SGER: Impact of the 1997-98 El Nino Event on Abyssal Benthic Boundary Layer Communities in the NE Pacific

预测1998年春季和夏季沿着加州海岸将发生一次重大的厄尔尼诺事件。1997 - 98年厄尔尼诺现象的发展速度超过了近代历史上的任何观测，包括1982 - 83年的厄尔尼诺现象，当时被认为是世纪的事件。根据以往的结果，在1992 - 93厄尔尼诺和前所未有的规模预测1997 - 98年事件，我们预计颗粒有机物通量（POM，食品供应）进入深海和随之而来的影响，底栖边界层（BBL）社区的大幅度下降。使用我们以前的长时间序列数据集进行比较，我们将重新建立我们的POM通量测量和海底摄影在连续的基础上，通过这个厄尔尼诺事件，并进行季节性测量的沉积物群落活动，以测试三个假设。1)作为对食物供应的一种估计，在深海深处的POM通量将大大低于过去7年在同一深度测得的通量，同时表层沃茨的上升流和初级生产也在下降。2)根据沉积物群落耗氧量估计，沉积物群落活动将显著降低，同时减少对BBL的POM供应。3)移动的底栖巨型动物的活动将随着英国广播公司的POM供应减少而显著增加。我们预测，1997 - 1998年的重大厄尔尼诺事件将深刻影响海底边界层社区，创造一个时间标记，以评估未来的深海生物过程的速度。这是一个前所未有的机会，可以研究大规模自然现象对深海群落的影响，这种现象只发生在几十年到几百年的时间尺度上。

A major El Nino event is predicted along the California coast in Spring and Summer 1998. The rate of development of this 1997 98 El Nino exceeds anything observed in recent history, including the 1982 83 El Nino which was then considered the event of the century. Based on previous results during the 1992 93 El Nino and the unprecedented magnitude predicted for the 1997 98 event, we expect a major decline in particulate organic matter flux (POM; food supply) into the deep sea and a concomitant impact on benthic boundary layer (BBL) communities. Using our previous long time series data set for comparison, we will re establish our POM flux measurements and sea floor photography on a continuous basis through this El Nino event and make seasonal measurements of sediment community activity to test three hypotheses. 1) The flux of POM, as an estimate of food supply, at abyssal depths will be significantly lower than fluxes measured at the same depths over the past 7 years in conjunction with a decline in upwelling and primary production in surface waters. 2) Sediment community activity, as estimated from sediment community oxygen consumption, will be significantly lower in conjunction with decreasing POM supply to the BBL. 3) Activity of the mobile epibenthic megafauna will significantly increase in conjunction with decreasing POM supply to the BBC. We predict that the major El Nino event of 1997 98 will profoundly influence the benthic boundary layer community, creating a time mark from which to evaluate future rates of biological processes in the deep sea. This is an unprecedented opportunity to study the effects of a natural large scale phenomenon, which only occurs on time scales of decades to centuries, on deep sea communities.