Action: Designate a Marine Protected Area and prohibit aquaculture activity
Key messagesRead our guidance on Key messages before continuing
- One study examined the effects of prohibiting aquaculture activity in a protected area on subtidal benthic invertebrate populations. The study was in Tapong Bay lagoon (Taiwan).
COMMUNITY RESPONSE (0 STUDIES)
POPULATION RESPONSE (1 STUDY)
- Crustacean abundance (1 study): One before-and-after study in Tapong Bay lagoon found that two and a half years after removing oyster aquaculture in a marine protected area, the biomasses of amphipods and shrimps had decreased, and that the biomass of crabs had not changed.
- Mollusc abundance (1 study): One before-and-after study in Tapong Bay lagoon found that two and a half years after removing oyster aquaculture in a marine protected area, the biomasses of gastropods and bivalves had decreased.
- Worm abundance (1 study): One before-and-after study in Tapong Bay lagoon found that two and a half years after removing oyster aquaculture in a marine protected area, the biomass of polychaete worms had stayed the same.
Aquaculture systems can negatively impact subtidal benthic invertebrate communities through pollution and diminished water quality (Wu et al. 1994). Ceasing or prohibiting aquaculture activity in an area, for instance following relocation to a different area or following decommissioning, would remove the source of harm and potentially allow for subtidal benthic invertebrate communities to recover over time (Johannessen et al. 1994). Specific areas can be designated as protected, and specific management measures taken to prohibit aquaculture (Lin et al. 2009). Inside protected areas where this activity is prohibited, the threat to subtidal invertebrate communities is removed, and previously impacted populations are, in theory, able to recover over time.
When this intervention occurred outside of a marine protected area, evidence has been summarised under “Threat: Pollution – Cease or prohibit aquaculture activity”.
Johannessen P., Botnen H. & Tvedten Ø.F. (1994) Macrobenthos: before, during and after a fish farm. Aquaculture Research, 25, 55–66
Lin H.J., Shao K.T., Hsieh H.L., Lo W.T. & Dai X.X. (2009) The effects of system-scale removal of oyster-culture racks from Tapong Bay, southwestern Taiwan: model exploration and comparison with field observations. ICES Journal of Marine Science, 66, 797–810.
Wu R.S.S., Lam K.S., MacKay D.W., Lau T.C. & Yam V. (1994) Impact of marine fish farming on water quality and bottom sediment: A case study in the sub-tropical environment. Marine Environmental Research, 38, 115–145.
Supporting evidence from individual studies
A before-and-after study in 1999–2004 of 39 sampling stations in Tapong Bay lagoon, southwestern Taiwan (Lin et al. 2009) found that removing oyster aquaculture in a marine protected area led to decreases in the biomasses of four out of six invertebrate groups, after two and a half years. Biomass of sea snails (gastropod molluscs) declined by 98% (before: 4.40; after: 0.06 g/m2), bivalve molluscs by 97% (before: 274; after: 8.56 g/m2), amphipods (crustaceans) by 98% (before: 0.51; after: 0.01 g/m2), and shrimps by 50% (before: 0.12; after: 0.06 g/m2). There were no significant changes in the biomasses of polychaete worms (before: 0.32; after: 1.55 g/m2), and crabs (before: 1.59; after: 0.93 g/m2). In 1997, Tapong Bay became a National Scenic Area and oyster culture, which was intensive in the area, was prohibited. In June 2002, all oyster racks were removed. Invertebrates (>0.5 mm) in the sediment were surveyed using a core (10 cm diameter; 20 cm depth) at 30 stations (3 cores/station) in August 1999, October 2002, and January and November 2004. Crabs and shrimps were sampled in 2001–2004 (unspecified number of surveys) using a net at nine stations (4 nets/station). All invertebrates were identified and wet-weighed.