Spatial distribution of Chlorpyrifos and Endosulfan in USA coastal waters and the Great Lakes

Between 1994 and 1997, 258 tissue and 178 sediment samples were analyzed for chlorpyrifos throughout the coastal United States and the Great Lakes. Subsequently, 95 of the 1997 tissue samples were reanalyzed for endosulfan. Tissue chlorpyrifos concentrations, which exceeded the 90th percentile, were found in coastal regions known to have high agricultural use rates but also strongly correlated with sites near high population. The highest concentrations of endosulfans in contrast, were generally limited to agricultural regions of the country. Detections of chlorpyrifos at several Alaskan sites suggest an atmospheric transport mechanism. Many Great Lakes sites had chlorpyrifos tissue concentrations above the 90th percentile which decreased with increasing distance from the Corn Belt region (Iowa, Indiana, Illinois, and Wisconsin) where most agriculturally applied chlorpyrifos is used. Correlation analysis suggests that fluvial discharge is the primary transport pathway on the Atlantic and Gulf of Mexico coasts for chlorpyrifos but not necessarily for endosulfans. (PDF contains 28 pages)

Wadge Bank trawl fishery studies. Pt. 4. An analysis of the length frequency measurements of the sea bream (Lethrinus nebulosus) made in 1949 and 1953 to 1958

Length frequency distributions of the sea bream collected during the period 1953 to 1958 have been analysed. The increase in average sizes of the sea bream with depth suggests a movement to deeper waters with increase in size. By numbers, the sea bream is more abundant between 21 and 30 fathoms than in deeper areas. The recruitment was continuous and regular. There is no sign of entry or progression of a dominant brood throughout the period under study. Length frequency distribution shows three distinct modes. The first mode occurs regularly but does not progress beyond 40cm, recruitment being balanced by natural and fishing mortality. The other two which are not regular are probably the result of fishing outside regular areas. Short sections of “growth” lines which fit into one another when extrapolated, are evident. The larger lines obtained by extrapolation are parallel to one another. These tentative "growth lines" indicate that this species which enters the fishing grounds, when 15 cm or larger in length are exploited by the trawl fishery for a period of three to four years. This species appears to be six months old when it enters the fishing grounds and increases in length by about 37.5 cm in the next 30 months. Later growth slows down. The average size of the specimens sampled continued to get smaller from 1953 till 1957. It is shown that this reduction in size is due to increased fishing effort.

The fishing centres of Lake Niassa (Mozambique): results of a frame survey made in June 1983

Results of the first frame survey of the fishing centres on the Mozambican coast of Lake Niassa, held in June 1983, are presented. A total of 41 fishing centres were detected in the area and visited. Through direct enquiries in each centre, an estimated number of 3,380 fishermen and 1,230 fishing boats (of which 25 motorized) was established. The results also provided information on the types and quantities of fishing gear used. A first estimation of the approximate total annual catch in the area gave a figure in the order of 9,100 tons., of which approximately equals 90% is landed during the rainy season. The survey is a part of a research programme on the fishing resources of Lake Niassa and of a project for the collection and organization of fisheries statistics from the artisanal fisheries of the Mozambican side of Lake Niassa.

Observations on the spawning of four species on tuna (Neothunnus macropterus, Katsuwonus pelamis, Auxis thazard and Euthynnus lineatus) in the Eastern Pacific Ocean, based on the distribution of their larvae and juveniles

