Sex ratio of the sole Euryglossa orientalis (Bl. & Schn.) (family: Soleidae) from the Karachi coast

This paper present a study on sex ratio and reveals segregation or aggregation of males and females in accordance with environmental conditions, the differential behaviour of sexes, and due to fishing.

Fecundity of the sole Euryglossa orientalis (Bl. & Schn.)(family: Soleidae) from Karachi coast

During the present study fecundity of 30 ovaries of Euryglossa orientalis was determined. Fecundity ranged from 9922 to 8389 with a mean value of 36361. The number of ova in the dorsal lobe was less than that of ventral lobe. Log-log relationship between fecundity and total length, fish weight, ovary weight and ovary length were determined.

Fat and water distribution patterns in the flesh of the common cat-fish Wallago attu (Bl. & Schn.)

The quantitative distributional pattern of fat and water has been studied in the flesh of the various zones corresponding to the dorsal and ventral regions of the body of a common cat-fish, Wallago attu. The ventral aspect of the body showed more accumulation of fat than the dorsal aspect. The fat content in the ventral region also exhibited an increase from the anterior to the posterior zones. In the dorsal region, however, the back portion of the body, behind the dorsal fin, generally possessed low fat content. On an average, the highest fat accumulation was observed in the caudal peduncle region. The distribution of water followed an almost opposite pattern of distribution, indicating an inverse relationship with fat.

Allometric study of skeleton weight, body weight and length relationship of Euryglossa orientalis (Bl. & Schn.) (Family: Soleidae) from Karachi coast

Present study deals with the family Soleidae (common sole) Euryglossa orientalis (Bl. & Schn.) of the order Pleuronectiformis from Karachi coast. Separate equation (regression line) for describing the length weight relationships for male and female combined are justified. Allometric studies were made on skeleton weight relative to the length and the weight of the fish. The regression equation 'a' and 'b' values of standard length/skeleton weight and body weight/skeleton weight are statistically significant.

The littoral ascidians of Monterey Bay and vicinity

In addition to describing the species of tunicates found areound Monterey Bay California, it provides a taxonomic key. This is a student paper done for a University of California Berkeley Zoology class. Since UCB didn't have its own marine lab at the time, it rented space at Hopkins Marine Station where this work was done. Donald Putnam Abbott went on to earn his Ph.D. from Berkeley and later became a Stanford professor at Hopkins Marine Station. (PDF contains 35 pages)

The distribution of cirripeds and gastropods on plain vertical rock surfaces in the upper intertidal and splash zones

This is a student paper done for a University of California Berkeley Zoology class. Since UCB didn't have its own marine lab at the time, it rented space at Hopkins Marine Station where this work was done. Cadet Hand earned his Ph.D. from Berkeley and went on to become Director of the Bodega Marine Laboratory. Donald Putnam Abbott also earned his Ph.D. from Berkeley and later became a Stanford professor at Hopkins Marine Station. (PDF contains 26 pages)

The A Posteriori Aspects of Estuarine Modeling

This exercise is the application of an analytical method for systematically modeling ecosystems data to observations made on a naturally eutrophic, mesohaline planktonic microcosm. The theory and experimental design are briefly outlined and the particular steps in the acutal modeling process follow. Then there is a discussion as to how the whole endeavor can be refined to culminate in models with predictive capabilities. (PDF has 16 pages.)

Some effects of tropical storm Agnes on water quality in the Patuxent River estuary

A post Agnes study emphasizing environmental factors...weekly sampling at eight stations from 28 June to August 30, 1972. Spatial and temporal changes in the distribution of many factors, e.g., salinity, dissolved oxygen (DO), seston, particulate carbon and nitrogen, inorganic and organic fractions of dissolved nitrogen and phosphorus, and chlorophyll a were studied and compared to earlier extensive records. Patterns shown by the present data were compared especially with a local heavy storm that occurred in the Patuxent drainage basin during July 1963. Some interesting correlations were observed in the data. (PDF has 39 pages.)

Some effects of Hurricane Agnes on water quality in the Patuxent River Estuary

A post-Agnes study that emphasized environmental factors was carried out on the Patuxent River estuary with weekly sampling at eight stations from 28 June t o 30 August 1972. Spatial and temporal changes in the distribution of many factors , e.g., salinity , dissolved oxygen, seston, particulate carbon and nitrogen, inorganic and organic fractions of dissolved nitrogen and phosphorus, and chlorophyll a were studied and compared t o extensive earlier records. Patterns shown by the present data were compared especially with a local heavy storm that occurred in the Patuxent drainage basin during July 1969. Estimates were made of the amounts of material contributed via upland drainage. A first approximation indicated that 14.8 x l0 (3) metric tons of seston were contributed t o the head of the estuary between 21 and 24 June. (PDF contains 46 pages)

The Empirical Modeling of an Ecosystem

The authors have endeavored to create a verified a-posteriori model of a planktonic ecosystem. Verification of an empirically derived set of first-order, quadratic differential equations proved elusive due to the sensitivity of the model system to changes in initial conditions. Efforts to verify a similarly derived set of linear differential equations were more encouraging, yielding reasonable behavior for half of the ten ecosystem compartments modeled. The well-behaved species models gave indications as to the rate-controlling processes in the ecosystem.

