Field study and numerical simulation of developing red tide in the northern Strait of Hormuz

The catastrophic event of red tide has happened in the Strait of Hormuz, the Persian Gulf and Gulf of Oman from late summer 2008 to spring 2009. With its devastating effects, the phenomenon shocked all the countries located in the margin of the Persian Gulf and the Gulf of Oman and caused considerable losses to fishery industries, tourism, and tourist and trade economy of the region. In the maritime cruise carried out by the Persian Gulf and Gulf of Oman Ecological Research Institute, field data, including temperature, salinity, chlorophyll-a, dissolved oxygen and algal density were obtained for this research. Satellite information was received from MODIS and MERIS and SeaWiFS sensors. Temperature and surface chlorophyll images were obtained and compared with the field data and data of PROBE model. The results obtained from the present research indicated that with the occurrence of harmful algal blooms (HAB), the Chlorophyll-a and the dissolved oxygen contents increased in the surface water. Maximum algal density was seen in the northern coasts of the Strait of Hormuz. Less concentration of algal density was detected in deep and surface offshore water. Our results show that the occurred algal bloom was the result of seawater temperature drop, water circulation and the adverse environmental pollutions caused by industrial and urban sewages entering the coastal waters in this region of the Persian Gulf ,This red tide phenomenon was started in the Strait of Hormuz and eventually covered about 140,000 km2 of the Persian Gulf and total area of Strait of Hormuz and it survived for 10 months which is a record amongst the occurred algal blooms across the world. Temperature and chlorophyll satellite images were proportionate to the measured values obtained by the field method. This indicates that satellite measurements have acceptable precisions and they can be used in sea monitoring and modeling.

A livelihoods study of farmers and fishers in Dang Kom Village - Kandal Province

The main objective of this study was to build the capacity of the CFDO and provincial staff to conduct livelihoods studies using a more participatory approach. The livelihoods study team comprised one person from the CFDO, four people from the Kandal Provincial Fisheries Office and two from the Kandal Department of Women's Affairs. Before conducting the field study, the team members participated in a three-day training workshop on how to use various PRA tools and techniques. The study team then spent five days in the village finding out about people’s livelihoods and the resources available to them. [PDF contains 37 pages]

Effects of the Cessation of Sewage Sludge Dumping at the 12-Mile Site: Proceedings of the 12-Mile Dumpsite Symposium, Ocean Place Hilton Hotel, Long Branch, New Jersey, 18-19 June 1991

This study owes its inception to the wisdom and experience of the staff of the Northeast Fisheries Science Center who, after several decades of surveys in the New York Bight, recognized a unique opportunity to capitalize on the decision to stop ocean dumping of sewage sludge and designed an innovative field study to evaluate effects on living marine resources and their habitats. For decades ocean dumping was viewed as a cheap and effective means for disposal of wastes generated by urbanized coastal areas. Even after the 12-mile site was closed, sewage sludge continued to be dumped at Deepwater Dumpsite 106. The 6-mile site off the NewJersey coast is still used as a dumpsite for dredged material from New York Harbor areas. Discussions continue on the propriety of using the deep ocean spaces for disposal of a variety of material including low level radioactive wastes. Consequently, managers are still faced with critical decisions in this area. It is to be hoped that the results from the 12-mile study will provide the necessary information on which these managers can evaluate future risks associated with ocean waste disposal. (PDF file contains 270 pages.)

Oceanographic, meteorological, satellite and aircraft observations for project Little Window 2: May 1971

ENGLISH: In May 1971, a joint united states - Mexican experiment, Project Little Window 2, (LW-2) involving data collected by satellite, aircraft and ship sensors was made in the southern part of the Gulf of California. LW-2 was planned as an improved and enlarged version of LW-l (conducted the previous year; Stevenson and Miller, 1971) with field work scheduled to be made within a 200 by 200 km square region in the Gulf of California. The purposes of the new field study were to determine through coordinated measurements from ships, aircraft and satellites, the utility of weather satellites to measure surface temperature features of the ocean from space and specifically to evaluate the high resolution infrared sensors aboard N~ 1, ITOS 1 and NIMBUS 4 and to estimate the magnitude of the atmospheric correction factors needed to bring the data from the spacecraft sensors into agreement with surface measurements. Due to technical problems during LW-2, however, useful data could not be obtained from ITOS 1 and NIMBUS 4 so satellite information from only NOAA-1 was available for comparison. In addition, a new purpose was added, i.e., to determine the feasibility of using an Automatic picture Transmission (APT) receiver on shore and at sea to obtain good quality infrared data for the local region. SPANISH: En mayo 1971, los Estados Unidos y México realizaron un experimento en conjunto, Proyecto Little Window 2 (LW-2), en el que se incluyen datos obtenidos mediante captadores de satélites, aviones y barcos en la parte meridional del Golfo de California. Se planeó LW-2 para mejorar y ampliar el proyecto de LW-l (conducido el año anterior; Stevenson y Miller, 1971), realizándose el trabajo experimental en una región de 200 por 200 km cuadrados, en el Golfo de California. El objeto de este nuevo estudio experimental fue determinar mediante reconocimientos coordinados de barcos, aviones y satélites la conveniencia de los satélites meteorológicos para averiguar las características de la temperatura superficial del océano desde el espacio, y especialmente, evaluar los captadores infrarrojos de alta resolución a bordo de NOAA 1, ITOS 1 Y NIMBUS 4, y estimar la magnitud de los factores de corrección atmosféricos necesarios para corregir los datos de los captadores espaciales para que concuerden con los registros de la superficie. Sin embargo, debido a problemas técnicos durante LW-2, no fue posible obtener datos adecuados de ITOS 1 y NIMBUS 4, as1 que solo se pudo disponer de la información de NOAA 1 para hacer las comparaciones. Además se quiso determinar la posibilidad de usar un receptor de Trasmisión Automático de Fotografias (APT) en el mar para obtener datos infarojos de buena calidad en la región local. (PDF contains 525 pages.)

