Estuarine monitoring for decision support of agri-food effluent management

卡文迪什农场在PEI的新安南经营着一家大型马铃薯加工厂。该设施的废水 ** 排入Barbara-Weit河口。由于城市污水、农业中的一般营养物富集和卡文迪什污水，河口已经发生了富营养化。富营养化 ** 表现为海藻或海莴苣片的过度生长，导致本地海草 ** 物种的迁移。在严重的情况下，海莴苣在夏末分解，导致氧气减少，可能导致生活在河口的生物死亡。卡文迪什农场正在考虑消除污水排放，** 和土地应用废水。考虑到土地应用将是相当昂贵的，卡文迪什农场 ** 污水本身可能会或可能不会对河口的影响作出重大贡献，成本效益分析是 ** 作出这样的决定至关重要。第一个需要研究的问题是，有多少进入河口的营养物质是由卡文迪什农场贡献的？这将通过测量流量、** 营养物浓度和确定进入Barbara-Weit河口的营养物来源来实现。其次，** 这项研究将回答目前的健康状况，或在这个河口的富营养化水平的问题。这一目标将部分通过对河口进行密集的溶解氧监测来实现。使用区域（南部 ** 圣劳伦斯湾）模型已经开发的调查员，这项研究将使用氧气数据来回答问题，需要多少氮减少，以改善河口的氧气状况。作为富营养化的第二个衡量标准，海草和海莴苣的相对分布将使用船声纳调查进行检查。能够预测恢复自然植物栖息地所需养分去除量的区域模型也在开发之中。这项研究将为卡文迪什农场提供信息，以 ** 评估污水土地应用的成本效益，为河口提供基线监测，以记录 ** 从河口去除污水的好处，如果发生这种情况，还将为 ** 区域模型提供数据，以使圣劳伦斯湾南部的累积影响评估成为可能。

Cavendish Farms operates a large potato processing plant in New Annan, PEI. Wastewater from this facility**discharges into the Barbara-Weit estuary. The estuary has undergone eutrophication as a result of municipal**sewage effluent, general nutrient enrichment from agriculture, and the Cavendish effluent. Eutrophication**manifests as an overgrowth of sheets of algae, or sea lettuce, causing displacement of the native seagrass**species). In severe cases, the sea lettuce decomposes in late summer leading to reduced oxygen with potential**mortality of organisms living in the estuary. Cavendish farms is considering removing the effluent discharge,**and land applying the wastewater. Given that land application would be quite costly, and that Cavendish Farm**effluent may or may not itself be contributing significantly to estuarine impacts, a cost benefit analysis is**essential to making such a decision. The first question to be examined is how much of the nutrients entering the**estuary are being contributed by Cavendish Farms? This will be accomplished through measuring the flow,**nutrient concentrations, and determining the origin of nutrients entering the Barbara-Weit estuary. Secondly,**the study will answer the questions of the current health status, or level of eutrophication in this estuary. This**will be partly accomplished by intensive dissolved oxygen monitoring of the estuary. Using regional (Southern**Gulf of St. Lawrence) models already developed by the investigator, this research will use the oxygen data to**answer the question of how much nitrogen reduction is required to improve the oxygen status of the estuary. As**a second measure of eutrophication, the relative distribution of seagrass and sea lettuce will be examined using**boat sonar survey. Regional models that can predict how much nutrient removal is required to restore the**natural plant habitat are also under development. This research will give Cavendish Farms the information to**assess the cost benefits of land application of effluent, provide baseline monitoring for the estuary to document**the benefits of removal of the effluent from the estuary should that occur, and will also contribute data to**regional models to enable cumulative impacts assessment in the Southern Gulf of St. Lawrence.