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

Biological Survey of the Panama Canal Zone (1911)

With the cooperation of several of the executive departments, and of the Field Museum of Natural History, a party of about 10 naturalists was accordingly sent to the zone, and the results so far accomplished have been very satisfactory. Large collections of biological material have been received, including specimens of a considerable number of genera and species new to science. It also seemed important to determine exactly the geographical distribution of the various organisms inhabiting the Isthmus, which is one of the routes by which the animals and plants of South America have entered North America and vice versa. The estimated cost of the survey which would have to be met by the Institution is $11,000...

Magnitude and extent of sediment toxicity in selected estuaries of South Carolina and Georgia

Toxic chemicals can enter the marine environment through numerous routes: stormwater runoff, industrial point source discharges, municipal wastewater discharges, atmospheric deposition, accidental spills, illegal dumping, pesticide applications and agricultural practices. Once they enter a receiving system, toxicants often become bound to suspended particles and increase in density sufficiently to sink to the bottom. Sediments are one of the major repositories of contaminants in aquatic envronments. Furthermore, if they become sufficiently contaminated sediments can act as sources of toxicants to important biota. Sediment quality data are direct indicators of the health of coastal aquatic habitats. Sediment quality investigations conducted by the National Oceanic and Atmospheric Administration (NOAA) and others have indicated that toxic chemicals are found in the sediments and biota of some estuaries in South Carolina and Georgia (NOAA, 1992). This report documents the toxicity of sediments collected within five selected estuaries: Savannah River, Winyah Bay, Charleston Harbor, St. Simons Sound, and Leadenwah Creek (Figure 1). (PDF contains 292 pages)

Enforcement of associated protected measures in particularly sensitive sea areas

The distinguished character of Particularly Sensitive Sea Areas (PSSAs) is that every application for PSSAs must be accompanied by Associated Protected Measures (APMs) which can make PSSAs efficient in practice.1 That is why APMs are regarded as the core feature of every PSSA.2 APM is “an international rule or standard that falls within the purview of an international maritime organization (IMO) and regulates international maritime activities for the protection of the area at risk.” So far, APMs have been approved by IMO as following: -Compulsory or recommended pilotage -Mandatory ship reporting -An area to be avoided -Traffic separation schemes -Discharge prohibition or regulations -Mandatory no anchoring areas -Deep water routes -Emission control areas (PDF contains 5 pages)

Biologische Verbindungen zwischen den Rotbarschbeständen Westgrönlands und der Irmingersee

Two redfish species are expected to live off western Greenland in a broad distribution area. Except for a small population of adults in the Godthab Fjord, only juvenile and adolescent specimens have been met there, tending to increase in age from the north to the south. As taxonomic identification of single specimens is difficult the distribution of species stocks cannot be clearly identified. This paper deals with spawning areas, migration and drifting routes around Greenland respectively in relation to distributional pattern of juvenile redfish off western Greenland.

Sablefish, Anoplopoma fimbria, Populations on Gulf of Alaska Seamounts

Sablefish, Anoplopoma fimbria, were tagged and released on Gulf of Alaska seamounts during 1999–2002 to determine the extent, if any, of emigration from the seamounts back to the continental slope and of movement between seamounts. Seventeen sablefish from Gulf of Alaska seamounts have been recovered on the continental slope since tagging began, verifying that seamount to slope migration occurs. Forty-two sablefish were recovered on the same seamounts where they were tagged, and none have been recaptured on seamounts other than the ones where they were released. Sablefish populations on Gulf of Alaska seamounts are made up of individuals mostly older than 5 years and are maledominant, with sex ratios varying from 4:1 up to 10:1 males to females. Males are smaller than females, but the average age of males is greater than that of females, and males have a greater range of age (4–64 yr) than females (4–48 yr). Otoliths of seamount fish frequently have an area of highly compressed annuli, known as the transition zone, where growth has suddenly and greatly slowed or even stopped. Because transition zones can be present in both younger and older seamount fish and are rare in slope fish, formation of otolith transition zones may be related to travel to the seamounts. The route sablefish use to reach the seamounts is so far unknown. One possibility is that fish enter the eastward-flowing North Pacific Current off the Aleutian Islands or western Gulf of Alaska and travel more or less passively on the current until encountering a seamount. The route from seamount back to slope would likely be the northwardflowing Alaska Current. These routes are discussed in light of tag recovery locations of slope- and seamount-tagged fish.

