» Fishes

Seafood Safety: Background and Issues

Although seafood consumption can contribute to a healthy diet, some fish and shellfish can cause foodborne illnesses or contain environmental contaminants. This report discusses whether current food safety programs are sufficiently protecting consumers, and if not, what changes should be considered. Read More

Hepatotoxicity of Mercury to Fish

Tissue samples from spotted gar (Lepisosteus oculatus) and largemouth bass (Micropterus salmoides) were collected from Caddo Lake. Gar and bass livers were subjected to histological investigation and color analysis. Liver color (as abs at 400 nm) was significantly correlated with total mercury in the liver (r2 = 0.57, p = 0.02) and muscle (r2 = 0.58, p = 0.01) of gar. Evidence of liver damage as lipofuscin and discoloration was found in both species but only correlated with liver mercury concentration in spotted gar. Inorganic mercury was the predominant form in gar livers. In order to determine the role of mercury speciation in fish liver damage, a laboratory feeding study was employed. Zebrafish (Danio rerio) were fed either a control (0.12 ± 0.002 µg Hg.g-1 dry wt), inorganic mercury (5.03 ± 0.309 µg Hg.g-1 dry wt), or methylmercury (4.11 ± 0.146 µg Hg.g-1 dry wt) diet. After 78 days of feeding, total mercury was highest in the carcass of zebrafish fed methylmercury (12.49 ± 0.369 µg Hg.g-1 dry wt), intermediate in those fed inorganic mercury (1.09 ± 0.117 µg Hg.g-1 dry wt), and lowest in fish fed the control diet (0.48 ± 0.038 µg Hg.g-1 dry wt). Total mercury was highest in the viscera of methylmercury fed zebrafish (11.6 ± 1.86 µg Hg.g-1 dry wt), intermediate in those fed inorganic diets (4.3 ± 1.08 µg Hg.g-1 dry wt), and lowest in the control fish (below limit of detection). Total mercury was negatively associated with fish length and weight in methylmercury fed fish. Condition factor was not associated with total mercury and might not be the best measure of fitness for these fish. No liver pathologies were observed in zebrafish from any treatment. Read More

Online Training in Watershed Management

This Web site offers a variety of self-paced training modules that represent a basic and broad introduction to the watershed management field. Read More

Evaluation of a Common Carp (Cyprinus carpio L.) Exclusion and Trapping Device for Use in Aquatic Plant Founder Colony Establishment

The focus of this study was to design and evaluate a trapping system that would reduce populations of common carp within water bodies in conjunction with establishment of native aquatic macrophytes founder colonies. A pond study and field study were conducted. A pond study was performed at the Lewisville Aquatic Ecosystem Research Facility, located in Lewisville, Texas, followed by a field study within a constructed wetland located in southern Dallas, Texas. For the pond study, twelve funnel traps were constructed (four reps of each type: control, dual-walled and ring cage). Two anti-escape devices were tested with funnels including steel fingers and hinged flaps. Ring cage and dual-walled treatments were planted using native pondweeds, while controls were left unplanted (additional bait and a drift fence scenarios were also tested). Common carp were introduced into the study pond. Chi-square statistical analyses were utilized and showed ring cage treatments using fingers as well as the use of a drift fence to be most effective. Following completion of the pond study, the two most effective treatments (controls and ring cages) were tested within the Dallas, Texas wetland; no carp were caught during the field test. Read More

From the Edge: Science to Support Restoration of Pacific Salmon

Library Holdings. According the preface, this report represents the scientific understanding of salmon and salmon declines in the year 2000. The report provides an overview of salmon population trends, and ways to aid in and measure recovery. Read More

Marine Ecosystems and Global Change

The ocean is a vital component of the metabolism of the Earth and plays a key role in global change. In fact, the oceans cover so much of the Earth’s surface that our planet has been described as the Water Planet, and it could be argued that its most extensive ecosystems are marine. Marine ecosystems are inextricably involved in the physical, chemical, biological and societal processes of global change. It is impossible to describe and understand the Earth system without understanding the ocean, the special characteristics of the environment that it provides for life, the changes that it is undergoing and the manner in which these changes interact with the total Earth System. Understanding the functioning of marine ecosystems and how they respond to global change is also essential in order to effectively manage global marine living resources, such as fisheries. The GLOBEC project is an international response to the need to understand how global change will affect the abundance, diversity and productivity of marine populations, from zooplankton to fish, that comprise a major component of oceanic ecosystems. GLOBEC’s goal is to advance our understanding of the structure and functioning of such ecosystems, their major subsystems, and responses to physical forcing so that a capability can be developed to forecast the response of marine ecosystems to global change. This volume in the IGBP Science Series, “Marine Ecosystems and Global Change”, gives topical examples of the scientifi c problems that GLOBEC is tackling, the innovative approaches adopted, and some selected scientific achievements. It has been written at a time when GLOBEC is in the mid-phase of its implementation. The ultimate achievements of GLOBEC research will be presented in a final synthesis at the end of the project. Read More

Healthy Animals Newsletter

Healthy Animals is an online compilation of animal health-related research news put out each quarter by the Information Staff of the Agricultural Research Service. ARS is the chief scientific agency of the U.S. Department of Agriculture. Each issue profiles one aspect of ARS research. Links take readers to detailed stories on new findings important to the health of livestock, poultry and fish. And a list of all ARS research laboratories that work to improve animal health is just a click away. Read More

Smithsonian Ichthyology

Ichthyology is the study of fishes. Research by staff and associates in the Division covers a broad spectrum of the great diversity of fishes, generally relying on the vast resources of the national fish collection. The fish collection, at the National Museum of Natural History, is the largest in the world, with approximately 540,000 lots (a lot consists of all specimens of a species collected at the same time and place) and about 4 million specimens. Read More

Aquaculture

Aquaculture, often referred to as fish farming, is the art, science and business of cultivating aquatic animals (including finfish, molluscs, crustaceans) and plants in fresh or marine waters. Read More

Imperiled Freshwater Organisms of North America

This website provides access to maps and lists of imperiled freshwater organisms of North America as determined by the American Fisheries Society (AFS) Endangered Species Committee (ESC). At this website, one can view lists of animals by freshwater ecoregion, by state or province boundary, and plot distributions of these same creatures by ecoregions or political boundaries. Read More

Mission

EERL's mission is to be the best possible online collection of environmental and energy sustainability resources for community college educators and for their students. The resources are also available for practitioners and the public.

EERL & ATEEC

EERL is a product of a community college-based National Science Foundation Center, the Advanced Technology Environmental and Energy Center (ATEEC), and its partners.

Contact ATEEC 563.441.4087 or by email ateec@eicc.edu