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– Orwell & Stour (United Kingdom)

Site name: Orwell & Stour Country: United Kingdom GIG Region: NEA
GIG Type: TW04 Site code: ---- Altitude(m a.s.l.): ----
Area (km²): ---- Mean depth (m): ---- Mixing regime: ----
Alkalinity (m eq/l): ---- Retention time (yr): ---- Chlorophyll a (µg/l): ----
Total phosphorus (µg/l): ---- Eutrophication status: Medium Hydromorphological status: High


The Stour and Orwel estuaries are transitional water bodies located on the south east coast of England (Anglian River Basin District). There are relatively pristine with almost unique banks characterized by overhanging forests in their middle reaches. In striking contract the shared mouth of both estuaries is dominated by the large port facilities at Felixstowe to the north and the city of Harwich to the south. In addition the most upstream areas on the Stour cross the densely populated area of Ipswich (ca. 128000 inhabitants). The Orwel in contrast flows across mostly agricultural land.

The typology of both estuaries are mixed, polyhaline, and mesotidal with extensive intertidal are and are currently classified as moderate to good ecological potential and on good chemical status. The main activities found at the lower estuary are shipping, shipyard and other small industries, fish farming, and recreational boating. Due to nearby population centres and or agriculture, nutrients constitute an important pressure on the estuary. Large alterations to the original hydromorphology of the systems (shipping facilities and dredging) also contribute to the suite of pressures on the estuaries. The WISER sampling on these UK estuaries took place in July 2009. We sampled on 3 sites on the Stour and 2 on the Orwel under mainly polyhaline conditions. The gear chosen in this exercise was a seine net (5mm square mesh). The 32 sampling events yielded 19 different species and over 1800 individual fish.

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WISER: "Water bodies in Europe: Integrative Systems to assess Ecological status and Recovery"
Online: [date: 2024/05/23]
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