THE VIRGINIAN-PILOT
Copyright (c) 1995, Landmark Communications, Inc.
DATE: Sunday, September 10, 1995 TAG: 9509100038
SECTION: LOCAL PAGE: B2 EDITION: FINAL
SOURCE: BY DEBBIE MESSINA, STAFF WRITER
DATELINE: VIRGINIA BEACH LENGTH: Medium: 56 lines
About 50 percent more dolphins were sighted off Virginia's coast in the Virginia Marine Science Museum's bottlenose dolphin count this year than were tallied in 1994.
Preliminary numbers show that 846 dolphins were recorded in July during the third annual dolphin count, while 579 were counted last year and 412 in 1993.
Those figures are higher than the actual number of dolphins as they are unanalyzed counts and include duplication.
W. Mark Swingle, a marine biologist with the museum who coordinates the count, estimates that about 200 dolphins could be subtracted from the total once the data is analyzed to eliminate duplicate sightings.
Researchers hope to spend time editing the numbers further and compute a more accurate count in October. In 1994, the count dropped from 579 to 407 after analysis, and in 1993 from 412 to 335.
These numbers should be considered minimums because dolphins spend 90 percent of their time under water and are in constant motion, making them difficult to count.
Another significant finding of the count, which encompasses 120 miles of coastline, is that this year's results confirmed previous dolphin distribution patterns.
In the previous two counts, 75 percent of the dolphins were sighted off the Virginia Beach coast, while the rest were scattered from Chesapeake Bay north to the Maryland state line.
This year, possibly up to 90 percent of the dolphins counted were seen off Virginia Beach's coast. Plus, the actual numbers of dolphins on the Eastern Shore fell.
``The distribution was even more drastically south this year,'' Swingle said.
Swingle cannot yet explain the skewed distribution but said water temperature and food sources are potential factors.
As the numbers are studied, Swingle will extract the number of dolphin calves or neonates to examine.
In the last two years, the number and percentage of calves has risen enough to warrant closer study. Last year 39 calves were counted, representing 9.6 percent of the total.
In 1993, 20, or 6 percent, were counted.
``What began as an interesting experiment has developed into an exciting and useful tool for examining the relative abundance and distribution of Virginia's most common marine mammal,'' Swingle wrote in a preliminary report.
``Data collected from the dolphin count and other museum research will provide valuable information for the future management and conservation of Virginia's coastal bottlenose dolphins.'' by CNB