V-notch numbers trending down

First published in Landings, December, 2015.

In 1982, the Maine Lobstermen’s Association (MLA) began collecting data on the number of V-notched lobsters present in traps to measure the impact of this conservation program on the lobster population. In 2002, lobstermen from Massachusetts and New Hampshire were invited to join this data collection effort.

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DMR photo.

The survey takes place in early October each year; this year the survey was held during the week of October 12. The fall was chosen because there has historically been a good run of egg-bearing and V-notched lobsters at a time when the weather is still good enough to haul regularly.

During any two days of the survey week, lobstermen record the number of females, eggers, V-notch, short and oversize females on a data card. The results from this survey are used as a tool to track the effectiveness of V-notching as a conservation measure to protect lobster brood stock in the Gulf of Maine. The data are kept by the MLA and are available to scientists and managers.

Unfortunately, participation in the survey has reached an all-time low with just over 25 cards mailed back to the MLA in each of the last two years. When the survey began in 1982 there were almost 200 and the number of participants remained in the low to mid 100s until the early 2000s.

Despite the low number of participants, the survey had still captured some of the major trends in the lobster fishery. For example, the pounds of lobster per trap hauled has increased significantly, tracking the dramatic increase in lobster abundance and landings over the past 30 years.

What connection does V-notching have to lobster abundance? “V-notching allows lobsters a chance to molt and reproduce [resulting in more lobsters],” explained Kathleen Reardon, lead lobster biologist at the Department of Marine Resources. “V-notching is making a difference.” no notch with eggs

In recent years, the DMR has reported that sea sampling data show a reduction in V-notching rates. The DMR has raised concerns that lobstermen are less enthusiastic about notching female lobsters with visible eggs and conversations with lobstermen have confirmed this. This trend is also reflected in the MLA V-notch survey data. The percent of egged lobsters and no V-notch per trap hauled was 8.1% for 2015 compared to just 1.4% in 1985. This year’s data show an improvement over 2010 which saw the highest percent of egged lobsters with no V-notch at 20.8% per trap hauled.

The MLA survey is also capturing the increase in short lobsters carrying eggs. This data point was added to the survey in 2005. Since that time, the data from the V-notch survey show that the percentage of short lobsters with eggs hauled during the MLA survey to be between 40% and 50%, and reached more than 60% in three of the survey years, 2006, 2010, and 2015. shorts with eggs

To ensure a continued healthy population of lobsters, V-notching remains essential. A mature female lobster may carry up to 100,000 fertilized eggs upon her abdomen and while not all of those eggs will survive to maturity, they do lead to more lobsters in the Gulf of Maine.