighed.…”

“…In addition, estuaries have different physical and environmental characteristics, therefore the response of dinoflagellate cysts to eutrophication in coastal waters may also depend on the type of estuary that is being investigated (Pospelova et al, 2002). A recent study by Price et al (2016) has shown that dinoflagellate cyst assemblages in estuaries vary by biogeographic province, and that within a biogeographic province samples from the same estuary type generally had more similar assemblages compared to a different estuary type.…”

From bi-polar to regional distribution of modern dinoflagellate cysts, an overview of their biogeography

“…Mudie and Harland (1996;text-fig.6) were the first to attempt a global-scale biogeographic synthesis for modern dinocyst-acritarch assemblages. Subsequently, a multitude of studies have helped to improve our knowledge on the biogeography of the dinocyst group from local (e.g., Radi et al, 2007;Limoges et al, 2010;Price et al 2016) to global scale (Marret and Zonneveld, 2003;Zonneveld et al, 2013). The latest worldwide atlas published in 2013 illustrates the distribution of 71 taxa based on 2405 sites.…”