Managing invasive carp (Cyprinus carpio L.) for habitat enhancement at Botany Wetlands, Australia

Abstract

ABSTRACT1. In Australia, the carp Cyprinus carpio L. is regarded as a threat to the native fish and the aquatic environment. In recent years, Botany Wetlands, a significant coastal wetland in the Sydney region, has been invaded by the undesirable cyprinids, carp and goldfish (Carrasius auratus L.).2. In 1996 a cyprinid removal programme commenced at Botany Wetlands with the objective of managing the invasive species, increasing fish diversity, reducing cyanobacterial blooms and hence enhancing the aquatic habitat. Using electrofishing and gill netting, 4073 carp and 261 goldfish, amounting to 10 117 kg of cyprinid biomass were removed between 1996 and 2004. The captured carp ranged from 60 to 835 mm. Males matured before females. Carp between 350 and 680 mm in length grew at the rate of 1.66 AE 0.38 g day À1 .3. The success of the programme was monitored by assessing four indicators related to carp populations and two related to habitat. The former included the pattern of length-frequency distribution, mean weight per size class, condition factor (CF) and the catch per unit effort (CPUE), and the latter the Secchi disc transparency and cyanobacterial counts. After 8 yr of removal, the plots of carp length-frequency distribution flattened, CF decreased from 2.86 to 1.82 and CPUE decreased from 97 kg day À1 to 50 kg day À1 . A 10-fold decrease occurred in cyanobacterial counts and the Secchi disc transparency increased by 20%. More than 20 000 fingerlings of native Australian bass Macquaria novemaculeata (S.) have been introduced to the wetlands, increasing the potential for juvenile carp predation and biodiversity.

Strategies to Control a Common Carp Population by Pulsed Commercial Harvest

“…The present study contributes to the relatively small pool of published common carp stock assessments (Li and Mosman 1977;Linfield 1980;Pinto et al 2005). Common carp biomass was identified as increasing in our study system, while harvest has been variable; sufficiently high annual commercial fishing mortality (i.e., Year Biomass (kg/ha) FIGURE 5.…”

Sazanın (Cyprinus carpio L., 1758) Tatlısu Ekosistemlerine Etkileri İçin Deneysel Kanıt: Türkiye İç Suları İçin Yönetim Yönlendirmeleri Derlemesi

“…Also, following Weber and Brown (2009), control/management-oriented restoration studies, including those providing mitigation of an impact prior to intervention (e.g. Pinto et al 2005;Bio et al 2008;Thomasen and Chow-Fraser 2012), were excluded.…”

“…Results indicated that: (i) 0+ C. carpio increased nitrogen (but not phosphorus) and phytoplankton whilst partly suppressing large zooplankton (Cladocera) and enhancing small zooplankton (nauplii) through nutrient release by trophic cascade effects (Qin and Threlkeld 1990); (ii) at stocking densities similar to biomass levels found in reservoirs of central United States, 0+ C. carpio increased phosphorus and phytoplankton, reduced densities of benthic invertebrates and altered zooplankton community structure (Richardson et al 1990); and (iii) 0+ C. carpio increased sediment re-suspension from benthivorous feeding leading in turn to increased levels of turbidity and nitrogen (but not phosphorus) and reducing zooplankton and benthic invertebrate abundance (Cline et al 1994). Overall, findings from these experiments suggested that at high biomass 0+ C. carpio can significantly alter the abiotic and biotic components of shallow water columns.…”

Towards the successful control of the invasive Pseudorasbora parva in the UK

“…If risk is evaluated as high, then eradication may be appropriate if their population is spatially constrained (Myers et al 1998(Myers et al , 2000Zavaleta et al 2001;Simberloff 2002). If the species is spreading and invasive, however, then a programme of sustained control may be more appropriate, using population suppression, containment and small-scale eradications (Manchester and Bullock 2000;Secord 2003;Pinto et al 2005;Britton and Brazier 2006).…”