Biogeographic analysis of the Tortugas Ecological Reserve: Examining the refuge effect following reserve establishment

Almost 120 days at sea aboard three NOAA research vessels and one fishing vessel over the past three years have supported biogeographic characterization of Tortugas Ecological Reserve (TER). This work initiated measurement of post-implementation effects of TER as a refuge for exploited species. In Tortugas South, seafloor transect surveys were conducted using divers, towed operated vehicles (TOV), remotely operated vehicles (ROV), various sonar platforms, and the Deepworker manned submersible. ARGOS drifter releases, satellite imagery, ichthyoplankton surveys, sea surface temperature, and diver census were combined to elucidate potential dispersal of fish spawning in this environment. Surveys are being compiled into a GIS to allow resource managers to gauge benthic resource status and distribution. Drifter studies have determined that within the ~ 30 days of larval life stage for fishes spawning at Tortugas South, larvae could reach as far downstream as Tampa Bay on the west Florida coast and Cape Canaveral on the east coast. Together with actual fish surveys and water mass delineation, this work demonstrates that the refuge status of this area endows it with tremendous downstream spillover and larval export potential for Florida reef habitats and promotes the maintenance of their fish communities. In Tortugas North, 30 randomly selected, permanent stations were established. Five stations were assigned to each of the following six areas: within Dry Tortugas National Park, falling north of the prevailing currents (Park North); within Dry Tortugas National Park, falling south of the prevailing currents (Park South); within the Ecological Reserve falling north of the prevailing currents (Reserve North); within the Ecological Reserve falling south of the prevailing currents (Reserve South); within areas immediately adjacent to these two strata, falling north of the prevailing currents (Out North); and within areas immediately adjacent to these two strata, falling south of the prevailing currents (Out South). Intensive characterization of these sites was conducted using multiple sonar techniques, TOV, ROV, diver-based digital video collection, diver-based fish census, towed fish capture, sediment particle-size, benthic chlorophyll analyses, and stable isotope analyses of primary producers, fish, and, shellfish. In order to complement and extend information from studies focused on the coral reef, we have targeted the ecotone between the reef and adjacent, non-reef habitats as these areas are well-known in ecology for indicating changes in trophic relationships at the ecosystem scale. Such trophic changes are hypothesized to occur as top-down control of the system grows with protection of piscivorous fishes. Preliminary isotope data, in conjunction with our prior results from the west Florida shelf, suggest that the shallow water benthic habitats surrounding the coral reefs of TER will prove to be the source of a significant amount of the primary production ultimately fueling fish production throughout TER and downstream throughout the range of larval fish dispersal. Therefore, the status and influence of the previously neglected, non-reef habitat within the refuge (comprising ~70% of TER) appears to be intimately tied to the health of the coral reef community proper. These data, collected in a biogeographic context, employing an integrated Before-After Control Impact design at multiple spatial scales, leave us poised to document and quantify the postimplementation effects of TER. Combined with the work at Tortugas South, this project represents a multi-disciplinary effort of sometimes disparate disciplines (fishery oceanography, benthic ecology, food web analysis, remote sensing/geography/landscape ecology, and resource management) and approaches (physical, biological, ecological). We expect the continuation of this effort to yield critical information for the management of TER and the evaluation of protected areas as a refuge for exploited species. (PDF contains 32 pages.)

Summary document of the work being done in 1992-1993 regarding the migratory salmonid fisheries of the River Ribble catchment

This document lists the work on salmonid fisheries in the River Ribble catchment in the north west of England which was done in 1992-93. The document includes the following: analysis of historical catch data from the River Ribble covering 1937-1991; Ribble and Hodder stock assessment surveys 1992-93 including Swanside Beck; Ribble catch data from game angling log books 1993; results of salmon scale sampling 1993; results of microtagging programme in Hodder and Ribble 1993; Waddow Weir dish counter data 1993; Winkley Hall (Hodder), Locks Weir and Waddow Hall (Ribble) fish counter data 1993; number of fish and ova from Witcherwell Hatchery 1993.

