Marine Debris Survey Manual

Over the last several years, concern has increased about the amount of man-made materials lost or discarded at sea and the potential impacts to the environment. The scope of the problem depends on the amounts and types of debris. One problem in making a regional comparison of debris is the lack of a standard methodology. The objective of this manual is to discuss designs and methodologies for assessment studies of marine debris. This manual has been written for managers, researchers, and others who are just entering this area of study and who seek guidance in designing marine debris surveys. Active researchers will be able to use this manual along with applicable references herein as a source for design improvement. To this end, the authors have synthesized their work and reviewed survey techniques that have been used in the past for assessing marine debris, such as sighting surveys, beach surveys, and trawl surveys, and have considered new methods (e.g., aerial photography). All techniques have been put into a general survey planning framework to assist in developing different marine debris surveys. (PDF file contains 100 pages.)

Survey of fishes and water properties of south San Francisco Bay, California, 1973-82

The objective of this study was to describe the physical and ichthyological changes occurring seasonally and annually in the south San Francisco Bay, based on the results of 2,561 otter trawl and water samples obtained between February 1973 and June 1982. Temperature varied predictably among seasons in a pattern that varied little between years. Salinity also underwent predictable seasonal changes but the pattern varied substantially between years. The most abundant species of fish were northern anchovy (Engraulis mordax), English sole (Parophrys vetulus), and shiner surfperch (Cymatogaster aggregata). The majority of the common fish species were most abundant during wet years and least abundant in dry years. Numeric diversity was highest during the spring and early summer, with no detectable interannual trends. Species composition changed extensively between seasons and between years, particularly years with extremely high or extremely low freshwater inflows. All the common species exhibited clustered spatial distributions. Such spatial clustering could affect the interpretation of data from estuarine sampling programs. Gobies (Family Gobiidae) were more abundant during flood tides than during ebb tides. English sole were significantly more abundant in shallower areas. Shiner surfperch showed significant differences in abundance between sample areas.(PDF file contains 28 pages.)

Survey of fish protective facilities at water withdrawal sites on the Snake and Columbia Rivers

Proliferation of water withdrawals and new pump intake and screen designs has occurred with the growth of irrigated agriculture along the Columbia and Snake Rivers. Concern for the protection of anadromous and resident fish populations resulted in formulation of a survey of the water withdrawal systems. The survey included distribution studies of juvenile fish near pump sites and field inspection of those sites to determine adequacy of screening for protection of fish. A total of 225 sites were inspected in 1979 and 1980, with a follow-up inspection of 95 sites in 1982. Results indicated a definite trend toward lack of concern for the condition of fish protective facilities. Only 4 out of 22 sites not meeting criteria in 1979 had been upgraded to acceptable conditions. Of more concern, 13 of the sites meeting criteria in 1979 were below criteria when reinspected in 1982. Some of the discrepancies included lack of protective screens, poorly maintained screens, and screens permitting excessive velocity that could result in impingement of larvae or small fish. A conclusion from these surveys is that if adequate protection for fish is to exist, screens for water withdrawals need to be properly installed, inspected, and maintained. (PDF file contains 40 pages.)

Ichthyoplankton survey of the estuarine and inshore waters of the Florida Everglades, May 1971 to February 1972

