Browsing by Author "Kunzmann, Andreas"

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    Co-culture of sea cucumber Holothuria scabra and red seaweed Kappaphycus striatum
    (John Wiley & Sons Ltd, 2014) Beltran-Gutierrez, Marisol; Ferse, Sebastian C.A.; Kunzmann, Andreas; Stead, Selina M.; Msuya, Flower E.; Hoffmeister, Thomas S.; Slater, Matthew J.
    Commercially valuable sea cucumbers are potential co-culture species in tropical lagoon environments, where they may be integrated into established aquaculture areas used for seaweed farming. In the current study, wild-caught juvenile sea cucumbers, Holothuria scabra, and red seaweed Kappaphycus striatum were co-cultured on Zanzibar, United Republic of Tanzania. Sea cucumbers (97 g 31 SD, n = 52) were cultured in mesh enclosures at initial cage stocking densities of 124 21 SD and 218 16 SD g m 2 under seaweed culture lines. Over 83 days, individual growth rate (1.6 g d 1 0.2 SD) of sea cucumbers at low stocking density was significantly higher (v2 = 8.292, d.f. = 1, P = 0.004) than at high-stocking density (0.9 g d 1 0.1 SD). Seaweed individual growth rates [6.27 ( 0.3 SE) g d 1] were highest in co-culture with sea cucumber at low density but did not differ significantly from high sea cucumber density or seaweed monoculture treatments (v2 = 3.0885, d.f. = 2, P = 0.2135). Seaweed growth varied significantly (v2 = 35.6, d.f. = 2, P < 0.0001) with sampling period, with the final sampling period resulting in the highest growth rate. Growth performance for seaweed and sea cucumbers (v2 = 3.089, d.f. = 2, P = 0.21 and v2 = 0.08, d.f. = 1, P = 0.777 respectively), did not differ significantly between monoculture and co-culture treatments, yet growth in co-culture was comparable with that reported for existing commercial monoculture. Results indicate H. scabra is a highly viable candidate species for lagoon co-culture with seaweed. Co-culture offers a more efficient use of limited coastal space over monoculture and is recommended as a potential coastal livelihood option for lagoon farmers in tropical regions.
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    Growth performance of the sea cucumber Holothuria scabra and the seaweed Eucheuma denticulatum: integrated mariculture and effects on sediment organic characteristics
    (Inter Research, 2016) Namukose, Mary; Msuya, Flower E.; Ferse, Sebastian C.A.; Slater, Matthew J.; Kunzmann, Andreas
    Deposit-feeding sea cucumbers play a key role in marine ecosystems through bioturbation, burrowing and feeding on organic matter in marine sediments. Many deposit-feeding holothurians have therefore been recommended for integrated multitrophic aquaculture systems (IMTA). We set up an integrated mariculture system of sea cucumber Holothuria scabra and seaweed Eucheuma denticulatum in Bweleo, Unguja Island of Zanzibar, Tanzania, to investigate the effect of stocking density on the growth and survival of culture species, total organic matter (TOM) and total organic carbon (TOC) content in the sediment. Treatments that included a fixed stocking density (500 g, ca. 200 g m−2) of E. denticulatum and 4 sea cucumber stocking densities (monoculture, low, medium and high density; 0, 150 ± 5, 236 ± 24, 345 ± 48 g m−2, mean ± SD) of medium-sized H. scabra (114 ± 37 g) were established. Stocking density of H. scabra did not influence survival of either species. Seaweed cultured under high stocking density of H. scabra had a higher specific growth rate of 2.33% d−1 than that cultured at the medium or low densities or without sea cucumbers. Sea cucumbers cultured at low stocking density had a higher mean growth rate of 0.80 g d−1 compared to those cultured at medium or high densities. TOM and TOC in sediments decreased over the experimental period at medium sea cucumber stocking density, while at low and high stocking densities, organic matter accumulated. The study demonstrates that the integration of E. denticulatum and H. scabra at 200 g m−2 enhances seaweed growth and can reduce organic matter content in the sediments.
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    Integrated seaweed – sea cucumber farming in Tanzania
    (Western Indian Ocean Journal of Marine Science, 2018) Kunzmann, Andreas; Beltran-Gutierrez, Marisol; Fabiani, Godfrey; Namukose, Mary; Msuya, Flower E.
    We review piloted co-culture experiments of the sea cucumber Holothuria scabra with different seaweed species in existing lagoon-based seaweed farms in Tanzania during 2011-2014. Key questions were whether stocking densities would influence growth rates of both species, and whether deposit feeders would modify organic components in the sediments. From a social perspective, we investigate if local people are readily willing to become involved in sea cucumber farming as an optional livelihood. Seaweed-specific growth rates between 0.32 and 4.1 %d−1 were reported, showing significantly higher values for those treatments combined with sea cucumbers than for the seaweed monoculture (F3,1=3.20, p<0.05) at Zanzibar sites. Sea cucumber growth rates ranged from 0.14 to 1.6 gd-1, and all of the studies showed that the treatments holding H. scabra at a low stocking density (average of 130 gm-2) presented a higher growth performance than when it was stocked at more than 200 gm-2. Total organic matter in sediments increased in all treatments over the sampling periods (p<0.05). Some 88 percent of the surveyed local people showed willingness to participate in this type of mariculture for livelihood. The survey identified theft and lack of credit as the main hindrances for this activity. H. scabra is viable for lagoon co-culture with seaweed when taking into account proper stocking density, implications on total organic matter and total organic carbon in the system, and local acceptance by local people.