The study of the ergosan and vibromax effects on growth performances, survival rate and increase of the resistance to some of the environmental stresses in post larvae stage of the Indian white shrimp

In this study, which has been done in Hormoz larve Hatchery at Kohestak in Minab at 1385, the efficiency of Ergosen and Vibromax vaccine and the effect of them on growth factors such as total length, Carapase, dry weight and the number of upper mordents of rostrum and survival of the stages of larvae and post larvae of Indian white shrimp was studied. Thus in order to comparison the effects of Vibromax and Ergosen, each of them separately, in one treatment, and in another simultaneously with one control treatment was used. Vaccination against larvae shrimps was done through Artemia. This study used four treatments with three replicates in a completely randomized design and comparison of means was done through Duncan test. Breeding larvae and post larvae of Indian white shrimp from zoa I stage to PL 15 was done in 20 litter plastic buckets. Present results indicated that the highest amount of growth and survival factors in larvae stage (from zoa to PL1), and also in stages of PL5 and PL15, in the treatment of Ergoson effect + vaccine and it was with a little difference from that treatment of Ergoson effect which was in high significance difference in regard to control treatment at α<0.01 level and treatment of vaccine effect and control treatment at α<0.01 level often have no significant difference. This research used environmental stress tests to study the quality of post larvae under experiment. Studying in this field showed that feeding vaccine to larvae of Indian shrimps which was done through Artemia nauplii enrichment ,and ergosen , in treatment of ergosen vaccine lead to more resistance of post larvaes against salinity stress tests and formalin .This case was observed in every three stages ,so that in stress formalin test 100 parts per million and also 10 and 20 salinity parts in thousands the most survival was observed in treatment of Ergosan effect+vaccine and after that in treatment of Ergoson effect and with a little difference in treatment of vaccine effect. Of course this case, in treatment of Ergoson effect + vaccine due to the synergistic properties vaccine with Ergoson was more than to other treatments, while every three treatments, in most stages had significant difference toward control treatment at α<0.01 level and the control treatment because of not having Ergoson and nauplii artemia with vaccine, having the least survival rate in this stages.

The study of Indian shrimp larvae feeding by enriched rotifer with vitamin C and unsaturated fatty acid (epa, dha) and its effects on growth factors, survival rate and environmental stresses

In this experiment, the feeding of Indian white shrimp larvae by unenriched rotifers (treatment 1) and enriched with highly unsaturated fatty acid (treatment 2) and highly unsaturated fatty acid along with vitamin C (treatment 3) on the growth factors, survival and resistance against salinity and formalin stress tests were studied and their differences with control treatment including newly hatched Artemia nauplii is compared. In this the study four treatments in a completely randomized design with 3 replicates per treatment were used. Farming of shrimp larvae of Zoea II to postlarvae 5 was done in 20 liter plastic bucket. Present results indicated that growth factors and survival rate of stage Zoea II to postlarvae 1 in treatments 1, 2 and 3 improve rather than control in which this case was due to optimal size rotifer rather than Artemia nauplii. Also, treatments 2 and 3 feeding with oil liver cod emulsion enriched rotifer have the highest concentration of DHA (mg/g DW) and the ratio DHA/EPA in which due to have shown the highest growth factors and a significant difference (P<0.05) with treatments 1 and control. The highest survival at stage PL1 were observed in treatment 3 that was enriched with ascorbyl palmitate in which have to the synergistic properties of vitamin C rather than treatments 2, 1 and control and showed a significant difference (P<0.05). But in stage PL5 the highest amount of growth and survival rates were related to control treatment which showed a significant difference (P<0.05) with other treatments that control has higher size rather than treatments 1, 2 and 3. Also, among experiment treatments that the two treatments 2 and 3 due to enrichment had higher growth and survival rates compared with treatment 1 in which their differences have also been significant (P<0.05). In the case of stress tests, results indicated that the highest survival rate has been reported when specimens were offered a diet containing high levels of highly unsaturated fatty acids with vitamin C. So that in stage PL1 in the salinity stress tests 10 and 20 ppt the highest survival rate was observed in treatment 3. As for the second, treatment 2 showed a significant difference (P<0.05) with treatment 3. It is worth mentioning that treatment 3 showed a higher survival rate compared to treatment 2 due to the synergistic properties of vitamin C. The difference between these two treatments with treatment 1 and control was also significant. No significant difference was observed in formalin stress test 100 ppm in this stage between treatments 3 and 2 which shows the highest survival rate. But their difference with treatments 1 and control was significant (P<0.05). Also, in stage PL5 in the salinity stress tests 10 and 20 ppt the highest survival rate was observed in treatment 3 which showed no significant difference (P<0.05) with control treatment. While their difference in the amount of survival rate with treatment 1 and 2 was significant (P<0.05). In this stage, the highest observed survival rate in formalin stress test 100 ppm included treatments control, 3 and 2 among which there were no significant differences (P<0.05). While the difference between these three treatments with treatment 1 was significant.

