Odontocete Stranding Patterns in the Main Hawaiian Islands 1937–2002): how do they compare with live animal surveys?

In this study we (1) synthesized 65 yr of odontocete stranding data around the main Hawaiian Islands (1937–2002); (2) analyzed stranding patterns and trends over time; and (3) compared occurrence patterns based on sightings of live animals with stranding data and evaluated the compatibility of these data sets. From 1937 to 2002, 202 odontocete strandings were recorded by the National Marine Fisheries Service, Pacific Islands Regional Office. Strandings increased through time due to increased reporting effort and occurred throughout the year. The four most common of 16 species reported were Kogia spp. (18%), spinner dolphins (Stenella longirostris) (15%), striped dolphins (Stenella coeruleoalba) (11%), and sperm whales (Physeter macrocephalus) (10%). The highest proportion of strandings was recorded on O‘ahu (48%), followed by Maui/La¯na‘i (24%), Kaua‘i (12%), Hawai‘i (11%), and Moloka‘i (5%). Comparison with four previously published live animal survey studies suggests that stranding records are a good indicator of species composition and yield reasonable data on the frequency of occurrence of species in the region they cover.

Results of abundance surveys of juvenile Atlantic and gulf Menhaden, Brevoortia tyrannus and B. patronus

The estuarine populations of juvenile Atlantic and gulf menhaden (Brevoortia tyrannus and B. patronus) were sampled during two-boat, surface-trawl, abundance surveys extensively conducted in the 1970s. Juvenile Atlantic menhaden were sampled in 39 estuarine streams along the U.S. Atlantic coast from northern Florida into Massachusetts. Juvenile gulf menhaden were sampled in 29 estuarine streams along the Gulf of Mexico from southeast Texas into western Florida. A stratified, two-stage, cluster sampling design was used. Annual estimates of relative juvenile abundance for each species of menhaden were obtained from catch-effort data from the surveys. There were no significant correlations, for either species, between the relative juvenile abundance estimates and fishery-dependent estimates of year-class strength. From 1972 to 1975, the relative abundance of juvenile Atlantic menhaden in north Atlantic estuaries decreased to near zero. (PDF file contains 22 pages.)

Bestandserfassung und -überwachung des atlanto-skandischen Herings. EU-Studie "Hydroacoustic Surveys of Atlanto-Scandian Herring in the Norwegian Sea, 1998-2000 (ASH-II)"

The atlanto-scandian herring consists of two major stocks, i.e. the Icelandic summer spawner and the Norwegian spring spawner. Both stocks have recovered well after complete collapse in the seventies and allow for a controlled fishery. The total allowable catch of the Norwegian spring spawner is currently 1.3 mill. t. The resumption of the fishery is accompanied by an annual and multi-national survey with Norwegian, Faeroe Islands, Icelandic and Russian contribution. In 1998 the EU will contribute to the survey with the Swedish vessel ”Argos” and in 1999 with the ”Walther Herwig III” under Dutch, Swedish and German participation. About half of the survey costs are covered by the EU by means of a funded study, the other half is contributed by the participating nations.

Recent trends in the distribution patterns and catch rates from trawl surveys in Lake Victoria, Tanzania

Trawl surveys to assess the stocks of Lake Victoria (Tanzania) for estimates of biomass and yield, together with the establishment of exploitation patterns, are being undertaken under the Lake Victoria Fisheries Research Project. Preliminary surveys to establish the sampling stations and strategy were carried out between October 1997 and February 1998. Three cruises to cover the whole of Tanzanian waters were undertaken with 133 sampling stations. Data on each rates, species composition, and distribution were collected. Three sampling areas were designated: area A, B and C. In each area, almost the same distribution pattern over depth was found. Lates niloticus (L) formed over 90% of the total catch. Most L. niloticus were from 5-40 cm TL. Abundance decreased with depth, few fish were found deeper than 40m and most fish were caught at <20 m deep. Catch rates varied considerably between stations and areas. Area A had the highest catch rates with little variation over the stations. There is an indication of recovery of species diversity compared with the surveys of RV Kiboko(1985 and 1989)

Preliminary observations on the use of a frame trawl in hydroacoustic surveys

Thirteen hauls were made during the hydroacoustic survey of the Ugandan waters of Lake Victoria from 7-19 February 1999. Ten of the hauls were made above the oxycline which was clearly visible as a strong echo on the echogram at between 25 and 35 m depth in most of the sampled areas. The remaining three hauls targeted the oxycline. Approximate equal weights of Rastrineobola argentia and Haplocromine cichlids were caught in total, but with marked differences between hauls. Near the surface R. argentia dominated the catches. In midwater Haplochromines were dominant. At the oxycline Caridina niloticus was abundant

Fishery resource surveys: beyond length-weight relationship models

Fisheries resource surveys are regular management tools for rational exploitation of commercial fisheries. In a growing number of cases, the use of these resource surveys has been largely restricted to assessment of the relative well being of fish stocks and the potential yields of such fisheries. This paper seeks to demonstrate that the data from such surveys can also be easily used to evaluate species diversity of such fisheries, both in terms of species richness and equitability of distribution. Using published data on two freshwater and two marine fisheries as case studies, Shannon-Wiener Diversity Function and Simpson's Index were computed for each of these fisheries. These biodiversity indices gave a deeper insight into the environmental status of each of these fisheries, beyond what the length-weight relationship models can reveal. Generally, while the marine fisheries showed more species richness, the freshwater fisheries apparently had more stable and equilibrated fish communities

On distribution of pollen in lakes. [Translation from: Palynology in geological research in the Baltic Soviet Republics p113-119. Vilnius, 1973.]

