Fiddler on the Beach

A sand fiddler crab emerges from his burrow. Photographed at North Peninsula State Park, Florida.

In the last post (and quite some time ago) I wrote about how closely connected our world is to off-world things. The Sun, Moon, and tides are all non-living components of the natural world that interact with one another.  But they also interact with many living components as well.  In fact, there are many species that live their lives completely governed by the rise and fall of the tides.  One of my favorite is the sand fiddler crab (Uca pugilator).  I mean, who doesn't love a boy with a giant claw? Fiddler crabs live in burrows created in the mud or sand along coastal areas. And although I don't normally see them on the beach, I do see them up and down Jefferson Creek where I kayak in Delaware.  But only if I'm very quiet, and very lucky to catch a glimpse of them.  These crabs will scatter and retreat to their burrows when startled.  They also do this during high tides, only to emerge again during low tide when they spend their time feeding and trying to attract mates.  The crabs live by the tidal patterns; their behavior is triggered by the Earth’s rotation itself.  These triggers can also come in the form of changes in temperature, light, or even color.   

Seashore Ornithology: The Brown Pelican

One of my favorite shorebirds is by far the brown pelican (Pelecanus occidentalis).  It is small in comparison to the other members of its genus, and it is a fairly common bird in my neck of the woods.  But that makes them no less interesting.  They also have a relatively rich fossil record.  Fossil Pelecanus are known from the Early Oligocene around 30 million years ago, and by that point they were already very like modern forms.

A pair of Pelecanus occidentalis fly above the beach at North Peninsula State Park, Florida.

Brown pelicans are known for diving for their meals, which they catch in large gular pouches attached to their lower bill.  On land, they move about rather clumsily with their large bodies and webbed feet.  But in flight, they are truly magnificent.  Their long broad wings make them brilliant gliders. And when they flock together, which they do more often than not, they are a sight to see as they soar gently above the sand and waves.

Beach Blogging

Thalassa! Thalassa!

Time for a holiday! This week I'll be spending my days by the beach and bay, and am looking forward to a little relaxation, plenty of time outdoors, and a chance to share it with you all. The sea, home of our earliest ancestors, has always held a certain appeal to me.  While our more recent ancestors may have moved away from it for more terrestrial way of life, there are many plants and animals that never left.  And even more that returned to the waters and shorelines of the world secondarily.  I think I've always envied them a bit.  Combined with the endless hours I spent as a child combing the beach and watching the water, I always look forward to being able to return myself. So with that in mind, keep an eye out here and on Twitter for seaside science (among other things) this week.

Things I Learned This Semester #2

Callinectes sapidus, photographed at the Maryland Science Center.

Back in 2008, Maryland Governor Martin O'Mally and Virginia Governor Timothy Kaine, at the advice of the Maryland Department of Natural Resources and the Virginia Institute of Marine Science, made the difficult decision to pass regulations regarding the harvesting of Atlantic blue crabs (Callinectes sapidus) in the Chesapeake Bay.  By shortening the harvesting season, putting limits on the number of bushels allowed to be collected, and curbing the catching of female crabs, they hoped to allow the record low populations to rebound.  Well, good news everyone! Four years later, and the crab population has reached its highest levels in the last 19 years!  A dredge survey made public back in April shows a population rise of 66%, of which 587 million individuals are juveniles.  This is great news for the crabs, but also for the watermen that make a living off of them, and for those of us who love picking a good crab on a late summer evening.  Sustainable fisheries management for the win!

Cold Fish in the Chesapeake Bay

Dead spot and croaker on the shores of the Chesapeake Bay in Stevensonville, Maryland. Photo by Charles Poukish, from the Associated Press.

There have been several reports since the beginning of the new year regarding the mass deaths of animals across the globe. Starting with the death of around 5,000 red-winged blackbirds (Agelaius phoeniceus) in Arkansas on New year's Eve, media outlets have been quick to pick up on other stories of other mass bird deaths and fish kills. Not only that, but some have been quick to suggest conspiracy theories - from toxic chemicals, to U.F.O.'s, to the coming apocalypse - as the reason for these mass deaths. I'm not going to touch any of that, or perpetuate the notion that these events are in any way, shape, or form related to one another, because they are not. But I do want to talk about one of the instances that hits a little closer to home for me, and its real cause: a recent mass fish kill on the Chesapeake Bay, and its link to global climate change.

Hagfish Day 2010!

So apparently today is the 2nd annual Hagfish Day, the celebration of the beauty of the ugly. I can certainly get into that.

Hagfish, doing their slimy, knotty thing. From the Vancouver Aquarium YouTube channel.

Like a Shark Out of Saltwater

Here's another piece of local news from the Maryland area. The brother started kayaking on the Potomac River this summer. I wonder what he would think of this NBC Washington headline:

"8-Foot Shark Caught in Potomac River"

Photos (above and below) taken by Christy Henderson, from Buzz's Marina.