Toxic marine phytoplankton, zooplankton grazers, and pelagic food webs

Turner, Jefferson T.; Tester, Patricia A.

doi:10.4319/lo.1997.42.5_part_2.1203

Cited by 379 publications

(276 citation statements)

References 87 publications

Supporting

Mentioning

265

Contrasting

Unclassified

Order By: Relevance

“…The chemical structures of this group of toxins, including saxitoxin (STX) and approximately 57 derivatives, are well described from the genus and from seafood (Munday, 2014). Paralytic shellfish toxins are sodium-ion channel blockers that can cause potent neurotoxic syndromes in humans as well as fish, seabirds and marine mammals (Cembella, 1998;Turner and Tester, 1997;Turner, 2014). Reported effects on copepods offered PST-containing Alexandrium spp., however, range from none to adverse effects on ingestion rate, egg production, egg hatching and offspring development duration (Dutz, 1998;Frangopulos et al, 2000;Guisande et al, 2002).…”

Section: Introductionmentioning

confidence: 99%

Distinctly different behavioral responses of a copepod, Temora longicornis , to different strains of toxic dinoflagellates, Alexandrium spp.

Hansen

Nielsen

et al. 2017

Harmful Algae

View full text Add to dashboard Cite

A B S T R A C TZooplankton responses to toxic algae are highly variable, even towards taxonomically closely related species or different strains of the same species. Here, the individual level feeding behavior of a copepod, Temora longicornis, was examined which offered 4 similarly sized strains of toxic dinoflagellate Alexandrium spp. and a non-toxic control strain of the dinoflagellate Protoceratium reticulatum. The strains varied in their cellular toxin concentration and composition and in lytic activity. High-speed video observations revealed four distinctly different strain-specific feeding responses of the copepod during 4 h incubations: (i) the 'normal' feeding behavior, in which the feeding appendages were beating almost constantly to produce a feeding current and most (90%) of the captured algae were ingested; (ii) the beating activity of the feeding appendages was reduced by ca. 80% during the initial 60 min of exposure, after which very few algae were captured and ingested; (iii) capture and ingestion rates remained high, but ingested cells were regurgitated; and (iv) the copepod continued beating its appendages and captured cells at a high rate, but after 60 min, most captured cells were rejected. The various prey aversion responses observed may have very different implications to the prey and their ability to form blooms: consumed but regurgitated cells are dead, captured but rejected cells survive and may give the prey a competitive advantage, while reduced feeding activity of the grazer may be equally beneficial to the prey and its competitors. These behaviors were not related to lytic activity or overall paralytic shellfish toxins (PSTs) content and composition and suggest that other cues are responsible for the responses.

show abstract

Section: Introductionmentioning

confidence: 99%

Distinctly different behavioral responses of a copepod, Temora longicornis , to different strains of toxic dinoflagellates, Alexandrium spp.

Hansen

Nielsen

et al. 2017

Harmful Algae

View full text Add to dashboard Cite

show abstract

“…Both of these rates are difficult to quantify with measurements. Grazing losses inflicted on A. fundyense are a complex function of both the heterotrophic and autotrophic communities (Teegarden and Cembella, 1996;Turner and Tester, 1997;Campbell et al, submitted;Turner and Borkman, submitted). In the absence of observations sufficient to prescribe spatially and temporally varying grazing pressure on A. fundyense, we parameterize the impact of grazing with a constant specific loss rate m (day -1 ).…”

Section: Population Dynamics Modelmentioning

confidence: 99%

Mechanisms regulating large-scale seasonal fluctuations in Alexandrium fundyense populations in the Gulf of Maine: Results from a physical–biological model

