Post lobster fishing season, CBFHA conducts larval tows to find the abundance lobster larvae. The abundance of the early life history stages of commercially important species is often used to predict annual recruits to a fishery.

The life history of lobster can be divided into a series of developmental phases based on morphological, physiological, behavioural, and ecological considerations. The lifecycle consists of embryonic, larval, post-larval, shelter-restricted juvenile, emergent juvenile, vagile juvenile, adolescent, and adult phases. Soon after hatching from the egg, the pre-larva undergoes a molt that results in the first larval stage.

Figure 1. The lifecycle of a lobster.
Figure 1. The lifecycle of a lobster.
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Technicians typically sample in two locations in LFA 27, False Bay and Dingwall. The larval tow consists of 8-10 tows, there is a net on the back of the fishing vessel to tow, the net captures the samples by putting samples in a cylinder container, once the time (10 minutes) is up, the net is reeled back in to look at the contents.

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The contents are transferred into a gridded tray for technicians to identify the specimens that were collected. Below are pictures of not only lobster larvae that can be collected, but crab, isopod, amphipod, copepods larvae. Additionally, pipefish, skeleton shrimp, krill, and monkfish eggs can be seen during larval tows.

Grid tray to analyze and identify species caught during the larval tow.
Grid tray to analyze and identify species caught during the larval tow.
Crab Larvae
Crab Larvae
Isopod Larvae
Isopod Larvae
Amphipod Larvae
Amphipod Larvae
Copepods
Copepods
Shrimp Skeleton
Shrimp Skeleton
Pipefish
Pipefish

Below are pictures from over the years of our technicians doing larval tows!