Ecologic and hydrographic studies of Elkhorn Slough, Moss Landing Harbor and near coastal waters, July 1974 to June 1976

In July 1974, we began a two-year baseline study of the Moss Landing Elkhorn Slough marine environment for Pacific Gas and Electric Company as mandated by the Coastal Commission. The original proposal included strong recommendations for more complete oceanographic studies and a third year of data collection. These further studies were not funded. This report is divided into three sections: oceanography, benthic invertebrate ecology and fish and zooplankton ecology. (PDF contains 480 pages)

Feeding Ecology of Humpback Whales in Continental Shelf Waters near Cordell Bank, California

Daytime feeding behavior of humpback whales (Megaptera novaeangliae) in Gulf of the Farallones, California, and adjacent waters was observed during autumn of 1988 to 1990. Bodega Canyon, Cordell Bank, and the Farallon Islands were the primary sites of feeding activity. Fecal samples of whales and zooplankton tows contained euphausiids exclusively, dominated by Thysanoessa spinifera (79%), with lesser amounts of Euphausia pacifica (14%), Nyctiphanes simplex (4%), and Nematoscelis difficilis (3%). In 1988 and 1990, whales also were infrequently observed feeding on small schooling fish, presumably Pacific herring (Clupea pallasii), northern anchovy (Engraulis mordax), and juvenile rockfish (Sebastes spp.). Feeding was the most common behavior observed (52%), and less frequently traveling (23%), milling (21 %), and resting (4%). Whales used different methods to consume euphausiid prey at the surface (0-10 m), in shallow water (11-60 m), and deep water (61-140 m). Humpback whales fed at the surface 56% of time in 1988 and 32% of time in 1990, using primarily lateral lunges to capture swarms of euphausiids. In 1989, no surface feeding was observed; however, deep, long-duration dives were followed by extended surface intervals with many respirations. These 1989 observations coincided with increased prey depth as indicated by depth sounder records of diving whales and prey scattering layers. In 1989, increased prey depth and associated feeding behaviors were strongly associated with unusually high surface temperatures, calm seas, and changes in water circulation. Environmental conditions in 1989 triggered the most intense and wide-spread occurrence of red tide in this region since 1980. Red tide samples collected throughout this period contained Alexandrium (=Gonyaulax) catenella and Noctiluca scintillans. Surface feeding was observed only in 1988 and 1990, when surface prey were available and red tides were very limited in extent, duration, and intensity. Annual variations in humpback whale feeding behavior were related to prey availability which is affected by corresponding environmental conditions. (PDF contains 94 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.)

Seasonal Climatologies and Variability of Eastern Tropical Pacific Surface Waters

Interannual variability caused by the El Nino-Southern Oscillation in the eastern tropical Pacific Ocean (ETP) is analogous to seasonal variability of comparable magnitude. Climatological spatial patterns and seasonal variability of physical variables that may affect the ETP ecosystem are presented and discussed. Surface temperature, surface salinity, mixed layer depth, thermocline depth, thermocline strength, and surface dynamic height were derived from bathythermograph, hydrocast, and CTD data. Surface current velocity, divergence, and upwelling velocity were derived from ship drift reports. Surface wind velocity, wind stress, wind divergence, wind stress curl, and Ekman pumping velocity were derived from gridded pseudostress data obtained from Florida State University. Seasonal maps of these variables, and their deviations from the annual mean, show different patterns of variation in Equatorial (S°S-SON) and Tropical Surface Water (SOlS0N). Seasonal shifts in the trade winds, which affect the strength of equatorial upwelling and the North Equatorial Countercurrent, cause seasonal variations in most variables. Seasonal and interannual variability of surface temperature, mixed layer depth, thermocline depth and wind stress were quantified. Surface temperature, mixed layer depth and thermocline depth, but not local wind stress, are less variable in Tropical Surface Water than in Equatorial Surface Water. Seasonal and interannual variability are close to equal in most of the ETP, within factors of 2 or less. (PDF file contains 70 pages.)

