Assessment of the hydrogeological impacts of aggregate extraction in the Delamere area, Cheshire

This is a technical report on the assessment of the hydrogeological impacts of aggregate extraction activities in the Delamere Area, Cheshire. The first aim of the study was to carry out Stage 3-appropriate assessment, under the EU Habitats Directive (92/43/EEC), of the possible hydrogeological impacts of aggregate extraction activities authorised by the Cheshire CC on candidate Special Areas of Conservation (cSAC) on the Delamere sandsheet, Cheshire. Identifying possible impacts if these activities on the hydrogeological environment, construction of a numerical groundwater flow model of the groundwater system to investigate and quantify impacts and to produce a report as required under Stage 3 of the Habitats Regulations. Secondly, to identify the future potential impacts of the continued extraction of sand and gravel reserves from above and below the water tables from within the Delamere sandsheet, thus releasing reserves identified within the Area of Search of the Cheshire Replacement Minerals Local Plan 1999. This aspect of the study should assist in identifying the implications of further working within Delamere for North West sub-regional apportionment.

Hydroacoustic evaluation of spawning red hind (Epinephelus guttatus) aggregations along the coast of Puerto Rico in 2002 and 2003

Red hind (Epinephelus guttatus) have been overfished in the Caribbean and were included with seven other regional grouper species deemed vulnerable to risk of extinction. The Puerto Rico Department of Natural and Environmental Resources desired to map spawning red hind aggregations within commonwealth waters as part of their resource management program for the species. Mobile hydroacoustic surveys were conducted over 3-day periods in 2002 and 2003, indexed to the full moon phase in February or March when red hind were known to aggregate. Four vessels concurrently sampled the southwest, south, and southeast coasts of Puerto Rico in 2002. In 2003, three vessels conducted complementary surveys of the northwest, north, and northeast coasts of the island, completing a circuit of the coastal shelf-spawning habitat. These surveys indicated that red hind spawning aggregations were prevalent along the south and west coasts, and sparse along the north coast during the survey periods. Highest spawning red hind concentrations were observed in three areas offshore of the west coast of Puerto Rico, around Mona and Desecheo islands (20,443 and 10,559 fish/km2, respectively) and in the Bajo de Cico seasonal closed area (4,544 fish/km2). Following both 2002 and 2003 surveys, a series of controlled acoustic measurements of known local fish species in net pens were conducted to assess the mean target strength (acoustic backscatter) of each group. Ten species of fish were measured, including red hind (E. guttatus), coney (E. fulvus), white grunt (Haemulon plumieri), pluma (Calamus pennatula), blue tang (Acanthurus coeruleus), squirrel fish (Holocentrus spp.), black durgeon (Melichtyhs niger), ocean file fish (Canthidermis sufflamen), ocean surgeon fish (Acanthurus bahianus), and butter grouper (Mycteroperca spp.). In general, the mean target strength results from the caged fish experiments were in agreement with published target strength length relationships, with the exception of white grunt and pluma.

The economic importance of marine angler expenditures in the United States.

In 1998, the National Marine Fisheries Service (NMFS) began a series of marine angler expenditure surveys in the coastal regions of the United States (U.S.) to evaluate marine recreational fishing expenditures and the financial impacts of these expenditures in each region and the U.S. as a whole. In this report, we use the previously estimated expenditure estimates to assess the total financial impact of anglers’ saltwater expenditures. Estimates are provided for sales, income, employment, and tax impacts for each coastal state in the U.S. Aggregate estimates are also provided for the entire U.S., excluding Alaska, Hawaii, and Texas. Direct, indirect, and induced effects associated with resident and non-resident angler expenditures were estimated using a regional input-output modeling system called IMPLAN Pro. Nationwide, recreational saltwater fishing generated over $30.5 billion in sales in 2000, nearly $12.0 billion in income, and supported nearly 350,000 jobs. Approximately 89 cents of every dollar spent by saltwater anglers was estimated to remain within the U.S. economy. At the state level, many of the goods anglers purchased were imports, and, as such, as little as 44 cents of every dollar stayed in Rhode Island and as much as 80 cents of every dollar stayed in Georgia. In the Northeast, the highest impacts were generated in New Jersey, even though recreational fishing expenditures in Massachusetts and Maryland were considerably higher. In the Southeast, the highest impacts were generated in Florida, and on the Pacific Coast, the highest impacts were generated in California. Expenditures on boat maintenance/expenses generated more impacts than any other expenditure category in the U.S. Expenditures on rods and reels was the single most important expense category in terms of generating impacts in most of the Northeast states. Expenditures on boat expenses generated the highest in most Southeast states, and expenditures for boat accessories produced the highest impacts in most Pacific Coast states.(PDF file contains 184 pages.)

