Biology: Recent submissions
Now showing items 101-120 of 228
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Effect of Coronary Ablation and Adrenergic-Stimulation on In-Vivo Cardiac-Performance in Trout (Oncorhynchus-Mykiss)
(1994-01)In fish, catecholamine-induced changes in cardiac performance in vivo are the result of complex interactions between the direct adrenergic effects on the heart and peripheral circulation and the reflex responses to increased ... -
Larval cardiorespiratory ontogeny and allometry in Xenopus laevis
(1995)Very little is known about the early development of cardiorespiratory regulatory mechanisms in newly hatched amphibian larvae. We tested whether early cardiovascular responses to hypoxia reflect local flow regulation in ... -
Effect of Boundary Layers on Cutaneous Gas Exchange
(1990)Boundary layers may offer significant resistance to cutaneous oxygen uptake by amphibians in water. This hypothesis was tested by measuring resistance to oxygen uptake as a function of water velocity in bullfrogs submerged ... -
Costs of locomotion and vertic dynamics of cephalopods and fish
(2000-12)The world's oceans are three-dimensional habitats that support high diversity and biomass. Because the densities of most of the constituents of life are greater than that of seawater, planktonic and pelagic organisms had ... -
Circulation time, blood reserves and extracellular space in a cephalopod
(1984)Octopus vulgaris Cuvier has a fully enclosed blood system that includes large blood sinuses behind the eyes and around the gut. It would be useful to know the mean circulation time, the minimal number of heartbeats needed ... -
The Forces Acting on Swimming Squid
(1988)1. Analysis of cine fils and intramantle pressure records for squid Loligo opalescens Berry swimming in a tunnel respirometer provided estimates of all the forces acting in the horizontal and vertical planes for swimming ... -
Food-Web Structure of Seagrass Communities across Different Spatial Scales and Human Impacts
(2011-07)Seagrass beds provide important habitat for a wide range of marine species but are threatened by multiple human impacts in coastal waters. Although seagrass communities have been well-studied in the field, a quantification ... -
Coastal food web structure, carbon storage, and nitrogen retention regulated by consumer pressure and nutrient loading
(2000-03)By factorial field experiments we analyzed the relative effects of increased nutrient (N+P) loading and natural grazing pressure on species composition, carbon storage, and nitrogen retention in the Baltic Sea littoral ... -
Effects of eutrophication, grazing, and algal blooms on rocky shores
(2006-01)Eutrophication can profoundly change rocky shore communities. These changes often cause the replacement of perennial, canopy-forming algae such as Fucus spp. with annual, bloom-forming algae such as Enteromorpha spp. ... -
The Biodiversity of the Mediterranean Sea: Estimates, Patterns, and Threats
(2010-08)The Mediterranean Sea is a marine biodiversity hot spot. Here we combined an extensive literature analysis with expert opinions to update publicly available estimates of major taxa in this marine ecosystem and to revise ... -
Overestimating Fish Counts by Non-Instantaneous Visual Censuses: Consequences for Population and Community Descriptions
(2010-07)Background: Increasingly, underwater visual censuses (UVC) are used to assess fish populations. Several studies have demonstrated the effectiveness of protected areas for increasing fish abundance or provided insight into ... -
Regional-scale effects of eutrophication on ecosystem structure and services of seagrass beds
(2012-09)Using large-scale field surveys across 12 estuaries in two provinces in Atlantic Canada, we analyzed changes in phytoplankton and benthic macroalgal communities as well as the canopy structure of eelgrass beds and quantified ... -
Assessing the Value of Recreational Divers for Censusing Elasmobranchs
(2011-10)Background: Around the world, researchers are using the observations and experiences of citizens to describe patterns in animal populations. This data is often collected via ongoing sampling or by synthesizing past ... -
Large-Scale Absence of Sharks on Reefs in the Greater-Caribbean: A Footprint of Human Pressures
(2010-08)Background: In recent decades, large pelagic and coastal shark populations have declined dramatically with increased fishing; however, the status of sharks in other systems such as coral reefs remains largely unassessed ... -
Strong bottom-up and top-down control of early life stages of macroalgae
(2001-06)In contrast to most pelagic primary producers, benthic macrophytes pass through morphologically distinct life stages, which can be subject to different ecological controls. Using factorial field experiments, we investigated ... -
Rapid Global Expansion of Invertebrate Fisheries: Trends, Drivers, and Ecosystem Effects
(2011-03)Background: Worldwide, finfish fisheries are receiving increasing assessment and regulation, slowly leading to more sustainable exploitation and rebuilding. In their wake, invertebrate fisheries are rapidly expanding with ... -
Complex interactions of climatic and ecological controls on macroalgal recruitment.
(2002-11)Little is known about the cumulative effects of multiple (>2) environmental controls on species performance and interactions in aquatic ecosystems. We asked how changes in climatic (temperature, ultraviolet radiation) and ... -
Two centuries of multiple human impacts and successive changes in a North Atlantic food web
(2004-10)European colonization of North America, severely altered terrestrial and aquatic ecosystems alike. Here, we integrate archaeological, historical, and recent data to derive the ecological history of the Quoddy Region, Bay ... -
Long-term change in a meso-predator community in response to prolonged and heterogeneous human impact
(2013-01)Sharks and rays' abundance can decline considerably with fishing. Community changes, however, are more complex because of species interactions, and variable vulnerability and exposure to fishing. We evaluated long-term ... -
Spatiotemporal Patterns in Nest Box Occupancy by Tree Swallows Across North America
(2012-06)Data from the North American Breeding Bird Survey (BBS) suggest that populations of aerial insectivorous birds are declining, particularly in northeastern regions of the continent, and particularly since the mid-1980s. ...
