Decline in oyster populations in traditional fishing grounds; is habitat damage by static fishing gear a contributory factor in ecosystem degradation?

• Published in: Journal of sea research 2018-10, Vol.140, p.40-51
• Main Authors: Ibrahim, Al-Maslamani, David, Smyth, Bruno, Giraldes, Mark, Chatting, Mohammed, Al-Mohannadi, Lewis, Le Vay
• Format: Article
• Language: English
• Subjects: Abundance; Corals; Damage; Ecosystem degradation; Ecosystem providers; Ecosystem services; Ecosystems; Fish; Fish populations; Fishing; Fishing effort; Fishing gear; Fishing grounds; Fishing zones; Habitat associated fishery; Habitat recovery; Limestone; Marine ecosystems; Marine environment; Marine fishes; Marine molluscs; Offshore; Offshore drilling rigs; Oyster population decline; Oysters; Pearl oysters; Restocking; Sea grasses; Seeding; Shellfish; Territorial waters; Trap fishing; Traps
• ISSN: 1385-1101; 1873-1414
• DOI: 10.1016/j.seares.2018.07.006

The territorial waters of Qatar once supported dense assemblages of the pearl oyster Pinctada radiata. The oysters settled on a patchy network of limestone platforms (hairãt) and provided a suite of ecosystem services to the surrounding marine environment. Commercially important fish species are associated with hairãt and as a result, industrial fishing with traps focused on these areas. This study has shown that heavily-fished areas are presently in a state which can be considered non-favorable to conservation while areas closed to fishing are recovering. It is probable that an increase in fishing activity using traditional Gargoor traps and grapple retrieval are responsible for the current ecological status of the hairãt. The intensity in trap fishing appears to be having a detrimental effect on species such as corals, sea grasses and oysters. The decline in the standing stock of oysters is dramatic with an estimated reduction ratio of 580:1 between 2002 and 2016. As fishing damage appears to be a significant contributor to these losses, measures such as spatial protection of productive shallow offshore habitats and restriction on fishing effort are urgently required to address the decline. Strategic oyster stock enhancement through the re-seeding of selected areas could boost the recovery of damaged hairãt as P. radiata ecosystem services return. •Artisanal trap fishing introduced to protect benthos in 1992.•Broken shell/coral, substrate gouges, abandoned fishing gear debris recorded.•Evidence of fishing damage at >50% of sites.•Oyster population decline of 580:1 in