Quarterly ichthyoplankton sampling was conducted at 16 estuarine and 24 inshore stations along the Florida Everglades from May 1971 to February 1972. The area is one of the most pristine along lhe Florida coast. The survey provided the first comprehensive information on seasonal occurrence, abundance (under 10 m' of surface area), and distribution of fish eggs and larvae in this area. A total of 209,462 fish eggs and 78,865 larvae was collected. Eggs were identified only as fish eggs, but among the larvae, 37 families, 47 genera, and 37 species were identified. Abundance of eggs and larvae, and diversity of larvae, were greatest in the inshore zone. The 10 most abundant fish families which together made up 90.7% of all larvae from the study area were, in descending order of abundance: Clupeidae, Engraulidae, Gobiidae, Sciaenidae, Carangidae, Pomadasyidae, Cynoglossidae, Gerreidae, Triglidae, and Soleidae. Clupeidae, Engraulidae, and Gobiidae made up 59.9% of all larvae. The inshore zone (to a depth of about 10 m) was a spawning ground and nursery for many fishes important to fisheries. The catch of small larvae (<>3.5 mm SL) indicated that most fishes identified from the 10 most abundant families spawned throughout the inshore zone at depths of <> 10 m, but Orthopristis chrysoptera, Gerreidae, and Prionotus spp. spawned at depths > 10 m, with offshore to inshore (eastward) larval transport. Salinity was one of several environmental factors that probably limited the numbers of eggs and larvae in the estuarine zone. Abundance of eggs and larvae at inshore stations was usually as great as, and sometimes greater than, the abundance of eggs and larvae at offshore stations (due west of the Everglades). (PDF file contains 81 pages.)

Survey of El Nino 1957-58 in its relation to tropical pacific meteorology

ENGLISH: The survey aims at demonstrating the close relationship between anomalies of sea temperature observed along the tropical Pacific coast of the Americas and those observed in the oceanwide tropical belt. The survey also covers the variations, from 1952 to the present, of the trade-wind circulations which prove to be responsible for the major part of the anomalies in sea surface temperature. Finally, the thermal feedback effects of the oceanic anomalies upon the large-scale circulation of the atmosphere are treated in a preliminary fashion. SPANISH: El estudio trata de demostrar la estrecha relación que existe entre las anomalías observadas de la temperatura del mar a lo largo de la costa tropical de las Américas y las observadas en la faja tropical de todo el océano. El estudio incluye también las variaciones, desde 1952 hasta el presente, de la circulación de los vientos alisios que demuestra ser responsable por la mayor parte de las anomalías de temperatura de la superficie del mar. Finalmente los efectos termales de las anomalías oceánicas sobre la circulación en gran escala de la atmósfera son tratados en forma preliminar. (PDF contains 62 pages.)

A summary of the inventory survey of Nigeria inland waters and preliminary estimates of their fish yield potentials

A summary of the inventory survey of Nigeria inland waters is presented. The survey reveals that Kano State tops the list in reservoir development with an existing water surface area of about 42,773 ha, while Anambra State has the least with about 38 hectares. No reservoir was recorded for Lagos and Rivers States. However, in aspects of existing fish ponds, a total of about 471 ha was recorded for Plateau State and about 5 ha for Niger State. Preliminary estimates of Nigeria's fish yield potentials based on established production records of comparable water bodies in the tropics, at different levels of management, show that the available water mass in the country, estimated at about 12.5 million hectares, could yield a minimum of about 334,214 metric tonnes (m.t.) of fish per annum with little or no management and a maximum of about 511,703 metric tonnes per annum with adequate management. Comparison of the potential yields from inland sources with the projected fish production in Nigeria (1981-1985) based on supply and demand statistics shows that potential yield from inland sources even at a low level of management is relatively higher than the projected inland production and more than double the observed production. The variation between the potential and the observed fish yields in the country has been attributed to the absolute lack of management strategies for our various inland waters. The paper elaborates on possible management strategies for various categories of inland waters as a prelude towards increased fish production in the country

Market survey of the periwinkle Tympanotonus fuscatus in Rivers State: Sizes, prices, trade routes and exploitation levels