The distribution and size composition of finfish, American lobster, and long-finned squid in Long Island Sound based on the Connecticut Fisheries Division Bottom Trawl Survey, 1984–1994

The distribution, abundance, and length composition of marine finfish, lobster, and squid in Long Island Sound were examined relative to season and physical features of the Sound, using Connecticut Department of Environmental Protection trawl survey data collected from 1984 to 1994. The following are presented: seasonal distribution maps for 59 species, abundance indices for 41 species, and length frequencies for 26 species. In addition, a broader view of habitat utilization in the Sound was examined by mapping aggregated catches (total catch per tow, demersal catch per tow, and pelagic catch per tow) and by comparing species richness and mean aggregate catch/tow by analysis of variance (ANOVA) among eight habitat types defined by depth interval and bottom type. For many individual species, seasonal migration patterns and preference for particular areas within Long Island Sound were evident. The aggregate distribution maps show that overall abundance was lower in the eastern Sound than the central and western portions. Demersal and pelagic temporal abundance show opposite trends—demersals were abundant in spring and declined through summer and fall, whereas pelagic abundance was low in spring and increased into fall. The analysis of habitat types revealed significant differences for both species richness and mean catch per tow. Generally, species richness was highest in habitats within the central area of the Sound and lowest in eastern habitats. The aggregate mean catch was highest in the western and central habitats, and declined eastward. (PDF file contains 199 pages.)

Quantitative composition and distribution of the macrobenthic invertebrate fauna of the Continental Shelf ecosystems of the Northeastern United States

From the mid-1950's to the mid-1960's a series of quantitative surveys of the macrobenthic invertebrate fauna were conducted in the offshore New England region (Maine to Long Island, New York). The surveys were designed to 1) obtain measures of macrobenthic standing crop expressed in terms of density and biomass; 2) determine the taxonomic composition of the fauna (ca. 567 species); 3) map the general features of macrobenthic distribution; and 4) evaluate the fauna's relationships to water depth, bottom type, temperature range, and sediment organic carbon content. A total of 1,076 samples, ranging from 3 to 3,974 m in depth, were obtained and analyzed. The aggregate macrobenthic fauna consists of 44 major taxonomic groups (phyla, classes, orders). A striking fact is that only five of those groups (belonging to four phyla) account for over 80% of both total biomass and number of individuals of the macrobenthos. The five dominant groups are Bivalvia, Annelida, Amphipoda, Echninoidea, and Holothuroidea. Other salient features pertaining to the macrobenthos of the region are the following: substantial differences in quantity exist among different geographic subareas within the region, but with a general trend that both density and biomass increase from northeast to southwest; both density and biomass decrease with increasing depth; the composition of the bottom sediments significantly influences both the kind and quantity of macrobenthic invertebrates, the largest quantities of both measures of abundance occurring in the coarser grained sediments and diminishing with decreasing particle size; areas with marked seasonal changes in water temperature support an abundant and diverse fauna, whereas a uniform temperature regime is associated with a sparse, less diverse fauna; and no detectable trends are evident in the quantitative composition of the macrobenthos in relation to sediment organic carbon content. (PDF file contains 246 pages.)

