CHAETOMORPHA BALLS FOUL NEW HAMPSHIRE, USA BEACHES

Abstract

The present paper reports the occurrence of extensive green balls, or aegagropilous seaweed populations (Norton and Mathieson 1983), from two New Hampshire, USA beaches. Tens of thousands of these balls washed ashore at North Beach (Plaice Cove), Hampton (Fig. 1) during mid summer of 2002, disappearing shortly thereafter. Newspaper and magazine reports included speculation that they were everything from extra-terrestrial life, to a unique phytoplankton, entangled masses of plastic string, Brillo pads ®, seagrass fibers, and finally seaweeds (Anonymous 2002a-g; Bergeron, 2002). Sensational headlines about aegagropilous seaweeds have been reported elsewhere (Norton and Mathieson 1983), including “mystery balls” at Torbay in Great Britain (Newton 1950) and “sea manure” at Nahant near Boston, Massachusetts (Anonymous 1903; Wilce et al. 1982). In discussing these Cladophora balls at Torbay, Newton (1950) notes that they occur sporadically, sometimes cast up in enormous numbers and at other times totally absent. By contrast, Wilce et al. (1982) describes a long, persistent history associated with the nuisance ball-forming brown alga Pilayella littoralis (L.) Kjellman at Nahant, which produces extensive sludge-like masses up to 0.5m thick. When buried in sand, primarily in winter, the algal sludge eventually decomposes and in warm weather produces noxious volatile sulfides. Aegagropilous seaweeds are distinctive loose-lying forms that consist of radially arranged branches (filaments) of either individual or multiple plants entangled together into spherical balls (Kjellman 1893; Dickinson 1933; Norton and Mathieson 1983). Some of the best known examples are the “lake balls” produced by several species of the green alga Cladophora (Kjellman 1898; Lorenz 1901; Brand 1902; Acton 1916; Nakazawa and Abe 1973; Kurogi 1980a,b; Kanda 1982) and designated as “Special Natural Monuments” in Japan (Kurogi 1980b). Similar balls are also formed by several marine species of Cladophora, as well as at least 54 other seaweeds, including 25 red, 18 green and 11 brown algae (Norton and Mathieson 1983; Mathieson et al. 2000). Algae Volume 17(4): 283-292, 2002