Application of an acoustic–trawl survey design to improve estimates of rockfish biomass

Biomass estimates of several species of Alaskan rockfishes exhibit large interannual variations. Because rockfishes are long lived and relatively slow growing, large, short-term shifts in population abundance are not likely. We attribute the variations in biomass estimates to the high variability in the spatial distribution of rockfishes that is not well accounted for by the survey design currently used. We evaluated the performance of an experimental survey design, the Trawl and Acoustic Presence/Absence Survey (TAPAS), to reduce the variability in estimated biomass for Pacific ocean perch (Sebastes alutus). Analysis of archived acoustic backscatter data produced an acoustic threshold for delineating potential areas of high (“patch”) and low (“background”) catch per unit of effort (CPUE) in real time. In 2009, we conducted a 12-day TAPAS near Yakutat, Alaska. We completed 59 trawls at 19 patch stations and 40 background stations. The design performed well logistically, and Pacific ocean perch (POP) accounted for 55% of the 31 metric tons (t) of the catch from this survey. The resulting estimates of rockfish biomass were slightly less precise than estimates from simple random sampling. This difference in precision was due to the weak relationship of CPUE to mean volume backscattering and the relatively low variability of POP CPUE encountered. When the data were re-analyzed with a higher acoustic threshold than the one used in the field study, performance was slightly better with this revised design than with the original field design. The TAPAS design could be made more effective by establishing a stronger link between acoustic backscatter and CPUE and by deriving an acoustic threshold that allows better identification of backscatter as that from the target species.

Mussel recovery and species dynamics at four California rocky intertidal sites: 1992 data report

This is an interim report for a study of mussel recovery and species dynamics at four California rocky intertidal sites. Conducted by Kinnetic Laboratories, Inc. (KLI), and funded by the Minerals Management Service (MMS), the initial experimental field study began in spring 1985 and continued through spring 1991. The initial field study included six sites along the central and northern California coast. In 1992, MMS decided to continue the work started by KLI through an in-house study and establishment of the MMS Intertidal (MINT) team. Four of the original six sites have been continued by MMS. The study methods of the original study have been retained by the MINT team, and close coordination with the original KLI team continues. In 1994, the MMS Environmental Studies Program officially awarded a contract to the MINT team for this in-house study. This interim report presents the results from the fall 1992 sampling, the first year of sampling by the MINT team. The report presents a limited statistical analysis and visual comparison of the 1992 data. The next interim report will include data collected during fall 1994 and will present a broader statistical analysis of both the 1992 and 1994 data sets.

Lake Nasser fisheries: literature review and situation analysis

This study sought to improve the baseline knowledge of the fisheries of Lake Nasser and to make recommendations for the improved management of the fisheries, including stock assessment. This review draws heavily from the most recent reviews of Lake Nasserr and its fisheries, including van Zwieten et al. (2011), Habib et al. (2014) and Habib (2015). It is supplemented with findings from the field study described in the final technical report, Lake Nasser fisheries: Recommendations for management, including monitoring and stock assessment (Halls 2015).

The fishery potential of the minor lake (Nabisojjo) - Luwero District

Luwero district before the creation of Nakasongola District had a share of south-western portion of Lake Kyoga. After loosing the portion of the lake, they want to resort the minor lake (Nabisojjo) for supply of fish at least to the population around this lake. The plans were to start commercial fishing. The lake is 45 km from Luwero town adjacent 10 the road going to Ngoma town. River Nabisojjo, a tribulary of river Mayanja flows through the lake on its way to river Kafu. The main objective of the scientific field study on Lake Nabisojjo was therefore to generate information on the status of the lake fishery and recommend to the local authorities the next line of action.

