Alexandrium fundyense cysts in the Gulf of Maine: Long-term time series of abundance and distribution, and linkages to past and future blooms
Alexandrium fundyense cysts in the Gulf of Maine: Long-term time series of abundance and distribution, and linkages to past and future blooms
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DOI：
10.1016/j.dsr2.2013.10.002
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发表时间：
2014-05-01
影响因子：
3
通讯作者：
Butman, Bradford
中科院分区：
文献类型：
--
作者：
Anderson, Donald M.;Keafer, Bruce A.;Butman, Bradford
在这里，我们记录了缅因湾 (GOM) 沿海水域 9 年来（1997 年和 2004-2011 年）的亚历山大藻孢囊丰度和分布模式，并确定了这些模式与每次秋季孢囊调查前后发生的水华严重程度或规模的几个指标之间的联系。我们还探索了两种胞囊丰度测量的相对效用，并证明 GOM 胞囊计数可以根据沉积物体积标准化，揭示与干重标准化确定的有意义的模式相当的模式。胞囊浓度在空间上变化很大。两个不同的苗床（此处定义为> 300 个孢囊 cm(-3) 的积累区）是明显的，一个位于芬迪湾 (BOF)，一个位于缅因州中部海岸。总体而言，苗床位置随着时间的推移保持相对恒定，但其面积变化了 3-4 倍，总胞囊丰度多年来变化超过 10 倍。 2009 年，缅因州中部海岸发生了一次异常强烈的 A.fundyense 水华，并出现了明显的红水条件，之后发生了一次大规模扩张，但这一特征到 2010 年底就消失了。因此，该区域系统只有两个苗床，其测深、沉积物特征、水流、生物学和环境条件都需要持续数十年或更长时间。秋季沉积物 0-1 厘米和 0-3 厘米层中的包囊丰度与明年发生的水华程度的地理测量（即包囊 --> 水华）之间存在强正相关关系，例如由于贝类毒性而关闭的海岸线长度或贝类关闭的最南纬度。一般来说，这些水华地理范围的指标与水华发生后沉积物中的孢囊数量无关（水华->孢囊）。然而，0-3 cm 胞囊丰度与指示水华强度或营养细胞丰度的先前水华指标之间存在显着的正相关性（例如，累积贝类毒性、贝类中可检测毒性的持续时间和水华终止日期）。这些数据表明，可以利用胞囊丰度凭经验预测即将到来的水华的地理范围，相反，使用水华和毒性事件的其他指标来预测作为明年水华接种物的后续胞囊种群的大小。这是了解 A.fundyense 水华动态的重要一步，同时也增强了我们对 GOM 中这种形成 HAB 的物种的预测能力。 (C) 2013 Elsevier Ltd. 保留所有权利。
Here we document Alexandrium fundyense cyst abundance and distribution patterns over nine years (1997 and 2004-2011) in the coastal waters of the Gulf of Maine (GOM) and identify linkages between those patterns and several metrics of the severity or magnitude of blooms occurring before and after each autumn cyst survey. We also explore the relative utility of two measures of cyst abundance and demonstrate that GOM cyst counts can be normalized to sediment volume, revealing meaningful patterns equivalent to those determined with dry weight normalization.Cyst concentrations were highly variable spatially. Two distinct seedbeds (defined here as accumulation zones with > 300 cysts cm(-3)) are evident, one in the Bay of Fundy (BOF) and one in mid-coast Maine. Overall, seedbed locations remained relatively constant through time, but their area varied 3-4 fold, and total cyst abundance more than 10 fold among years. A major expansion of the mid-coast Maine seedbed occurred in 2009 following an unusually intense A. fundyense bloom with visible red-water conditions, but that feature disappeared by late 2010. The regional system thus has only two seedbeds with the bathymetry, sediment characteristics, currents, biology, and environmental conditions necessary to persist for decades or longer. Strong positive correlations were confirmed between the abundance of cysts in both the 0-1 and the 0-3 cm layers of sediments in autumn and geographic measures of the extent of the bloom that occurred the next year (i.e., cysts --> blooms), such as the length of coastline closed due to shellfish toxicity or the southernmost latitude of shellfish closures. In general, these metrics of bloom geographic extent did not correlate with the number of cysts in sediments following the blooms (blooms --> cysts). There are, however, significant positive correlations between 0-3 cm cyst abundances and metrics of the preceding bloom that are indicative of bloom intensity or vegetative cell abundance (e.g., cumulative shellfish toxicity, duration of detectable toxicity in shellfish, and bloom termination date). These data suggest that it may be possible to use cyst abundance to empirically forecast the geographic extent of the forthcoming bloom and, conversely, to use other metrics from bloom and toxicity events to forecast the size of the subsequent cyst population as the inoculum for the next year's bloom. This is an important step towards understanding the excystment/encystment cycle in A. fundyense bloom dynamics while also augmenting our predictive capability for this HAB-forming species in the GOM. (C) 2013 Elsevier Ltd. All rights reserved.