Net cages are mainly located on the coastal areas of Peng-hu and Ping-tung counties. Generally, there are two kinds of disasters occurred in the fish farming industries: one is caused by typhoon attack, while the other is caused by human vandalism. This paper is focus on how to prevent the damages induced by poaching or vandalism. Since high-valued fish are raised in the net cages, they are often become the targets of illegal intruders for stealing at night, especially when the net cages are lack of security system. Under such unsecured situation, entrepreneurs would not dare to invest in this industry and may keep a suspicious attitude towards it. Compare to land aquaculture, marine aquaculture is far more complicated in terms of techniques involved in production progress. Surely over-fishing has serious deplete the stock of biomass in the sea in the past decades. Recently, the skyrocketed oil price even deteriorate the fishing industry to such a level that fishing boats can only operate for a season in each year and end up losing money. However, Fisheries Agency has planned to recycle commercial fishing boats, and hopefully by doing so, this aquacultural industry will turn into a new trend in the near future. This research looks into 700 hectares of net cage park, Southern Oceanic Park, and suggests that the fishery authority turn this area into special district, adjust the fishery law, designate San-fu port as the park¡¦s operation center, finally set up a security system, then we may reduce the damage caused by unlawful activities. The geographical make-up of Liu-chiu provides ideal conditions for the present net cage area. The sea waters outside of San-fu port are also blessed with the same geographical advantage. This research looks at ¡§man-made calamities¡¨, namely vandalism and theft, so as to prevent damage and loss and protect resources and equipment. The areas chosen for this study include the surrounding sea waters of Liu-chiu aquaculture zone and the highly representative San-fu fishing port. There are also discussions on the installation of automatic alarm system in the eventual marine park. As an officer in a law enforcement administration for coastal affaires, my past contact with net cage fishermen revealed the damage and loss they have been undergoing and their sense of helplessness. On top of that, relevant documents turned out to be insufficient. Therefore, this research aims to figure out a way to fill this security gap by integrating public power from governmental services with protection and safety solutions on the part of individuals. To put this initiative to work, it is necessary to map out a special marine park where security mechanism could be automatically triggered by local facilities. This will then allow public power and personal endeavor to work simultaneously in the special zone and prevent any illegal activities. With its high applicability and pertinence, the eventual security system will hopefully entice more entrepreneurs, thus maintaining a sound net cage aquaculture.

Oyster farming is an important mariculture along the western coast of Taiwan. There is always impacts on the oyster farming. The information of frequency, size and timing of tyhoon every year is strongly connected to the decisions of starting and harvesting of oyster culture. Climate change or variation seem to examine the future management of an oyster farm. This study aims to understand the adaptive strategies of oyster farmers in Tainan to possible climate change or variability. To analyze the mechanism of adaptive capacity and decision-making through a qualitative approach, specially , with focus groups, in-depth interviews, and semi-structured questionnaires. The results revealed abundant adaptation existing in the oyster farmers in Tainan, such as selecting small-size or median-size oyster as a way to cope with typhoon. However information exchange is rare among focus groups and more training and out reach courses are suggested.

Thesis--Auburn University, 2009. / Abstract. Includes bibliographic references (p.27-29).

Thesis (M.S.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains vi, 78 p. : ill. Vita. Includes abstract. Includes bibliographical references.

Thesis (M.S.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains xv, 104 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 81-84).

