Effect of Aquathol K Treatments on Activity Patterns of Largemouth Bass in Two Coves of Lake Seminole, Georgia

Thirty largemouth bass ( Micropterus salmoide s Lacepde) were implanted with radio tags in late October 2003 in two coves of Lake Seminole, Georgia, and tracked over a 24-hour period about every 10 days to determine their response to herbicide application. After five weeks of tracking, hydrilla ( Hydrilla verticillata Royle) in each cove was treated in early December 2003 with dipotassium salt of endothall (Aquathol K; 7-oxabicyclo [2.2.1] heptane-2,3-dicarboxylic acid) at a rate of 3.5 ppm. Largemouth bass were tracked during application and tracking continued for three months post treatment to assess effects of herbicide treatment on activity patterns. The treatment in Desser Cove successfully reduced hydrilla in approximately half the cove. However, the treatment in Peacock Lake completely eliminated all submersed aquatic vegetation (SAV) by April 2004. Movement and activity centers remained similar between treatment periods in Desser Cove, but increased after treatment in Peacock Lake. Depth occupied by telemetered fish decreased after Aquathol K treatment in both coves. In general, behavior of largemouth bass did not change appreciably during treatment, and only minor changes were observed in the posttreatment period in Peacock Lake, where all SAV was eliminated. Fish showed little attraction to or movement away from treatment areas, and fish migration from either cove was nil after treatment. Application of Aquathol K and subsequent reduction of SAV had little effect on largemouth bass behavior or movement. (PDF has 8 pages.)

Descriptions of Oscillatoria agardhii, O.prolifera and O.rubescens only [Translation from: Translation from: Flora Slodkowodna Polski. Tom 2. Cyanophyta, Glaucophyta (ed. K. Starmach) p350-352. Warsaw, Polska Academia Nauk, 1966]

Short morphological observations are given for the Cyanophyceae Oscillatoria Agardhii, Oscillatoria prolifica and Oscillatoria rubescens.

Review of investigation on the feeding of the European grayling [Translation from: Flora Slodkowodna Polski. Tom 2. Cyanophyta, Glaucophyta (ed. K. Starmach) p350-352. Warsaw, Polska Academia Nauk, 1966]

The composition of the food of the European grayling and the character of its feeding has been studied fully enough, but this knowledge is scattered in the literature and often contradictory. rare exceptions, analysis of the results of different investigations. Therefore the proposed short outline of the history of the study of the problem with a description of the basic data on the feeding of the grayling in different geographical areas is presented as expedient and opportune, primarily in relation to the determination of immediate problems and the trend of research.

Contribution à l'étude des modifications hydro-sédimentaires consécutives à la réouverture artificielle de l'embouchure du Comoé à Grand-Bassam

The Bassam artificial inlet was opened (in September 22, 1987) in order to revacuate offshore invasive aquatic plants. This has considerably modified the hydro-sedimentary environment of the lagoonal domain at Grand-Bassam. Tidal currents effect has confered the lagoonal waters an estuarine feature, the saline intrusion (25-35%o) increased beyond the Moossou bridges up to the confluence of the Comoe river. This has led to a cleaning of the river lower course and above all to the bottoms of the lagoon, which were previously confined. The remobilization of mud (from lagoonal bottoms around Bouet Island) evacuated offshore, has exposed lagoonal and oceanic sandy features. This new system remains fragile, with the seasonal (low river-flow) clogging.

Biological Characteristics and Fishery Assessment of Alaska Plaice, Pleuronectes quadrituberculatus, in the Eastern Bering Sea

Alaska plaice, Pleuronectes quadrituberculatus, is one of the major flatfishes in the eastern Bering Sea ecosystem and is most highly concentrated in the shallow continental shelf of the eastern Bering Sea. Annual commercial catches have ranged from less than 1,000 metric tons (t) in 1963 to 62,000 t in 1988. Alaska plaice is a relatively large flatfish averaging about 32 cm in length and 390 g in weight in commercial catches. They are distributed from nearshore waters to a depth of about 100 m in the eastern Bering Sea during summer, but move to deeper continental shelf waters in winter to escape sea ice and cold water temperatures. Being a long-lived species (>30 years), they have a relatively low natural mortality rate estimated at 0.20. Maturing at about age 7, Alaska plaice spawn from April through June on hard sandy substrates of the shelf region, primarily around the 100 m isobath. Prey items primarily include polychaetes and other marine worms. In comparison with other flatfish, Alaska plaice and rock sole, Pleuronectes bilineatus, have similar diets but different habitat preferences with separate areas of peak population density which may minimize interspecific competition. Yellowfin sole, Pleuronectes asper, while sharing similar habitat, differs from these two species because of the variety of prey items in its diet. Competition for food resources among the three species appears to be low. The resource has experienced light exploitation since 1963 and is currently in good condition. Based on the results of demersal trawl surveys and age-structured analyses, the exploitable biomass increased from 1971 through the mid-1980’s before decreasing to the 1997 level of 500,000 t. The recommended 1998 harvest level, Allowable Biological Catch, was calculated from the Baranov catch equation based on the FMSY harvest level and the projected 1997 biomass, resulting in a commercial harvest of 69,000 t, or about 16% of the estimated exploitable biomass.

