Fish movement patterns in Virgin Islands National Park, Virgin Islands Coral Reef National Monument and adjacent waters

NOAA’s National Centers for Coastal Ocean Science (NCCOS)-Center for Coastal Monitoring and Assessment’s (CCMA) Biogeography Branch, National Park Service (NPS), US Geological Survey, and the University of Hawaii used acoustic telemetry to quantify spatial patterns and habitat affinities of reef fishes around the island of St. John, US Virgin Islands. The objective of the study was to define the movements of reef fishes among habitats within and between the Virgin Islands Coral Reef National Monument (VICRNM), the Virgin Islands National Park (VIIS), and Territorial waters surrounding St. John. In order to better understand species’ habitat utilization patterns among management regimes, we deployed an array of hydroacoustic receivers and acoustically tagged reef fishes. Thirty six receivers were deployed in shallow near-shore bays and across the shelf to depths of approximately 30 m. One hundred eighty four individual fishes were tagged representing 19 species from 10 different families with VEMCO V9-2L-R64K transmitters. The array provides fish movement information at fine (e.g., day-night and 100s meters within a bay) to broad spatial and temporal scales (multiple years and 1000s meters across the shelf). The long term multi-year tracking project provides direct evidence of connectivity across habitat types in the seascape and among management units. An important finding for management was that a number of individuals moved among management units (VICRNM, VINP, Territorial waters) and several snapper moved from near-shore protected areas to offshore shelf-edge spawning aggregations. However, most individuals spent the majority of their time with VIIS and VICRNM, with only a few wide-ranging species moving outside the management units. Five species of snappers (Lutjanidae) accounted for 31% of all individuals tagged, followed by three species of grunts (Haemulidae) accounting for an additional 23% of the total. No other family had more than a single species represented in the study. Bluestripe grunt (Haemulon sciurus) comprised 22% of all individuals tagged, followed by lane snappers (Lutjanus synagris) at 21%, bar jack (Carangoides ruber) at 11%, and saucereye porgy (Calamus calamus) at 10%. The largest individual tagged was a 70 cm TL nurse shark (Ginglymostoma cirratum), followed by a 65 cm mutton snapper (Lutjanus analis), a 47 cm bar jack, and a 41 cm dog snapper (Lutjanus jocu). The smallest individuals tagged were a 19 cm blue tang (Acanthurus coeruleus) and a 19.2 cm doctorfish (Acanthurus chirurgus). Of the 40 bluestriped grunt acoustically tagged, 73% were detected on the receiver array. The average days at large (DAL) was 249 (just over 8 months), with one individual detected for 930 days (over two and a half years). Lane snapper were the next most abundant species tagged (N = 38) with 89% detected on the array. The average days at large (DAL) was 221 with one individual detected for 351 days. Seventy-one percent of the bar jacks (N = 21) were detected on the array with the average DALs at 47 days. All of the mutton snapper (N = 12) were detected on the array with an average DAL of 273 and the longest at 784. The average maximum distance travelled (MDT) was ca. 2 km with large variations among species. Grunts, snappers, jacks, and porgies showed the greatest movements. Among all individuals across species, there was a positive and significant correlation between size of individuals and MDT and between DAL and MDT.

Swimming crab Callinectes amnicola (Decapoda-Portunidae) capture analysis of a lagoon with high continental influence (Aby Lagoon, Cote d'Ivoire, West Africa)

The study describes the main causes of captures and productions decreasing of swimming crab Callinectes amnicola (Decapoda Portunidae) in Aby lagoon complex. For that, docks of two Sub Prefectures of Adiaké and Assini-Mafia respectively including the villages of Adiaké, Anga, Assomlan, Epleman, Aby and Man-Man, M'Bratty, Assini-Ngouankro and Assini-Mafia were studied from 2006 to 2009 and completed with previous results obtained from 1988 to 2005. Field investigators were identified by site/village and they recorded daily activities of fishermen (number of effective fishermen, number of gears and area of fishing, duration of fishing, types and quantity of bait) and landing of swimming crabs. During recent period of the study, total production decreased from 3742 tons in 2006 to 1500 tons in 2009. Matrix correlations and correlation analysis indicated that this downward trend was due to the increase of the number of fishermen, number of fishing gear, the decrease in female crabs capture and degradation of the environment related to gradual closure of the Assini-Mafia channel. Despite this decline, total production in Aby lagoon remained high compared to the productions of some lagoons of the country and the region. Given the importance of fishing swimming crabs in Aby lagoon, since it concerns many young people and it is a source of income, stringent measures for sustainable and responsible management must be taken and implemented as part of a co-management plan involving all stakeholders to sustainably manage the resource

A comparative study on the hatching of common carp eggs in hapa and hatchery (model CIFE D-80)

Common carp (Cyprinus carpio) eggs were incubated to study the efficiency of hatching in hapa and hatchery. During incubation the recorded temperature was 21-28 degree C and 20-31 degree C, dissolved oxygen 6-9 ppm. and 3-5 ppm., total alkalinity 180-250 ppm. and 28-62 ppm. respectively in the hatchery (model C.I.F.E. D-80) and hapa. CO sub(2) was totally absent in the hatchery, but recorded 3-10 ppm. in the hapa. The flow of water was maintained at 1.25 l/minute/jar in the hatchery. Under the above environmental conditions the eggs hatched in 42-51 hrs. in the hatchery and 61-81 hrs. in the hapa from egg to spawn thereby establishing the hatchery to be a better hatching system for carp eggs.