Changes in the size structure of the yellowfin tuna population of the tropical eastern Pacific Ocean from 1947 to 1955

ENGLISH: Morphometric studies by Godsil (1948), Godsil and Greenhood (1951), Royce (1953) and Schaefer (1952, 1955) have indicated that the yellowfin tuna of the Eastern Pacific are distinct from those of the Central Pacific. Tagging of yellowfin tuna by the California Department of Fish and Game, and by the Inter-American Tropical Tuna Commission in the Eastern Pacific, and by the Pacific Oceanic Fishery Investigations in the Central Pacific, have not yet revealed any migrations between these areas. Shimada and Schaefer (1956) have compared changes in population abundance and fishing intensity, considering the population in the Eastern Pacific as a separate entity. They conclude " ... the amount of fishing has had a real effect upon the stock of Eastern Pacific yellowfin tuna, taken in the aggregate, over the period studied. The evidence suggests also that for this species the intensity of fishing in some recent years has reached and might have even exceeded the level corresponding to the maximum equilibrium yield." Tagging experiments by the California Department of Fish and Game and by the Inter-American Tropical Tuna Commission have yielded returns in the order of one to five percent (Roedel 1954, and unpublished data of both agencies), a level much lower than that at which fishing intensity would be expected to noticeably affect the population size. These results are probably a reflection of the inadequacies of the present tagging methods, but they could lend doubt to the conclusions of Shimada and Schaefer. It is desirable, therefore, to examine other, independent, evidence as to the effects of fishing on the population. At the high levels of fishing intensity suggested by Shimada and Schaefer, in addition to changes in quantity, measurable changes would be expected to have occurred in the quality of the yellowfin tuna stocks, because the average age and size of the fish would have been reduced by the high mortality rates accompanying high fishing intensities. A continuing regular program of sampling catches and determining their length composition, to assess changes in the size composition of the stocks, was initiated by the Commission in 1954 but direct measurements are not available for the earlier, more dynamic period of growth of the fishery. Consequently, other, more general indications of possible changes in the size composition were sought. SPANISH: Los estudios morfométricos efectudos por Godsil (1948), Godsil y Greenhood (1951), Royce (1953) y Schaefer (1952, 1955), han demostrado que el atún aleta amarilla del Pacífico Oriental es distinto del que habita el PacÍfico Central. Los experimentos del Departamento de Pesca y Caza de California y de la Comisión Interamericana del Atún Tropical en el Pacífico Oriental, así como los de las Investigaciones Pesqueras del Océano Pacífico en el Pacífico Central,consistentes en la marcación de atunes aleta amarilla, aún no han puesto de manifiesto movimientos migratorios entre dichas áreas. Shimada y Schaefer (1956) han hecho estudios comparativos sobre la abundancia de la población y la intensidad de la pesca, considerando a la población del Pacífico Oriental como una entidad separada. Su conclusión es que " ... la intensidad de la pesca ha tenido un definido efecto sobre la población del atún aleta amarilla del Pacífico Oriental, tomada en conjunto, a lo largo del período estudiado. La evidencia de que se dispone sugiere así mismo que, por lo que hace a esta especie, la intensidad de la pesca en los últimos años ha alcanzado y quizás aún sobrepasado el nivel correspondiente a la máxima pesca de equilibrio". Los experimentos de mar•cación del Departamento de Pesca y Caza de California y de la Comisión Interamericana del Atún Tropical han producido recuperaciones ,entre el uno y el cinco por ciento (Roedel 1954 y datos inéditos de ambos organismos), lo que constituye un nivel mucho más bajo de aquél en que la intensidad de la pesca podría considerarse que afectaría notablemente el tamaño de la población. Estos resultados reflejan probablemente lo inadecuados que son aún los métodos de marcación, pero ellos podrían, quizá, poner en tela de juicio las conclusiones de Shimada y Schaefer. Por lo tanto,es deseable examinar otras fuentes de evidencia independientes, relacionadas con el efecto que la pesca tiene sobre la población. En efecto, si los altos índices de pesca sugeridos por Shimada y Schaefer son correctos, es de esperar que, además de los cambios en la magnitud de la población, se hayan producido otros, concomitantes y sensibles, en la calidad de los stocks de atún aleta amarilla, puesto que tanto el promedio de edad como el de tamaño de los individuos habrían disminuído debido a las elevadas tasas de mortalidad inherentes a las altas intensidades de pesca. En 1954 la Comisión inició un programa ininterrumpido para tomar muestras y determinar en ellas las frecuencias de tallas y evaluar de este modo los cambios correlativos que tuvieran lugar en los stocks pero, infortunadamente, este sistema de evaluación directa no fué practicado en el período anterior, que fué precisamente el de rápida expansión de la pesquería. En tal virtud, hubo de ser necesario buscar indicios más generales referentes a los cambios posibles en la composición de tamaños. (PDF contains 20 pages.)

