We are forecasting the timing of when the Maine lobster fishery will shift into its high-landings mode for the summer. Our goal is to provide 2-3 months advance notice of this uptick so that the lobster industry can prepare appropriately for the high-landings period.
2016 Final Forecast
Temperatures in Maine’s coastal waters have been warm throughout the beginning of 2016. The temperatures at 50-meters (164 ft) at four coastal NERACOOS buoys in the Gulf of Maine remain approximately 1 degree Celsius (1.8 degrees Fahrenheit) warmer than normal. Across the region, sea surface temperatures have been running 0.5 – 1 degrees Celsius warmer than normal over the past week, with the Maine coast being at the cool end of the range. Based on the current buoy temperatures, our forecast predicts a 41% chance that the season will start three weeks earlier than normal, a 56% chance that it will start two weeks early, and only a 3% chance that it will begin one week early. We consider the normal high-landings period for Maine lobster to start between July 3 and 10.
Most similar year: 2013
Of past years for which we have landings records, the forecasted uptick date probabilities in 2013 were most closely aligned with our forecast for this year. For much of the forecasting period this year though, the probabilities have been more heavily loaded in the June 12 to June 19 bin, which resembled the forecast for 2012. Only this week have we seen a large portion of the probability become concentrated in the June 19 to June 26 bin, which makes the forecast closely resemble that of 2013.
Our forecast is generated using 50m water temperatures at several buoys from the NERACOOS array. Most of these buoys currently show ocean temperatures at 50m slightly below those experienced in 2012. These waters at depth appear to be holding heat that was not released during the record warm winter. However, we have not seen the 50m temperatures rise for the spring since we began this year’s forecast; they have just ceased cooling and remain well above the seasonal average. This contrasts with the surface temperatures along the coast. The spring weather in northern New England has been colder than normal, resulting in very little warming at the surface. Surface temperatures averaged over the last eight days show temperatures along the immediate coast at close to normal values for this time of year. This is a result of the relatively cool weather of the last two weeks. Offshore, waters are still 0.5 – 1.5 degrees Celsius above average, and as a whole, the average surface temperature in the Gulf of Maine is close to the 2012 value. We expect that the warm weather forecasted for this week will cause the surface temperatures to trend upward, and we are already seeing above-normal temperatures along the coast in the satellite image from yesterday.
The accuracy of our models peaks around this time of year, so unless there is a major change in ocean conditions, this will be our last forecast for this season. Our predictions have only changed slightly from week-to-week. According to the model, statewide landings are most likely to begin their summer uptick around June 19, and there is a 97% chance that the high-landings period will begin between June 12 and June 26.
Although temperatures in 2012 appear to offer the most similar analogue to this year, there are some important differences between 2012 and 2016. First, temperatures along the coast started the year above 2012 levels, but they have since moderated. At 50m, this would be the second warmest year in the NERACOOS record, while surface temperatures are only slightly above normal for this time of year. This year’s steady temperatures from early March through mid-April contrast with a short period of very warm waters during late March and early April of 2012. The warm burst in 2012 is most apparent in the surface data from that year. The extent to which this warm period may have affected the timing of lobster molting and the fishery uptick is unknown. Lobstermen reported seeing shedders as early as April in 2012, and it may be that this spike in temperatures cued an early shed and synchronized it along the coast. If the strong synchrony along the coast in 2012 resulted from this warm spike, then it would suggest that the 2016 uptick will be early but will follow a more typical pattern of progression along the Maine coast.
While the ocean temperatures and seasonal cycle this year most closely resemble those of 2012, the probability distribution of potential fishery start dates in this final forecast appear very similar to the 2013 forecast. In 2013, June 26 would have been defined as the statewide fishery start date according to our definition; this date is just over one week earlier than the July 3-July 10 period we use as a baseline.
In summary, the consistently warm temperatures this spring give us a high-degree of confidence that the lobster fishery will shift into the high-landings summer mode ahead of schedule. This year’s more moderate spring warming compared with 2012 suggests that the fishery is more likely to look like 2013, a warm year with the landings uptick occurring in the June 19 to June 26 window.
All 2016 Forecasts
Water temperatures at 50-m depth have remained relatively stable over the forecast period. All of the forecasts we have issued so far this year indicate that the high landings period for the Maine lobster fishery will begin 2-3 weeks earlier than normal.
If you’d like to look at how water temperatures this year compare to past years in more detail, please visit the NERACOOS climatology viewer. For more information on how we generate these forecasts, please download the Lobster Forecast Methods document. Please contact Kathy Mills with any feedback on the forecast at [email protected].
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