Laboratory comparison of potential natural baits for potting New Zealand scampi, Metanephrops challengeri

Abstract

The effectiveness of potting methods for harvesting seafood is heavily reliant on the attractiveness of the bait to the target species. Consequently, the introduction of potting methods for a new species requires a method for more quickly screening the attractiveness of potential baits without the need for experimentally deploying large numbers of pots. Here, we developed a laboratory method for quantifying the attractiveness of six natural baits and a positive control to a deep-sea lobster species, New Zealand scampi, Metanephrops challengeri (Balss, 1914), using a binary choice flume. Scampi had the highest levels of attraction to pilchard, Sardinops sagax (Jenyns, 1842), and minced pilchard bait bound with alginate. A polychaete meal bait bound with alginate released free amino acids at the highest rate, but elicited a weaker attraction response from scampi, suggesting that the chemical profile, rather than the quantity of amino acids released by the bait, is more important in eliciting a response. This was confirmed by the similar response of scampi to minced pilchard baits bound with alginate containing 1% and 10% by wet weight, a result that would potentially allow for the reduction of the amount of pilchard tissue required for forming baits for use in commercial potting. The results indicate that laboratory methods can be used to provide a rapid assessment of the attractiveness of a variety of potential baits to a target species prior to deployment in potting experiments in the field.