Estuarine Habitats
河口濕地(Chinese)

The mixing of fresh water and salt water is an important feature of estuaries. The nutrients carried in from the ocean in the river and in the salt wedge transform estuaries into very fertile areas for plant growth. In fact, estuaries are among the most biologically productive ecosystems on Earth. Studies have shown that primary productivity, or the rate at which plants convert the sun's energy by photosynthesis into food that animals can use, is higher in estuaries than in grasslands, forests, and even areas of intensive agriculture.

Evidence of the estuarine food chain can be seen during a visit to any estuary. Bufflehead are often seen diving in shallow water to find snails and other invertebrates living in soft estuarine sediments. In the Bay of Fundy and at the mouth of the Fraser River, shorebirds gather in flocks exceeding 100,000 birds to probe the mudflats with long bills in search of small invertebrates. Common Mergansers and Great Blue Herons find Pacific and Atlantic estuaries especially attractive places to catch small fish. Sandpipers fall prey to Peregrine Falcons that hunt along estuarine beaches, and dead fish, birds, and mammals are scavenged by Bald Eagles.

河口半鹹水濕地(Blackish Water Marsh)
最近自然歷史步行導覽活動
最近綠色文化生態旅遊活動

由於列治文位於菲沙河口三角洲地帶，菲沙河流域涵蓋卑詩省四分之一面積，水流量十分充沛，導致該地區西海岸一帶大多為半鹹水生態(brackish) ，包括溫哥華市西南角的 Pacific Spirit公園海岸，機場所在的海島(Sea Island) 與其西北角的愛歐娜海灘，列治文海堤的鱘魚淺灘 (Sturgeon Bank)，三角洲市的魏斯得漢島(Westham Island)以及布蘭斯維克岬 (Brunswick Point)。每天漲潮時，海水常可上達新西敏市，最遠可達匹特河岸(Pitt River)。半鹼水溼地是世界上生物產量最豐富的地區，每年每公頃產量可達平均五公噸，這是鹼水溼地產量的三倍。
　　
通常在生長末期，這些植物大多凋零死亡，而創造出大量的有機腐植物，隨著潮水而沖出附近水域。這些有機腐植物提供許多浮游生物營養食物的來源，維繫著整個河口潮間河道與溼地的食物鏈。半鹼水溼地不僅提供魚類與水鴨覓食與棲息地，同時也是一些老鼠 (Mice, Voles)的家，它們大多躲在漂木的下方，而水貂(Mink)與短尾鼬(Weasel) 則獵食這些哺乳類動物。春天季節，您也不難發現紅翅黑鳥在溼地中尋找棲息地築巢，養育他的幼鳥。白尾鷹(Northern Harrier) 隨時在草原溼地上低空尋找獵物，當然最引人注目的水鳥莫過成百上千的雪雁(Snow Geese)。淺水溼地中可以發現吃草的綠頭鴨 (Mallard)、赤頸鴨(Wigeon)、綠翅鴨(Teal)，以及吃水生動物的白帽鵲鴨(Bufflehead)、環嘴鷿鷈(Grebe)、鏡冠秋沙鴨(Hooded Merganser)。

河流中你可以看見多種水鳥，通常河岸的水鴨子多為覓食植物根莖與種子的戲水鴨(Dabbler)；或潛水的潛水鴨 ，如上述小型潛鳥。而河流中央則為深水潛水鳥，如西方鷿鷈(Grebe)、潛鳥(Loon)、鸕鶿(Cormorant) ，以及來自鹼水海域的紅胸秋沙鴨(Red-Breasted Merganser)，當然也包括常見的各種海鷗(Gull)，它們是雜食性的動物。每年的春天，菲沙河的中支河口處，總有數以百萬隻的Eulachon魚遷移至河口處產卵。其中一種獵食者為海獅(Sea Lion) 常可見成群出沒於河中Swishwash海島附近捕食，還有白頭鵰(Bald Eagle)與燕鷗(Tern) ，以及以上所提到的深水潛鳥之一的紅胸秋沙鴨。