Use of aerial survey and aerophotogrammetry methods in monitoring manatee populations

We evaluated the use of strip-transect survey methods for manatees through a series of replicate aerial surveys in the Banana River, Brevard County, Florida, during summer 1993 and summer 1994. Transect methods sample a representative portion of the total study area, thus allowing for statistical extrapolation to the total area. Other advantages of transect methods are less flight time and less cost than total coverage, ease of navigation, and reduced likelihood of double-counting. Our objectives were: (1) to identify visibility biases associated with the transect survey method and to adjust the counts accordingly; (2) to derive a population estimate with known variance for the Banana River during summer; and (3) to evaluate the potential value of this survey method for monitoring trends in manatee population size over time. (51 page document)

Social ecology of bottlenose dophins in Monterey Bay, California

Between 1990 and 1995, Pacific coastal bottlenose dolphins (Tursiops truncatus gillii) were studied using photo-identification during 228 boat-based surveys of the coastal strip (<1 km offshore) between Marina and New Brighton Beach in Monterey Bay (18 km of coastline). The study period encompassed 3 regular (1990, 1991 and 1995) and 3 El Niño years (1992, 1993, 1994). Based on dorsal fin markings, 97 unique individuals were identified. Eighteen animals (19%) showed a high level of site fidelity (defined as presence in at least 5 of the 6 years), although their overall range was larger than the study area. Thirty-eight animals (39%) were transient, leaving for periods of time, and 41 (42%) were occasional encounters. The rate of discovery indicated a pulsed recruitment of new individuals into the study area, with periods of stable school composition, especially during non-El Nino years, and periods of high school fluidity. Encounter rate was significantly higher in El Niño (81%) than non-El Niño years (61%). School size averaged 16 individuals (C.I.3, =0.05) and was significantly larger in El Niño years. Schools where calves were present were twice as large (mean=15; S.D.=8) than schools without calves (mean=8; S.D.=6). Newborns represented 12% of the sightings and were seen year round with a peak in summer and fall. Crude birth rate ranged between 0.09 and 0.17 (mean=0.13; S.D.=0.03). Five females calved in consecutive years and a resident female calved once a year for the duration of the study, possibly indicating a high rate of mortality for calves in this area. Individuals often traveled as subgroups of more consistent composition than the school itself, possibly indicating that a stronger social bond exists within these units which may function as “bands” (sensu Wells 1991) of same sex individuals traveling within a larger school of mixed composition. (ppt file of poster)

The effects of stress on benthic algal communities

The effects of stress on both microalgal and macroalgal communities are considered. On one hand the contrasting approaches of studies of these two communities reflect intrinsic differences in plant size, longevity and ease of handling. On the other hand they reveal that biological monitoring of the potentially deleterious effects of man's activities has focused largely on freshwater environments in which macroalgae only occasionally dominate. Large conspicuous plants can be readily investigated as individuals, whereas it is virtually impossible to trace effects of stress on an individual cell of a vegetatively-reproducing microalga; a population approach is almost inevitably necessary. However, rapid turnover rates, a spectrum of ecological characteristics distributed between many taxa, and the potential for statistical analysis, have facilitated the use of microalgae in environmental impact studies. Failure to extend such investigations into marine systems rests as much on man's ability to ignore environmental deterioration until it affects his quality of life as on the visual dominance of seaweeds around our coasts. However, large gaps remain in our knowledge of both large and small algae; some reported community changes over time are suspect, and the causes of even blatant changes are not always apparent.

Age validation of Dover sole (Microstomus pacificus) by means of bomb radiocarbon

We used bomb radiocarbon (14C) in this age validation study of Dover sole (Microstomus pacificus). The otoliths of Dover sole, a commercially important fish in the North Pacific, are difficult to age and ages derived from the current break-andburn method were not previously validated. The otoliths used in this study were chosen on the basis of estimated birth year and for the ease of interpreting growth zone patterns. Otolith cores, material representing years 0 through 3, were isolated and analyzed for 14C. Additionally, a small number of otoliths with difficult-to-interpret growth patterns were analyzed for 14C to help determine age interpretation. The measured Dover sole 14C values in easier-to-interpret otoliths were compared with a 14C reference chronology for Pacific halibut (Hippoglossus stenolepis) in the North Pacific. We used an objective statistical analysis where sums of squared residuals between otolith 14C values of Dover sole and the reference chronology were examined. Our statistical analysis also included a procedure where the Dover sole 14C values were standardized to the reference chronology. These procedures allowed an evaluation of aging error. The 14C results indicated that the Dover sole age estimates from the easier-to-interpret otoliths with the break-and-burn method are accurate. This study validated Dover sole ages from 8 to 47 years.