Tympanotonus fuscatus was collected from 23 markets through Rivers State (Nigeria), a few in neighbouring states, and from an unexploited population at Buguma. The size distribution of shells was determined,and information on prices and trade routes was also obtained. The mean shell length of specimens from the unexploited Buguma population was 46.4 mm, compared to 30.4 mm for the Buguma market samples. Mean sizes in other markets showed a geographic pattern: the smallest were from the Adoni-Ogoni-Opobo sector (28.1-30.9); the largest were from the Nembe-Brass sector (37.7-44.2) and Bendel State (35.7-45.6); The results suggest the population structure of Tympanotonus in much of Rivers State has been strongly impacted by overharvesting. They show that local market as well as some in Cross River State, are increasingly being supplied by road with specimens from the Benin River area of Bendel State. Differences between shell types; and relations between shell size, selling price and market distance from source, are also discussed

Culturable fish seeds in Nigerian waters: A research survey (1978-1985)

The desired species identified in this survey include mullets, catfishes, fast growing fish predators, species for control of weeds and grass it, ponds, cichlids and shrimps. Five coastal states: Lagos, Ondo, Bendel, Rivers, and Cross River were covered in the studies. Investigations were also carried into the major rivers and their tributaries. A combination of the estimation methods of Le Cren, (1962) and Pitcher and Mac Donald (1973) was employed in the analysis of data. From the detailed data collected from (1978-1985), the survey indicated that about 100 million fish seeds can be collected annually from Nigerian waters using appropriate gear-seine nets, cast nets, and fish traps. Of this number, 60% is available along the coastal belt of the country while 40% is in the major rivers, their tributaries and swamps. At the present level of fish culture development in Nigeria, this is more than enough, even after allowing for 50% mortality due to handling and transportation stress

A preliminary survey of the helminth fish parasites in Imo River

A preliminary survey of the helminth fish parasites was carried out in Imo River (Nigeria). A total of 191 fishes belonging to 15 genera were examined and only 13.6% were infested with various species of helminth parasites which is low percentage of infection. The following helminth parasites were recorded. Wenyonia virilis, kainji; Wenyonia sp., Procamallanus laeviconchus; Procamallanus sp., Sprionoura congolense; Spironoura sp., Cucullanus sp. and Serradacnitis serrata. It was found that helminth parasites showed some degree of specificity in their distribution within their fish hosts. This specificity could be as a result of the physiochemical and physiological factors operating in the gut such as pH, osmotic tension, oxygen tension and nutrient levels. The results also revealed that age and sex influence helminth parasites infections in fishes

Preliminary survey of parasites of Clarias in the Niger Delta area of Nigeria

A total of 160 Clarias lazera were collected with line hood between April and June 1984 from the Niger Delta area and observed for the presence of parasites. The results revealed the presence of three classes of endo-parasites: Trematodes (47%), nematodes (46%) and cestodes (7%). It was found that, the parasites have great affinity for the spleen (34%) and the liver (28.3%). Also, smaller fish habored more parasites than large fish. Though the investigation is still continuing, the study reveals the presence of parasites in Clarias and calls for measures to prevent wide-spread infestation in fish ponds and suggests treatment of infested fish

Data collected on tuna spawning survey cruise July 1-20, 1957: data report

Studies of gonads of yellowfin and skipjack tunas (Neothunnus macropterus and Katsuwonus pelamis) carried out by the Inter-American Tropical Tuna Commission indicate that during summer months the offshore area in the region of the Revilla Gigedo Islands is a spawning location for these two species (Schaefer and Orange, 1956). In July of 1957 a cruise "Tuna Spawning Survey" was made aboard the vessel ORCA to make plankton hauls and to collect ancillary data for the primary purpose of surveying abundance of tuna larvae in this region. (PDF contains 17 pages.)

