people and large animals to obtain the 

 blood meal they need to mature their eggs. 



The 



marsh 



mosquito, 



Aedes 



sol 1 icitans , lays its eggs on wet mud in 

 the higher marsh rather than in the low 

 marsh. The eggs develop to the hatching 

 point, then wait until they are flooded by 

 an extra high tide or heavy rain before 

 hatching. In warm weather they can become 

 adults in about one week, emerging from 

 the pools in hordes. Were the eggs laid 

 in the low marsh, the eggs (or larvae) 

 would be rapidly eaten by the predators 

 that come in on the high tide. Even 

 though the low marsh is not involved in 

 mosquito reproduction, it has been heavily 

 ditched for "mosquito control." The marsh 

 often suffers heavily from damage during 

 ditching and from careless disposal of the 

 spoils from the ditches. The effects on 

 the mosquitoes are minimal. 



Insects are preadapted to survival in 

 the marsh. Their impermeable exoskeleton 

 evolved to prevent drying on land, and 

 also prevents water loss to seawater or 

 entry of salts into the body. Their 

 excretion of waste nitrogen as 

 water-saving uric acid reduces their need 

 for water, so many can survive on plant 

 juices or the body fluids of prey. Some 

 avoid submersion by walking up the grass 

 or flying at high tide, but others can sit 

 it out and survive underwater. 



Predators on insects include some 

 parasitic wasps and, more important, a 

 variety of spiders from web spinners to 

 wolf and jumping spiders. In some of the 

 experiments at Great Sippewissett Salt 

 Marsh, the plant hoppers did not increase 

 proportionately to other herbivores 

 because of intense spider predation. 

 Apparently, most of the predation was by 

 the tiny, web- spinning Grammonota inornata 

 and Dictyna roscida , neither of which is 

 more than 2 mm in length (Vince 1979). 

 The former species, which is the most 

 abundant spider in Massachusetts marshes, 

 builds a sheet web close to the ground as 

 a very effective means of trapping plant 

 hoppers. 



The larger insect herbivores (such as 

 plant bugs) in New England salt marshes 

 are eaten mainly by the large wolf spider, 

 Pardosa distincta . Pardosa actively hunt 



prey both visually and tactilely instead 

 of building a web. Pardosa prey upon 

 marsh amphipods about their own size, 

 which they flip over and bite on their 

 less-protected underside. 



Another spider, Clubiona maritima , 

 also hunts, but moves much more slowly and 

 detects its prey by touch. Though spiders 

 sometimes climb Spartina as the tide 

 rises, they can survive underwater. Their 

 greatest need at high tide is a refuge 

 from predators. 



4.1.2. Reptiles 



Reptiles, such as sea turtles and 

 marine crocodiles, can be fully adapted to 

 seawater. Although the author has seen 

 alligators, rattlesnakes, and water snakes 

 in salt marshes of the southeastern U.S., 

 the only reptile seen in any great numbers 

 in New England salt marshes is the 

 diamond-backed terrapin ( Malaclemys 

 terrapin ). The terrapin, common in 

 unpolluted waters all along the Atlantic 

 coast south of Cape Cod, is not a "sea 

 turtle" but is more closely related to the 

 terrestrial box turtles. It feeds on a 

 variety of small animals including fish, 

 mollusks, and crustaceans abundant in the 

 marsh creeks. The terrapin does not live 

 on the low marsh but feeds there during 

 low tide. Terrapins used to be much more 

 abundant than at present, but their 

 population was reduced by coastal 

 development and by hunting during the 

 height of their popularity as a food item. 



4.1.3. Birds and Mammals 



One of the most widely recognized 

 values of salt marshes is their support of 

 both migrant and resident bird 

 populations. Very few bird species 

 actually nest in regularly flooded 

 marshes. Those that do include clapper 

 rails ( Ral lus longirostris ) (Figure 10), 

 willets ( Catoptrophorus semipalmatus ) , 

 long-billed marsh wrens " ( Cistothorus 

 palustris ) , boat-tailed grackles 

 ( Ouiscal us major ) , red-winged blackbirds 

 ( Agelaius phoeniceus ) , and sharptailed and 

 seaside sparrows ( Ammospiza caudacuta and 

 A. maritima ). 



The number of species that nest in 

 drier areas but feed on the low marsh or 



18 



