Fish are amazing and interesting organisms in our Chesapeake Bay (CB). The CB is the largest of the 850 estuaries around the US (Murdy, 1997). Over 20 major tributaries contribute to the water levels in the CB and over 295 different fish species exist throughout the CB. Of those
295 fish species, 32 species exist in the CB year-round. Diversity of fish species occurs in the
Upper, Middle, and Lower CB areas. The differences in fish species vary in the food webs and food chains that exist in the ecosystems of the CB watershed.
The following 32 fish species are labeled “year-round residents of the CB”. These fish are seen all year in our CB: bay anchovy, striped bass, feather blenny, striped blenny, white catfish, smallmouth flounder, green goby, naked goby, seaboard goby, hogchoker, banded killifish, marsh killifish, rainwater killifish, spotfin killifish, striped killifish, sheepshead minnow, mummichog, silver perch, white perch, yellow perch, dusky pipefish, northern pipefish, lined seahorse, Atlantic silverside, inland silversides, rough silverside, skilletfish, northern stargazer, fourspine stickleback, oyster toadfish, blackcheek tonguefish, and windowpane. These fish are all important survivors in the CB.
Fish survive for many reasons. One major reason why one fish will survive over another fish is due to their food consumption. Fish benefit and function from the energy provided by numerous food sources. The CB is an estuarine nursery area with shallow habitats including sea grass beds and marsh creeks. Fish find the CB as a flourishing feeding area where ocean spawning fish eat and freshwater fish devour their meals. The brackish water of the CB brings larval crabs and juvenile from the high salinity ocean to feast here. The variety of food sources for fish species is plentiful in the CB.
Diverse fish species live and thrive in the CB. The CB has anadromous fish that live in the salty ocean and migrate to the freshwater of the CB to spawn. These fish can tolerate saltier environments for daily survival but prefer the CB’s freshwater- brackish water for spawning.
River herring, alewife, striped bass are examples of anadromous fish. Semianadromous fish include the white perch and black drum. Catadromous fish live in lower salinities (freshwater) and spawn in salt environments (ocean). The only true catadromous CB fish is the American Eel.
This organism swims from freshwater areas of the Upper Bay to the farthest Lower Bay to spawn.
Natural recruitment (reproducing of young) & swimming patterns of fish varies throughout the
CB. In fish, recruitment & feeding promotes growth for a multitude of species.
The CB offers numerous environments for fish survival. Fish swim in diverse aquatic environments. The fish are located in marshes, aquatic grass beds, flooded flatlands, hardbottom reef areas, deep, open water places, and freshwater tributaries. The diversity of salinity in the CB may assist in fish survival. The varying of water depth is a positive factor for fish existence. The CB can reach depths of 174 ft., but only 10% of the CB is 60 ft deep and 50% is less than 20 ft. deep. This shallow CB environment allows for fish survival.
As temperatures and salinities change throughout the seasons, the movement of fish species through the CB alters. Toward the beginning of autumn, menhaden and other marine species move out of the Lower CB and down the coast. Menhaden migration causes larger fish to mobile themselves south. Menhaden predators include bluefish, weakfish, and sandbar sharks.
Then, the food chain continues! Sand tigers, dusky, hammerhead sharks, and others will consume the smaller species in the food chain. The migratory pattern of larger fish is to find saltier and more distant environments where food exists. Research shows that smaller fish travel smaller distances and larger fish migrate farther locations from our CB. Fish survival depends on the

location and capture of food sources. Environmental changes impact the food chain and the types fish species that live in the CB.
Fish move in and out of the CB for numerous reasons. Colder temperatures and spawning behaviors allow several fish to be residents of the CB. Atlantic Croaker is one of the last to spawn & migrate around the CB. Often the young Atlantic croaker is too small to swim great distances and it stays in smaller tributaries to survive the winter weather. Striped bass and white perch are year-round residents in the CB. Winter flounder is often found in the Upper CB.
Summer flounder, striped bass, bluefish, weakfish, and Atlantic menhaden are just examples of fish that migrate south for the winter. My migrating south to other areas of the United States, more people benefit from all these fish. The fisherman in Massachusetts and North Carolina collect fish that exist in the CB. The Summer flounder are seen back in the CB by May. Many marine fish use the CB as a nursery specifically in the coastal zone.
Fish survival is altered by many environmental situations. Eutrophication is the gradual changing of a body of water. Eutrophication is the accumulation of nutrients in an area and the effects on the living organisms. The concerns in the CB are excess nutrients of phosphorus, nitrogen, and other organic material. The build up of material on the bottom of the CB and greater phytoplankton production cause concerns to the fish populations. The increased nutrients cause less sunlight to penetrate to the bottom and aquatic plants die. The fish that survive in the camouflaged of these environments perish due to eutrophication. Fish will undergo stress when their natural environment changes.
Pollution and over fishing are other causes of fish decline. Fish populations change naturally overtime and differ each year. But, pollution will seriously change the survival of fish species in an area. Citizens of the CB watershed need to make more environmentally- sound choices. Over fishing can collapse fish populations. If the fishermen deplete the population, then everyone is affected by this fish decline. The food chains and food webs of numerous CB fish are altered. Fish survival depends on many factors and environmental improvements.