ENGLISH: Knowledge of spawning habits is useful in the elucidation of the life history, ecology and population structure of tropical tunas, and is essential to the sound management of these resources. Until recently, little was known concerning the spawning of tunas, or about the distribution of their larval and juvenile stages, in the Eastern Pacific Ocean. Nichols and Murphy (1944) reported the capture off Colombia of young scombroids ultimately identified as frigate mackerel, Auxis thazard (Schaefer and Marr, 1948a). Fowler (1944) reported the capture off Manzanillo, Mexico of two young tunas, one of which is definitely and the other most likely Neothunnus macropterus (Klawe, 1959). In 1947, young of N. macropterus, K. pelamis, A. thazard and E. lineatus were caught offshore from Central America (Schaefer and Marr, 1948a, 1948b, and Schaefer, 1948). Further collections of young N. macropterus, A. thazard and E. lineatus were made in the same general area in the spring of 1949 (Mead, 1951). In January and February 1955, Clemens (1956) carried Out experiments in rearing young tunas, E. lineatus and A. thazard, in shipboard aquaria, using fish caught off Central America. Matsumoto (1958) reported captures of larval N. macropterus and K. pelamis in the area along the 120th meridian of west longitude. Klawe (1958 and 1961b) reported captures of larval N. macropterus and Auxis from the Revillagigedo Islands. Captures of young Auxis and E. lineatus in the Gulf of Panama in January 1922 during the Dana Expedition have recently been reported by Matsumoto (1959). Capture of juveniles of K. pelamis, E. lineatus and Auxis in the area off tropical Mexico and in the area of outlying islands during the SCOT Expedition has been reported by Klawe (1960a). SPANISH: El conocimiento sobre los hábitos del desove es útil para el esclarecimiento de la historia natural, ecología y estructura de las poblaciones de atunes tropicales, y es esencial para la acertada administración de estos recursos. Hasta hace poco tiempo no se sabía mucho sobre el desove de los atunes o acerca de la distribución de sus larvas y juveniles en el Océano Pacífico Oriental. Nichols y Murphy (1944) informaron sobre la captura frente a Colombia de escómbridos jóvenes últimamente identificados como melva, Auxis thazard (Schaefer y Marr, 1948a). Fowler (1944) también informó sobre la captura de dos atunes jóvenes frente a Manzanillo, México, uno de los cuales era definitivamente Neothunnus macropterus y el otro era lo más probable que también lo fuera (Klawe, 1959). En 1947 se capturaron especímenes juveniles de N. macropterus, K. pelamis, A. thazard y E. lineatus frente a la América Central (Schaefer y Marr, 1948a, 1948b, y Schaefer, 1948). Otras recolecciones de ejemplares jóvenes de N. macropterus, A. thazard y E. lineatus fueron hechas en la misma área general durante la primavera de 1949 (Mead, 1951). En enero y febrero de 1955, Clemens (1956) efectuó experimentos de crianza de atunes jóvenes, E. lineatus y A.. thazard, en acuarios a bordo para lo que empleó peces capturados frente a la América Central. Matsumoto (1958) informó sobre capturas de larvas de N. macropterus y K. pelamis en el área a lo largo del meridiano 120 de longitud oeste. Klawe (1958 y 1961b) ha dado cuenta también de capturas de larvas de N. macropterus y Auxis en las Islas Revillagigedo. Matsumoto (1959) ha informado recientemente acerca de capturas de ejemplares jóvenes de Auxis y E. lineatus en el Golfo de Panamá en enero de 1922 durante la Expedición Dana. Klawe (1960a) informó así mismo que durante la Expedición SCOT se capturaron juveniles de K. pelamis, E. lineatus y Auxis en el área frente a la zona tropical de México y en la región de las islas alejadas del continente.

Schooling habits of yellowfin tuna (Neothunnus macropterus) and skipjack (Katsuwonus pelamis) in the Eastern Pacific Ocean, as indicated by purse seine catch records, 1946-1955

ENGLISH: These aspects of the schooling habits of the yellowfin and skipjack tuna may be investigated by means of the logbook records of the catches of individual sets of the nets of purse-seine vessels. For both purposes it must be assumed that a set is made, in each case, on a single school of fish. The study of school sizes based on these data requires the additional assumption either that the entire school is captured or that each set captures a constant fraction of the school upon which it is made. In this paper we report on the results of such investigations based on logbook records of the purse-seine fleet. SPANISH: Estos aspectos de los hábitos gregarios de los atunes aleta amarilla y barrilete pueden ser investigados a base de los registros de bitácora en que se anotan las pescas resultantes de cada una de las operaciones con la red de encierre que realizan los barcos rederos. Para ambos propósitos hay que suponer que las operaciones se efectúan, en cada caso, en un cardumen independiente. El estudio de los tamaños de los cardúmenes o manchas, a base de estos datos, requiere una suposición adicional: que el cardumen entero es capturado o, en su defecto, que en cada operación con la red se pesca una fracción constante de la mancha objeto de la pesca. En el presente artículo damos cuenta de los resultados de dichas investigaciones basadas en los registros de bitácora que lleva la flota de embarcaciones que utilizan redes de encierre. (PDF contains 47 pages.)

Evaluating approaches and technologies for monitoring organic contaminants in the aquatic environment, Ann Arbor, MI, July 21-23, 2006: workshop proceedings

