Reef Madness

Last week we explored the dynamic barrier islands, a great place for wildlife and a popular vacation destination. This week, we venture beyond the island into the coral reefs just offshore. As an avowed landlubber, I'll probably never get to see a coral reef for myself, but I'll live vicariously through myself telling you all about them.

Coral reef (Smithsonian)

Coral reefs are hard, rocky structures made of the skeletal remains of what was once living coral. Corals are a marine animal, not a plant, and the best-known form a symbiotic relationship with algae. Because algae needs sunlight for photosynthesis, many coral reefs are found in clear, shallow water. Cold water corals that live in the deep sea. Without sunlight, these organisms filter feed plankton. Because of their inaccessibility, we are still learning about them.

Coral polyps (NPS)

The most popular corals are the shallow ones, because they are relatively easy to reach. Scuba diving, snorkeling, and even glass bottomed boats bring humans right to the biological hot spots. People are drawn to coral, not just because of the beauty of the coral itself, but the amazing biodiversity found within the reef. Fishes, crustaceans, sponges, anemones, and countless other sea creatures call the reef home. The coral structure provides hiding places for mobile critters and anchorages for sessile ones. Hiding places benefit predator and prey alike- they provide somewhere to hide from bigger fish, or place to launch a quick strike at an unsuspecting meal.

Coral reef (NPS)

Cold water corals provide the same habitat and ecosystem, and may be even more important than their shallower counterparts. Most sea life can be found near the coast and relatively shallow. Corals in the deep sea for a sort of island in an area that is otherwise mostly devoid of life.

Deep sea cold water coral (Joint Nature Conservation Committee)

Like just about every ecosystem in the world, coral reefs are in trouble. Coral is dying as sea temperatures and carbonic acid levels rise. The algae component of the coral either dies or evacuates in a process known as coral bleaching. Some corals show some resistance to slightly warmer temperatures. Research into this is continuing. If you ever get a chance to explore coral reefs, either by boat or underwater, remember to look but don't touch.
This week's information comes from NOAA and the Smithsonian Institute.

Getaway Islands

Summer is here and for many people it's the perfect time to relax at the beach. If you're at an East Coast beach, odds are you're on a barrier island. The Atlantic barrier islands extend from Canada to Florida, then up Florida's Gulf Coast and all the way around to Mexico. Prior to development, many of these islands came and went at the whims of the tides and storms. Now that we've built homes and resorts on them, there is a vested interest to make them more permanent by using jetties to block the outflow of sand and beach replenishment to restore what's been lost. Let's take a look at the natural history of where you built that sand castle.

Grassy dune in New Jersey

Barrier islands, if left to nature, live and die by the tides. Ocean currents carry sand away from the islands. The sand either moves out to the sea floor, where it can be brought back to the island by currents, or it is carried to another part of the island or to a different island. Strong storms can accelerate the process, wiping islands off the map or opening up a new inlet to the back bay.

Hurricane Irene cut these inlets across Hatteras Island (NOAA) 

Barrier islands can move toward the mainland as wind blows sand over the dunes to the bay side. The marshes fill in with sand and build up new dunes, while ocean moves to where the dunes originally were and new marshes form in the bay on the edge of the old marshes.

Salt marsh at Assateague Island (NPS)

The islands are important because they are barriers protecting the mainland from such storms. A few weeks ago we looked at hurricanes on this blog. Barrier islands absorb the brunt of the storm surge that comes in ahead of the hurricane. Developed barrier islands still absorb the storm surge, but not as well as undeveloped islands from times past. Impermeable surfaces like roads and parking are terrible at absorbing water, while sand drains quickly. If the dunes have been removed from an island, the storm surge rushes right over top with nothing but buildings to slow it down.
Barrier islands are also important as habitat for critters other than summer vacationers. On an undeveloped island, different plants and animals that can tolerate different amounts of salt water and exposure to the air make their homes in different zones. Clams live beneath the sandy shore, while birds that prey on them scurry above. Grasses hold the dunes in place, and at the highest points of the island you can find trees and shrubs where songbirds and mammals live. Brackish marshes on the other side of the dunes host crabs and serve as a nursery where fish can eat and grow before venturing into the open sea. Wading shorebirds take advantage of this bounty. Beyond the marsh is the back bay and the mainland.

