Throughout the western United States, the invasive annual grass, medusahead (Taeniatherum caput-medusae L. Nevski), is rapidly invading grasslands once dominated by native perennial grasses, such as bluebunch wheatgrass (Pseudoroegneria spicata (Pursh) A). It is also invading grasslands dominated by less undesirable invasive annual grasses, especially cheatgrass (Bromus tectorum L.). Understanding...
We examined the diets and weight-length relationships of juvenile bluefish Pomatomus saltatrix from Sandy Hook Bay, New Jersey, during 1981, 1983, and 1984. Diets consisted of a variety of polychaete, crustacean, and fish prey. Opossum shrimp Neomysis americana. sand shrimp Crangon septemspinosa, grass shrimp Palaemonetes vulgar is, bay anchovy Anchoa...
Juvenile red hake Urophycis chuss were collected while they were inhabiting sea scallops Placopecten magellanicus , and the effects of appetite and food availability on prey consumption and growth were examined under laboratory conditions. Fish took increasing amounts of live amphipods Gammarus annulatus with increasing periods of food deprivation up...
The diel feeding periodicity of juvenile Chinook salmon Oncorhynchus tshawytscha was determined from stomachs collected in coastal waters off Oregon in 2000 and 2003. Juvenile Chinook salmon exhibited a diurnal feeding pattern with morning and evening feeding periods. There were differences in the duration and magnitude of the dawn and...
Off-highway vehicle (OHV) recreation impacts species and ecosystems around the world, and is particularly prevalent in the United States. Our study examines the impact of OHVs on one of several species restricted within the United States to the Algodones Dunes, California. This dune system attracts many OHV enthusiasts annually, and...
A recent trend of enhancing freshwater emergent wetlands for waterfowl and other wildlife has raised concern about the effects of such measures on juvenile salmonids. We undertook this study to quantify the degree and extent of juvenile Pacific salmon Oncorhynchus spp. utilization of enhanced and unenhanced emergent wetlands within the...
Larval and age-0 sablefish Anoplopoma fimbria reside in neustonic waters of the North Pacific during spring and summer. We estimated the potential impacts of elevated surface temperatures on ecological processes of growth, conversion efficiency, and behavior in early juvenile sablefish. Growth experiments tested a wide range of temperatures from 6...
The effects of reduced food availability on the behavior of juvenile walleye pollock Theragra chalcogramma were examined in laboratory experiments designed to test for potential energy-conserving responses. Groups of juvenile fish were held on 1 of 6 ration treatments ranging from ad libitum to near starvation, and then vertical distribution...
Behavioral responses of juvenile bluefish P. saltatrix L. exposed to cold water in a vertical thermal gradient were measured under controlled laboratory conditions. The temperature regime was similar to conditions that these fish encounter in their inshore and estuarine habitats along the Middle Atlantic coast. Measures included activity, schooling, position...
Pan et al. claim that our results actually support a strong linear positive relationship between productivity and richness, whereas Fridley et al. contend that the data support a strong humped relationship. These responses illustrate how preoccupation with bivariate patterns distracts from a deeper understanding of the multivariate mechanisms that control...