Species Composition and Food Habits of Dominant Fish Predators in Salt Marshes of an Urbanized Estuary, the Hackensack Meadowlands, New Jersey
by Melissa J. Neuman¹, Guillermo Ruess², and Kenneth W. Able²
¹National Oceanic and Atmospheric Administration, National Marine Fisheries Service, 501 W. Ocean Blvd., Suite 4200, Long Beach, CA 90802-4213
²Marine Field Station, Institute of Marine and Coastal Sciences, Rutgers University, c/o 132 Great Bay Blvd., Tuckerton, NJ 08087-2004
The Hackensack Meadowlands, in heavily urbanized northern New Jersey, have undergone many types of human alteration within the past three centuries. In the last five years, attempts have been made to restore portions of the estuary to a salt marsh. To examine how fish fauna have responded to these efforts, we compared spatial and temporal patterns in the distribution and food habits of the dominant fishes collected in 457 gill-net samples during May to November 2001 from two tidal-marsh creeks in the Meadowlands. One of the creeks, Mill Creek, which has undergone two phases of mitigation since 1987, is dominated by both common reed (Phragmites australis) and salt-marsh cordgrass (Spartina alterniflora). The other, Doctor Creek, a man-made creek created in 1999–2000, is dominated solely by salt-marsh cordgrass. Water quality of the two creeks is similar in temperature but differs in salinity and dissolved oxygen: Mill Creek's salinity is 1.5 to 2 parts per thousand higher than that of Doctor Creek; it also has more frequent hypoxic conditions than Doctor Creek. We collected a total of 509 fishes representing ten species, and the dominant species (> 1% of the catch) were Morone americana (white perch, 46%); Pomatomus saltatrix (bluefish, 22%); Alosa pseudoharengus (alewife, 20%); Morone saxatilis (striped bass, 7%); and Brevoortia tyrannus (Atlantic menhaden, 3%). Overall fish species diversity and abundance were higher at Mill Creek than at Doctor Creek. The dominant piscivores (white perch, bluefish, striped bass) were found at almost all collection sites within each creek. The stomachs of most of these fish were 20% to 40% full, indicating that many of the fish collected had fed recently. Diet composition in both creeks was similar with respect to the consumption of fish; however, crustaceans made up a significant portion of the diet in Mill Creek fish, whereas detritus and microbenthos composed a large proportion of the diet of fish collected in Doctor Creek. Though both sites occur in a highly urbanized area, each appears to be providing fish habitat and food for typical marsh creek predators.
Key words: distribution and abundance; fish predators; food habits; Hackensack Meadowlands; Morone americana; Morone saxatilis; New York metropolitan area, Pomatomus saltatrix; salt-marsh creeks; urban estuary