The 66 k-Da protein identified as a light meromyosin is involved in the setting of surimi

The 66 kilo-Dalton (k-Da) protein split off from the cross linked myosin heavy chain (CMHC) formed due to the setting of Alaska pollack surimi, frozen-storage of Pacific cod flesh, and vinegar-curing of Pacific mackerel mince was identified as a light meromyosin (LMM). Puncture and stress-relaxation tests showed that the actomyosin subunits (AMS) of Alaska pollack surimi, upon setting at 30°C, transformed into gel, although the elasticity of this gel was very low when compared to the gels from surimi or actomyosin (AM). Electrophoretic studies showed that the band due to LMM in the gel from AMS gradually disappeared with the progress of setting but higher molecular weight polymer did not form. The intensity of the bands due to other myosin sub-fragments decreased a little. The findings suggest that at setting temperature, LMM of MHC molecule leads to an unfolding resulting in an intramolecular aggregation through non-covalent interactions, and thus plays a significant role in the crosslinking of MHC.

Macrobenthos off Mahim (Bombay), west coast of India in relation to coastal pollution and aquaculture

Deterioration of water quality clearly indicated a moderate to severe coastal pollution around Mahim whereas a relatively healthy marine environment towards offshore was noticed. Foraminifera, polychaetes, crustaceans and pelecypods were the dominant macro faunal groups encountered in the area. The occasional inhabitants like pennatularians, nemertines, sipunculids, ophiuroids and fish larvae were mostly restricted to offshore regions. Biomass and population density of macro fauna were moderate and showed fluctuating trend. Similarity coefficients of foraminifera (0.89) and polychaetes (0.81) were high for offshore unpolluted stations (3 and 4) as compared to near shore coastal stations (1 and 2). Faunal diversity was relatively more in unpolluted zone. The diversity index (H) was more at station 3 for polychaetes (1.39) and at station 4 for foraminifers (0.54). In general, biomass was high during post monsoon excepting station 1 which was invariably under severe pollution stress throughout the study period. Foraminifera were abundant at sandy bottom while polychaetes preferred muddy (clayey silt) bottom. A noticeable ecological modification associated with faunal abundance and diversity were related to deteriorating marine water quality due to anthropogenic waste disposals. The prevailing water quality around Mahim is unsuitable for any kind of culture practices and also for harvesting economically important marine species.

Vertical distribution of molluscs in the intertidal area in and around Mumbai, India

Vertical distribution of intertidal molluscs in and around Mumbai had been studied. Each species has an upper and lower limit of distribution along the vertical intertidal gradient and are concentrated at particular levels or zones where they find optimum living conditions. Zonation of the intertidal area with reference to molluscs at rocky shores of TIFR, Bandstand and NCPA has similarities. However, there is no similarity in zonation among rocky, sandy and muddy shores. Rocky intertidal zones are more diverse and dense in terms of molluscs. The mid and lower littoral zones have rich diversity. The upper littoral zone at some sites, especially Girgaon chowpatty is totally devoid of molluscs due to anthropogenic activities. Gafrarium divaricatum, Nerita oryzarum, N. polita and Neritina crepidularia have established themselves in all three marked zones, indicating their power to adjust with the wide fluctuations in surrounding environmental conditions.