Larvae of Nearshore Fishes in Oceanic Waters near Oahu, Hawaii

Larvae of over 50 families of nearshore fishes were taken in oceanic waters about 13 km offshore of the leeward (southwest) coast of Oahu, Hawaii during 1977-78, The five most frequently taken families (Labridae, Parapercidae, Serranidae, Gobiidae, and Carangidae) made up over 50% of the total nearshore larvae. Most other families were taken very infrequently. Comparison of catch data from three types of nets indicated that 1.25-m diameter bongo nets often sampled larvae as well or better than a 3-m Isaacs-Kidd trawl and that smaller, 70-cm diameter bongo nets were often as effective as the larger nets for certain abundant taxa. Only a few taxa showed evidence of seasonal patterns in abundance. Irregular temporal variability in abundance of some taxa may have been related to occasional recent influxes of surface water from closer to shore. Most larvae taken were late preflexion stage or older. Densities of even the most abundant taxa were rarely greater than 0.001 m-3. The nearshore fish larvae were not dominated by taxa with large larvae or with larvae possessing apparent specializations to pelagic existence, Most taxa taken were pelagic spawners as adults, but larvae of demersal spawners were roughly as well represented as demersal spawners are among the nearshore fish fauna. Previous studies of waters closer to shore probably sampled insufficient volumes for any but a few exceptionally abundant taxa. Sampling with volumes filtered of the order of 104-105 m3 will be necessary to determine if the dominant taxa taken by the present study are ever more abundant closer to shore, (PDF file contains 23 pages.)

Nutrient distributions for Georges Bank and adjacent waters in 1979

In this report we describe the temporal and spatial distributions of inorganic nutrients over Georges Bank and in adjacent waters and discuss major features with respect to tbe nutrient environments of pbytoplankton. Nitrate and orthophosphorus were rapidly depleted from the surface layer of much of the study area in spring, but major differences were found between the shallow areas on Georges Bank and the surrounding stratified waters. In the "well-mixed" area of Georges Bank, the depletion encompassed the entire water column and ammonium became the dominant form of inorganic nitrogen throughout. Dissolved silicon was depleted slowly over central Georges Bank, reaching a minimum concentration in September while orthophosphorus gradually increased during the summer. The nutrient environment of phytoplankton over central Georges Bank may be described as vertically uniform but temporally changing in the relative availability of the various nutrients. In areas that undergo stratification (e.g., the central Gulf of Maine), a quasi-steady state was established as the surface water layer formed, consisting of declining nutrient gradients from below the euphotic layer to the top of the water column. These intergrading nutrient environments are relatively stable through time. Destratification reintroduced nutrients to depleted areas beginning in October; however, dissolved silicon was again depleted over shallow Georges Bank in late autumn though nitrate remained abundant. Slope water has been found to enter the bottom layer of the Gulf of Maine via the Northeast Channel. High nutrient concentrations observed in the bottom water of the Northeast Channel are consistent with this mechanism being the nutrient source for the Gulf of Maine. (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.)

Configurations and relative efficiencies of shrimp trawls employed in southeastern United States waters

Common shrimp trawl designs employed in the southeastern United States shrimp fishery are the flat, balloon, semiballoon, jib, and super X-3. Recent innovations in trawl design and rigging, including the twin trawl rigging and tongue trawl design, have improved the efficiency of shrimp trawling gear. A description of the construction techniques for the different designs indicate differences which affect gear performance. Measurements of horizontal spread and vertical opening for 76 trawl configurations indicate the relative efficiencies of the different designs. Maximum horizontal spreading efficiency was achieved by the "twin" and "tongue" trawl designs followed by the super X-3, jib, balloon, and semiballoon designs. Designs having the greatest vertical openings were the tongue and flat trawl designs followed by the semiballoon. Maximum total gape dimension was demonstrated by the "Mongoose" tongue trawl. Comparison of trawl spreading efficiency and door area to headrope length ratio indicates that a range of 70-80 in square (per door) of door area is required for each foot of trawl headrope length for maximum efficiency with conventional trawl designs and 66-75 in square per foot of headrope for tongue trawl designs. (PDF file contains 18 pages.)