The mechanical effects of water flow on fish eggs and larvae

The impact of mechanical stresses upon ichthyoplankton entrained in power plant cooling systems has long been considered negligible. Arguments and evidence exist, however, to show that such a supposition is not universally true, especially in nuclear power plants. The mechanisms of mechanical damage can be detailed in terms of pressure change, acceleration, and shear stress with in the fluid flow field. Laboratory efforts to quantify the effects of mechanical stress have been very sparse. A well-planned bioassay is urgently needed. (PDF has 11 pages.)

An Analysis of 1974 Striped Bass spawning success in the Potomac Estuary.

ABSTRACT: The Potomac River Fisheries Program is concerned with the longterm effects of power plant ichthyoplankton entrainment on striped bass(hforone smatilis) recruitment. Since striped bass population fluctuations are determined strongly by environmental conditions during spawning and early development, assessment of power plant-induced ichthyoplankton mortalities must consider the mechanisms controlling spawning success. Ichthyoplankton distributions for 1974, spawning population abundance and fecundity, and environmental conditions were considered for analysis. Loss of the early part of the spawn (including the peak) accounted for the highest mortalities among ichthyoplankton. This was due to the proximity of these distributions to the salt wedge where transport into regions un!ivorable to survival seems to have occurred. The later, successful portion of the spawn occurred further upstream, in fresh tidal portions of the river. The sequence of events Ieading to an assessment of factors affecting ichthyoplankton surnnl are evaluated. Due to high early mortalities in ichthyoplankton, 1974 spawning success was low, and a poor yearclass is projected.

On Selecting the excess temperature to minimize the entrainment mortality rate

In selecting an excess temperature at which to operate a power plant cooling system it has been customary to consider only thermal stresses and to use the ratio of the number of organisms killed to the number of organisms entrained. This frequently leads to the selection of a low excess temperature, AT, which, in turn, requires a large volume flow of cooling water. When mortalities due to physical and chemical stresses are included and the total number of entrained organisms killed is taken as the measure of the environmental damage, it becomes evident that the choice of a low excess temperature is seldom, if ever, best.

Extreme events and ecological forecasting

Almost all extreme events lasting less than several weeks that significantly impact ecosystems are weather related. This review examines the response of estuarine systems to intense short-term perturbations caused by major weather events such as hurricanes. Current knowledge concerning these effects is limited to relatively few studies where hurricanes and storms impacted estuaries with established environmental monitoring programs. Freshwater inputs associated with these storms were found to initially result in increased primary productivity. When hydrographic conditions are favorable, bacterial consumption of organic matter produced by the phytoplankton blooms and deposited during the initial runoff event can contribute to significant oxygen deficits during subsequent warmer periods. Salinity stress and habitat destruction associated with freshwater inputs, as well as anoxia, adversely affect benthic populations and fish. In contrast, mobile invertebrate species such as shrimp, which have a short life cycle and the ability to migrate during the runoff event, initially benefit from the increased primary productivity and decreased abundance of fish predators. Events studied so far indicate that estuaries rebound in one to three years following major short-term perturbations. However, repeated storm events without sufficient recovery time may cause a fundamental shift in ecosystem structure (Scavia et al. 2002). This is a scenario consistent with the predicted increase in hurricanes for the east coast of the United States. More work on the response of individual species to these stresses is needed so management of commercial resources can be adjusted to allow sufficient recovery time for affected populations.