The Feasibility of Enhancing Red Sea Urchin, Strongylocentrotus iranciscanus, Stocks in California: An Analysis of the Options

The California fishery for red sea urchins, Strongylocentrotus franciscanus, has undergone explosive growth in recent years and is approaching full exploitation. Thus, there is considerable interest in enhancing stocks to maintain a high rate of landings. Fishable stocks of red sea urchins in different areas appear to be limited at three stages in their life history: By the availability of larvae, by the survival of newly settled to mid-sized animals, and by the food available to support growth and reproduction of larger animals. Here I review other efforts, notably the extensive Japanese work, to enhance fishable stocks of benthic marine invertebrates, and consider the potential options for red sea urchins at different points of limitation. These include collecting or culturing seed for outplanting, physical habitat improvement measures, improving the food supply, and conservation measures to protect existing stocks until alternate methods are proven and in place. The options are compared in terms of biological feasibility, capital and labor requirements, and potential implications for change in the structure of the fishing industry.

Initial Hydraulic modelling and Levee Stability Analysis of the Triple M Ranch Restoration Project

“Advanced Watershed Science and Policy (ESSP 660)” is a graduate class taught in the Master of Science in Coastal and Watershed Science & Policy program at California State University Monterey Bay (CSUMB). In 2007, the class was taught in four 4-week modules, each focusing on a local watershed issue. This report is one outcome of one of those 4-week modules taught in the fall 2007 session. (Document contains 32 pages)

A quantitative analysis of the phytoplankton of the Gulf of Panama: I. Results of the regional phytoplankton surveys during July and November 1957 and March 1958

