Carp finally find fans as fertiliser demand skyrockets for veggie gardens during pandemic SatSaturday 16 Fisherman Garry Warrick is busy supplying carp for the fertiliser market and human consumption. ( Share Print text only Cancel Commercial fishermen and fish fertiliser suppliers are struggling to keep up with a demand for carp as people spend more time gardening and growing their own food during the pandemic. Key points: Carp accounts for 90 per cent of fish biomass in some areas of the Murray-Darling Basin A carp trap on the River Murray in Blanchetown removes an average of 80 tonnes of carp a year Fishermen are seeing increasing consumer demand for carp in Australia, but its use in fish fertiliser is skyrocketing