Ecological forecasting: new tools for coastal and marine ecosystem management

Policy makers, natural resource managers, regulators, and the public often call on scientists to estimate the potential ecological changes caused by both natural and human-induced stresses, and to determine how those changes will impact people and the environment. To develop accurate forecasts of ecological changes we need to: 1) increase understanding of ecosystem composition, structure, and functioning, 2) expand ecosystem monitoring and apply advanced scientific information to make these complex data widely available, and 3) develop and improve forecast and interpretative tools that use a scientific basis to assess the results of management and science policy actions. (PDF contains 120 pages)

An environmental assessment of the John Pennekamp Coral Reef State Park and the Key Largo Coral Reef Marine Sanctuary (Unpublished 1983 Report)

The Pennekamp Coral Reef State Park was established in 1960 and the Key Largo National Marine Sanctuary in 1975. Field studies, funded by NOAA, were conducted in 1980 - 1981 to determine the state of the coral reefs and surrounding areas in relation to changing environmental conditions and resource management that had occurred over the intervening years. Ten reef sites within the Sanctuary and seven shallow grass and hardbottom sites within the Park were chosen for qualitative and quantitative studies. At each site, three parallel transects not less than 400 m long were run perpendicular to the reef or shore, each 300 m apart. Observations, data collecting and sampling were done by two teams of divers. Approximately 75 percent of the bottom within the 18-m isobath was covered by marine grasses, predominantly turtle grass. The general health of the seagrasses appeared good but a few areas showed signs of stress. The inner hardbottom of the Park was studied at the two entrances to Largo Sound. Though at the time of the study the North Channel hardbottom was subjected to only moderate boat traffic, marked changes had taken place over the past years, the most obvious of which was the loss of the extensive beds of Sargassum weed, one of the most extensive beds of this alga in the Keys. Only at this site was the green alga Enteromorpha encountered. This alga, often considered a pollution indicator, may denote the effects of shore run off. The hardbottom at South Channel and the surrounding grass beds showed signs of stress. This area bears the heaviest boat traffic within the Park waters causing continuous turbidity from boat wakes with resulting siltation. The offshore hardbottom and rubble areas in the Sanctuary appeared to be in good health and showed no visible indications of deterioration. Damage by boat groundings and anchors was negligible in the areas surveyed. The outer reefs in general appear to be healthy. Corals have a surprising resiliency to detrimental factors and, when conditions again become favorable, recover quickly from even severe damage. It is, therefore, a cause for concern that Grecian Rocks, which sits somewhat inshore of the outer reef line, has yet to recover from die-off in 1978. The slow recovery, if occurring, may be due to the lower quality of the inshore waters. The patch reefs, more adapted to inshore waters, do not show obvious stress signs, at least those surveyed in this study. It is apparent that water quality was changing in the keys. Water clarity over much of the reef tract was observed to be much reduced from former years and undoubtedly plays an important part in the stresses seen today over the Sanctuary and Park. (PDF contains 119 pages)

The potential impact of Ocean Thermal Energy Conversion (OTEC) on fisheries

The commercial development of ocean thermal energy conversion (OTEC) operations will involve some environmental perturbations for which there is no precedent experience. The pumping of very large volumes of warm surface water and cold deep water and its subsequent discharge will result in the impingement, entrainment, and redistribution of biota. Additional stresses to biota will be caused by biocide usage and temperature depressions. However, the artificial upwelling of nutrients associated with the pumping of cold deep water, and the artificial reef created by an OTEC plant may have positive effects on the local environment. Although more detailed information is needed to assess the net effect of an OTEC operation on fisheries, certain assumptions and calculations are made supporting the conclusion that the potential risk to fisheries is not significant enough to deter the early development of IDEe. It will be necessary to monitor a commercial-scale plant in order to remove many of the remaining uncertainties. (PDF file contains 39 pages.)

Use of macroinvertebrate communities to detect environmental stress in running waters

This paper presents an account of some current uses of RIVPACS (River Invertebrate Prediction and Classification System), a software package developed by the Institute of Freshwater Ecology (UK). Background information is also given on the unique data-set on which the system is based. Before discussing RIVPACS, we consider the range of environmental stresses encountered in flowing-water systems and some of the ways in which stresses may affect macroinvertebrate communities. The wide application and relevance of the RIVPACS approach was recognised when it was chosen as the biological method for use throughout the UK in the 1990 River Quality Survey (RQS). In the concluding section we list some lessons learnt both from the 1990 survey and from our own testing exercise, and we outline current developments which will lead to a new version of RIVPACS for use in the 1995 RQS.

Surface mucous as a source of genomic DNA from Atlantic billfishes (Istiophoridae) and swordfish (Xiphiidae)

Procedures for sampling genomic DNA from live billfishes involve manual restraint and tissue excision that can be difficult to carry out and may produce stresses that affect fish survival. We examined the collection of surface mucous as a less invasive alternative method for sourcing genomic DNA by comparing it to autologous muscle tissue samples from Atlantic blue marlin (Makaira nigricans), white marlin (Tetrapturus albidus), sailfish (Istiophorus platypterus), and swordfish (Xiphias gladius). Purified DNA from mucous was comparable to muscle and was suitable for conventional polymerase chain reaction, random amplified polymorphic DNA analysis, and mitochondrial and nuclear locus sequencing. The nondestructive and less invasive characteristics of surface mucous collection may promote increased survival of released specimens and may be advantageous for other marine fish genetic studies, particularly those involving large live specimens destined for release.

