I Scream, You Scream, We All Scream for Isoprene

Plants are well known for absorbing carbon dioxide from the atmosphere and replacing it with oxygen as part of the photosynthesis process. But that’s not the only thing they put into the air. Trees emit tons of a chemical known as isoprene every year, mostly during summer months. It’s surprising to learn that plants contribute to air pollution. 

An abundance of isoprene can lead to formation of greater amounts of ozone by combining with nitrogen in the form of NO and NO2. Ozone in higher levels of the atmosphere is good because it blocks harmful UV rays from the sun, but at our level it’s a major pollutant.  

The current theory is that plants produce isoprene as a method of heat resistance. Like water vapor and oxygen, it is emitted through the pores in a plant’s leaf. Not every plant produces isoprene, but the biggest producers in the US are oaks and poplars.  

Shenandoah National Park (NPS)

Isoprene is what gives the Blue Ridge Mountains their blue appearance. The chemical haze scatters blue light, which makes the mountains appear blue from a distance. It also gives the Smoky Mountains their smoky appearance. 

Great Smoky Mountains (NPS)

We learn such shocking things about nature. I had no idea before today that plants are polluting the air with volatile organic compounds, which when man-made seem to be about the worst thing under the sun. Yet here they are, also giving some of our national parks their distinguishing features and even namesakes. 

Information comes from National Center for Biotechnology Information and Department of Energy Office of Science.

Winter Seals

Since moving from the Northwest to the Northeast 5 1/2 years ago I haven't been going on as many excursions into the natural world, especially during winter. But I decided to make an exception and visit the Jersey Shore to see some seals that I heard were visiting. My first attempt was postponed a week due to bitter cold. The second attempt was still chilly, but a much nicer day. To top it all off, I met up with some friends I hadn't seen since moving from the Northeast to the Northwest over 15 years ago. 

Four seals visit New Jersey in the winter months. They are the harbor seal (most common), gray seal, harp seal, and hooded seal (least common). The seals I saw were harbor seals, and there were two or three dozen of them. After spring arrives, the seals return north to Canada and New England. Since it was getting to be the end of their time in my neck of the beach, I put my discomfort aside and ventured outdoors. 

I arrived in the Sandy Hook area early, so I stopped by the Twin Lights State Historic Site for a quick view. The lighthouse is on top of a hill about 200 feet above sea level, one of the highest coastal points along the Atlantic. From the heights you can see just how narrow the Sandy Hook peninsula is. A few turkey vultures down the hill were basking in the sun.

Sandy Hook seen from Twin Lights

Seals haul out when the tides are low, so I had to check a tide table to plan my trip. Low tides were around 5 AM and 5 PM. I opted for the evening low since there's still light at that hour. And because I didn't want to get up at 3 in the morning on a Saturday. The exact time of the low tide wasn't important. Seals don't wait until the tide reaches its lowest point to haul out. A few hours early was fine, and the seals were at the appointed location ahead of me and my entourage. A small crowd was gathered along a fence, looking into the bay. I said "I bet those rocks everyone is looking at are actually seals." Sure enough, one of the "rocks" moved. 

Harbor seals in Sandy Hook Bay

Harbor seals in Sandy Hook Bay through a scope (NPS photo)

It's important to keep your distance from seals (or any other marine life) not just because it's a federal law, but because seals especially are easily annoyed and will leave if disturbed. Any unnecessary movement burns valuable calories that are keeping them warm. And there's a reason they're on land, so let them stay there doing seal things. There could be any number of reasons for seals to haul out. They bask in the sun to warm up, just like reptiles and amphibians. Mother seals nurse their pups on land. They need to rest just like we do. Their time in the water is spent hunting prey and trying not to become prey. It's exhausting.

I'm glad the day went how it did. Usually wildlife can sense me coming, and I wind up seeing nothing except some tracks and scats. But the seals didn't disappoint. It was great seeing my friends again, and since one is a shark enthusiast, it was a thrill for her to see shark food in its natural environment. In spite of the chill, I would make this an annual tradition.

Seal information came from Conserve Wildlife Foundation of New Jersey. The NPS picture of seals comes from a post on Gateway National Recreation Area's Facebook page