Comparison of echogram measurements against data expectations and assumptions for distinguishing seafloor substrates

Defining types of seafloor substrate and relating them to the distribution of fish and invertebrates is an important but difficult goal. An examination of the processing steps of a commercial acoustics analyzing software program, as well as the data values produced by the proprietary first echo measurements, revealed potential benef its and drawbacks for distinguishing acoustically distinct seafloor substrates. The positive aspects were convenient processing steps such as gain adjustment, accurate bottom picking, ease of bad data exclusion, and the ability to average across successive pings in order to increase the signal-to-noise ratio. A noteworthy drawback with the processing was the potential for accidental inclusion of a second echo as if it were part of the first echo. Detailed examination of the echogram measurements quantified the amount of collinearity, revealed the lack of standardization (subtraction of mean, division by standard deviation) before principal components analysis (PCA), and showed correlations of individual echogram measurements with depth and seafloor slope. Despite the facility of the software, these previously unknown processing pitfalls and echogram measurement characteristics may have created data artifacts that generated user-derived substrate classifications, rather than actual seafloor substrate types.

Humpback and Fin Whaling in the Gulf of Maine from 1800 to 1918

The history of whaling in the Gulf of Maine was reviewed primarily to estimate removals of humpback whales, Megaptera novaeangliae, especially during the 19th century. In the decades from 1800 to 1860, whaling effort consisted of a few localized, small-scale, shore-based enterprises on the coast of Maine and Cape Cod, Mass. Provincetown and Nantucket schooners occasionally conducted short cruises for humpback whales in New England waters. With the development of bomb-lance technology at mid century, the ease of killing humpback whales and fin whales, Balaenoptera physalus, increased. As a result, by the 1870’s there was considerable local interest in hunting rorquals (baleen whales in the family Balaenopteridae, which include the humpback and fin whales) in the Gulf of Maine. A few schooners were specially outfitted to take rorquals in the late 1870’s and 1880’s although their combined annual take was probably no more than a few tens of whales. Also in about 1880, fishing steamers began to be used to hunt whales in the Gulf of Maine. This steamer fishery grew to include about five vessels regularly engaged in whaling by the mid 1880’s but dwindled to only one vessel by the end of the decade. Fin whales constituted at least half of the catch, which exceeded 100 animals in some years. In the late 1880’s and thereafter, few whales were taken by whaling vessels in the Gulf of Maine.

A comparative survey of the fish populations of 10 West-Midlands meres of SSSI status

This is a comparative survey of the Fish Populations of 10 West-Midlands Mere of Site of Special Scientific Interest Status. The meres of the Shropshire-Cheshire plain (West Midlands) comprise over 60 water bodies. Water quality in the meres ranges from naturally eutrophic to nutrient limited and some of them have received Site of Special Scientific Interest status (SSSIs). This survey was commissioned in order to obtain quantitative information on the fish fauna of selected SSSIs and evaluate the likely impact of fish on other species within the community. The current survey was concerned with 10 of the West Midlands’ meres, a cross section of sites was selected. Sites were widely distributed from Marton Pool in the south-western part of Shropshire to Tabley moat in Chesire. Meres varied in size, depth and nutrient status. All were to be sampled using the methods outlined. The report is divided into different sections for clarity and ease of reference. The materials and methods section provides an outline of the location and status of each mere and information on known fish species present. The results were considered individually and comparatively, relative abundance of fish, species present, their diet, sex, age, parasite burdens and growth. Inter-site comparisons were made using information derived from echo-soundings, growth rate, diet, and species abundance for each site. The final section will be in the form of a general discussion, comparative information from longer term studies, conclusions and recommendations.

The Kent estuary 1992 surveys. Summary of results

This is the Kent estuary 1992 surveys: Summary of results produced by the National Rivers Authority in 1993. The report summarises routine and baseline water quality surveys carried out on the Kent estuary during 1992. Baseline surveys are designed to respond to regional, national, and European requirements. During 1992 baseline surveys were carried out in June and December. Unfortunately, in June, samples could only be taken from stations 3, 7 and 8. For ease of interpretation the results have been presented in graph form, including the maximum and minimum parameter concentration and the appropriate Environmental Quality Standards (EQS). The parameters measured in this survey were physical parameters (temperature, BOD, dissolved oxygen, Ph, salinity, conductivity); nutrients (ammonia, phosphate, and nitrate); metals (Mercury, Nickel, Arsenic, Cadmium, Chromium, Cooper, Boron, and Zinc) and organic compounds.