Comparing autonomous underwater vehicle (AUV) and vessel-based tracking performance for locating acoustically tagged fish

Autonomous underwater vehicles (AUV’s) are increasingly used to collect physical, chemical, and biological information in the marine environment. Recent efforts include merging AUV technology with acoustic telemetry to provide information on the distribution and movements of marine fish. We compared surface vessel and AUV tracking capabilities under rigorous conditions in coastal waters near Juneau, Alaska. Tracking surveys were conducted with a REMUS 100 AUV equipped with an integrated acoustic receiver and hydrophone. The AUV was programmed to navigate along predetermined routes to detect both reference transmitters at 20–500 m depths and tagged fish and crabs in situ. Comparable boat surveys were also conducted. Transmitter depth had a major impact on tracking performance. The AUV was equally effective or better than the boat at detecting reference transmitters in shallow water, and significantly better for transmitters at deeper depths. Similar results were observed for tagged animals. Red king crab, Paralithodes camtschaticus, at moderate depths were recorded by both tracking methods, while only the AUV detected Sablefish, Anoplopoma fimbria, at depths exceeding 500 m. Strong currents and deep depths caused problems with AUV navigation, position estimation, and operational performance, but reflect problems encountered by other AUV applications that will likely diminish with future advances, enhanced methods, and increased use.

1983 Biscayne Bay hydrocarbon study: final report

A two year, comprehensive, quantitative investigation was conducted to analyze and identify the spatial distribution of petrogenic and biogenic hydrocarbons in sediments, surface waters, fish and shellfish of Biscayne Bay, Florida. The goal for the first year of the project was to establish baseline information to support oil spill impact assessment and clean-up. One hundred fifty-five sediment and eleven biota samples were collected. The areas sampled included the Miami River, Intracoastal Waterway, tidal flats, access canals and environmentally sensitive shorelines. The second year of the study centered on areas exhibiting petroleum contamination. These areas included the Miami River, Little River, Goulds Canal, Black Creek and Military Canal. Surface and subsurface sediment, biota and surface water were collected. Sample collection, analyses, and data handling for the two year project were conducted so that all information was court-competent and scientifically accurate. Chain of custody was maintained for all samples. Total hydrocarbon content of surface sediments ranged from below detection limits to a high of 2663.44 pg/g. Several sample stations contained petroleum contamination. The majority of biota samples exhibited hydrocarbon concentrations and characteristics that indicated little, if any, petroleum contamination. Surface water samples ranged from 0.78 to 64.47 μg/L and several samples contained petroleum hydrocarbons. Our results indicate several areas of petroleum contamination. These areas are characterized by industrial complexes, port facilities, marinas, major boating routes and many of the major tributaries emptying into Biscayne Bay.

Intermingling and seasonal migrations of Greenland halibut (Reinhardtius hippoglossoides) populations determined from tagging studies

A total of 7244 Greenland halibut (Reinhardtius hippoglossoides, Walbaum) were tagged in Greenland waters between 1986 and 1998 to increase information on stock delineations, to clarify migration routes, and to describe the seasonal movements of fjord populations. At present 517 recaptured Greenland halibut have been recorded. For Greenland halibut released in Davis Strait, Baffin Bay, and the fjords of southwestern and eastern Greenland, a substantial portion of recovered fish demonstrated migratory behavior, up to 2500 km, primarily to Denmark Strait between Greenland and Iceland. The recaptured fish provided evidence of intermingling between the population in Denmark Strait and the populations in Davis Strait and the southwest Greenland fjords. These observations support those of other studies that indicate that Greenland halibut inhabiting Davis Strait and the fjords of southwestern and eastern Greenland originate in the spawning grounds west of Iceland. The high mobility of offshore Greenland halibut within Baffin Bay and Davis Strait suggests that Greenland halibut migrate extensively between feeding and spawning areas. Greenland halibut in the fjords of northwestern Greenland appear to be resident in behavior and do not intermingle with offshore or more southerly inshore populations. A seasonal pattern in the recovery of these fish indicates that Greenland halibut aggregate in the inner part of fjords during the second half of the year (when inshore waters are not covered with ice).