ENGLISH: 1. Quantitative phytoplankton samples were collected by the Inter-American Tropical Tuna Commission at the surface and ten meters in the Gulf of Panama, as follows: a) 18-21 March, 1958 (31 stations)-during the height of the upwelling season, b) 10-12 July, 1957 (10 stations)-during the transition to the rainy season at a time when mild upwelling winds reappear, c) 7-8 November, 1957 (15 stations)-during the height of the rainy season. 2. Maximum phytoplankton populations occurred during the upwelling season, followed by a considerable decline during July, and a further Subsidence during November. 3. A remarkable regional uniformity in species composition was observed during the surveys despite regional differences in growth conditions. Diatoms overwhelmingly dominated the communities. 4. During all surveys, the innermost regions, generally north of 8°30'N, were the most productive. The least productive areas were in the offing of San Miguel Bay and Parita Bay, suggesting that nutrient accretion via runoff is inadequate to sustain sizeable autotrophic plant populations in those regions. 5. During all surveys, phytoplankton growth appeared to be limited by nutrient availability. 6. During all surveys, phytoplankton growth appeared to be related to depth of the water column. 7. Although below average rainfall contributed to unusually favorable growth conditions (reduced stability, increased transparency and, presumably, nutrient reserves) during the November survey relative to November 1955 and 1956 at 8°45'N, 79°23'W, the anticipated heightened phytoplankton response was not observed. 8. During the November survey, the local diatom responses and their regional fluctuations could be satisfactorily related to the accompanying surface salinity conditions. However, this correspondence is undoubtedly attributable to factors associated with the observed salinity levels, probably nutrients, rather than salinity directly. 9. Unusually warm conditions occurred during the March survey, attributable to considerably weaker upwelling winds than normally occurring then, which contributed to a considerably lower standing crop and a retardation in succession of three to five weeks relative to that observed during 1955-1957 at 8°45'N, 79°23'W in the Gulf of Panama. 10. During the March survey, a well defined inverse relationship existed between mean temperature and mean diatom abundance in the upper ten meters, and between transparency and mean diatom abundance. A direct relationship occurred between surface salinity and mean diatom abundance in the upper ten meters. These relationships are interpreted to indicate that diatom abundance primarily reflected the nutrient concentrations associated with a given upwelling intensity, rather than describing casual relationships. 11. The survey results indicate that the phytoplankton dynamics observed at 8°45'N, 79°23'W from November, 1954 through May, 1957 are generally representative of the Gulf of Panama. 12. The following new forms, to be described in a later publication, were observed during the surveys: Actinoptychus undulatus f. catenata n.f., Asterionella japonica f. tropicum n.f., Leptocylindrus maximus n. sp., Skeletonema costatum f. tropicum n.f. SPANISH: 1. La Comisión Interamericana del Atun Tropical recolectó en el Golfo de Panama muestras cuantitativas de fitoplancton en la superficie y a los diez metros, como sigue: a) Del 18 al 21 de marzo de 1958 (31 estaciones)-durante el maximum de la estación de afloramiento. b) Del 10 al 12 de julio de 1957 (10 estaciones)-durante la epóca de transición a la estación lluviosa cuando reaparecen los vientos ligeros que causan el afloramiento. c) Del 7 al 8 de noviembre de 1957 (15 estaciones)-durante el maximum de la estación lluviosa. 2. Las poblaciones maximas de fitoplancton aparecieron durante la estación de afloramiento, seguido por una considerable disminución durante el mes de julio y una calma durante noviembre. 3. Durante la investigación se observó una remarcable uniformidad regional en la composición de las especies a pesar de las diferencias regionales en las condiciones de crecimiento. Las diatomeas predominaban en gran numero en las comunidades. 4. Durante todas las investigaciones, las regiones mas cerca de la costa, generalmente al norte de los 8°30'N, eran las mas productivas. Las areas menos productivas fueron las mar afuera de las Bahias de San Miguel y Parita, lo que sugiere que el aumento en las sales nutritivas causado por las escorrentias es inadecuado para sostener poblaciones grandes de plantas autotróficas en estas regiones. 5. Durante todas las investigaciones, el crecimiento del fitoplancton parecio estar limitado por la disponibilidad de las. sales nutritivas. 6. Durante todas las investigaciones el crecimiento del fitoplancton parecio estar relacionado con la profundidad de la columna de agua. 7. Aunque las precipitacion por debajo del promedio normal contribuyo a condiciones desusadamente favorables de crecimiento (estabilidad reducida, aumento de la transparencia y, presumiblemente, de la reserva de sales nutritivas) durante la investigación de noviembre en relación a noviembre de 1955 y de 1956 en los 8°45'N, 79°23'W, no se observo-la alta reacción de fitoplancton que se esperaba. 8. Durante la investigación de noviembre, las reacciones locales de las diatomeas y sus fluctuaciones regionales pudieron relacionarse en forma satisfactoria con condiciones asociadas con la salinidad de la superficie. Sin embargo, esta correspondencia puede atribuirse sin duda a factores asociados con los niveles observados de salinidad, probablemente con las sales nutritivas, en lugar de directamente con la salinidad. 9. Condiciones calurosas no comunes ocurrieron durante la investigación de marzo, las que pueden atribuirse a que los vientos que ocasionan el afloramiento fueran mas debiles que los normales, lo que contribuyó a que la cosecha estable fuera considerablemente mas baja y a la demora de tres a cinco semanas en la sucecion relativa a la que se observó durante 1955-1957 en los 8°45'N, 8°23'W, en el Golfo de Panama. 10. Durante la investigación de marzo, existió una relación inversa bien definida entre la temperatura y la abundancia media de las diatomeas en los diez metros superiores, y entre la transparencia y la abundancia media de las diatomeas. Una relación directa ocurrio entre la salinidad de superficie y la abundancia media de las diatomeas en los diez metros superiores. Estas relaciones se interpretan como indicadoras de que la abundancia de diatomeas refleja primeramente las concentraciones de las sales nutritivas asociadas con una intensidad de afloramiento dada, en lugar de describir relaciones causales. 11. Los resultados de la investigacion indican que la dinamica del fitoplancton observada en los 8°45'N, 79°23'W, desde noviembre de 1954 a mayo de 1957, es generalmente representativa del Golfo de Panama. 12. Durante las investigaciones se observaron las siguientes formas nuevas, las que seran descritas en una publicación posterior: Actinoptychus undulatus f. catenata n.f., Asterionella japonica f. tropicum n.f., Leptocylindrus maximus n. sp., Skeletonema costatum f. tropicum n.f.