Antibacterial effect of the Indian squid, Loligo duvauceli (d'Orbigny), ink

The ink of the Indian squid Loligo duvauceli (d'Orbigny) was tested for antibacterial activity. The antibacterial effect of bacteria present in the ink gland was also tested. Only one type of bacteria was found to be present in the ink gland of squid and was identified as Photobacterium leiognathi. Among the various forms of ink extracts, the precipitated and freeze-dried ink showed more pronounced antibacterial effect against Gram-negative bacteria, Salmonella, spp. Escherichia coli, Vibrio cholerae, V. parahaemolyticus and Pseudoinonas spp., and a less pronounced effect against Gram-positive bacteria, Staphylococcus spp. and Micrococcus spp., P. leiognathi did not inhibit any of the above bacteria. The antibacterial activity was associated with the compounds of the ink.

Effects of physiological doses of vitamin D sub(3) (Cholecalciferol) on induced molting and growth in giant freshwater prawn, Macrobrachium rosenbergii (de Man)

Effects of three different doses of vitamin D sub(3) on molting, growth, and calcium and phosphate composition of tissue and molt during the grow-out of the giant freshwater prawn Macrobrachium rosenbergii (average weight 10.56 ± 0.20 g), obtained from a grow-out pond, were studied. Intramuscular doses of vitamin D sub(3) (100, 500 and 2000 IU/kg body weight) were given on the 1st, 3rd, 5th, 7th, 9th, 11th, 13th, 15th, 20th, 25th and 30th days. All the experimental animals were fed with a basal diet containing fish meal, shrimp meal, wheat flour, groundnut de-oiled cake, soybean meal and wheat bran at 3% of the body weight. The numbers of molts were recorded as 20±0.50, 29±1.16, 51±1.87, and 30±1.60 in control, 100, 500 and 2000 IU/kg body weight physiological doses, respectively. Maximum growth was recorded in prawns given 500 IU/ kg dose. Survival was between 58.33 ± 9.13 and 77.77 ± 8.61%. The ash content and calcium level increased significantly (p<0.05) and recorded the highest values in 500 IU/kg physiological dose. However, the inorganic phosphate (P sub(i)) content recorded the highest values in tissue in 2000 IU/kg dose (p<0.05, F = 50.60613). There is no significant difference in calcium contents (p>0.05) in both tissue and molt at 500 and 2000 IU/kg doses. It was found that a higher physiological dose (2000 IU/kg) of vitamin D sub(3) increased the rate of mortality. Results have shown that vitamin D sub(3) has a positive impact on the growth and survival of M. rosenbergii and it interferes with the metabolism of Ca and P sub(i), in tissue, and alters molting frequency. Results on physiological dose suggest an alternative and effective dietary supplementation method of vitamin D sub(3) in the grow-out phase of M. rosenbergii.

Economics of operation of 38' G.R.P. fishing vessels issued by the A.D.B. Fisheries Project: a case study

The author gives a financial and economic valuation of the operation of vessels in the 38 foot GRP class. He discusses particularly the materials and methods of fishing they use, species composition of their catches, their rate of return, break-even analysis, financial and social analysis.

Morphometry, length-weight relationship and biology of Sepia aculeata (d'Orbigny, 1848) from Mumbai coast, India

Seventeen morphometric characters of Sepia aculeata of Mumbai coast have been studied and the relationships of morphometric characters with dorsal mantle length (DML) were established. The characters compared showed a fair to high degree of correlation ('r' 0.63-0.99). Number of arm suckers and shell rings were related with DML. The shell rings also showed high degree of correlation with DML ('r' 0.79-0.95). However, the relationship between arm suckers and DML was not so good ('r' 0.1-0.4). The length-weight relationship is described as W=0.1821336 L sub(2.801102). Food and feeding analysis confirm the carnivorous feeding behaviour of the species. Mature females found in all months indicate that it has prolonged spawning season with two peaks, september and march-april. Absolute fecundity ranged from 214 to 4143 eggs.

Response of fishes to the underwater D.C. field

Response to external electric field (D. C.) of three different varieties of fish namely Puntius ticto, Heteropneustis fossilis and Tilapia mossambica having different anatomical and behavioural characteristics were studied. Clearly distinguished reactions occurred one after another m all the varieties of fish with the increase in field intensity with minor specific variations. These reactions can be broadly classified into initial start (first reaction), forced swimming (galvanotaxis), slackening of body muscle (galvanonarcosis) and state of muscular rigidity (tetanus). The orientation of the organism (projection of nervous element) to the surrounding field has been found to have important bearing on the behaviour reactions. Clearly differentiated anodic taxis and true narcosis set in when fish body axis was parallel to the lines of current conduction. But with greater angle between the body axis and the current lines, fish did not show well marked reactions. Fish body, when perpendicular to current lines responded for anodic curvature and off balance swimming followed by tetanus.

Induced breeding of Indian carps using Des Gly^10 [D-Ala^6] LHRH ethylamide

Details are given of a study conducted in order to determine the efficacy of Des Gly^10 [D-Ala^6] LHRH ethylamide in the induction of spawning in Cirrhinus mrigala and Labeo fimbriatus . Findings shows this LHRH analogue to be a promising substitute for the pituitary gland extract which is currently used. Further studies are required to standardize the dose and method of administration in the various cultivable species in India.

Abalone R&D at AQD

Details are given of the results of research conducted at the SEAFDEC Aquaculture Department on abalone (Haliotis asinina). The following areas are covered: reproductive biology; induced spawning; raising abalone in the hatchery; and, cage culture trials.