McGillicuddy

Anderson

Lynch

et al. 2005

Deep Sea Research Part II: Topical Studies in Oceanography

149

132

View full text Add to dashboard Cite

Observations of Alexandrium fundyense in the Gulf of Maine indicate several salient characteristics of the vegetative cell distributions: patterns of abundance are gulf-wide in geographic scope; their main features occur in association with the Maine Coastal Current; and the center of mass of the distribution shifts upstream from west to east during the growing season from April to August. The mechanisms underlying these aspects are investigated using coupled physical-biological simulations that represent the population dynamics of A. fundyense within the seasonal mean flow. A model that includes germination, growth, mortality, and nutrient limitation is qualitatively consistent with the observations. Germination from resting cysts appears to be a key aspect of the population dynamics that confines the cell distribution near the coastal margin, as simulations based on a uniform initial inoculum of vegetative cells across the Gulf of Maine produces blooms that are broader in geographic extent than is observed. In general, cells germinated from the major cyst beds (in the Bay of Fundy and near Penobscot and Casco Bays) are advected in the alongshore direction from east to west in the coastal current. Growth of the vegetative cells is limited primarily by temperature from April through June throughout the gulf, whereas nutrient limitation occurs in July and August in the western gulf. Thus the seasonal shift in the center of mass of cells from west to east can be explained by changing growth conditions: growth is more rapid in the western gulf early in the season due to warmer temperatures, whereas growth is more rapid in the eastern gulf later in the season due to severe nutrient limitation in the western gulf during that time period. A simple model of encystment based on nutrient limitation predicts deposition of new cysts in the vicinity of the observed cyst bed offshore of Casco and Penobscot Bays, suggesting a pathway of re-seeding the bed from cells advected downstream in the coastal current. A retentive gyre at the mouth of the Bay of Fundy tends to favor re-seeding that cyst bed from local populations.

show abstract

“…Studies on the effects of PST-containing prey on consumers have shown variable results (Turner & Tester 1997) ranging from non-detectable in some copepods (Colin & Dam 2003) to decreased feeding (Teegarden 1999), decreased fecundity (Guisande et al 2002a), delayed development (Frangopulos et al 2000) and direct mortality in others (Colin & Dam 2003). Furthermore, the copepods Calanus finmarchicus (Turriff et al 1995), Eurytemora herdmanii and Acartia tonsa, as well as the barnacle Semibalanus balanoides (Teegarden 1999;Teegarden et al 2001) have been shown to avoid feeding on PST-containing prey when offered together with a nontoxic food option.…”

Section: Introductionmentioning

confidence: 99%

Copepods induce paralytic shellfish toxin production in marine dinoflagellates

Selander¹,

Thor

Toth³

et al. 2006

Proc. R. Soc. B.

177

208

View full text Add to dashboard Cite

Among the thousands of unicellular phytoplankton species described in the sea, some frequently occurring and bloom-forming marine dinoflagellates are known to produce the potent neurotoxins causing paralytic shellfish poisoning. The natural function of these toxins is not clear, although they have been hypothesized to act as a chemical defence towards grazers. Here, we show that waterborne cues from the copepod Acartia tonsa induce paralytic shellfish toxin (PST) production in the harmful algal bloom-forming dinoflagellate Alexandrium minutum. Induced A. minutum contained up to 2.5 times more toxins than controls and was more resistant to further copepod grazing. Ingestion of non-toxic alternative prey was not affected by the presence of induced A. minutum. The ability of A. minutum to sense and respond to the presence of grazers by increased PST production and increased resistance to grazing may facilitate the formation of harmful algal blooms in the sea.

show abstract

Toxic marine phytoplankton, zooplankton grazers, and pelagic food webs

Cited by 379 publications

References 87 publications

Distinctly different behavioral responses of a copepod, Temora longicornis , to different strains of toxic dinoflagellates, Alexandrium spp.

Distinctly different behavioral responses of a copepod, Temora longicornis , to different strains of toxic dinoflagellates, Alexandrium spp.

Mechanisms regulating large-scale seasonal fluctuations in Alexandrium fundyense populations in the Gulf of Maine: Results from a physical–biological model

Copepods induce paralytic shellfish toxin production in marine dinoflagellates

Contact Info

Product

Resources

About