Genetically identical explants of the New Zealand marine sponge Mycale hentscheli were cultured in two different habitats at 7 m depth using subsurface mesh arrays to determine the effect of environment on survival, growth and biosynthesis of the biologically active secondary metabolites, mycalamide A, pateamine and peloruside A. Two 27 cm 3 explants were excised from each of 10 wild donor sponges at Capsize Point, Pelorus Sound. One explant from each donor sponge was grown in arrays next to the wild donor sponge population for 250 days, while the second explant from each donor was translocated and grown at 7 m at Mahanga Bay, Wellington Harbour for 214 days. Growth rate measured by surface area and survival of explants was monitored in situ using a digital video camera. Explant surface area correlated positively with blotted wet weight ( r 2 = 0.93). The mean concentration of each of the three compounds was determined analytically from 1H NMR spectra of replicate 30-g samples from each of 10 donor sponges at the start of the trial, and compared to mean concentrations in donors and explants at the end of the trial. Phenomenal growth rates were achieved for explants both at Capsize Point (3365 ± 812%, 95% CI) and Mahanga Bay (2749 ± 1136%, 95% CI). Explant survival was high: 100% at Capsize Point and 90% at Mahanga Bay. Wild donor sponges regressed in size and experienced 40% mortality by the end of the trial. Mycalamide A was present in relatively high concentrations in donors and explants throughout the trial. Pateamine was more variable among individuals and was present at lower concentrations in Capsize explants at the end of the trial. Peloruside A was highly variable among wild donor sponges. Only 50% of donors contained detectable concentrations of peloruside A, and only those sponges and their explants grown in their native environment at Capsize Point continued to biosynthesise peloruside A. No explants at Mahanga Bay contained peloruside A after 214 days in culture, indicating the production of this compound may be environmentally controlled. Our results demonstrate that in-sea aquaculture of M. hentscheli is a viable method for supply of mycalamide A, pateamine and peloruside A, and that environmental conditions may be critical for the biosynthesis of peloruside A. Furthermore, results show the potential to establish cultivars to maximize peloruside A yield.