英语答案Unit 5.doc

Unit 5 Marine Disasters Text A Part I Understanding and Learning Text A Background information 1. Notable occurrences of Harmful Algal Blooms In 1972 a red tide was caused in New England by a toxic dinoflagellate Alexandrium (Gonyaulax) tamarense. In 2005 the Canadian HAB was discovered to have come further south than it has in years prior by a ship called “The Oceanus”, closing shellfish beds in Maine and Massachusetts and alerting authorities as far south as Montauk (Long Island, NY) to check their beds. Experts who discovered the reproductive cysts in the seabed warn of a possible spread to Long Island in the future, halting the areas fishing and shellfish industry and threatening the tourist trade, which constitutes a significant portion of the islands economy. Brittany, in France, in 2009 was experiencing recurring algal blooms caused by the high amount of fertilizer discharging in the sea due to intensive pig farming, causing lethal gas emissions that have led to one case of human unconsciousness and three animal deaths. 2. The United States Coast Guard (USCG) is a branch of the United States Armed Forces and one of the seven U.S. uniformed services. The Coast Guard is a maritime, military, multi-mission service unique among the U.S. military branches for having a maritime law enforcement mission (with jurisdiction in both domestic and international waters) and a federal regulatory agency mission as part of its mission set. It operates under the Department of Homeland Security during peacetime, and can be transferred to the Department of the Navy by the President at any time, or by Congress during time of war. The Coast Guard motto is Semper Paratus (Latin for Always Ready or Always Prepared). Detailed Study of the Text 1.Harmful algal blooms may cause harm through the production of toxins or by their accumulated biomass, which can affect co-occurring organisms and alter food-web dynamics. (Para.1) Meaning: There are two ways that HAB may cause harm: one is