Nantucket Night Hikes
THE PHOSPHORESCENCE!
This week, The Nantucket Independent

continues a summer series entitled

Night Hikes. This series will help you

to discover the island's natural world as the light of day fades into nighttime.

At dusk, while some Nantucket critters

bed down for the evening, the night shift of birds, reptiles, amphibians, animals,

fish and insects emerge, looking for food, love and vocal chord exercise.

Stars come out, planets glow and sparkle and as the air cools, a whole

new world opens up.

Less destination-oriented and much

more of a what's-out-there guide, we will also share with you what there is to

see, hear and feel out in Nantucket's

harbors, saltmarshes and ponds. Gelatinous greenish blue glowing globs of no-brain jellyfish, fireflies of the sea, are lighting up the shallows of Nantucket Sound and the harbors right now, but you'll have to venture out at night to see them.

The much-ballyhooed phosphorescence is the natural neon that swarms in the inland waters of Nantucket for those who love nocturnal marine adventures this time of year. Can't sleep because of the humidity? All hot and sweaty from clubbing or dancing at the Box? Get out to the harbor or the north shore for a liquid laser lightshow that the fog can't stop.

Not an electric form of microscopic plankton as many islanders and seasonal visitors believe, the bioluminescence seen near shore from mid-August to mid-September is emitted from clear, walnut- to lemon-size jellyfish called Leidy's comb jelly that are classified as a plankton and have no brains. When agitated in the water, these non-stinging jellyfish, that appear nearly clear and almost invisible during daylight hours, produce green-blue chemical light along eight rows of combs tightly lined with cilia (tiny hairs) that pulse in concert with each other to move the jellyfish through the water and suck in food.

The bioluminescence is created by a chemical reaction produced by the interaction of the organic molecule luciferin and the enzyme luciferase, and is similar to the natural glow of fireflies.

But you shouldn't confound yourself with the biology of this simple invertebrate, though you may want to hold them in your hands or close to the surface of the water to see their cilia vibrating in unison. To see these spectacular underwater shooting stars while they're here, I like Polpis Harbor in one of my kayaks on a calm, clear and cool evening when most of the boats are moored so I can have the harbor all to myself. I prefer my sit-on-top sea kayak because it's nice to be able to get out on a sandbar or beach and splash around in the water to get the comb jellies to do their thing.

You can start your paddle whenever you choose, but the jellyfish with flashlights won't be visible until it's almost completely dark.

Polpis Harbor is found at the water end of two access points. The first, labeled Polpis Harbor Road, is on the north side of Polpis Road just before its intersection with Wauwinet Road. The second access point is on the north side of Wauwinet Road opposite 19 Wauwinet Road.

If kayaking isn't for you, Steps Beach is the perfect wading place for seeing the "phosphorescence" on Nantucket. Find Lincoln Avenue by going down to the end of North Beach Street, heading left onto Jefferson Avenue and then another left up Cobblestone Hill. At the top of the cobblestone road, go right. At the west end of Lincoln Avenue look for a public way down toward Nantucket Sound and the stairs beyond that lead down to the beach.

Bolt down the 41 steps leading to Steps Beach, find a patch of sand for your towel and remember where you put it because it will get dark. As with kayaking through Polpis Harbor, you don't want any light other than moon, stars and lights from the houses on the Cliff. That glare alone could spoil your phosphorescence experience.

I like to find a good stretch of shallow, even shoreline on a warm night and walk along calf- to knee-deep in the water, stirring up the jellies and watching them turn on and turn off. Try it underwater as well. Because there is no sting, there is nothing to fear.

The Leidy's comb jellies are swarming all around the island right now, so you've got plenty of time to get

out there and see the lights. I

NIGHTWANDERINGS 101

Before venturing out into the night, it's a good idea to heed basic safety and personal comfort advice.

Bring a good flashlight and a compass and/or GPS (global positioning system) unit that are easy to carry if you get butterflies when the sun goes down. Maps of the island properties owned by the Nantucket Islands Land Bank and Nantucket Conservation Foundation will aid your wanderings, as will a copy of my book, "Walking Nantucket."

Choose a bug repellent that works for you, and lather up before you head out. Pay particular attention to your legs, ankles and booted feet. While it is the biting, winged bugs you want to fend off because of their immediate itchy sting, by far the most critical defense should be against deer ticks that carry Lyme disease, Babesiosis and Ehrlichiosis.

If you can, stuff your pants into your socks - although that may not be practical in warmer weather - and apply repellent. If you wear shorts, the more repellent the better, on your legs and ankles. And when you get home, check your body for ticks.

When paddling at dusk and into the early evening, have a loud whistle and strobe light attached to your life preserver. Turn the strobe on after the light fades or during foggy conditions. Be sure to tell someone where you are going and when you plan to return.

Take plenty of water and snacks. Always bring all trash back with you, and any that you care to pick up along the way.

- Peter B. Brace