John R. Moring

An improved gastric lavage device for removing stomach contents from live fish

An improved gastric lavage apparatus was developed to remove stomach contents of live fish. A polypropylene pipette and polyethylene tubing were connected to a compression sprayer by quick-disconnect fittings. This enabled the operator to choose different sizes of pipettes depending on the size of the fish being sampled. Water was flushed into the stomach of the fish forcing the stomach contents out through the esophagus. Stomach contents were deposited in a measuring trough and collected on fine screening. The apparatus is inexpensive to construct and is effective in removing all of the stomach contents from fish, while causing no mortality. It is portable and contains no breakable parts, making it well suited for field work.

Differences in Mortality between Largemouth and Smallmouth Bass Caught in Tournaments

Abstract We monitored nine tournaments on three lakes in Maine between June and October 1989 to determine initial and delayed mortality rates of largemouth bass Micropterus salmoides and smallmouth bass M. dolomieu. Initial mortalities were defined as fishes that were dead at the weigh-in, whereas delayed mortalities were fishes that died during a 48-h holding period after the tournament. Total mortalities (initial and delayed) for both species ranged from 0 to 19.5%. Mortalities were lowest in tournaments that minimized both the number of steps and the time elapsed between the removal of a fish from a live well and the subsequent release of the fish into the lake, We estimated that 8.9% of smallmouth bass and 3.2% of largemouth bass died during tournaments; the probability of either species dying in a large tournament was significantly higher than in a small tournament.

Downstream migratory behavior of hatchery-reared, radio-tagged Atlantic salmon (Salmo salar) smolts in the Penobscot River, Maine, USA

Abstract Migratory patterns and timing of smolt movements of Atlantic salmon ( Salmo salar ) were assessed by placing radio tags on salmon in 1990 and 1991 and releasing fish at Howland, Maine, about 91 km upstream from the mouth of the Penobscot River. Fish movements were tracked by vehicles on streamside roads and by airplanes. Fish released in April moved quickly into the main channel of the river, although 47% of the signals ceased or became stationary within 10 km of the release site, owing to predation, battery failure, or cessation of migratory behavior. Only 3% of smolts were tracked over 40 km downstream. Of those fish actively migrating downstream, the passage rate averaged 3.7 km day −1 , ranging from 0.5 to 15.7 km day −1 .

Ecological Importance of Submerged Pulpwood Logs in a Maine Reservoir

Abstract Log drives in Maine from the 1830s to 1976 left an estimated 3.6–7.2 × 106 m3 of pulpwood logs submerged in the Kennebec River system, principally in Wyman Lake and Indian Pond. Because favorable economics have led to commercial log salvaging, we assessed the ecological value of submerged pulpwood logs in Wyman Lake. Three species of fishes, longnose suckers Catostomus catostomus, white suckers C. commersoni, and golden shiners Notemigonus crysoleucas, showed an attraction to submerged logs. Yellow perch Perca flavescens, the most numerous fish species collected, did not exhibit a clear association with submerged logs. Food habits of yellow perch shifted from a largely planktonic diet in areas lacking submerged logs to a diet dominated by benthic macroinvertebrates in areas containing logs. The amount of bark in the sediment was highest at the sites containing the most submerged logs, particularly in the former log holding area, but this had no clear effect on invertebrate biomass. Total biomass ...

The Creation of the First Public Salmon Hatchery in the United States

Abstract The first public salmon hatchery in the United States was constructed in 1871 at what was then known as Craigs Pond Brook, Maine. Funded by a consortium of northeastern states, the eggs and juveniles reared at the hatchery were intended to assist rehabilitation of depressed runs of wild Atlantic salmon (Salmo salar) in New England. By 1876, however, Atlantic salmon also were being distributed to at least 19 states and several countries, including such unlikely destinations as North Carolina, Texas, and Nebraska. Commercial weir operators on the Penobscot River sold live adult Atlantic salmon from their traps and these were transported in semi-submerged “salmon cars” to a holding pond at the hatchery. These cars were actually wooden boats with 100 holes drilled to provide circulation and oxygen. Charles Atkins, the first superintendent of the hatchery, developed several innovative culture techniques that are still in use today, such as his modification of the “Russian dry method” of spawning whic...