A quantitative analysis of the phytoplankton of the Gulf of Panama II. On the relationship between C14 assimilation and the diatom standing crop

ENGLISH: The Inter-American Tropical Tuna Commission has maintained a hydro-biological station in the Gulf of Panama located at 8°45'N, 79°23'W in connection with their ecological investigation of the anchoveta (Cetengraulis mysticetus), a tuna baitfish (see Peterson, 1961, for references) . The depth is approximately 42 meters at mean low water at this station. Routine hydrographic and biological observations have been made (Schaefer, Bishop and Howard, 1958; Schaefer and Bishop, 1958; Forsbergh, 1963), including the collection of quantitative phytoplankton samples from November 1954 through May 1957 (Smayda, 1959; unpublished). The seasonal and regional variations in phytoplankton growth in the Gulf of Panama have also been investigated (Smayda, 1963). The relationships existing between C1 4 assimilation as determined by 24 hour in situ experiments and diatom standing crop at 10 meters when expressed as cell numbers, cell volume, cell surface area and cell plasma volume have been assessed for 30 observations made between November 1954 and May 1957 at 8°45'N, 79°23'W. The average cell volume and cell surface area characteristics for 110 diatom species and varieties are presented. SPANISH: Las relaciones existentes entre la asimilación del C14 , determinadas después de 24 horas de experimentos in situ, y la cosecha estable de las diatomeas a 10 metros, expresando el número de células, volumen celular, área de la superficie celular y volumen del plasma celular, han sido determinadas por medio de 30 observaciones hechas entre noviembre de 1954 y mayo de 1957, a los 8°45'N, 79°23'W. Se presenta, para 110 especies y variedades de diatomeas, el promedio de las características del volumen celular y del área de la superficie celular. (PDF contains 67 pages.)

A quantitative analysis of the phytoplankton of the Gulf of Panama III. General ecological conditions and the phytoplankton dynamics at 8°45'N, 79°23'W from November 1954 to May 1957

Bi-weekly phytoplankton samples were collected at 0, 10, and 20 m and enumerated by the Utermöhl sedimentation technique; 14C productivity measurements at 10 m, oblique zooplankton tows, and routine hydrographic observations were also made. Northerly winds induce upwelling during December-April, followed by a rainy season; a slight resurgence in upwelling may occur during July and/or August. Annual variations in upwelling intensity and rainfall occur. During upwelling, the upper 50 m, about 30 per cent of the total volume of the Gulf of Panama, is replaced with water 5 to 10 C colder than the more stratified, turbid and nutrient impoverished watermass present during the rainy season. The mean annual runoff accompanying an average annual precipitation of 2731 mm is estimated to equal a layer of fresh water 3.2 m thick. About 10 per cent of the phytoplankton phosphate and inorganic nitrogen requirements during the rainy season are accreted. (PDF contains 260 pages.)

An analysis of the structure of fish marketing and distribution in Kwara State of Nigeria

A study was conducted examining the structure of fish marketing in Kwara State and also the conduct of participants within the market structure. The performance of the marketing system was evaluated, highlighting bottlenecks in the system and means of overcoming them

An analysis of the historical catch data from the migratory salmonid fisheries of the River Ribble

The Ribble catchment is the largest and most diverse river system within National Rivers Authority (NRA), North West's Central Area. The river is approximately 100km in length and rises in a limestone area west of the Pennines. This report examines changes in the size and composition of the salmon and sea trout catches from the Ribble migratory salmonid fisheries during the years 1937 to 1991. Comparisons are made between the rod and net fisheries for both salmon and sea trout of the Ribble and Hodder. Patterns of catches shown by the Ribble fisheries are compared with those of other individual rivers and with patterns for the North West Region as a whole. An attempt is made to identify if any relationship exists between catch and stock abundance. Catch patterns shown by the Ribble and Hodder salmon fisheries are compared with electronic resistivity counter data from the two rivers. Annual salmon catch patterns and redd count data are compared both locally and regionally. Recommendations for future studies are made in the light of the report's findings.

Comparing the identification of southern California juvenile rockfishes (genus Sebastes spp.) by restriction site analysis of the mitochondrial ND3/ND4 region and by morphological characteristics

Rockfish (Sebastes spp.) juveniles are often difficult to identify by using morphological characters. This study independently applies morphological characters and a key based on mitochondrial restriction site variation to identify juvenile rockf ishes collected in southern California during juvenile rockfish surveys. Twenty-four specimens of Sebastes were examined genetically without knowledge of the morphological assignment. Seventeen fish were identified genetically as S. semicinctus, S. goodei, S. auriculatus, S. jordani, S. levis, S. rastrelliger, and S. saxicola. Identities for the remaining fish were narrowed to two or three species: 1) three fish were either S. carnatus or S. chrysomelas; 2) one fish was either S. chlorosticus, S. eos, or S. rosenblatti; and 3) three fish could have been either S. hopkinsi or S. ovalis, the latter for which we now have distinguishing mitochondrial markers. The genetic and morphological assignments concurred except for the identity of one fish that could only be narrowed down to S. hopkinsi or S. semicinctus by using morphological characters. Genetics excluded more species from multispecies groupings than did the morphological approach, especially species within the subgenus Sebastomus. Species in the genetically unresolvable groups may be similar because of recent divergence or because of interspecies introgression.