The Summer Flounder, Scup, and Black Sea Bass Fishery of the Middle Atlantic Bight and Southern New England Waters

Summer flounder, Paralichthys dentatus, scup, Stenotomus chrysops, and black sea bass, Centropristis striata, cooccur within the Middle Atlantic Bight and off southern New England and are important components of commercial and recreational fisheries. The commercial otter trawl fishery for these species is primarily a winter fishery, whereas the recreational fishery takes place between late spring and autumn. The otter trawl fishery generally targets summer flounder, and less frequently scup, while black sea bass occurs as bycatch. Trips in which all three species were present yielded highest aggregate landings per unit of effort (LPUE) levels and occurred more often than trips landing only one or two species. More than 50% of the trips in the trawl fishery landed at least two of the three species. In contrast, greater than 75% of the recreational landings of each species occurred as a result of trips landing only one species. Differences in the fisheries resulted from the interactions of seasonal changes in species distributions and gear selectivity. (PDF file contains 18 pages.)

San Francisco Bay regional sediment management strategy development

The San Francisco Bay Conservation and Development Commission (BCDC), in continued partnership with the San Francisco Bay Long Term Management Strategies (LTMS) Agencies, is undertaking the development of a Regional Sediment Management Plan for the San Francisco Bay estuary and its watershed (estuary). Regional sediment management (RSM) is the integrated management of littoral, estuarine, and riverine sediments to achieve balanced and sustainable solutions to sediment related needs. Regional sediment management recognizes sediment as a resource. Sediment processes are important components of coastal and riverine systems that are integral to environmental and economic vitality. It relies on the context of the sediment system and forecasting the long-range effects of management actions when making local project decisions. In the San Francisco Bay estuary, the sediment system includes the Sacramento and San Joaquin delta, the bay, its local tributaries and the near shore coastal littoral cell. Sediment flows from the top of the watershed, much like water, to the coast, passing through rivers, marshes, and embayments on its way to the ocean. Like water, sediment is vital to these habitats and their inhabitants, providing nutrients and the building material for the habitat itself. When sediment erodes excessively or is impounded behind structures, the sediment system becomes imbalanced, and rivers become clogged or conversely, shorelines, wetlands and subtidal habitats erode. The sediment system continues to change in response both to natural processes and human activities such as climate change and shoreline development. Human activities that influence the sediment system include flood protection programs, watershed management, navigational dredging, aggregate mining, shoreline development, terrestrial, riverine, wetland, and subtidal habitat restoration, and beach nourishment. As observed by recent scientific analysis, the San Francisco Bay estuary system is changing from one that was sediment rich to one that is erosional. Such changes, in conjunction with increasing sea level rise due to climate change, require that the estuary sediment and sediment transport system be managed as a single unit. To better manage the system, its components, and human uses of the system, additional research and knowledge of the system is needed. Fortunately, new sediment science and modeling tools provide opportunities for a vastly improved understanding of the sediment system, predictive capabilities and analysis of potential individual and cumulative impacts of projects. As science informs management decisions, human activities and management strategies may need to be modified to protect and provide for existing and future infrastructure and ecosystem needs. (PDF contains 3 pages)