Measures of turbidity in coastal waters, Coconut Island, Oahu, Hawaii, August 31 - September 2, 2005: workshop proceedings

A three day workshop on turbidity measurements was held at the Hawaii Institute of Marine Biology from August 3 1 to September 2, 2005. The workshop was attended by 30 participants from industry, coastal management agencies, and academic institutions. All groups recognized common issues regarding the definition of turbidity, limitations of consistent calibration, and the large variety of instrumentation that nominally measure "turbidity." The major recommendations, in order of importance for the coastal monitoring community are listed below: 1. The community of users in coastal ecosystems should tighten instrument design configurations to minimize inter-instrument variability, choosing a set of specifications that are best suited for coastal waters. The IS0 7027 design standard is not tight enough. Advice on these design criteria should be solicited through the ASTM as well as Federal and State regulatory agencies representing the majority of turbidity sensor end users. Parties interested in making turbidity measurements in coastal waters should develop design specifications for these water types rather than relying on design standards made for the analysis of drinking water. 2. The coastal observing groups should assemble a community database relating output of specific sensors to different environmental parameters, so that the entire community of users can benefit from shared information. This would include an unbiased, parallel study of different turbidity sensors, employing a variety of designs and configuration in the broadest range of coastal environments. 3. Turbidity should be used as a measure of relative change in water quality rather than an absolute measure of water quality. Thus, this is a recommendation for managers to develop their own local calibrations. See next recommendation. 4. If the end user specifically wants to use a turbidity sensor to measure a specific water quality parameter such as suspended particle concentration, then direct measurement of that water quality parameter is necessary to correlate with 'turbidity1 for a particular environment. These correlations, however, will be specific to the environment in which they are measured. This works because there are many environments in which water composition is relatively stable but varies in magnitude or concentration. (pdf contains 22 pages)

In situ measurement of dissolved inorganic carbon speciation in natural waters, pH, pC02, TA, & TC02, Honolulu, Hawaii, February 16-18, 2005: workshop proceedings

The Alliance for Coastal Technology (ACT) convened a workshop on the in situ measurement of dissolved inorganic carbon species in natural waters in Honolulu, Hawaii, on February 16, 17, and 18, 2005. The workshop was designed to summarize existing technologies for measuring the abundance and speciation of dissolved inorganic carbon and to make strategic recommendations for future development and application of these technologies to coastal research and management. The workshop was not focused on any specific technology, however, most of the attention of the workshop was on in situ pC02 sensors given their recent development and use on moorings for the measurement of global carbon fluxes. In addition, the problems and limitations arising from the long-term deployment of systems designed for the measurement of pH, total dissolved inorganic carbon (DIC), and total alkalinity (TA) were discussed. Participants included researchers involved in carbon biogeochemistry, industry representatives, and coastal resource managers. The primary questions asked during the workshop were: I. What are the major impediments to transform presently used shipboard pC02 measurement systems for use on cost-eficient moorings? 2. What are the major technical hurdles for the in situ measurement of TA and DIC? 3. What specific information do we need to coordinate efforts for proof of concept' testing of existing and new technologies, inter-calibration of those technologies, better software development, and more precise knowledge quantzjjing the geochemistry of dissolved inoeanic carbon species in order to develop an observing system for dissolved inorganic carbon? Based on the discussion resulting from these three questions, the following statements were made: Statement No. 1 Cost-effective, self-contained technologies for making long-term, accurate measurements of the partial pressure of C02 gas in water already exist and at present are ready for deployment on moorings in coastal observing systems. Statement No. 2 Cost-effective, self-contained systems for the measurement of pH, TA, and DIC are still needed to both fully define the carbonate chemistry of coastal waters and the fluxes of carbon between major biogeochemical compartments (e.g., air-sea, shelf-slope, water column-sediment, etc.). (pdf contains 23 pages)

Applications of in situ Fluorometers in Nearshore waters, Cape Elizabeth, Maine, February 2-4,2005: workshop proceedings

