Aquaculture and Fisheries Commons^™

Fisheries Research Contract Report No. 10 - Mother-Of-Pearl Shell (Pinctada Maxima): Stock Evaluation For Management And Future Harvesting In Western Australia, Anthony M. Hart, Kim J. Friedman

Fisheries Research Contract Reports

The West Australian Pearling industry is one of Australia's most valuable aquaculture industries, currently generating around $120 - $160 million annually. The majority of pearl shell used to culture pearls come from the pearling beds in the inshore waters near Broome. The fishery for pearl oysters preferentially targets smaller (120mm - 165mm DVM) shell (hereafter defined as 'culture' shell), that are more suitable for culturing of pearls, leaving larger MOP oysters (175mm+) on the pearling grounds. These larger pearl oysters, the majority of which are female (protandric hermaphrodites), form a major component of the broodstock for the

fishery. Although MOP …

Fisheries Research Contract Report No. 3 - Early Life History Of Abalone (Haliotis Rubra, H. Laevigata): Settlement, Survival And Early Growth. Final Report For Frdc Project 1998/306, Dr Sabine Daume

Fisheries Research Contract Reports

Australian abalone fisheries produce a high value, export-orientated products that provided 60% of the world supply in 1994 (Fleming, 2000). With wild abalone fisheries declining in countries worldwide, the interest in aquaculture products has increased substantially. The world production of abalone from aquaculture in 1999 was approximately 7,775 tonnes with only 89 tonnes (ca. 1%) being produced in Australia (Fleming, 2000). Abalone farming is expected to develop into a major industry and is a significant investment opportunity (McNamara, Victorian Aquaculture Strategy, May 1997). Future production from the numerous farms and sites either established, under construction or approved in Australia, could …

Adding Nutrients To Enhance The Growth Of Endangered Sockeye Salmon: Trophic Transfer In An Oligotrophic Lake, Phaedra E. Budy, Chris Luecke, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

Snake River sockeye salmon Oncorhynchus nerka, listed under U.S. law as endangered in 1991 in response to a decline in anadromous adult numbers, spend their first 1–2 years in Redfish Lake, Idaho, before migrating to the sea. To determine how nutrient enhancement might influence phytoplankton, zooplankton, and fish production, we performed fertilization experiments in large enclosures in this oligotrophic lake using juvenile kokanee (lacustrine O. nerka) as analogues for endangered sockeye salmon. Fertilization of the metalimnion substantially increased chlorophyll a (150%), phytoplankton biovolume (75%), primary productivity (250%), and zooplankton biomass (200%), and moderately increased fish growth (12%) over our control …

Growth And Survival Of Colorado Squawfish In The Upper Colorado River, D. B. Osmundson, Ronald J. Ryel, T. E. Mourning

Wildland Resources Faculty Publications

Growth and adult survival rates were estimated for the endangered Colorado squawfish Ptychocheilus lucius inhabiting the upper Colorado River by using data from fish captured during 1990–1995. Mean annual growth rates of fish aged 3–6 years ranged from 32.2 (age 6) to 82.0 (age 3) mm/year. Growth rates for older fish were highest for fish 400–449 mm total length, TL, (42.7 mm/year) and declined to 19.8 mm/year for fish 500–549 mm TL. Fish 550 mm and longer grew an average 9.5 mm/year. Survival rates for fish 550 mm and longer were estimated by comparing measured size distributions with simulated stable …

Simulated Growth And Production Of Endangered Snake River Sockeye Salmon: Assessing Management Strategies For The Nursery Lakes, Chris Luecke, Wayne A. Wurtsbaugh, Phaedra E. Budy, H. P. Gross

Watershed Sciences Faculty Publications

We examined the potential of employing a series of lake management strategies to enhance production of endangered Snake River sockeye salmon (Oncorhynchus nerka) in its historical nursery lakes in central Idaho. We used a combination of limnological sampling, experimentation, and simulation modeling to assess effects of lake fertilization and kokanee reduction on growth and survival of juvenile sockeye salmon. Juvenile sockeye salmon from a broodstock of this endangered species are being introduced into the lakes from 1995 to 1998. Results of our analyses indicated that several lakes were suitable for receiving broodstock progeny. Field experimentation and simulation modeling indicated that …

Effects Of Daphnia Availability On Growth And Food Consumption Of Rainbow Trout In Two Utah Reservoirs, R. Tabor, Chris Luecke, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

We monitored the diet and growth of stocked rainbow trout Oncorhynchus mykiss in two Utah reservoirs during 1986 and 1989–1990. For the first month after stocking, juvenile rainbow trout in both reservoirs fed extensively on large Daphnia spp. In East Canyon Reservoir where Daphnia were abundant, this pattern continued throughout the summer, fall, and winter. Growth of rainbow trout in East Canyon Reservoir was generally good throughout 1989–1990. In Causey Reservoir, where Daphnia were less abundant and smaller, rainbow trout fed progressively less on smaller Daphnia throughout the summer, fall, and winter, while other prey items (snails, aquatic insects, and …

Modeling Oyster Populations. Iv. Rates Of Mortality, Population Crashes, And Management, E. N. Powell, J. M. Klinck, E. E. Hofmann, S. M. Ray

CCPO Publications

A time-dependent energy-flow model was used to examine how mortality affects oyster populations over the latitudinal gradient from Galveston Bay, Texas, to Chesapeake Bay, Virginia. Simulations using different mortality rates showed that mortality is required for market-site oysters to be a component of the population's size-frequency distribution; otherwise a population of stunted individuals results. As mortality extends into the juvenile sizes, the population's size frequency shifts toward the larger sizes. In many cases adults increase despite a decrease in overall population abundance. Simulations, in which the timing of mortality varied, showed that oyster populations are more susceptible to population declines …

