Data collected also included weather conditions, wave height and the relative amount of light. The table lists the beaches surveyed, the density of horseshoe crabs and the estimated number of horseshoe crabs on each of the twelve dates. Three peaks were identified in each state during the survey period. The peaks on each side were on the same dates, May 6th, May 18th and June 4th. The maximum peak occurred during the full moon date on May 18th.
Weather plays a critical role, greatly affecting the spawning activity of the horseshoe crabs.
A severe thunderstorm occurred during the night high tide on June 2nd adversely affecting both volunteers and horseshoe crabs. Many of the volunteers could not conduct the count due to the dangerous lightening and high amplitude waves kept the horseshoe crabs from spawning in great numbers. The maximum peak estimate for 2000 was 272,770 during the full moon date, May 18th. This estimate is the total of the estimates on 11 beaches both in New Jersey and Delaware. The estimates from the twelve dates for each beach in 1999 and 2000 were added and the number compared between the two years.