Experimental Culture of Young Rainbow Smelt Osmerus mordax

Abstract There is a large demand for rainbow smelt as a bait and food fish, and culture of the species has economic potential. In 1979, we began experiments to define optimum conditions for incubation of eggs and growth of larvae and juveniles. Hatching success was 40–80% in fresh and brackish water, but zero in full-strength seawater. The timing of hatching was determined for incubation temperatures of 6 to 20°C. Larvae fed most successfully in full-strength seawater on the cultured marine rotifer Brachionus plicatilis. Eyed eggs were also stocked in two ponds, one newly constructed and one with a well-established food base. Larval fish raised exclusively with natural foods (primarily cyclopoid copepods, chironomids, and Chaoborus sp.) reached 44 mm total length within 6 months in the newly constructed freshwater pond, and 83 mm in the established pond; rates of 0.22 and 0.41 mm/day, respectively. Rainbow smelt in the latter pond reached commercial baitfish size before the first winter of life. Fish in t...

Fish Discoveries by the Lewis and Clark and Red River Expeditions

Abstract The Lewis and Clark Expedition of 1804–1806 and the Red River Expedition of 1806 were two early explorations of the land acquired by the United States in the Louisiana Purchase in western North America. They were the first such western excursions to include natural history investigations as part of the trip objectives—a reflection of Thomas Jeffersons strong scientific curiosity. Whereas Lewis and Clark were briefly trained but conscientious amateurs, the Red River party included naturalist Peter Custis. Both expeditions discovered new species of fishes, which were later formally described by others, but the detailed descriptions of the Lewis and Clark Expedition are much more useful to modern ichthyologists than the simple, often erroneous, identifications of a trained naturalist of the day.

Marking Experiments with Atlantic Salmon in the United States in the 1870s and 1880s

Abstract Newly-examined records, long inaccessible, provide details on the first marking experiments with Atlantic salmon (Salmo salar) conducted in the United States. The studies were designed and conducted by Charles Atkins, superintendent of what is today known as Craig Brook National Fish Hatchery, Maine, in the 1870s and 1880s. These experiments provided evidence of the age of spawning adults and kelts, post-spawning movements and negative growth, and homing instincts—in some cases the first such evidence. These relatively primitive tagging techniques resulted in surprising numbers of recaptures in the lower Penobscot River, particularly in light of the limited recovery system.

Feeding of underyearling walleye surfperch,Hyperprosopon argenteum, in a Northern California Bay

A study of the feeding of underyearling walleye surfperch (Hyperprosopon argenteum) was based on fish collected in seven areas of Humboldt Bay, California, during September and October 1969. Crustaceans were found in all stomachs containing food, but the type of major food consumed varied with distance from the entrance channel. Amphipods were universally consumed, with cypris stages more important in areas with high tidal exchange, and terrestrial moth flies (Psychoda spp.) and harpacticoid copepods more important in backwater areas. Collections indicate daylight feeding and probably limited diurnal movements of underyearling walleye surfperch, a different pattern of feeding behavior than walleye surfperch of inshore waters of southern California.

Commercial Aquaculture of Fishes in Maine: Status and Future Prospects

Abstract The finfish aquaculture industry of Maine is in a relative state of infancy, with production primarily of rainbow trout (Salmo gairdneri) and brook trout (Salvelinus fontinalis). Coho salmon (Oncorhynchus kisutch) were reared in floating pens in the early 1970s, but operations ceased. Today, there is a pilot program in the ocean ranching of Pacific salmon, and interest in pen-rearing of Atlantic salmon (Salmo salar), pen-fattening of bluefin tuna (Thynnus thynnus), and culture of American eels (Anguilla rostrata), rainbow smelt, and flatfishes. To increase finfish production by the aquaculture industry in Maine, several economic, social, and legislative problems must be overcome. But the result could be a significant increase in the states economy, currently one of the poorest in the nation.