Effects of perturbations on estuarine microcosms

Microcosms containing planktonic communities from Chesapeake Bay responded to enrichment with sewage by developing larger standing crops of phytoplankton and zooplankton. Data suggest that increased productivity would be reflected up the food chain but might increase existing problems with dissolved oxygen and might lead to qualitative changes in the composition of the zooplankton. Either phosphorus or nitrogen was removed more rapidly from solution depending on where and when the experimental water was obtained. Increases in standing crop of algae were associated with loss of nitrogen from solution in two experiments and losses of both nitrogen and phosphorus from solution in one experiment.

Report on the pinniped and sea otter tagging workshop 18-19 January 1979 Seattle, Washington

The Marine Mammal Tagging Office has been created by consensus of the agencies responsible for marine mammal management and the scientific community dealing with marine mammal tagging and marking. The purpose of ths office is to facilitate the dissemination of information with regard to tagging, marking, tags, and marks; to determine the need for new and better materials for tags; and to stimulate research, development, and testing programs. The American Institute of Biological Sciences was requested to coordinate a workshop to determine the status of pinniped tagging both nationally and internationally. Approximately 30 scientists were invited to participate in the workshop which was held on 18-19 January 1979 at the Sand Point Laboratory of the National Marine Fisheries Service in Seattle, Washington. Topics included ranged from specific tagging programs to general considerations and similar problems encountered by researchers. Participants also participated in one of three working groups -- Sea Otters, Phocids, and Otariids --to address pertinent issues. These break-out sessions resulted in the general recommendations and specific considerations sections of this report. Abstract authors include: Alton Y. Roppel; Ken Pitcher; Burney J. Le Boeuf; Wybrand Hoek; Robert M. Warneke; Don B. Siniff; Doug P. DeMaster; Daniel J. Miller; Ian Stirling; Roger L. Gentry; Lanny H. Cornell; James E. Antrim; Edward D. Asper; Mark Keyes; R. Keith Farrell; Donald G. Calkins; Bob DeLong; T. A. Gornall; Tom Otten; and, Ancel M. Johnson (PDF contains 54 pages)

Ongoing monitoring of Tortugas Ecological Reserve: Assessing the consequences of reserve designation

Over the past five years, a biogeographic characterization of Tortugas Ecological Reserve(TER) has been carried out to measure the post-implementation effects of TER as a refuge for exploited species. Our results demonstrate that there is substantial microalgal biomass at depths between 10 and 30 m in the soft sediments at the coral reef interface, and that this community may play an important role in the food web supporting reef organisms. In addition, preliminary stable isotope data, in conjunction with prior results from the west Florida shelf, suggest that the shallow water benthic habitats surrounding the coral reefs of TER will prove to be an important source of the primary production ultimately fueling fish production throughout TER. The majority of the fish analyzed so far have exhibited a C isotope signature consistent with a food web which relies heavily on benthic primary production. Fish counts indicate a marked increase in the abundance of large fish (>20 cm) within the Reserve relative to the Out and Park strata, across years. Faunal collections from open and protected soft bottom habitat near the northern boundary of Tortugas North strongly suggest that relaxation of trawling pressure has increased benthic biomass and diversity in this area of TER. These data, employing an integrated Before - After Control Impact (BACI) design at multiple spatial scales, will allow us to continue to document and quantify the post-implementation effects of TER. (PDF contains 58 pages)

Extreme events and ecological forecasting

Almost all extreme events lasting less than several weeks that significantly impact ecosystems are weather related. This review examines the response of estuarine systems to intense short-term perturbations caused by major weather events such as hurricanes. Current knowledge concerning these effects is limited to relatively few studies where hurricanes and storms impacted estuaries with established environmental monitoring programs. Freshwater inputs associated with these storms were found to initially result in increased primary productivity. When hydrographic conditions are favorable, bacterial consumption of organic matter produced by the phytoplankton blooms and deposited during the initial runoff event can contribute to significant oxygen deficits during subsequent warmer periods. Salinity stress and habitat destruction associated with freshwater inputs, as well as anoxia, adversely affect benthic populations and fish. In contrast, mobile invertebrate species such as shrimp, which have a short life cycle and the ability to migrate during the runoff event, initially benefit from the increased primary productivity and decreased abundance of fish predators. Events studied so far indicate that estuaries rebound in one to three years following major short-term perturbations. However, repeated storm events without sufficient recovery time may cause a fundamental shift in ecosystem structure (Scavia et al. 2002). This is a scenario consistent with the predicted increase in hurricanes for the east coast of the United States. More work on the response of individual species to these stresses is needed so management of commercial resources can be adjusted to allow sufficient recovery time for affected populations.

Ecological forecasting: new tools for coastal and marine ecosystem management

Policy makers, natural resource managers, regulators, and the public often call on scientists to estimate the potential ecological changes caused by both natural and human-induced stresses, and to determine how those changes will impact people and the environment. To develop accurate forecasts of ecological changes we need to: 1) increase understanding of ecosystem composition, structure, and functioning, 2) expand ecosystem monitoring and apply advanced scientific information to make these complex data widely available, and 3) develop and improve forecast and interpretative tools that use a scientific basis to assess the results of management and science policy actions. (PDF contains 120 pages)