62 



BIOLOGICAL REPORT 31 



resident species are associated with the marsh 

 throughout their life cycles. The most abundant of 

 these, the Atlantic silverside (Fig. 4.9), lives only 1 

 year, and the relatively few that survive the winter 

 by migrating into deeper waters return to spawn in 

 spring. Mummichogs (Fig. 4. 1 0) live several years, 

 surviving the winter by residing in the bottom of 

 creeks or marsh pools, often in the more brackish 

 upper reaches of the marsh. The striped killifish on 

 the other hand winters in the lower sandier reaches 

 of the marsh during the winter months. These latter 

 species utilize plants and animals in their diets, feed- 

 ing on algae that lives on the surface of the marsh, 

 but obtaining higher quality food through the con- 

 sumption of eggs of other species like the horse- 

 shoe crab, small bivalves like Gemma gemma, and 

 other invertebrates. 



m 



Fig. 4.9. The silversides (Menidia menidia). Photo by 

 J. Teal. 



Fig. 4.10. The mummichog (Fundulus heteroclitus) 

 Photo by J Teal. 



Nonresident species differ in their use of the 

 marsh. Some use the marsh as spawning grounds, 

 others for protective nursery grounds with abun- 

 dant food for the growth of juveniles. The three- 

 spined stickleback enters the marsh from Buzzards 

 Bay in spring to spawn and then returns with its 

 young back into the bay. Other invading fishes, such 

 as the alewife, the Atlantic menhaden, the tautog, 

 the sea bass, and the winter flounder use the marsh 

 as a nursery ground and are only present as juve- 

 niles during mid and late summer. Bluefish and 

 striped bass enter the marshes as moderate to large 

 adults for brief periods during high tide and leave 

 during ebbing tide, feeding on many of the smaller 

 resident species in late summer. 



In a study of the fish populations of Great 

 Sippewissett salt marsh in West Falmouth, Werme 

 ( 1 98 1 ) found that resident fish were far more abun- 

 dant than nonresidents (Table 4.7), as is often the 

 case for other fish and bird assemblages. Two resi- 

 dent species, Atlantic silverside and mummichog, 

 accounted for more than 90% of the fish in the marsh. 

 Large differences were found in the growth rates 

 between the resident and nonresident species, with 

 nonresidents growing an average of 1 times as 

 quickly as the resident fish (Table 4.8). Investiga- 

 tion of gut contents and fullness of the dominant 

 resident and nonresident species were consistent 

 with their different growth rates, with invading fish 

 maintaining higher feeding rates than the resident 

 fishes and generally consuming a higher percentage 

 of animal foods (Table 4.9). Resident species 

 tended to be more omnivorous, frequently with high 

 levels of algae and detritus in their guts. While their 

 diet was generally lower in quality than that of the 

 nonresidents, resident species increased the per- 

 centage of animals in their diet during spawning and 

 overall maintained much larger populations (Table 

 4.7). 



Other nondominant species found in the marshes 

 of Buzzards Bay include bay anchovy (Anchoa 

 mitchilli), sheepshead minnow. American eel 

 {Anguilla rostrata), striped mullet (Mugil 

 cephalus), northern pipefish (Syngnathusfuscus), 

 burterfish, black sea bass, cunner ( Taiitogolabrus 



