Why is there so much life in the 
Barnegat Bay?
Answer: Detritus !!!

The Amazing Detrital Food Chain
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So just what is DETRITUS?

Tons and Tons of Food
Though made up of anything that has died and deteriorated on the marsh, and bayshore,  90% is said to be made up of plant matter, 
and most of this is comprised of  Marsh Grasses

Most important of these Grasses are from the genus Spartina: 

 Cord Grass and Salt Hay   

Cordgrass (Spartina alterniflora) 

1.The only vascular plant found in the              lower areas of tidal influence, where it          survives 2 flood tides a day.

2.Grows to more than 5 ft., and survives          flooding by trapping oxygen in chambers    in its roots.

Salt Marsh Grasshopper Adult 
(Orchelimum fidicinium) 
Salt Hay (Spartina patens)

1. Found only on the high marsh where it        survives 2 high tides a month on the new      and full moon. 

2. Can be distinguished by its shadowed        "cow lick" appearance, as in the photo           above.

Salt Marsh Grasshopper Juv.
(Orchelimum fidicinium) 
In other ecosystems the primary consumers would be herbivores (vegetarians), like deer, rabbits, and insects.   But In an intertidal environment  with low insect diversity, the only serious vegetarian is the "Salt Marsh Grasshopper" which is said to utilize less than 10%  of  primary producers (Spartina Grasses).   The rest of these "Bay Side Wheat Fields"  will create a  detrital food chain  of  organisms so numerous in their populations  that there's no other ecosystem that can compete with it.
Though only part of the process of decomposing, it will eventualy break down to particulate matter, and nutrients that will be carried by the tides, and marsh based animals that feed on it.  With the exception of the end of the season when all but the roots and rhizomes will enter the process, the individual blades that break off are rapidly replaced.  If you could see all the Spartina production throughout the season, it might be as much as 10 times what you can see at one time, creating a constant flow of food into Barnegat Bay Estuary


Just a few of the primary consumers called  Detrivores that thrive on Detritus , and they in turn will be consumed by predators, like secondary, and tertiary consumers.

a.  Coffee bean snails ( Melampus bidentatus ) feed on it as the tides leave "wrack lines" on the  grass.

b.  Shore Shrimp (Palaemonetes vulgaris )feed on it as it drifts with the tides.

c. Marsh Fiddlers (Uca pugnax) scoop it up off the marsh floor.

d.  Ribbed Muscles (Modiolus demissus) filter it as it flows along the banks of tidal creeks.

e.  Baltic Isopods (Idotea baltica) one of many small crustaceans that feed on it as it settles on the shallow benthic shore  line.
A Simple Detrital Food Chain Example

1.  The Cordgrass thrives off the energy from the sun.
2.  The grass is decomposed into Detritus by fungi and bacteria
3.  The Detritus feeds the Fiddler Crabs as they scoop it up off the marsh floor          where they live by the thousands.
4.  The heron eats the crabs, and shares it with  its young.

But these chains are not always this direct, and simple

Primary Producers 
Primary Consumers

Not only does this Harvest supply particulate matter for the immense populations of Detrivores, but it's said to kick start the Plankton Food Chain with the Tons of Nitrogen left by the fungal and bacterial microbes that break it down.
Primary Consumers 
Secondary Consumers

Secondary Consumers
Tertiary Consumers
 Though every living animal in this picture, and more, will eventually become food for something else, none would exist in either form, or the massive populations found in the environs of the Barnegat Bay Estuary were it not for: 

"Our Amazing Detrital Food Chain".

Have a special interest in the detrital food chain let me know.   Questions, Comments?  I'de love to hear them, or answer them.  This page is fundamental to this entire site, and therefore key to my interests.  Use my GUEST BOOK to send me your messages. 

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