Microalgae for eco responsible lobster fishing?

Québec’s commercial lobster fishery (Homarus americanus) is facing a considerable obstacle: the mackerel and herring stocks traditionally used as bait are in decline.

Decline of traditional baits

To attract the delicious decapod crustacean¹ into traps, fishermen use more or less fresh whole mackerel, plaice and herring, which possess an olfactory signature that lobsters find tantalizing. But access to this “bouette” – a term used by the industry , derived from “bait” – is facing difficulties: moratoriums prohibiting their exploitation are currently in effect in the Gulf of St. Lawrence. To put it simply bouette is scarcer, supply is less reliable, and prices are going up. So fishermen have to turn to alternatives, because the situation is compromising both the economic viability of this industry and the sustainable-fisheries certification² they need to sell their products on certain markets. Such alternatives can already be found on the market, called bait cakes. Unfortunately, these little “cakes” are for the most part made with flesh or oils from fish species currently at risk, which greatly limits their eco responsible value.

Microalgae-based bait assessment in the Biodôme laboratories

The Biodôme’s physiology, aquaculture and conservation research team was approached by players of the biotechnology industry to evaluate different formulations for microalgae-based bait, an eco responsible alternative for commercial lobster fishing in eastern Canada. The microalgal biomass produced in bioreactors comes from cultures that are based on the use of CO₂ emitted by industries for the growth of microalgae. This process contributes to reducing these industries’ carbon footprint, and the biomass produced can then lend itself to commercialization.

The future of microalgae?

Microalgaes are arousing considerable interest around the world because of their enormous application potential in the renewable-energy, the pharmaceutical and the nutraceutical industries. They are renewable, sustainable and economical sources of biofuels, bioactive drugs and food ingredients. But are microalgae just as tantalizing for lobsters? In collaboration with our partners ( AllGaea company and a private donor), we’ll be evaluating the attraction features of different microalgae-based formulations capable of stimulating the chemically receptive antennules of the lobster and initiating an active movement towards the bait.

The laboratory I supervise has aquatic, analytical equipment and expertise that can be used for the assessment of the alternative bait’s attractiveness to the lobster.  In controlled conditions, the lobster is exposed to the proposed formulations. Preliminary tests are currently underway with a controlled photoperiod (blue light during the day and red for nighttime conditions). Identification of a formulation that stimulates active movement of the lobster may eventually lead to trials at sea. Will lobsters be tempted by this new bait in a real-life situation? Thanks to the collaboration of a lobster fisher in the Minganie area, we’ll be able to verify that at a later fishing season.

This research project is made possible by the Space for Life Foundation, see details.

Notes:

¹Most commercially fished crustaceans are decapods (lobster, crabs). There are about 45,000 species of crustaceans, 15,000 of which are decapods. Crustaceans are characterized by a segmented body covered with an exoskeleton (carapace), and decapods all have five pairs of large thoracic legs.

²Gaspésie lobster fishery in Québec, Canada, achieves MSC certification (Marine Stewardship Council press release)