The animals are beautiful. They are nearly clear except for the four leaf clover shaped reproductive organs at their center. The characteristic jellyfish pulse is also gracefully mesmerizing.
An observant and curious boater took a great picture of a dense smack of moon jellies at the Brownsville marina on August 11th of this year. The image worked its way around UW Aquatic and Fisheries Sciences department, and received several responses. One referred to the recent (July, 2010) conference… Third International Jellyfish Blooms Symposium.
Our region’s own Jenny Purcell of Western Washington University organized the first session listed on the conference page and provided a session summary that really hits on the complexities of jelly blooms.
Globally, blooms impact economies and the environments that support them. Lots of factors can go into creating blooms, including climate change, altered salinity and excess nutrients/food. Murkier water and low oxygen can also favor jellies over their fish competitors. Even manmade structures in the water can create extra habitat for to support the jellyfish life cycle. Fishing can also remove some of their predators and competitors.
The life cycle of a jelly is a strange (though not uncommon) combination of sexual and asexual reproduction and of planktonic (floating in the water) and benthic (attached to a surface in the water) forms. The jellies we see floating around are the adult male or female medusa. The boys put their sperm into the water (like many marine critters). The girls use the sperm to fertilize eggs that they brood until the larvae are released into the water. The larvae soon find a shaded place (that’s why man-made structures come in handy) to settle and grow into a polyp – like a tiny anemone. That polyp divides into a budding colony and each bud breaks off to grow into a new medusa. You might check out the Jelly Zone for more about jellies.
But why is an aggregation of jellyfish called a “smack”. I don’t know, any ideas? Sarah Asper-Smith of Alaska found odd group names so intriguing that she illustrated an ABC book with unusual names for each letter called Smack of Jellyfish. It comes out in November. Good stuff.
With my wife and oldest son’s help, we came up with a few aggregation names we feel should catch on…
bull kelp bed –> a flogging
sand dollar bed –> a treasure
urchin bed –> a thorn
crab aggregation –> a drool
dogwinkle snail gathering –> a pound
Is anyone with me? Please comment with your own inspired new name for an aggregation of something. Have a jolly jelly day! JEff
Jeff Adams is a Washington Sea Grant Marine Water Quality Specialist, affiliated with the University of Washington’s College of the Environment, and based in Bremerton. You can follow his Sea-life blog, email to email@example.com or call at 360-337-4619.