Install a pump on or above the seabed in docks, ports, harbour, or other coastal areas to increase oxygen concentration
Overall effectiveness category Unknown effectiveness (limited evidence)
Number of studies: 1
Background information and definitions
Habitats and invertebrate populations within many ports, harbours, and docks around the world have deteriorated due to anthropogenic pressures, such as pollution and eutrophication, and the consequent decline in water quality and oxygenation (Russell et al. 1983). Improving water quality to these environments, for instance by increasing water mixing and oxygenation, can be achieved by installing a pump underwater. Installing a pump can help increase oxygen concentration in seawater, improve overall water quality, and potentially help promote subtidal benthic invertebrate biodiversity (Russell et al. 1983; Yamochi & Oda 2002).
Russell G., Hawkins S.J., Evans L.C., Jones H.D. & Holmes G.D. (1983) Restoration of a disused dock basin as a habitat for marine benthos and fish. Journal of Applied Ecology, 43–58.
Yamochi S. & Oda K. (2002) An attempt to restore suitable conditions for demersal fishes and crustaceans in the Port of Sakai-Semboku, north Osaka Bay, Japan. Aquatic Ecology, 36, 67–83.
Supporting evidence from individual studies
A before-and-after study in 1995–1998 in one area of seabed in Osaka Bay, Japan (Yamochi & Oda) found that installing a pump on the seabed of a port to mix seawater and increase oxygen concentration appeared to increase combined invertebrate and fish species richness and abundance, after four months. Data were not statistically tested. Species richness was seven times higher after installing the pump (14 species/survey) compared to before (7 species/survey), and abundance was 52 times higher after (11 individuals/transect) than before (0.2 individuals/transect). In May 1996, a jet stream pump system was installed on the seabed of a port with low water oxygen concentration, at 4 m water depth. One dredge net (2 m x 0.5 m, 0.7–1.5 cm mesh size) was deployed along ten 70 m transects during weekly surveys before (June–August 1996; seven surveys) and after installation (June–August 1998; six surveys). Invertebrates and fish caught were identified and counted and results presented as combined species richness and abundance.Study and other actions tested