Wading Through Research

by Luca Marazzi* Rhopalodia gibba belongs to the epithemioid group , that is to say it has v alves symmetric about a line (bilateral symmetry), but asymmetrical to the apical (longitudinal) axis, the raphe system is well developed, enclosed within a canal, and positioned near the valve margin 1 . It is longer and more slender than other species such as the lunate R. gibberula , and the more arched R. musculus ; it is found in the benthos, attached to substrata such as plant (epiphytic), or gliding more freely and opportunistically 2 . Interestingly, R. gibba seems to have declined significantly in the United Kingdom due to agricultural intensification and associated large use of nitrogen fertilizers. In fact, t his pennate ( bilaterally symmetric) diatom species lives in nitrogen poor habitats, but it has evolved an endosymbiosis with cyanobacteria that fix nitrogen 3 . So it does not like when there is too much nitrogen around, and loses its competitive edge against other fellow...

This post was written by guest blogger Mike Bush, a grad student in FIU's aquatic ecology lab ( http://faculty.fiu.edu/~trexlerj/ ). __________________________________________________________________________ Boaters trying to push whales back to deep waters. Photo from CNN.com        This will be another post on some wide-ranging animals that only occasionally visit the Everglades.   Last time I talked about small songbirds, but I’ll scale up a bit for this round.  

  This post was written by guest blogger Emily Nodine, a PhD candidate in FIU's Periphyton Lab ( http://algae.fiu.edu/research/ ). When people think about today’s Everglades or the “River of Grass,” they generally think of Lake Okeechobee, Everglades National Park, and the canals and water control structures in between.  But the watershed is actually much larger than that.  Lake Okeechobee does serve as the headwaters of the Everglades; prior to human alteration, Lake Okeechobee would slowly overflow southward during very wet periods, forming the shallow, slow-flowing sheet of water that earned it the title “River of Grass.”  Today, the Hoover Dike prevents this and the water flow is strictly controlled, mostly released to the east and west coasts via the St. Lucie and Caloosahatchee Rivers, but also southward to the Everglades through an extensive system of canals and water control structures.  But the water in Lake Okeechobee came from somewhere else, t...