Diet composition of mummichogs, Fundulus heteroclitus, from restoring and unrestricted regions of a New England (USA) salt marsh

Diet composition of mummichogs, Fundulus heteroclitus, from three marsh habitats (creeks, pools, and marsh surface) within tidally restored and an adjacent unrestricted (reference) region of Sachuest Point salt marsh (Middletown, RI, U.S.A.) was examined. Major diet components were detritus, copepods, diatoms, insects (larvae and adults), ostracods, and chironomids. Total length, wet weight, and gut fullness of mummichogs were equivalent within habitats between the restoring and unrestricted marshes. Diet composition and percent abundance of diet items were also similar within habitats between the unrestricted and restoring marshes. However, differences in diet patterns were observed among habitats (creeks, pools, and marsh surface) within each marsh. Fish collected from creeks had fuller guts than those sampled from the marsh surface for both the restoring and unrestricted marsh. Diet composition also differed among marsh habitats, but only within the restoring marsh. In the restoring marsh, fish sampled from the creeks consumed primarily detritus, diatoms, and ostracods, whereas fish from the pools consumed mainly detritus, copepods, chironomids, and insects. Differences in diet composition among habitats were most likely a reflection of prey availability. This study provides evidence that tidally restored marshes can provide similar food resources as unrestricted marshes, in terms of consumption patterns of dominant marsh consumers, within the first year after restoration, before major shifts in dominant vegetation (i.e. from Phragmites australis to Spartina spp.) occur. (C) 2001 Academic Press.