The amylolytic activities of alpha-amylase extracted from Mirror carp (Cyprinus carpio) and Nile tilapia (Oreochromis niloticus) were significantly reduced by purified amylase inhibitor albumin of wheat when tested under in vitro conditions. The action of this inhibitor was rapid and maximum levels of inhibition were attained within 20 minutes. For both carp and tilapia, the enzyme residual activities after inhibition were found to be related inversely to inhibitor concentration and positively to the initial enzyme activity levels. The curvilinear relationships between these parameters were explained by deriving equations of the type: A2 = a+b A1 - c I + d I2 where a, b, c and d are constants, Ai = Initial amylase activity (mU/min), A2 = Residual amylase activity (MU/min), I= Inhibitor concentration as ug protein. Inhibitions were greatest for amylases from gut tissue and ýowest for amylases from gut fluids. 1ug of purified inhibitor was found to contain a potency, to reduce 298 Units of carp gut tissue alpha-amylase and 532 Units of tilapia intestinal tissue alpha-amylase, by 50%. When amylase inhibitor extracted from wheat was incorporated in the feed of carp in its active form for three weeks, it caused a significant reduction in the specific growth rate to only 0.16%/day, while in carp fed autoclaved inhibitort such reduction in growth was not seen and the SGR was maintained at over 1.00%/day. However, despite the presence of active inhibitor in the intestine, the fish were able to maintain alpha-amylase activities in the gut contents at a level similar to that in fish fed denatured inhibitor. This was achieved by hyperactivation of enzyme secretions in the tissues of hepatopancreas and intestine. Hepatopancreas from fish fed active inhibitor exhibited more than two-fold increase in amylase, activity compared to those fed denatured inhibitor. By the third week of the experiment this difference in enzyme activity levels was not apparent but there were also no indications of adaptation or improvement in growth rate. Degenerations in hepatopancreas were also not apparent. Feeding carp with diet containing wheat with its inherent content of inhibitor also caused pancreas hyperactivity and some reduction in growth rate for a short period in comparison to those fish fed autoclaved wheat. In carp, the alpha-amylase activity did not vary depending on the raw or gelatinized nature of starch, both forms elicited equal increases in enzyme activity. However, autoclaving wheat, though effective in inactivating the inhibitor, was found to lower the biological value and digestibility of wheat proteins. Contrary to the result of the carp trials in Nile tilapia, the growth was not significantly reduced by feeding on diet containing active inhibitor and a SGR of 1.57%/day was recorded in comparison to 1.81i/day in tilapia fed denatured inhibitor. Samples of stomach and intestinal contents collected 4 hours after feeding did not reveal the presence of active inhibitor. Apparently the acidic protease, pepsin, in the stomach of tilapia caused the total destruction of the inhibitor in the diet before the contents were passed into the intestinal region. The presence of active amylase inhibitor in tilapia feed did not affect the digestibilities of starch and protein in the diet. Both the groups were able to digest carbohydrates and protein to levels of over 90%. The implications of these results are discussed in relation to feed formulation and fish nutrition.