The Alliance for Coastal Technologies (ACT) convened a workshop on Evaluating Approaches and Technologies for Monitoring Organic Contaminants in the Aquatic Environment in Ann Arbor, MI on July 21-23, 2006. The primary objectives of this workshop were to: 1) identify the priority management information needs relative to organic contaminant loading; 2) explore the most appropriate approaches to estimating mass loading; and 3) evaluate the current status of the sensor technology. To meet these objectives, a mixture of leading research scientists, resource managers, and industry representatives were brought together for a focused two-day workshop. The workshop featured four plenary talks followed by breakout sessions in which arranged groups of participants where charged to respond to a series of focused discussion questions. At present, there are major concerns about the inadequacies in approaches and technologies for quantifying mass emissions and detection of organic contaminants for protecting municipal water supplies and receiving waters. Managers use estimates of land-based contaminant loadings to rivers, lakes, and oceans to assess relative risk among various contaminant sources, determine compliance with regulatory standards, and define progress in source reduction. However, accurately quantifying contaminant loading remains a major challenge. Loading occurs over a range of hydrologic conditions, requiring measurement technologies that can accommodate a broad range of ambient conditions. In addition, in situ chemical sensors that provide a means for acquiring continuous concentration measurements are still under development, particularly for organic contaminants that typically occur at low concentrations. Better approaches and strategies for estimating contaminant loading, including evaluations of both sampling design and sensor technologies, need to be identified. The following general recommendations were made in an effort to advance future organic contaminant monitoring: 1. Improve the understanding of material balance in aquatic systems and the relationship between potential surrogate measures (e.g., DOC, chlorophyll, particle size distribution) and target constituents. 2. Develop continuous real-time sensors to be used by managers as screening measures and triggers for more intensive monitoring. 3. Pursue surrogate measures and indicators of organic pollutant contamination, such as CDOM, turbidity, or non-equilibrium partitioning. 4. Develop continuous field-deployable sensors for PCBs, PAHs, pyrethroids, and emerging contaminants of concern and develop strategies that couple sampling approaches with tools that incorporate sensor synergy (i.e., measure appropriate surrogates along with the dissolved organics to allow full mass emission estimation).[PDF contains 20 pages]

Ist die gegenwärtig verstärkte Einwanderung südlicher Fischarten in die Nordsee schon eine Folge des Treibhauseffektes

Due to the greenhouse effect,a long term warming of the atmosphere is expected. For most people the last relative mild winters and the previous two hot summers are clear signals for such a climatic change. Changes in species compositions and the sudden arrival of southern species in the North Sea are explained as consequences of the greenhouse effect. Comparing the situation in the last decades an attempt is made in this article to show the natural variability in the occurrence and to give an answer to the above question.

The ionic composition of surface waters in the English Lake District, related to bedrock geology, with some singular facts and speculation on the existence of mineral-rich groundwaters

This article is based on a survey of tarns conducted mainly in the summers of 1983 to 1985, plus a survey made in the winter of 1985, in which streams were sampled on the wide variety of rock-types occurring on the fringes of the Lake District. Differences in composition of major ions and their concentrations in the surface waters of Cumbria reflect the complex geological structure of the region. At altitudes above 300 m, on Borrowdale Volcanics and Skiddaw Slates, surface waters are derived from atmospheric precipitation, with additional inputs of some ions - especially calcium and bicarbonate - from catchment rocks and soils. In some of the low-lying large lakes on the fringes of the central fells, water composition is also dominated by inputs from upper catchments; examples are Wastwater, Ullswater and Haweswater. However in other lakes there is evidence (Derwentwater and Bassenthwaite Lake) of inputs from saline groundwater.

Information collected in Teesdale concerning free-swimming stages of brown trout (Salmo trutta L.)

During 1978 and 1979, electrofishing surveys were made in Teesdale - both to provide background information for ecological work on the streams, and to provide data so that the influence of discharge regime on the fish population densities could be examined. The discharge regimes of the different streams were compared using the Base Flow Index (BFI) as developed by the Institute of Hydrology. (PDF contains 30 pages)

Actinomycetes and actinophage in fresh water

Actinomycetes are a group of micro-organisms which lie, in classification, half-way between the fungi and the bacteria. They may be isolated from the plating of leaf washings, water samples and mud dilutions on to nutrient agar (with incorporated actidione to eliminate fungi). The predominant genus varied with the source of the sample. An attempt was also made to isolate the phages of some Actinomycetes. A search was made in the typical environments of the host, for the virus. In this way actinophage were also isolated; and shown to be capable of being transmitted from one host strain to another host strain within 1 sp or from one host to another within 1 genus; i.e. polyvalent.

Use of biological reference points for the conservation of atlantic salmon (Salmo salar L.)in the River Lune, North West England.

This paper deals with the development and use of biological reference points for salmon conservation on the River Lune, England. The Lune supports recreational and net fisheries with annual catches in the region of 1,000 and 1356 salmon respectively. Using models transported from other river systems, biological reference points exclusive to the Lune were developed; specifically the number of eggs deposited and carrying capacity estimates for age 0+ and 1+ parr. The conservation limit was estimated at 11.9 million eggs and between 1989 and 1998 was exceeded in two years. Comparison of juvenile salmon densities in 1991 and 1997 with estimates of carrying capacity indicated that 0+ and 1+ parr densities were at around 60 % of carrying capacity and may relate to the number of eggs deposited in 1990 and 1996 being approximately 70% of the target value. The paper discusses the management actions taken in order to ensure that the management target of the conservation limit being met four years out of five is delivered. It also discusses the balance between conservation and exploitation and the socio-economic decisions made in order to ensure parity of impacts on the rod and net fisheries. The regulations have been enforced since 1999 and the paper concludes with an assessment of the actions taken to deliver the management targets, over the last five years.