Physical soil characteristics of waterlogged and saline lands of five districts of Haryana, India

Physical characteristics of waterlogged and saline soils of five districts, namely Rohtak, Faridabad, Gurgaon, Sonipat and Jhajjar, of Haryana were studied to evaluate the aquaculture potential. The soil samples from 76 sites were procured and analysed for pH, electrical conductivity, soil particles and water retention capacity, since the knowledge of these parameters is essential for the preliminary evaluation of a site for aqua-farming. Six soil types were identified and clay-loam was observed to be the maximum at 45 (59.21%) sites, followed by silty-clay loam at 14 (18.42%), sandy-clay loam at six (7.89%), silty-loam at four (5.26%), sandy-loam at four (5.26%) and loam at three (3.94%) sites. The pH of soil indicated moderate to high alkaline conditions ranging between 8.01and 9.00 at 53 (69.73%) sites, 9.01 and 10.00 at 17 (22.36%) sites, and low between 7.01 and 8.00 at six (7.89%) sites. The electrical conductivity was found to range between <1 and 10 mmho cmˉ¹ with the value of <1.0 mmho cmˉ¹ at 36 (47.36%) sites. The water retention capacity was observed mostly to be moderate. The paper describes the interrelationship between these parameters with reference to the suitability for aqua-farming.

Macrobenthos of intertidal zone of Versova along the coast of Mumbai

To assess the biodiversity of macro benthos in the changing environment along the coast of Mumbai, the intertidal zone of Versova was identified. The water quality in this intertidal region was poor with low pH, salinity and dissolved oxygen, and high nitrite, nitrate, phosphate and ammonia. The substratum was sandy with 1.29% organic matter in it. Mean faunal density of 2257 no./m² was recorded during the study which was mainly contributed by polychaetes (83.5%) followed by amphipods (14.5%), while other groups represented were isopods, crabs, hermit crabs, unidentified decapods, pelecypods and gastropods. Average biomass of 34.83 g/m² (93.7%) was contributed by polychaetes. Shannon and Wiener Index (0.4107) indicated heavy pollution in the intertidal area of Versova.

Skipjack tuna (K. pelamis, L.) resources in the seas around Ceylon

Details are given of the source and processing of data, size composition, seasonal variation in occurrence, abundance and oceanic potential of Katsuwonus pelamis resources in the seas around Sri Lanka. The indirect evidences are indicative of the presence of skipjack resource in the oceanic range around the island, particularly the south and west of Sri Lanka.

Effect of microbial biofilm in the nursery phase of mrigal, Cirrhinus mrigala

The experiment was conducted for 35 days in nine cement tubs (1 x 1 x 1 m) having 15 cm sandy-loam soil base with three treatments in triplicate, viz., cow dung alone at the rate of 1 kg/tub (T sub(1)), cow dung at 1 kg/tub and feed at 10% body wt/d in two meals (T sub(2)), and cow dung at 1 kg and paddy straw at 200 g/tub (T sub(3)). Both manure and substrate were added on dry weight basis. All the tubs were stocked with 10 fry each mrigal (100,000/ha) of average weight of 0.09 g, seven days after the addition of manure and substrate. The total plate count of bacteria in water did not vary much between the treatments and the mean values were 5.13, 5.49 and 5.85 (CFU x 10 super(4)/ml) in T sub(1) T sub(2) and T sub(3) respectively. The number of phytoplankters and zooplankters in water differed significantly between the treatments. The average number of attached algae (no./cm³) and fish food organisms (no./cm³) recorded on the substrate were 145.28 and 70.67, respectively. The mean final weight of mrigal differed significantly (P < 0.05) between the treatments with T sub(3) registering the highest value of 6.93 g followed by T sub(2) (5.01 g) and T sub(1) (3.37 g). The specific growth rate and growth increment of fish also followed the same trend as that of weight recorded in the different treatments. Survival was higher in T sub(2) (83.33%), followed by T sub(3) (80.00%) and T sub(1) (76.67%). The study demonstrates that by the introduction of biodegradable substrates like paddy straw into the culture systems, significantly higher growth and survival can be obtained in the nursery rearing of mrigal.

Effect of thermal pollution on the hydrological parameters of River Jhelum (J & K)

The Buniyar hydroelectric project and the lower Jhelum Barrier at Gantamulla constructed across river Jhelum are in operation from several years. The two power stations have changed the hydrological features of the area where dam is situated. Therefore, the impact of hydroelectric projects on fishery resources of river Jhelum is a matter of great concern. The treated water from the power house is released through turbines, having cooling effect on them. The change in the hydrological parameters such as increase in temperature, depletion of oxygen etc. might have brought fishes under stress which is the main cause in decreased population of finfishes from site to site. The golden mahseer, Tor putitora which was once an abundant species in river Jhelum has disappeared due to human intervention. The prevailing water quality around hydroelectric projects is unsuitable for finfishes of river Jhelum.