Keine Erholung der westgrönländischen Grundfischbestände

Since 1991, the aggregate biomass of fish stocks inhabiting the West Greenland shelf stagnates at the lowest level. The latest survey results of cruise no. 152 conducted by FRV 'Walther Herwig III' do not indicate any improvements in state of the stocks, although no fishing effort was recently directed towards groundfish. The cod stock showed again a record low and is presently dominated by recruits of the year classes 1991 and 1993. Both year classes are considered to be weak and the cod stock is beyond the 'minimum biologically acceptable level'. Consequently, an increase in stock abundance is not expected either in short or long term. Other ecologically or economically important fish species, American plaice, redfish, wolffish and starry skate, were also found to have minimum stock abundances. By-catch estimates of juvenile groundfish taken by the shrimp fishery, operating at traditional grounds of cod and redfish fisheries, are indispensible. Analysis of climatological data from Nuuk/West Greenland indicates that climate during the past fourty years was characterized by two decades of anomalous warm conditions, and cooling which dominates the dimate since 1969. Anomalous cold events were encountered during 1983, 1984 and during 1992, 1993. Similar to the air temperature anomalies, autumn temperatures of the ocean surface layer indicate cold and warm periods during the past thirty years. In contrast to the colder than normal atmospheric conditions during the early nineties, however, the ocean conditions indicate intermediate warming.

Caractérisation des situations hydro-biologiques et potentialités de pêche thonière au Cap Lopez en Juin et Juillet 1972 et 1974

Surface temperature was measured by remote sensing through Cape Lopez (Gulf of Guinea) frontal region during the fishing season in June and July 1972 and 1974. Twelve typical situations are analysed through four main directions: surface situation, tendency, hydrobiological structure and availability to fisheries. The tuna behavior is analysed in relation with the frontal zone movements and a mechanism which tends to aggregate important shoals of tunas is presented.

Variations in eastern North Pacific demersal fish biomass based on the U.S. west coast groundfish bottom trawl survey (2003–2010)

In response to declining biomass of Northeast Pacific groundfish in the late 1990s and to improve the scientific basis for management of the fishery, the Northwest Fisheries Science Center standardized and enhanced their annual bottom trawl survey in 2003. The survey was expanded to include the entire area along the U.S. west coast at depths of 55–1280 m. Coast-wide biomass and species richness significantly decreased during the first eight years (2003–10) of this fishery-independent survey. We observed an overall tendency toward declining biomass for 62 dominant taxa combined (fishery target and nontarget species) and four of seven subgroups (including cartilaginous fish, flatfishes, shelf rockfishes, and other shelf species), despite increasing or variable biomass trends in individual species. These decreases occurred during a period of reduced catch for groundfish along the shelf and upper slope regions relative to historical rates. We used information from multiple stock assessments to aggregate species into three groups: 1) with strong recruitment, 2) without strong recruitment in 1999, and 3) with unknown recruitment level. For each group, we evaluated whether declining biomass was primarily related to depletion (using year as a proxy) or environmental factors (i.e., variation in the Pacific Decadal Oscillation). According to Akaike’s information criterion, changes in aggregate biomass for species with strong recruitment were more closely related to year, whereas those with no strong recruitment were more closely related to climate. The significant decline in biomass for species without strong recruitment confirms that factors other than depletion of the exceptional 1999 year class may be responsible for the observed decrease in biomass along the U.S. west coast.