Modeling Oyster Populations Ii. Adult Size And Reproductive Effort, E. E. Hofmann, J. M. Klinck, E. N. Powell, S. Boyles, M. Ellis

CCPO Publications

A time-dependent model of energy flow in post-settlement oyster populations is used to examine the factors that influence adult size and reproductive effort in a particular habitat, Galveston Bay, Texas, and in habitats that extend from Laguna Madre, Texas to Chesapeake Bay. The simulated populations show that adult size and reproductive effort are determined by the allocation of net production to somatic or reproductive tissue development and the rate of food acquisition, both of which are temperature dependent. For similar food conditions, increased temperature reduces the allocation of net production to somatic tissue and increases the rate of food acquisition. …

Age And Growth Of The Tautog, Tautoga Onitis (Pisces: Labridae), From Lower Chesapeake Bay And Coastal Waters Of Virginia, E. Brian Hostetter

Biological Sciences Theses & Dissertations

The tautog, Tautoga onitis (Pisces: Labridae), is rapidly gaining popularity in Virginia by anglers, spearfishermen and specialized commercial interests. In Virginia, tautog are seasonally abundant on hard bottom substrates in nearshore (ca. 2-10 m) habitats and inhabit offshore wrecks and reef areas (ca. 10-30 m) year round. Habitat restriction and slow growth of the species coupled with recent technological advances in marine electronics which simplify locating tautog populations by user groups may contribute to overexploitation of tautog within the region.

Tautog were collected over a two year period from the lower Chesapeake Bay and nearshore waters of the Atlantic Ocean …

The Effect Of Crowding On Growth Of The Cichlid Fish, Oreochromis Mossambicus, Bonnie A. Barrows

OES Theses and Dissertations

It has been reported that the Java tilapia, Oreochromis mossambicus, displays hypersensitivity to a substance it produces when biomass levels in a flow-through culture system exceed 20 g/1, resulting in reduced growth and high mortality. Experiments on the growth of this species in small tanks were conducted in order to determine whether O. mossambicus produces a growth-inhibiting compound under crowded conditions. This species was successfully maintained at biomass levels of 38 g/1 and 57 g/1 with a total mortality of only 4.5%.

The Java tilapia can grow rapidly in small aquaria, as indicated by the data taken during Experiment …

Growth And Activity Of Juvenile Mosquitofish: Temperature And Ration Effects, Wayne A. Wurtsbaugh, J. Cech

Watershed Sciences Faculty Publications

The effects of constant temperatures (10, 15, 20, 25, 30, and 35 C) and ration size on the growth rates and activity of juvenile mosquitofish Gambusia affinis (mean wet weight, about 20 mg) were measured in laboratory experiments. On ad libitum rations of Tubifex spp. worms, food-consumption rates of mosquitofish were very high, ranging from 7% dry body weight/day at 10 C to 83%/day at 35 C. Growth increased from 0% dry body weight/day at 10 C to 21%/day at 30 C and declined slightly at 35 C. Gross efficiencies (100 growth/food consumption) increased from 0 at 10 C to …

Agenda: New Sources Of Water For Energy Development And Growth: Interbasin Transfers: A Short Course, University Of Colorado Boulder. Natural Resources Law Center

New Sources of Water for Energy Development and Growth: Interbasin Transfers: A Short Course (Summer Conference, June 7-10)

Even before the [Natural Resources Law] Center was established [in the fall of 1981], the [University of Colorado] School of Law was organizing annual natural resources law summer short courses. To date four programs have been presented:

- July 1980: "Federal Lands, Laws and Policies-and the Development of Natural Resources"

- June 1981: "Water Resources Allocation: Laws and Emerging Issues"

- June 1982: "New Sources of Water for Energy Development and Growth: lnterbasin Transfers"

- June 1983: "Groundwater: Allocation; Development and Pollution"

(Reprinted from Resource Law Notes, no. 1, Jan. 1984, at 1.)

Faculty for this conference included University of …

Age And Growth Of The Utah Chub, Gila Atraria (Girard), In Panguitch Lake And Navajo Lake, Utah, From Scales And Opercular Bones, John M. Neuhold

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Previous literature indicates the opercular bone as a useful tool for the determination of age and growth of fish. The reliability and validity of this method is tested for two populations of Utah chub. Age and growth are calculated for 222 Utah chub collected from Panguitch Lake and 212 Utah chub collected from Navajo Lake, southern Utah, in 1952-1953 from both scales and opercular bones. Scales are measured with the aid of a projector. Opercular bones are measured directly. The center of growth of the opercular bone is posterior to the posterior lip of the fulcrum. Correction for curvature is …

The Opercular Bone As An Indicator Of Age And Growth Of The Carp Cyprinus Carpio Linnaeus, William J. Mcconell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As part of an investigation of the non-game fish resources of Utah, a study of the age and growth rate of the carp was instituted. A preliminary investigation indicated that the opercular method was superior to several other methods of determining age and growth in the carp. Age and growth were calculated from the opercular bones of 330 carp collected at Ogden Bay Refuge in 1950-51. Distances to annuli were measured directly. The relationship between the posterior radius of the opercular bone and the standard length of the carp was curvilinear. Past growth was calculated with a logarithmic nomograph. Expected …