Ecosystem structure of Gomishan Wetland

Gomishan Wetland is situated in the extreme southern part of the eastern coast of Caspian Sea. It is connected to the Caspian Sea, so its hydrological features are directly generated from the sea. The whole wetland area (which also consists of the northern part of the wetland that is situated in Turkmenistan republic) is calculated with the aid of the Satellite Images for the years of 1977, 1987 and 1998 respectively 5070, 16320 and 29520 hectares. To have better ideas about food chains in the aquatic ecosystem, five permanent stations was appointed in different parts of the wetland. During one year field study, at the beginning of each month, physical, chemical and biological characteristics of the water and the sediment was surveyed and different specimens were gathered, fixed and took to the laboratories for the relevant analyses. The factors measured in water samples were mainly consist of turbidity, pH, EC, DO, BOD, PO4, NO3, alkalinity, Cl and hardness . The factors measured from sediment samples were the percentage of Sand, Very Fine Sand, Silt, Clay, K, P, N, and Organic Carbon. Biological examinations of the water has been consist of planktonic sample collections, determination, counting and analysis of both phyto and zoo planktons of the wetland. For example the zooplanktons of the Gomishan Wetland are determined in 15 groups, belonging to 5 phyla. The seasonal changes are recognized considerable. The least density of the zooplanktons is occurred in February. The density of most of the groups is seen from the beginning of the summer until the mid autumn. The annual mean density for any 15-zooplankton groups and also the minimum and maximum density with %95 confidences, for each of them, is calculated for the environment of all of the stations and also for the whole wetland. The spatial distribution of the individuals within the population of each of the groups is introduced, according to regular or contagious or random distribution. Diversity indices are calculated for the zooplanktons living in the environment of the stations. Comparison of the wetland, with the southeastern Caspian Sea, from the point of view of zooplankton density and diversity is also obtained. Benthos invertebrates in each station from sediment samples were also extracted. The specimens were colored by Rose Bengal solvent and then were determinate and counted, in separate groups of macro and meio benthos. Among the macro benthos, the highest density was seen in the species of Fyrgula caspia. After that, more density was seen respectively in Apra ovata, Cerastoderma sp., Balanus sp., Nerds divesicolarr, lifytilaster lineatus and Dreissena sp. Among the meio benthos, the most density was seen in Foraminifera and then respectively in Ostracoda, Nernatoda and Bivalve larvae. The indices of diversity and distribution are also calculated. As the birds in this lagoon are of prime importance, all mid winter waterfowl censuses available from recent 13 years are gathered and analysis. Also a whole year (12 times, each at the beginning of one month) waterfowl census was undertaken, throughout the wetland. According to this study, the Eastern Ecosystem of the wetland, is supporting the most population (%75) of the waterfowls, the Middle Open Water Ecosystem and the Western Reed bed Ecosystem, are supporting respectively %14 and %11 of the population. Four of the species are found in the global threatened red list, and the wintering population of the 20 species of the site, in some years, are observed more than %I of the global populations. The Waterfowl Species Diversity and Similarity Indices are given also.

Invertebrate communities of Nabugabo Lakes: a vital support resource for the fisheries and ecosystem diversity

A field study of the invertebrate communities of the Nabugabo lakes(Nabugabo,Kayanja and Kayugi)showed the occurrence of copepoda, cladocera and rotifera(micro-invertebrates or zooplankton); Ephemeroptera and Diptera(macro-invertebrates or zoo-benthos). The most commonly encountered taxa were thermocyclops neglectus, moinamicrura,several rotiferan species(micro-invertebrates);P.adusta,chironomus, tanipodinae and trichoptera(macro- invertebrates). These organisms are assumed to be readily available as food sources for fishes in the Nabugabo lakes. Higher abundance and diversity of invertebrates occurred in Lake Nabugabo compared to Kayanja and Kayugi. There were no major differences in diversity and abundance of organisms between inshore and offshore areas of the different lakes. The highest diversity of macro-invertebrates(up to 15 taxa)was recovered from roots of macrophyte(higher water-based plants)such as Miscanthidium and Papyrus. The zooplankton of Nabugabo lakes typify a tropical assemblage with few species among genera and dominance of the communities by small-bodied organisms. Some taxa,common to many other water bodies such as Mesocyclops spp.,Calanoids(Copepoda), Caridina nilotica (Decapoda)were noticeably missing in the Nabugabo lakes community, probably due to environmental limitations including low conductivity and pH. Where they occur,these missing taxa have been shown to be key forage items for fishes and therefore their absence in Nabugabo lakes may have implications with respect to potential for fishery production. However other valuable invertebrate types such as cyclopoid copepods,ephemeroptera, chironomid and chaoborid larvae do occur in sufficiently high diversity and abundance to support viable fisheries resources. The high diversity and abundance of invertebrates associated with aquatic macrophytes such as Papyrus and Miscanthidium need to be protected through control of access and utilisation of shoreline vegetation.