Application of participatory rural appraisal (PRA) techniques in the verification of fisheries data and trend on Lake Kainji

After several years of surveys on the Kainji Lake fisheries activities by the Nigerian German Kainji Lake Fish promotion Project (KLFPP) trends regarding catches, yield and other parameter begin to emerge. However, it became obvious that some of the data were not quite as accurate as they were believed to be. Looking at the different editions of the statistical bulletin of Kainji Lake, concerning one given fisheries parameter, sometimes it is possible to reveal inconsistencies and unexplained trends. As compared to the survey method, PRA is primarily for analysis of differences in local phenomenon and processes. Therefore, PRA was used as a complementary tool to enhance the knowledge on issues like fisher women, entrepreneurs, gear ownership structure, mode of operation by owners of large gear number, preference in the use of twine and nylon gill nets, and reasons for misinformation on the number of fishing equipment owned by entrepreneurs, which cannot be done with frame survey. PRA techniques like timeline, mapping, seasonal calendar, transect walk and key informant interviews were utilized in the study process

Fishing gears survey of Lake Chad

The paper reports on a survey on gear assessment for the three intensive fishing seasons in Lake Chad (Nigeria). These seasons coincide with the flood period (Nov-Feb), the receding (March-June)and the recession period (July-September 2001). During this year the questionnaires were requested to ten fishers in each of the selected fishing islands. In the flood season, identified fishing gears on the lake included baited and un-baited Malian traps which constituted about 35% of the total gears recorded. While Ndurutu and Heri (Kung)traps represented, each, 3.2% of the total. About 15.9% of fishers employed hook lines of various length and sizes: Another 15.9% of fishers mounted fish fences (Dumba) during the season. Those that employ seine net accounted for about 11.1% while 9.5% use gill nets.The species belonging to the Cichilidae, Claridae and Osteoglossidae families dominated fish catches. During the receding period, hook lines and fences (Dumba) (6.20%) were found to be predominantly used on the lake due to reducing water level, followed by gill net and draw net which accounted for 17.9% and 16.1 % respectively. During the lake recession only two groups of active gears were recorded. Sixty percent of fishers use combined seine net with cutlass and scoop net, while 40% use to combine only cutlass with kabara net. Fish fences (Dumma)during the flood season were mounted with giant Malian traps of abut 1.5m by 0.5m diameter, covered with net of mesh size (6.3mm-25mm).Each Dumba contained between 150 and 2000 of such traps. Larger number of species was recorded from seine net followed by gill nets and the l kilometre multi mesh fleet drift net. The use of seine net and cutlass known as Genima was predominant during the lake recession

Fishing gear survey of Lake Alau

This report briefly documents the fishing gear commonly used by local fishers in Lake Alau (Nigeria). Five types of gears are described: gill-net, cast net, Gura trap, longlines, and Clap net

The survey of Lake Victoria's fishers

The findings are presented of a survey conducted regarding the fishers of Lake Victoria, which examined the relationships affecting supply flows of raw material on to the market, and also the characteristics of fishing activities and their effects on fish quality and distribution. Fish marketing plays a vital role in the lives of much of the lake basin's population, both in terms of employment and nutrition. The results of the survey comprise, in part, a base-line data set which will facilitate further research, analysis and management decision-making in relation to stakeholders of the lake's resources. Data collection, methods and research difficulties encountered are described and details given of a profile of a boat owner/renter and aslo of a profile of a crew member. The survey shows that Lake Victoria's fishery is one of very limited diversity. The fishers recount that they consistently target one or more of the 3 most common species within the lake (Nile perch, tilapia and dagaa) and very rarely consider any other species type. The largest proportion of fishers on the lake are Nile perch fishers; there is considerable demand for this species, and hence fishers have little incentive to either target alternative fish species, not to try and establish firm marketing outlets through the creation of arrangements with their principal buyers. In Kenyan waters, however, the number of Nile perch fishers is equaled by the number of dagaa fishers; this fish now commands a considerable portion of the market for fish from Lake Victoria through its availability as well as its relatively low prices. The tilapia fishery is in decline, and all 3 riparian states would not appear to be attracting investment almost certainly as a result of declining catches. For many of those working in Lake Victoria's fishery, the problems faced appear most often to be associated with the vagaries of an unstable market which may rise or fall depending on the state of the international market or the state of access roads to fish landings. (PDF contains 42 pages)