ReefBase 2.0: a contribution to environmental conservation on a global scale

The 1997 International Year of the Reef sees the release of ReefBase 2.0: a global database on coral reefs and their resources. It provides the most comprehensive and accessible repository of information to date. Containing information on over 7000 coral reefs in more than 123 countries, ReefBase 2.0 offers an extensive range of time-related data pertaining to coastal tourism, benthic environment ecology, fish population statistics, oceanography, socioeconomics, mariculture, and harvest activities. It also outlines the stresses causing reef degradation as well as management initiatives. Complemented by hundreds of digitized maps provided by the World Conservation Monitoring Centre (WCMC) and over 500 high quality photographs, ReefBase 2.0 is not only an essential tool for coral reef management but also an comprehensive guide for tourists, scuba divers and snorkelers alike. ReefBase has contributed substantially to the success of the International Coral Reef Institute (ICRI) and serves as the official database of the Global Coral Reef Monitoring Network (GCRMN), bringing together an increasing volume of data on coral reef health, management and significance to humanity, and making it widely available. Over the next five years, the information contained within ReefBase will be utilized as an instrument for developing coral reef health assessment criteria, sustainable management criteria, and providing continuously updated summaries of threats endangering coral reefs around the globe. This will be a strong basis for focused corrective action in an attempt to conserve coral reefs and properly manage their resources for future generations.

Sustainable utilization of inland water resources: an integrated program for research and management

In both developed and developing countries, there is increased competition for water resources, resulting in deficiencies in supply and in various forms of pollution. In developing countries, the nutritional potential of aquatic resources is very important. To realize this potential, integrated research and management for sustainable water resource use are needed. This requires a sound understanding of the structure and function of aquatic ecosystems. A programme is presented which stresses the interrelationships of the physical, chemical and biological components of aquatic systems and their catchments. The programme consists of 16 stages in 5 phases, which are as follows: System description; System functioning and modelling; Resource assessment/dynamics; Resource potential; and, Resource utilization for sustainability. This programme enables workers within different disciplines to identify how their expertise contributes to the overall research requirements to support resource development.

A Positive trajectory for corals at Little Cayman Island

Coral reefs are damaged by natural disturbances and local and global anthropogenic stresses. As stresses intensify, so do debates about whether reefs will recover after significant damage. True headway in this debate requires documented temporal trajectories for coral assemblages subjected to various combinations of stresses; therefore, we report relevant changes in coral assemblages at Little Cayman Island. Between 1999 and 2012, spatiotemporal patterns in cover, densities of juveniles and size structure of assemblages were documented inside and outside marine protected areas using transects, quadrats and measurements of maximum diameters. Over five years, bleaching and disease caused live cover to decrease from 26% to 14%, with full recovery seven years later. Juvenile densities varied, reaching a maximum in 2010. Both patterns were consistent within and outside protected areas. In addition, dominant coral species persisted within and outside protected areas although their size frequency distributions varied temporally and spatially. The health of the coral assemblage and the similarity of responses across levels of protection suggested that negligible anthropogenic disturbance at the local scale was a key factor underlying the observed resilience.

Characterization of Hypoxia: Topic I Report for the Integrated Assessment on Hypoxia in the Gulf of Mexico

Nutrient overenrichment from human activities is one of the major stresses affecting coastal ecosystems. There is increasing concern in many areas around the world that an oversupply of nutrients from multiple sources is having pervasive ecological effects on shallow coastal and estuarine areas. These effects include reduced light penetration, loss of aquatic habitat, harmfid algal blooms, a decrease in dissolved oxygen (or hypoxia), and impacts on living resources. The largest zone of oxygen-depleted coastal waters in the United States, and the entire western Atlantic Ocean, is found in the northern Gulf of Mexico on the Louisiana-Texas continental shelf. This zone is influenced by the freshwater discharge and nutrient flux of the Mississippi River system. This report describes the seasonal, interannual, and long-term variability in hypoxia in the northern Gulf of Mexico and its relationship to nutrient loading. It also documents the relative roles of natural and human-induced factors in determining the size and duration of the hypoxic zone.