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Distribution and Abundance of Fishes Associated with Submersed Aquatic Plants in the Potomac River
Author(s) -
Killgore K. Jack,
Morgan Raymond P.,
Rybicki Nancy B.
Publication year - 1989
Publication title -
north american journal of fisheries management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.587
H-Index - 72
eISSN - 1548-8675
pISSN - 0275-5947
DOI - 10.1577/1548-8675(1989)009<0101:daaofa>2.3.co;2
Subject(s) - biology , perch , alosa , fishery , aquatic plant , lepomis , myriophyllum , bay , micropterus , bass (fish) , macrophyte , ecology , fish migration , fish <actinopterygii> , geography , archaeology
The distribution and abundance of fishes in submersed aquatic plants of three relative densities (no plants, intermediate plant density, high plant density) were estimated in the tidal Potomac River near Alexandria, Virginia. Fish were sampled with a boat‐mounted electroshocker at night in May (when plants were emerging), August (peak plant densities), and November (plant senescence) of 1986. Mean densities of all plants ranged from 9 to 33 g/m 2 (dry‐weight basis) in May, and 400 to greater than 1,000 g/m 2 in August and November. Hydrilla verticillata was usually the dominant aquatic plant. In May, overall mean fish abundance was highest in areas of high plant density (36 fish/5 min shocking), whereas in August and November fish abundance was highest in areas of intermediate plant densities (100 and 62 fish/5 min electroshocking, respectively). Areas without plants contained a relatively high number of filter‐feeding fishes, including Atlantic menhaden Brevoortia tyrannus and blueback herring Alosa aestivalis . The fish assemblage in the vegetated sites comprised mainly brown bullhead Ictalurus nebulosus , banded killifish Fundulus diaphanus , pumpkinseed Lepomis gibbosus , largemouth bass Micropterus salmoides , and yellow perch Perca flavescens . The bay anchovy Anchoa mitchilli , white perch Morone americana , and inland silverside Menidia beryllina were distributed throughout all three sites during the study. Fish also were sampled with pop nets in aquatic plants and with seines between shore and the plant beds. More than five times more fish (9.8/m 2 ) were collected with pop nets in areas with intermediate plant density, where there were several codominant plant species, than in areas with dense hydrilla (1.8 fish/m 2 ). Shore‐zone fish densities estimated with seine hauls were higher in areas adjacent to dense hydrilla beds (9 fish/m 2 ) than in areas with no plants (1.5/m 2 ) or near intermediate plant densities (3.3/m 2 ), but the number of fish species was lowest near hydrilla.