Mississippi River sustenance of brown shrimp (Farfantepenaeus aztecus) in Louisiana coastal waters

Brown shrimp (Farfantepenaeus aztecus) are abundant along the Louisiana coast, a coastline that is heavily influenced by one of the world’s largest rivers, the Mississippi River. Stable carbon, nitrogen, and sulfur (CNS) isotopes of shrimp and their proventriculus (stomach) contents were assayed to trace riverine support of estuarine-dependent brown shrimp. Extensive inshore and of fshore collections were made in the Louisiana coastal zone during 1999–2006 to document shrimp movement patterns across the bay and shelf region. Results showed an unexpectedly strong role for nursery areas in the river delta in supporting the offshore fishery, with about 46% of immigrants to offshore regions arriving from riverine marshes. Strong river influences also were evident offshore, where cluster analysis of combined CNS isotope data showed three regional station groups related to river inputs. Two nearer-river mid-shelf station groups showed isotope values indicating river fertilization and productivity responses in the benthic shrimp food web, and a deeper offshore station group to the south and west showed much less river inf luence. At several mid-shelf stations where hypoxia is common, shrimp were anomalously 15N depleted versus their diets, and this d15N difference or mismatch may be useful in monitoring shrimp movement responses to hypoxia.

Stage-specific vertical distribution of Alaska plaice (Pleuronectes quadrituberculatus) eggs in the eastern Bering Sea

The stage-specific distribution of Alaska plaice (Pleuronectes quadrituberculatus) eggs in the southeastern Bering Sea was examined with collections made in mid-May in 2002, 2003, 2005, and 2006. Eggs in the early stages of development were found primarily offshore of the 40-m isobath. Eggs in the middle and late stages of development were found inshore and offshore of the 40-m isobath. There was some evidence that early-stage eggs occur deeper in the water column than late-stage eggs, although year-to-year variability in that trend was observed. Most eggs were in the later stages of development; therefore the majority of spawning is estimated to have occurred a few weeks before collection—probably April—and may be highly synchronized among local spawning areas. Results indicate that sampling with continuous underway fish egg collectors(CUFES) should be supplemented with sampling of the entire water column to ensure adequate samples of all egg stages of Alaska plaice. Data presented offer new information on the stage-dependent horizontal and vertical distribution of Alaska plaice eggs in the Bering Sea and provide further evidence that the early life history stages of this species are vulnerable to near-surface variations in hydrographical conditions and climate forcing.

Onshore-offshore distribution and abundance of tuna larvae (Pisces: Scombridae: Thunnini) in near-reef waters of the Coral Sea

The on-offshore distributions of tuna larvae in near-reef waters of the Coral Sea, near Lizard Island (14°30ʹS, 145°27ʹE), Australia, were investigated during four cruises from November 1984 to February 1985 to test the hypothesis that larvae of these oceanic fishes are found in highest abundance near coral reefs. Oblique bongo net tows were made in five on-offshore blocks in the Coral Sea, ranging from 0–18.5 km offshore of the outer reefs of the Great Barrier Reef, as well as inside the Great Barrier Reef Lagoon. The smallest individuals (<3.2 mm SL) of the genus Thunnus could not be identified to species, and are referred to as Thunnus spp. We found species-specific distributional patterns. Thunnus spp. and T. alalunga (albacore) larvae were most abundant (up to 68 larvae/100 m2) in near-reef (0–5.5 km offshore) waters, whereas Katsuwonus pelamis (skipjack tuna) larvae increased in abundance in the offshore direction (up to 228 larvae/100 m2, 11.1–18.5 km offshore). Larvae of T. albacares (yellowfin tuna) and Euthynnus affinis (kawakawa) were relatively rare throughout the study region, and the patterns of their distributions were inconclusive. Few larvae of any tuna species were found in the lagoon. Size-frequency distributions revealed a greater proportion of small larvae inshore compared to offshore for K. pelamis and T. albacares. The absence of significant differences in size-frequency distributions for other species and during the other cruises was most likely due to the low numbers of larvae. Larval distributions probably resulted from a combination of patterns of spawning and vertical distribution, combined with wind-driven onshore advection and downwelling on the seaward side of the outer reefs.

Impact evaluation of community-based coastal resource management projects in the Philippines

The benefits of decentralizing the management of coastal resources to local governments and resource users have long been recognized, but the best systems for coastal resources management depend on many factors. A number of community-based management and co-management projects were started in the Philippines in the early 1980s. This report describes a comparative assessment of these projects to determine where improvements can be made in the design of future community-based coastal resource management projects. Early and continuing involvement by project beneficiaries is one of the factors that contributes to the success of the project development, implementation, and evaluation.