Niche measures and feeding strategies of Barbodes gonionotus Bleeker and Oreochromis spp. from a ricefield in Bangladesh

Intra-and interspecific virtual niche measures and feeding strategies of Barbodes gonionotus and Oreochromis spp. were studied from a rice field in Bangladesh. Appropriateness and ease of interpretation of different indices were evaluated. Small sizes of both species had a relatively wider dietary breadth and used many of the resource categories available to them than the large size groups, though none were generalist feeder. The dietary overlap of large B. gonionotus on the small was greater than the reverse, but biologically insignificant. While the dietary overlap of large Oreochromis spp. on the small was significantly greater. Interspecific dietary width was relatively broader for B. gonionotus than Oreochromis spp. and overlap of B. gonionotus on Oreochromis spp. was significantly greater than the reverse. Evidence of significant intraspecific dietary overlap between the two sizes of tilapia reflects strong competition and cautions for mixed-size stocking in rice-fish system. Besides, there seem fewer opportunities for habitat segregation between B. gonionotus and Oreochromis spp., due to the significant interspecific dietary overlap of the former on the latter in rice-fish system. Tilapia specialized on periphytic detrital aggregate while silver barb tended to consume aquatic macrophytes and molluscs. Small sizes of B. gonionotus should be preferred for rice-fish integration over the Oreochromis spp. due to their broader niche width and pronounced ontogenetic dietary shifts with the aging of the stock.

Report of the baseline survey undertaken on the Chinese cage site in Napoleon Gulf, Northern Lake Victoria, 12 March 2012

The government of the People's Republic of China through a 2007 agreement with the Government of the Republic of Uganda, has establishment of an Agricultural Technology Demonstration Center (ATDC). The first phase covering the building of aquaculture infrastructure at Kajjansi ARDC is complete and the second operation phase has started in which facilities for cage culture have been set up in the Napoleon gulf, northern Lake Victoria near Jinja. The cage facility is aimed at boosting fish farming within the lake as a diversification to the traditional pond fish culture technology. NaFIRRI scientists as well as Chinese experts undertook a baseline survey in the chosen cage site on 12 March 2012. The survey covered determination of water depth, water transparency, measurement of selected physical-chemical parameters (temperature,dissolved oxygen, conductivity and pH; determination of the nutrient status and study of algae, invertebrate and fish communities at the site. Materials and methodologies used in the survey were based on the Standard Operating Procedures (SOPs) of NaFIRRI. The study area was divided into three study sites. Site 1 (upstream) was at 8.9 metre depth while site 2 (proposed cage site) and site 3 (downstream) were 6 and 4.3 metres deep respectively. Water transparency was lowest at site 1 (1.58 m) and highest at site 3 (1.64 m). Dissolved oxygen at the three sites ranged from 6.0 to 8 mg/I. Water temperature profiles fluctuated within narrow limits between 26.5 and 27.5 DC. Measurements of pH were between 7 (neutral) and 8 (alkaline) while electrical conductivity was between 98 and 101 uS/em. These observed physical-chemical parameters at the study site were considered suitable for cage fish rearing purposes. Nitrite-nitrogen levels varied within narrow limits from 0.043 to 0.0453 mgtl. Similarly, Ammonia-nitrogen varied between 0.015 and 0.0185 mg/1. Soluble reactive phosphorus (SRP) level was highest at site 3 (O.012mgll) compared to that at sites 1 and 2 (0.009mgll). Total suspended solids (TSS) were higher at site 1 (83.3mgll), thereafter decreasing to lower levels at sites 2 (24.8mgtl) and 3 (19.8mgl) respectively. The nutrient level results observed here all fall below the maximum permissible limits by NEMA and therefore the site is recommended for cage culture The algal community was constituted by four major groups: Blue greens,Greens, Cryptophytes, and Diatoms with blue greens as the common and dominant group. High algal biomass (19944961 ugtL) of the dominant blue green algae was observed at site 1 compared site 2 and 3 (58655.2 & 27487. 7 ugtL) respectively. Occurrence of toxicin producing algae: microsytis and cylindrospermopsis in the proposed cage area was considered to be of not much significance as their concentrations were below harmful levels. However, monitoring their presence, biomass and seasonality will be critical in order to follow when and where they occur and at what time of the year for ease of management of the cages

Technologies for Measuring Currents in Coastal Environments, Portland, Maine, October 26-28, 2005:workshop proceedings

