Estuary is an area where the river meets the sea. In an estuary, fresh and saltwater are mixed. The ratio between the two depends on the tide and the time of the year. During high tide, more saltwater can be found while less is found during the outgoing tide. Freshwater concentration is generally higher in spring due to the freshet/snow melt.
In an estuary, both fresh and saltwater fish species can be found. This is also where smoltification takes place for anadromous salmonids. It is also an important feeding ground for shore birds. Larger birds feed on juvenile salmon and sculpin, while smaller birds feed on a variety of invertebrates on mud flats when they are exposed during the outgoing tide.
A good example of an estuary is the lower section of the tidal portion of the Fraser River, where the tide can influence the water level by up to 14 feet.
In British Columbia, estuaries offer very good seasonal fishing for salmon when they return to spawn. They are also ideal places for targeting trout and other predatory species that feed on juvenile salmon and sculpin. In summer months, bottom fish such as flounders and soles, as well as freshwater coarse fish, offer fun fishing opportunities for families in estuaries.