Ghost crab (NPS)

Sandpiper feeding frenzy

The US has more barrier islands than any other country in the world. Best known are New York's Fire Island, Texas's South Padre Island, the Outer Banks of North Carolina, and the Jersey Shore. If you spend a summer weekend at the beach, be sure to check out the wild side of things.
This week's information comes from Science News for Students.

Species of the Month

As the snow disappears from higher elevations in the west, mountain hikes are once again becoming possible. That's where you'll meet our Species of the Month, although you are more likely to hear it than to see it. The American pika, though it looks rather mousy, is actually related to rabbits. Living high up in the rocky slopes of the Cascades, Sierras, and Rockies, it lets out a high pitched squeal as an alarm call when it spots a potential predator or passing hiker.

Pika adding to its cache of food (NPS)

Scientific name: Ochotona princeps

Kingdom: Animalia (animals)

Class: Mammalia (mammals)
Order: Lagomorpha (hares, pikas, rabbits) 

Range: Mountains of western North America from British Columbia south to New Mexico

Habitat: Talus fields within mountain meadows

Pika on the rocks (NPS)

Lifespan: Up to seven years, average is three years
Diet: Grasses and forbs
Predators: Weasels, coyotes, raptors, martens, foxes, bobcats
Conservation Status: No special protection, though seven subspecies are considered vulnerable
Other information: This little critter looks like a big, chunky mouse or a rabbit with short ears. They are active during the day, gathering plants during the summer for immediate consumption and also to stockpile for the long winter ahead. Pikas build haypiles of grasses and forbs, selecting plants with the highest protein content they can find. Haypiles are kept outside during the summer to dry, then moved to the den for winter. Pikas do not hibernate; they remain awake in a tiny cave within the rocks and under the snow, eating their way through that haypile. Like other lagomorphs, they frquently consume their scats. Food is not totally digested, so they eat the scat to absorb more nutrients. Eating it a second time more fully breaks down the plant material. Pikas communicate though alarm calls and scent marking. Scent glands are on the cheek. They rub their cheeks on rocks to mark their territory.

Pika (NPS)

Look for pikas at Mowich Lake in Mount Rainier National Park. This week's information once again comes from the good people at UM's Animal Diversity Web.

A Dove Affair

A little over a month ago, I was having a normal morning until I thought a mourning dove was about to crash into the dining room window. He pulled up and landed in the flower basket. Then I noticed he had pine needles in his mouth and passed them to his mate. They were building a nest. I was about to become a bird uncle!

Mother dove feeding one of the babies

I don't know for sure when the eggs hatched, but about three weeks later I got my first look at one of the babies. By then the flowers in the basket were dead and brown, perfect camouflage for the doves. A second baby was in there too, I just didn't notice it for another week. By that time, the babies were almost adult sized. They were up on the edge of the basket flapping their wings, getting ready to fledge the nest.

Baby dove

The last time I saw one of them it was on the edge of the basket flapping during a severe thunderstorm. Through the glass, I was trying to convince it to not try flying in such nasty weather. The next morning, it was gone. A few hours later I watched as the second baby flapped at the edge of the basket, then took off and flew into the neighbor's tree.

The children are getting older

It took less than a month to build a nest, lay eggs, hatch them, and fledge the nest. I was sure my little friends would be around at least until summer. Every now and then I'll look out the back window and see a pair of doves in the yard, or perched on the fence. To me they all look the same, but I can't help thinking it's the same ones I watched grow up.

Have the prodigal doves returned?

Hurricane!

With the beginning of June, the northern Atlantic is officially in hurricane season. Tens of millions of people along the East , and in Central America and the Caribbean are at risk from these monster storms annually. Let's have a look at where they come from.

Hurricane! (NOAA)

Hurricanes begin as a low pressure system that gains strength from warm ocean water in or near the tropics. The air moving in to the low pressure area rises, cools, and condenses into clouds. The low pressure continues to draw in more air, and the system begins spinning and forms an eye.

Hurricane formation (NASA)

Wind speeds increase as the storm grows. Despite winds that can exceed 150 miles per hour, most damage is caused by water. As the hurricane approaches land, the wind pushes the water ahead of it. This is called the storm surge. Once the hurricane makes landfall it rapidly loses strength without the warm ocean beneath it. As it moves along, it dumps tremendous amounts of rain, which can cause catastrophic flooding.

Where hurricanes form (NASA)

Thanks to the miracle of satellite radar, we know well in advance of when and where hurricanes will strike. If you are in a hurricane area and are earned to evacuate, please do. Information came from NASA this week.