On April 20th, 2010, a fire broke out on the Deepwater Horizon (DWH) offshore oil drilling rig on the Macondo prospect located off the coast of the Gulf of Mexico (GOM). This fire and resulting explosions resulted in the sinking of the Deepwater Horizon rig and the largest marine oil spill in history. An estimated 4.9 million (+/- 10%) barrels were released into the Gulf of Mexico over the ensuing 87 days. Many economically important fish species spawn in northern Gulf of Mexico waters; the spawning seasons and pelagic larval phase of many of these species occur within the temporal extent of the DWH oil spill (April through July). Fish eggs and larvae in waters exposed to Macondo oil likely experienced lethal and sublethal physiological effects, leading to potential losses in year class strength depending on the proportion of a population’s larval production encountering oil. Differing spatial distributions of larvae due to different spawning locations and seasons could predict that some species were disproportionately affected by the DWH oil spill. This study aims at quantifying the impact of the spill across numerous taxa, by estimating the proportion of species-, genus-, or family-specific fish larval abundances located within the spatial/temporal domain of the DWH spill until the Macondo well was capped. Estimates and related uncertainties were based on empirical ichthyoplankton data collected over 27 years and on observed and modeled distribution of surface oil slicks and concentrations. In addition, two hypothetical oil spills were simulated on the Western Florida Slope and on the Western interior of the Gulf of Mexico to assess the impact of oil spills to the ichthyoplankton from different offshore locations that would have occurred during the DWH spill period. Ichthyoplankton data collected during annual plankton surveys (and other resource surveys) as part of the Southeast Area Monitoring and Assessment Program – Gulf of Mexico (SEAMAP) during years 1982-2009 were used to describe the composition and distribution of ichthyoplankton in the northern Gulf of Mexico. The SEAMAP larval fish data along with oil surface distributions (both actual and simulated) were used to estimate the proportions of larvae of 115 selected fish taxa that were potentially exposed to DWH oil. Bootstrapping methods were applied to the SEAMAP data to quantify the variability. Proportions of larval fish potentially exposed to oil were calculated for four oil spill scenarios: (1) the DWH spill, (2) an September-December oil spill with the same spatial footprint as the DWH spill but occurring later in the year, (3) a west Florida Slope spill occurring during the months of April-July and centered at 27˚N, 85˚W, and (4) a western GOM spill occurring during the spring and centered at 27˚N, 93.5˚W. Spill scenarios (3) and (4) were modeled using the Connectivity Modeling System (CMS). The CMS is a Lagrangian model which predicts oil droplet distribution and degradation based on oil properties and ocean currents. Significant differences in the proportion of larvae potentially exposed were found in the DWH spill and the three simulations. The proportion of fish larvae exposed to the DWH spill varied between 0% (many species) and 26.8% (Cynoscion nebulosus). The proportion of fish larvae exposed to simulated spills varied between 0% and 78.9% (Bonapartia pedaliota in Western GOM spill). Both the west Florida Slope oil spill and the western GOM spills had a disproportionally greater impact on a larger number of taxa than the DWH spill, even after correcting for their larger spatial extent. For the DWH spill (Scenario 1), the potentially most impacted taxa were Cynoscion nebulosus, Engraulidae, Rachycentron canadum, and Etropus spp. If the DWH spill had occurred in the fall (Scenario 2), the most potentially impacted taxa would have been Leiostomus xanthurus, Elopidae, and Pomatomus saltatrix. For a west Florida slope exposure (Scenario 3), the potentially most impacted taxa would be Holocentridae, Acanthocybium solandri, Coryphaena spp., and Pomacanthidae. For a western GOM spill (Scenario 4), the most potentially impacted taxa would be Bonapartia pedaliota, Thunnus thynnus, Caranx spp., and Holocentridae.. The historical SEAMAP data set combined with the CMS modeling tool provides a powerful planning tool to understand the potential impacts of oil spills in the northern GOM and the relative sensitivity of locations in the Northern GOM to oil spill effects.

As we have come to depend on aquaculture to supplement natural fisheries, intensive culture methods have increased production. Accompanying environmental damage--non-point source pollution, loss of biodiversity and struggle for water--has offset food and financial gains. Problems surrounding food production are amplified in arid lands, as the potential of irrigated agriculture is weighed against the value of water. Through the following research, I studied integration of aquaculture and agriculture through multiple uses of water and nutrients, to reduce environmental impacts. When managed properly, integration can provide multiple cash crops, increased food and fiber production with reduced inputs. Integration allows for groundwater and nutrients in water and solid waste to be reused. Shrimp farms in Arizona use low-salinity ground water from aquifers for shrimp ponds and agricultural irrigation. On one of these farms, effluent is reused for irrigation of olive trees and other field crops. In Chapter 3, I described an experiment designed to quantify changes in the height of olive trees due to irrigation with shrimp effluent. Trees receiving effluent grew an average of 61.0 cm over the two-year experiment, 70.4 cm with fertilizer and 48.4 cm in the well water treatment. No negative effects due to effluent irrigation were found, while increases in water use efficiency were realized by producing two crops with the same irrigation water. Multiple uses of water are also possible in smaller scale agriculture systems. I performed a financial analysis of a small-scale aquaponics system, integrated hydroponics and aquaculture, in Chapter 4. Biological viability of such systems is clear. By building and managing this system for five months, I examined economic viability, by analyzing annual costs and revenue. Calculating net present value showed that the system was not financially viable unless labor costs were excluded. Financial returns were between 3,794 and 10,640 over six years. In five months, this system produced 181.4 kg of food, with fish feed, iron and water as the only inputs. This study showed potential for using small-scale aquaponics as a hobby, in schools, and as a tool for agricultural economics education, but not as a business opportunity.