The Alliance for Coastal Technologies (ACT) Workshop entitled "Technologies for Measuring Currents in Coastal Environments" was held in Portland, Maine, October 26-28, 2005, with sponsorship by the Gulf of Maine Ocean Observing System (GoMOOS), an ACT partner organization. The primary goals of the event were to summarize recent trends in nearshore research and management applications for current meter technologies, identify how current meters can assist coastal managers to fulfill their regulatory and management objectives, and to recommend actions to overcome barriers to use of the technologies. The workshop was attended by 25 participants representing state and federal environmental management agencies, manufacturers of current meter technologies, and researchers from academic institutions and private industry. Common themes that were discussed during the workshop included 1) advantages and limitations of existing current measuring equipment, 2) reliability and ease of use with each instrument type, 3) data decoding and interpretation procedures, and 4) mechanisms to facilitate better training and guidance to a broad user group. Seven key recommendations, which were ranked in order of importance during the last day of the workshop are listed below. 1. Forums should be developed to facilitate the exchange of information among users and industry: a) On-line forums that not only provide information on specific instruments and technologies, but also provide an avenue for the exchange of user experiences with various instruments (i.e. problems encountered, cautions, tips, advantages, etc). (see References for manufacturer websites with links to application and technical forums at end of report) b) Regional training/meetings for operational managers to exchange ideas on methods for measuring currents and evaluating data. c) Organize mini-meetings or tutorial sessions within larger conference venues. 2. A committee of major stakeholders should be convened to develop common standards (similar to the Institute of Electrical and Electronics Engineers (IEEE) committee) that enable users to switch sensors without losing software or display capabilities. (pdf contains 28 pages)

Limited resources? Let the habitat priority planner help!

In this time of scarce resources, coastal resource managers must find ways to prioritize conservation, land use, and restoration efforts. The Habitat Priority Planner (HPP) is a free geospatial tool created by the National Oceanic and Atmospheric Administration’s Coastal Services Center that has received wide praise for its ease of use and broad applicability to conservation strategic planning, restoration, climate change scenarios, and other natural resource management actions. Not a geographic information system (GIS) user? Don’t worry―this tool was designed to be used in a team setting. One intermediate-level GIS user can push the buttons to show quick results while a roomful of resource managers and stakeholders provide input criteria that determine the results. The Habitat Priority Planner is a toolbar for ESRI’s ArcGIS platform that is composed of three modules: Habitat Classification, Habitat Analysis, and Data Explorer. The tool calculates basic ecological statistics that are used to examine how habitats function within a landscape. The tool pre‐packages several common landscape metrics into a user‐friendly interface for intermediate GIS users. In addition, HPP allows the user to build queries interactively using a graphical interface for demonstrating criteria selections quickly in a visual manner that is useful in stakeholder interactions. Tool advocates and users include land trusts, conservation alliances, nonprofit organizations, and select National Estuarine Research Reserves and refuges of the U.S. Fish and Wildlife Service. Participants in this session will learn the basic requirements for HPP use and the multiple ways the HPP has been applied to geographies nationwide. (PDF contains 5 pages)

Teaching Students to Evaluate E-Reference Sources with Moodle Forums

This presentation will describe the use of online forums in Moodle, a course management system, to teach students to evaluate both print and electronic reference sources. For two semesters I have created an online forum called the Fishing Hole Scouting Report for an in-class exercise. Students are given 2-3 background questions and told to find the answers using both a library-approved reference source and Wikipedia. Students then evaluate the reference source for effectiveness and ease of use, compared to Wikipedia, and post their comments in the forum to share with the class. I will highlight the educational benefits of using Moodle forums for this purpose and discuss best practices for selecting the most effective sources and questions.

Skimmers: Their Development and Use in Coastal Louisiana

The origin, development, and utilization of the skimmer net is reviewed along with other historical shrimp gears used in coastal Louisiana. The skimmer was developed to catch white shrimp, Penaeus setiferus, observed jumping over the cork line (headrope) of trawls being worked in shallow waters. A description of the gear is presented including basic components and various frame designs used by fishermen during its development. The advantages of skimmers over bottom trawls include: multiple use as both trawl and butterfly net (wing net), ease of deployment, increased maneuverability, reduction and greater survivability of bycatch, and ability to cover more area due to increased speed and continuous fishing capability. Disadvantages may include compromising vessel stability when stored upright on the deck, possible damage to water bottoms when improperly rigged, and limitation to a 12-foot (3.6 m) maximum depth due to size restrictions. The growing popularity of the skimmer net is evident by its introduction into North Carolina and inquiries from other southeastern Atlantic and Gulf coast states.