Publication Date:
2019-07-17
Description:
The bloom-forming dinoflagellate Alexandrium fundyense has been extensively
studied due its toxin-producing capabilities and consequent impacts on human health and eco -
nomies. This study investigated the prevalence of resting cysts of A. fundyense in western Greenland
and Iceland, to assess the historical presence and magnitude of bloom populations in the
region, and to characterize environmental conditions during summer, when bloom development
may occur. Analysis of sediments collected from these locations showed that A. fundyense cysts
were present at low to moderate densities in most areas surveyed, with highest densities observed
in western Iceland. Additionally, laboratory experiments were conducted on clonal cultures established
from isolated cysts or vegetative cells from Greenland, Iceland, and the Chukchi Sea (near
Alaska) to examine the effects of photoperiod interval and irradiance levels on growth. Growth
rates in response to the experimental treatments varied among isolates, but were generally highest
under conditions that included both the shortest photoperiod interval (16 h light:8 h dark) and
higher irradiance levels (~146 to 366 μmol photons m−2 s−1), followed by growth under an
extended photoperiod interval and low irradiance level (~37 μmol photons m−2 s−1). Based on field
and laboratory data, we hypothesize that blooms in Greenland are primarily derived from
advected A. fundyense populations, as low bottom temperatures and limited light availability
would likely preclude in situ bloom development. In contrast, the bays and fjords in Iceland may
provide more favorable habitat for germling cell survival and growth and therefore may support
indigenous, self-seeding blooms.
Repository Name:
EPIC Alfred Wegener Institut
Type:
Article
,
isiRev
Format:
application/pdf
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