The virile crayfish (Orconectes virilis), an aggressive polytrophic species, has been introduced into many Arizona streams. I investigated competition and predation between this crayfish and several native Arizona fishes. I conducted field experiments to assess competition for food between crayfish and fish, and laboratory experiments to examine competition for shelter and food, and predation. In Sabino Creek, I manipulated crayfish densities in isolated pools to examine effects of crayfish on growth, mortality, and recruitment of Gila chub (Gila intermedia). Regardless of crayfish density, Gila chub declined slightly in weight and condition. Mortality and recruitment did not differ between densities of crayfish. I examined crayfish effects on benthic macroinvertebrates, a submerged aquatic macrophyte and associated invertebrates, and three fish species in a small stream in the White Mountains by fencing eight stream sections to prevent movement. The three fishes were speckled dace (Rhinichthys osculus), Sonora sucker (Catostomus insignis), and desert sucker (C. clarki). Molluscs > 10 mm and macrophytes were less abundant at sites with a high density of crayfish than at sites with low crayfish densities. Insect diversity was lower in high- vs. low-density sites. No treatment effect was observed on growth or condition of individually marked fish. Short-term laboratory experiments demonstrated predatory interactions and competition for shelter between crayfish and Gila chub, desert sucker, and speckled dace. Crayfish used shelter more than fish, displaced fish from shelter, and frequently attacked fish. Fish never attacked crayfish, and only once displaced crayfish from shelter. In predation experiments, crayfish preyed upon all species, but preyed most heavily upon desert suckers. Fish never altered use of the water column in the presence of crayfish. Density manipulation experiments in a laboratory measured food competition between crayfish and two native fishes. Growth of Gila chub was less affected by crayfish than by increased density of Gila chub. Thus crayfish are not strong competitors with Gila chub for food. However, growth of flannelmouth sucker (Catostomus latipinnis) was negatively impacted by presence of crayfish. These laboratory experiments provide evidence that introduced crayfish can reduce fish growth by competition for food, and that native fishes are vulnerable to crayfish predation.

Selenium bioaccumulates along the lower Colorado River and may impact fish and waterfowl. Selenium may be reduced in lakes or reservoirs by flushing (increasing the water exchange rate). Therefore, I monitored selenium levels in water, sediment, and bluegill (Lepomis macrochirus) in response to flushing on the Cibola NWR in the lower Colorado River Valley, California and Arizona. Selenium in the lakewater was below the detection level of 5.6 ppb wet weight (WW) but data from the US Geological Survey (1990-1995) showed that selenium levels in the water ranged from 1 to 3 ppb WW in the mainstem Colorado River 135 km upstream from Cibola Lake. There was no predictable trend in selenium in the sediment after flushing. It was the same after the first flushing, lower after the second flushing, and higher after the third flushing. Selenium levels in the biota also did not vary in a predictable way after flushing. It went up after the first flushing, down after the second flushing, and up after the third flushing. One might speculate that higher flushing rates, or continuous flushing might result in lower selenium levels in biota and sediment. However, selenium levels in the sediment (1.10 ppm DW) and bluegill (4.93 ppm DW) in Cibola Lake were not significantly different than levels in the sediment (0.86 ppm DW) and bluegill (4.83 ppm DW) in a comparable backwater lake (Mittry Lake, Arizona) that was continuously flushed. Therefore, flushing does not appear to be a viable strategy for managing selenium levels in backwater lakes along the lower Colorado River.