An analysis of the multigear, multispecies fishery in the Kenyan waters of Lake Victoria

Catch rates for both Nile perch (Lates niloticus) and dagaa (Rastrineobola argentea) from Kenyan waters of Lake Victoria have steadily increased through the 1980s, even though the fishing effort also increased during the same period. However, analysis of catch and effort data within and outside the Nyanza Gulf suggests an increase in catch rates due to a shift in effort from the inshore Gulf region to higher catch rates in the offshore region, rather than an increase in abundance. Analysis of catch rates by gear type both in and outside the Nyanza Gulf show that 1991 catch rates are lower than 1989 levels by 60-80% in some instances. Since the fishing power of these gears has increased during this period, it is likely that fish abundance declined more than catch rates. A dynamic population model is used to stimulate Nile perch dynamics. It indicates that a decline in catches should be anticipated.

Energy analysis of the ring seine operations, off Cochin, Kerala

Ring seines are lightly constructed purse seines adapted for operation in the traditional sector. Fish production and energy requirement in the ring seine operations, off Cochin, Kerala, India are discussed in this paper, based on data collected during 1997- 1998. The results reflect the Gross Energy Requirement (GER) situation that existed during 1997-1998. Mean catch per ring seiner per year worked out to be 211.9 t of which sardines (Sardinella spp.) constituted 44.3%, followed by Indian mackerel (Rastrelliger kanagurta) 29.7%, carangids 11.4%, penaeid prawns 2.2%, pomfrets 1.1% and miscellaneous fish 11.3%. Total energy inputs into the ring seine operations were estimated to be 1300.8 GJ. Output by way of fish production was determined to be 931.85 GJ. GER is the sum of all non-renewable energy resources consumed in making available a product or service and is a measure of intensity of non-renewable resource use. GER per tonne of fish landed by ring seiners was estimated to be 6.14. Among the operational inputs, kerosene constituted 73.4% of the GER, followed by petrol (12.7%), diesel (6.7%) and lubricating oil (2.4%). Fishing gear contributed 3.8%, engine 0.8% and fishing craft 0.3% of the GER. Energy ratio for ring seining was 0.72 and energy intensity 1.40.

Preliminary Analysis of the Feasibility of Transferring New Longline Technology to Small Artisanal Vessels off Northeastern Brazil

The catches of three longliners, including two recently converted small artisanal vessels and one large leased foreign longliner, were compared to provide some indication of the feasibility of transferring new longline technology to small vessels in the northeastern Brazilian pelagic longline fishery. Comparisons of catches between the two recently converted vessels operating across the same spatial and temporal scales showed no significant differences for the main target species, providing evidence to suggest that adoption of the technology was rapid and straightforward. A comparison of relative catch rates between one of the recently converted small longliners and the leased longliner across the same temporal scale, but in different areas, showed that while there were significant differences detected for some species, contributing to a significant reduction in total CPUE, the relative abundance of commercially important species within the operational range of the smaller vessels was sufficient for economically viable catches. The results showed that the net financial profit from the artisanal longliner was almost 10 times greater than that derived from existing fishing methods. The inclusion of some artisanal vessels in this fishery may help address the social and economic problems currently faced by fi

Competing for the Recreational Dollar: An Analysis of the California Commercial Passenger-Carrying Fishing Vessel Industry

California has a large and diverse marine recreational fishery. Anglers on commercial passenger-carrying fishing vessels (CPFV's) harvest a substantial proportion of California's marine recreational fisheries landings, accounting for about 40 percent and 16 percent of the total 1986 marine recreational catch in southern and northern California, respectively (NMFS, 1987). In 1986, 459,369 CPFV anglers landed some 2,835,021 fish in southern California, while 200,925 CPFV anglers landed 1,240, 100 fish in central and northern California.