Population structure, long-term connectivity, and effective size of mutton snapper (Lutjanus analis) in the Caribbean Sea and Florida Keys

Genetic structure and average long-term connectivity and effective size of mutton snapper (Lutjanus analis) sampled from offshore localities in the U.S. Caribbean and the Florida Keys were assessed by using nuclear-encoded microsatellites and a fragment of mitochondrial DNA. No significant differences in allele, genotype (microsatellites), or haplotype (mtDNA) distributions were detected; tests of selective neutrality (mtDNA) were nonsignificant after Bonferroni correction. Heuristic estimates of average long-term rate of migration (proportion of migrant individuals/generation) between geographically adjacent localities varied from 0.0033 to 0.0054, indicating that local subpopulations could respond independently of environmental perturbations. Estimates of average longterm effective population sizes varied from 341 to 1066 and differed significantly among several of the localities. These results indicate that over time larval drift and interregional adult movement may not be sufficient to maintain population sustainability across the region and that there may be different demographic stocks at some of the localities studied. The estimate of long-term effective population size at the locality offshore of St. Croix was below the minimum threshold size considered necessary to maintain the equilibrium between the loss of adaptive genetic variance from genetic drift and its replacement by mutation. Genetic variability in mutton snapper likely is maintained at the intraregional level by aggregate spawning and random mating of local populations. This feature is perhaps ironic in that aggregate spawning also renders mutton snapper especially vulnerable to overexploitation.

Description of embryonic development of Atka mackerel (Pleurogrammus monopterygius)

Atka mackerel (Pleurogrammus monopterygius) is hexagrammid fish that inhabits the temperate and subarctic North Pacific Ocean and neighboring seas (Fig. 1). This highly abundant fish is a critically important prey species (Sinclair and Zeppelin, 2002; Zenger, 2004) that supports a directed commercial trawl fishery (Lowe et al., 2006). Atka mackerel is a demersal spawner and males provide parental care to eggs (Zolotov, 1993). During breeding periods, sexually mature males aggregate on the bottom at nesting sites where they establish territories (Lauth et al., in press). Sexually mature females periodically visit male nesting territories from July to October to spawn batches of demersal egg masses (McDermott and Lowe, 1997; McDermott et al., 2007). Individual nests may consist of multiple egg masses deposited by different females, and males defend nesting territories for a protracted period lasting from the time territories are being established until all eggs within the territory are completely hatched (Lauth et al., 2007). Knowledge about the timing of the reproductive cycle and the use of spawning habitat are important for understanding population structure and the dynamics of stock recruitment, which in turn are important factors in the management of Atka mackerel populations.

Estimating species and size composition of rockfishes to verify targets in acoustic surveys of untrawlable areas

Rockfish (Sebastes spp.) biomass is difficult to assess with standard bottom trawl or acoustic surveys because of their propensity to aggregate near the seafloor in highrelief areas that are inaccessible to sampling by trawling. We compared the ability of a remotely operated vehicle (ROV), a modified bottom trawl, and a stereo drop camera system (SDC) to identify rockfish species and estimate their size composition. The ability to discriminate species was highest for the bottom trawl and lowest for the SDC. Mean lengths and size distributions varied among the gear types, although a larger number of length measurements could be collected with the bottom trawl and SDC than with the ROV. Dusky (S. variabilis), harlequin (S. variegatus), and northern rockfish (S. polyspinis), and Pacific ocean perch (S. alutus) were the species observed in greatest abundance. Only dusky and northern rockfish regularly occurred in trawlable areas, whereas these two species and many more occurred in untrawlable areas. The SDC was able to resolve the height of fish off the seafloor, and some of the rockfish species were observed only near the seafloor in the acoustic dead zone. This finding is important, in that fish found exclusively in the acoustic dead zone cannot be assessed acoustically. For these species, methods such as bottom trawls, long-lines, or optical surveys using line transect or area swept methods will be the only adequate means to estimate the abundance of these fishes. Our results suggest that the selection of appropriate methods for verifying targets will depend on the habitat types and species complexes to be examined.