Spring is here. There are many signs of it and it seems that every person I talk to enjoys a different little delight of spring. Yesterday, I spotted the first blooms of coastal anemones and a tiny violet on the side of Pillar Mountain, and a couple of days ago out on the water the first puffins were around.
The puffins came all at once travelling in large groups from their winter grounds in the open ocean to reclaim their nesting sites on shore. They come for that one purpose only: to lay their eggs and raise their chicks. In September they will all leave again and spend the rest of the year bobbing up and down on the waves with foraging expeditions under water.
Ocassionally the sun makes an appearance, and in a protected place with a cup of coffee to warm ones hands, it almost feels like a touch of summer. However, on the ocean it is still cold and breezy.
I know what I am talking about because I was out there yesterday. We took a small plankton net and showed a group of students from Anchorage how the ocean is waking up to spring. The tiny algae that fuel the food chains in the water are ready and growing; the sample was full of little brownish strands.
I did not have a microscope at hand but I know the diatoms in the sample would have looked like little delicate necklaces if magnified in such a way. Feeding on the algae in the sample were several small organisms, most of them tiny shrimplike copepods. These are important food for the herring that just arrived in the area.
Did you notice that there are more sea lions in St. Herman Harbor than usual? Well, they like to eat those herring and they need the fatty fish to grow and prosper.
If plankton are the tiny algae and small animals that drift with the ocean currents, everything that swims against it under its own power is called the nekton. Herring are nekton.
Lately, there has been another organism seen travelling the Kodiak seas that is neither plankton nor nekton, but pleuston. Pleuston is the community of organisms that are partly on the water and partly submerged. In a way, you could think of a sailboat as pleuston; the sail and deck are above the water, but the hull is partly submerged. Now imagine a sailboat that is very tiny and blue, the sail is made of chitinous material, same as your fingernails and instead of a keel it has a bunch of little tentacles.
The organism I am talking about is called a by-the-wind sailor, little raft or little sail. In the last weeks several people have come to the touch tank at the Kodiak Fisheries Research Center asking about these curious little creatures they have been seeing washed up on beaches.
By-the-wind sailors, also called velella velella, are curious creatures indeed. They belong into the class Cnidaria, along with sea anemones, coral and jellyfish. But scientists have argued for over 100 years whether they want to include these little rafts with the jellyfishes or give them their own class. As you know, jellyfish do not partly stick out of the water and when they do it means they are in trouble. One of the beauties of jellies is the way they move slowly contracting their umbrellas.
By-the-wind sailors have no means of self-propulsion and rely entirely on a little stiff sail that sticks out of the water, catches the breeze and blows them whereever the winds take them. Sometimes the winds take them to a beach and blow them ashore by the thousands. These mass strandings are common every spring along the West Coast from California to British Columbia. In the last two years there were mass strandings of blue sails when warm water masses brought the sailors with them and southwesterly winds blew them ashore.
Under each blue sail is a group of little polyps, each with one of two jobs. There are the dactylozooids for defense and there are the gonozooids for reproduction. Each gonozooid proceeds to grow and bud off numerous tiny jellyfish-like medusae, which will grow and release eggs or sperm into the water. The larvae developing from those eventually grow into the little rafts. Each little blue sail has only either male or female gonozooids.
To complete our simile we need to imagine a tiny sail boat with a little blue sail and a crew of all men or all women. No one ever goes on deck and, unfortunately, no one knows how to operate the sails. The boat is so small, it is at the mercy of the winds anyway. Should the winds decide to blow the boat ashore, however, at least there are thousands of others in the same situation.
Although related to the Portugese man-of-war, the by-the-sea sailors are not poisonous. Their cnidocysts or nettle cells are not powerful enough to deliver a sting to humans, however, it is advisable to keep one’s hands away from eyes and face after touching them, because sensitive people could develop an itch.
The Portugese man-of-war prefers warmer water and causes the most trouble off the east coast of Australia. Should you ever be there and encounter a blueish, pink or purple sail on something that looks like an inflated plastic toy trailing long tentacles, you do want to stay away from it. The sting of that bigger relative of our little blue sail is said to be very painful.
Even if the winds blow colder here than in Australia and the sun is a less common sight, at least our pleuston is less poisonous. The sea and its sailors never cease to amaze.