The Alliance for Coastal Technologies (ACT) Workshop "Applications of in situ Fluorometers in Nearshore Waters" was held in Cape Elizabeth, Maine, February 2-4,2005, with sponsorship by the Gulf of Maine Ocean Observing System (GoMOOS), one of the ACT partner organization. The purpose of the workshop was to explore recent trends in fluorometry as it relates to resource management applications in nearshore environments. Participants included representatives from state and federal environmental management agencies as well as research institutions, many of whom are currently using this technology in their research and management applications. Manufacturers and developers of fluorometric measuring systems also attended the meeting. The Workshop attendees discussed the historical and present uses of fluorometry technology and identified the great potential for its use by coastal managers to fulfill their regulatory and management objectives. Participants also identified some of the challenges associated with the correct use of Fluorometers to estimate biomass and the rate of primary productivity. The Workshop concluded that in order to expand the existing use of fluorometers in both academic and resource management disciplines, several issues concerning data collection, instrument calibration, and data interpretation needed to be addressed. Participants identified twelve recommendations, the top five of which are listed below: Recommendations 1) Develop a "Guide" that describes the most important aspects of fluorescence measurements. This guide should be written by an expert party, with both research and industry input, and should be distributed by all manufacturers with their instrumentation. The guide should also be made available on the ACT website as well as those of other relevant organizations. The guide should include discussions on the following topics: The benefits of using fluorometers in research and resource management applications; What fluorometers can and cannot provide in terms of measurements; The necessary assumptions required before applying fluorometry; Characterization and calibration of fluorometers; (pdf contains 32 pages)

Utilization of waste waters in fish production: preliminary results from fish culture studies in floating cages in a sewage pond, New Bussa, Nigeria

The utilization of waste waters in aquaculture were briefly reviewed. At the National Institute for Freshwater Fisheries Research (NIFFR), stocking density (20 to 160 fish/m super(3)) experiments using Sarotherodon galilaeus (without supplementary feeding) in floating cages were carried out in a sewage pond (0.4ha surface area). Cage culture of S. galilaeus was observed to have potentials in waste waters aquaculture. Recommendations were made on the execution of an intergrated waste water management and utilization.

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

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

Contributions to the biology of the engraulid Anchoa naso (Gilbert and Pierson, 1898) from Ecuadorian waters

ENGLISH: One phase of the duties of the Inter-American Tropical Tuna Commission is the gathering and interpretation of data concerning the life history of the commercially important bait species throughout the Eastern Pacific Ocean. During 1958 the Commission established a laboratory in Manta, Ecuador to study tuna. It was subsequently found that this fishery was dependent upon one species of anchovy, Anchoa naso, which was locally referred to as "colorado." During the calendar year 1959 approximately 380,000 scoops of bait were taken by the Manta tuna fleet (Schaefer, 1960), which at that time numbered about 23 vessels. Since then the fleet has increased by about 25 per cent and it is probable that the bait catch has increased also. Virtually nothing has been reported concerning the life history of this species. Hildebrand (1943) reviewed its taxonomy and reported standard lengths ranging from 32 to 135 mm. Peterson (1956) examined specimens from Central America and found them to range from 27 to 66 mm. He also indicated that the species spawned over a long period of time. The present report describes some aspects of the life history of Anchoa naso in Ecuadorian waters. The findings are based on 121 collections taken during the period March 1959 through June 1961. SPANISH: Una fase de las obligaciones de La Comisión Interamericana del Atún Tropical es la obtensión e interpretación de los datos concernientes a la historia natural de las especies de carnada comercialmente importantes en todo el Océano Pacifico Oriental. En el año de 1958 la Comisión estableció un laboratorio en Manta, Ecuador, para estudiar el atún. Se encontró subsecuentemente que esta pesquería dependía de una especie de anchoa, Anchoa naso, conocida localmente con el nombre de colorado. Durante el año calendario de 1959, la flota atunera de Manta, que en ese tiempo alcanzaba a unos 23 barcos, obtuvo aproximadamente 380,000 copas (scoops) de carnada (Schaefer, 1960). Desde entonces la flota ha aumentado en un 25 por ciento, y es probable que la captura de peces-cebo haya aumentado también. Nada se ha informado virtualmente sobre la historia natural de esta especie. Hildebrand (1943) revisó su taxonomia e informó sobre su longitud estándar, que varia entre los 32 y 135 mm. Peterson (1956) examinó especímenes de la América Central, y encontró que variaban entre los 27 y 66 mm. También indicó que la especie desova durante un largo periodo de tiempo. El presente informe describe algunos aspectos de la historia natural de la Anchoa naso en aguas ecuatorianas. Los hallazgos están basados en 121 recolecciones hechas durante el periodo de marzo de 1959 a junio de 1961. (PDF contains 30 pages.)