Annual variations of paralytic shellfish poisoning in Maine, USA 1997–2001

Interannual variability of shellfish toxicity in the Gulf of Maine: Time and space patterns and links to environmental variability

“…Ambiguous and/or uncertain locations were discarded. Over the 21-year record, sampling frequency at an individual station varies, but is approximately weekly at the most regularly sampled ''primary'' stations (Bean et al, 2005). For each station, we bin average the toxicity record into 8-day periods, beginning January 1 within each year.…”

“…Analysis of 13 years of toxicity at 8 stations along the western Maine coast show strong overall interannual differences in the timing and strength of toxic events, with distinct differences between stations, even between those relatively close in geographic space (Luerssen et al, 2005). Five years of data (Bean et al, 2005) show geographic differences in magnitude and interannual variability between eastern and western stations. A systematic analysis of these toxicity data across decades to summarize mean patterns, to quantify similarity of the toxicity spatial patterns between years or similarity in interannual variability between stations has not been carried out.…”

“…West of Penobscot Bay, however, seasonal toxicity often progresses from east to west (Franks and Anderson, 1992b;Shumway et al, 1988) in concert with the residual circulation . Superimposed on this seasonality is strong interannual variability, both as regional averages and at individual stations (Bean et al, 2005;Bricelj and Shumway, 1998;Hurst and Yentsch, 1981). Ten years of shellfish toxicity at 5 coastal stations along the western Gulf (Franks and Anderson, 1992b), show years of both episodic toxicity and sustained toxicity over several months.…”

Understanding interannual, decadal level variability in paralytic shellfish poisoning toxicity in the Gulf of Maine: The HAB Index

“…In the latter context, it has long been known that Penobscot Bay (Fig. 1) marks a boundary between a region to the west that exhibits toxicity relatively early in the season compared to areas in eastern Maine and the BOF (Hurst and Yentsch, 1981; Shumway et al, 1988; Bean et al, 2005; Luerssen et al, 2005; Thomas et al, 2010). Both Thomas et al (2010) and Nair et al (2013) used statistical approaches to identify multiple station clusters in the GOM that group together and are generally in close geographic proximity.…”

“…It is thus not surprising that the geographic extent and magnitude of PSP toxicity has been highly variable over the years that it has been monitored in Maine, New Hampshire, and Massachusetts (Shumway et al, 1988; Bean et al, 2005; Kleindinst et al, this issue). Here we describe a study that uses a simple approach to investigate interannual variability in Maine shellfish toxicity.…”