MISSION TIME: 7:00 a.m., September 25, 2019

As soon as the weather began to clear and it was safe for flight operations, a Post-Storm Impacts drone surveillance flight was launched over Mandahl Bay.

Tropical Storm Karen brought significant wave action to St. Thomas’s southern Caribbean coast and flash flooding to many areas of the island.

1. We were quite surprised to find calm and clear water on the island’s northern Atlantic side at Mandahl Bay.
2. The rear-most waters of the lagoon were so still we got mirror reflections of the sky and clouds.
3. For most of the flight we were able to see straight through to the lagoon and ocean floor.

Our mission had to abort after less than fifteen minutes when rain began to fall.

1. You may notice that for the final leg of the flight, air speed was increased.
2. Look carefully during the video and you will see the rippling of raindrops hitting the water in the last half of the mission.
   

For the most part we observed the expected life presence for this time of year and included a pleasant surprise: the continued presence of a recently arrive fever containing at least nine Spotted Eaglerays [Aetobatus narinari]. A ‘fever’ is a grouping of rays.

1. Mosquito and other insect presence is unusually high.
2. Barn Swallows [Hirundo rustica] can be seen flitting across the waters and actively hunting insects the entire video.
3. Butterflies can be observed making their way across the lagoon.
4. Keep an eye out for roosting pelicans and egrets in the mangrove trees.
5. White splashes, wide ripples and suspicious shadow movements may indicate life presence!

Our flight could detect no visible signs of storm runoff into the lagoon.

1. The waters are coated with a layer of leaves blown of trees during the storm.
2. The post-storm movement and re-alignment of these leaves gives us valuable clues regarding surface water flow rate and directions without having to disturb the Eco-system.
3. No human litter, spills or debris from TS Karen is visible in the water.

We are noting increased wind-burn stress on mangrove trees lining the east shore of the back lagoon.

1. The browning was noticed after wind effects of Hurricane Dorian, as observed in that post-storm flight.
2. The dead mangrove snags are remains from Hurricanes Irma and Maria in 2017.