The hydrography and biology of a bloom of the coccolithophorid Emiliania huxleyi in the northern North Sea

Abstract

In June=July 1994 a study was made of a small bloom of the coccolithophorid Emiliania huxleyi in an area of the North Sea to the east of the Shetland Islands. Observations on the hydrography of the study area indicated the bloom was associated with Atlantic water and was confined to an area in which a stable shallow mixed layer had formed. There was no evidence to suggest association of horizontal physical structure with the bloom development. High cell densities of >1-6 ð 10 6 cells dm 3 , together with low concentrations of PIC (<50 µg dm 3 ) and detached liths (2-3 ð 10 4 liths cm 3 ) indicated that the bloom was studied at an early stage of development. Biochemical and physiological observations indicated active growth was taking place. The results presented are discussed in comparison with previous studies carried out in both oceanic and shelf seas.

Biogeochemistry and carbon mass balance of a coccolithophore bloom in the northern Bay of Biscay (June 2006)

“…The PIC:POC ratio ranged between 0.23 and 0.66, except at station 7 ( $0.10) and in the surface sample at station 1 ( $0.20). Values of the PIC:POC ratio were higher than those reported in the same area (0.20-0.30) in June 2004 and in the North Sea in June 1994 (o0.25; Head et al, 1998).…”

“…The CAL to PP ratio (CAL:PP, Table 2) varied considerably from one station to another, ranging from 0.01 (station 8 at 20 m) to 1.13 (station 4bis at 3 m). The average CAL:PP ratio (0.29 70.25; n ¼18) during our cruise was higher than that reported in the Bay of Biscay in June 2004 (range 0.02-0.31; average 0.16 (n¼11); Harlay et al, 2010), than in the North Sea in July 1993 (0.03-0.18; van der Wal et al, 1995) and June 1994 (0.14-0.16; Head et al, 1998), and off Iceland in June 1991 (0.14-0.19; Ferná ndez et al, 1993).…”

“…8) due to the presence of coccolithophores, as supported by HPLC analysis of phytoplankton pigments (see hereafter), scanning electron microscope images (not shown) that identified E. huxleyi as the most abundant species, and anomalies of total alkalinity (TA) measured during this cruise and reported by Suykens et al (2010a). The PIC concentrations were typical for the study area and slightly higher than those reported in the northern North Sea in June 1994 (26-50 mg C L À 1 ; Head et al, 1998). The PIC:POC ratio ranged between 0.23 and 0.66, except at station 7 ( $0.10) and in the surface sample at station 1 ( $0.20).…”

Seasonal phytoplankton dynamics in the coastal waters of the north-eastern Adriatic Sea

“…Bernardi Aubry et al (2006) found E. huxleyi to be typical for the mixing period and summer deep waters in the northern Adriatic Sea. This coccolithophorid is ubiquitous in both coastal and oceanic waters and regularly forms extensive blooms, particularly at mid-latitudes (Head et al, 1998).…”

Phytoplankton community dynamics during late spring coccolithophore blooms at the continental margin of the Celtic Sea (North East Atlantic, 2006–2008)

“…Fe, Zn, and Mn) have been shown to influence coccolithophore physiology and control phytoplankton community assemblage to various extents (Nanninga and Tyrrell, 1996;Zondervan, 2007;Boyd et al, 2010, and references therein). However, only few studies have described the structure and the spatial and temporal dynamics of phytoplankton communities during these blooms along the western European continental margin (Head et al, 1998;Joint et al, 2001;Fileman et al, 2002;Lampert et al, 2002). This information is needed, as the importance of the phytoplankton community structure to the biological pump is still poorly understood (Smythe- Wright et al, 2010, and references therein).…”