Microplastic (MP) pollution is a major environmental concern for mountain ecosystem and high-mountain lakes in particular, which are recognized indicators of global change. In this study, the presence MPs was assessed abiotic (water sediment) biotic (zooplankton, tadpoles, fish) compartments two (Upper Lake Balma Lower Balma) Cottian Alps (northwest Italy). No were found water zooplankton sampl...

Levels of chlorinated organic contaminants in predator fish have been monitored annually in each of the Great Lakes since the 1970s. This article updates earlier reports with data from 1991 to 1998 for lake trout (Salvelinus namaycush) and (Lake Erie only) walleye (Sander vitreus) to provide a record that now extends nearly 30 years. Whole fish were analyzed for a number of industrial contamina...

BACKGROUND Salmonids are native from the North Hemisphere but have been introduced for aquaculture and sport fishing in the South Hemisphere and inhabit most rivers and lakes in temperate and cold regions worldwide. Five species are included in the Global Invasive Species Database: rainbow trout Oncorhynchus mykiss, Atlantic salmon Salmo salar, brown trout Salmo trutta, brook trout Salvelinus f...

—Retention and readability of small (2.5 3 1.0 3 0.1-mm) and large (3.0 3 1.5 3 0.1mm) visible implant (VI) tags were compared among different size-classes (211–470 mm total length, TL) of hatchery brook trout Salvelinus fontinalis. Among smaller size-groups (,400 mm TL), retention of large tags (63–86%) 100 d after tagging was less than retention of small tags (89–97%). Overall retention of la...

Brook trout (Sahelinus fontinalis Mitchill) with a chronically implanted dorsal aortic cannula were exposed to acidic environments. During exposure, trout developed severe metabolic acidosis as shown by decreases in standard plasma bicarbonate levels as well as negative base excess values. Reduced oxygen consumption seen in acidotic trout resulted from decreased gill oxygen transfer and reduced...

Conventional surplus production models indicate that destruction of fish populations by overfishing is difficult, if not impossible, but catastrophic declines in abundance of exploited populations are common. Surplus production models also do not predict large continuing fluctuations in yield, but large fluctuations in yield are common. Conventional surplus production models assume that fisheri...

Thiamine (vitamin B1) deficiency is a global concern affecting wildlife, livestock, and humans. In Great Lakes salmonines, thiamine deficiency causes embryo mortality and is an impediment to restoration of native lake trout (Salvelinus namaycush) stocks. Thiamine deficiency in fish may result from a diet of prey with high levels of thiaminase I. The discoveries that the bacterial species Paenib...

Recent studies indicate that co-planar 3,3',4,4',5-pentachlorobiphenyl (PCB) congeners or their metabolites may disrupt thyroid function in fishes. Although co-planar PCB have been detected at microgram per kilogram levels in fish from contaminated areas, few studies have examined mechanisms whereby, co-planar PCBs may alter thyroid function in fish. We treated immature lake trout by intraperit...