Systematic investigations of the distribution of pollen in stationary water bodies until now have hardly been conducted. For clarification of the problem of how the pollen of different plants which falls into a lake is deposited in relation to its physical properties, the character of the lake, wind currents and other factors, pollen analyses were carried out of surface samples of the bottom sediments of 13 Lithuanian lakes. Lakes were selected of different sizes (areas from 2333 ha. to 8 ha.) and different depths, not uniformly overgrown, situated in different physico-geographic regions of Lithuania. As a result of the investigation, it was established that in the surface layer of the sediments of the lakes of Lithuania pollen of woody species predominates.

Preliminary surveys of the fish and fisheries of the Nzoia, Nyando and Sondu Miriu rivers, Kenya

Three Lake Victoria rivers were sampled to assess fish abundance and distribution in preparation for assessment of catches from the river systems. Preliminary fish abundance data indicate that fishing potential upstream is negligible but that important commercial species are present in the downstream floodplain areas. Three catfish species were recorded in the Nzoia river system that have not been found previously in the Kenyan sector of the Lake Victoria system, together with possibly two undescribed Barbus species.

Herpetofaunal Inventories of the National Parks of South Florida and the Caribbean: Volume II. Virgin Islands National Park

Amphibian declines and extinctions have been documented around the world, often in protected natural areas. Concern for this alarming trend has focused attention on the need to document all species of amphibians that occur within U.S. National Parks and to search for any signs that amphibians may be declining. This study, an inventory of amphibian species in Virgin Islands National Park, was conducted from 2001 to 2003. The goals of the project were to create a georeferenced inventory of amphibian species, use new analytical techniques to estimate proportion of sites occupied by each species, look for any signs of amphibian decline (missing species, disease, die-offs, etc.), and to establish a protocol that could be used for future monitoring efforts. Several sampling methods were used to accomplish these goals. Visual encounter surveys and anuran vocalization surveys were conducted in all habitats throughout the park to estimate the proportion of sites or proportion of area occupied (PAO) by amphibian species in each habitat. Line transect methods were used to estimate density of some amphibian species and double observer analysis was used to refine counts based on detection probabilities. Opportunistic collections were used to augment the visual encounter methods for rare species. Data were collected during four sampling periods and every major trail system throughout the park was surveyed. All of the amphibian species believed to occur on St. John were detected during these surveys. One species not previously reported, the Cuban treefrog (Osteopilus septentrionalis), was also added to the species list. That species and two others (Eleutherodactylus coqui and Eleutherodactylus lentus) bring the total number of introduced amphibians on St. John to three. We detected most of the reptile species thought to occur on St. John, but our methods were less suitable for reptiles compared to amphibians. No amphibian species appear to be in decline at this time. We found no evidence of disease or of malformations. Our surveys provide a snapshot picture of the status of the amphibian species, so continued monitoring would be necessary to determine long-term trends, but several potential threats to amphibians were identified. Invasive species, especially the Cuban treefrog, have the potential to decrease populations of native amphibians. Introduced mammalian predators are also a potential threat, especially to the reptiles of St. John, and mammalian grazers might have indirect effects on amphibians and reptiles through habitat modification. Finally, loss of habitat to development outside the park boundary could harm some important populations of amphibians and reptiles on the island.

Herpetofaunal Inventories of the National Parks of South Florida and the Caribbean: Volume III. Big Cypress National Preserve

Amphibian declines and extinctions have been documented around the world, often in protected natural areas. Concern for this trend has prompted the U.S. Geological Survey and the National Park Service to document all species of amphibians that occur within U.S. National Parks and to search for any signs that amphibians may be declining. This study, an inventory of amphibian species in Big Cypress National Preserve, was conducted from 2002 to 2003. The goals of the project were to create a georeferenced inventory of amphibian species, use new analytical techniques to estimate proportion of sites occupied by each species, look for any signs of amphibian decline (missing species, disease, die-offs, and so forth.), and to establish a protocol that could be used for future monitoring efforts. Several sampling methods were used to accomplish these goals. Visual encounter surveys and anuran vocalization surveys were conducted in all habitats throughout the park to estimate the proportion of sites or proportion of area occupied (PAO) by each amphibian species in each habitat. Opportunistic collections, as well as limited drift fence data, were used to augment the visual encounter methods for highly aquatic or cryptic species. A total of 545 visits to 104 sites were conducted for standard sampling alone, and 2,358 individual amphibians and 374 reptiles were encountered. Data analysis was conducted in program PRESENCE to provide PAO estimates for each of the anuran species. All of the amphibian species historically found in Big Cypress National Preserve were detected during this project. At least one individual of each of the four salamander species was captured during sampling. Each of the anuran species in the preserve was adequately sampled using standard herpetological sampling methods, and PAO estimates were produced for each species of anuran by habitat. This information serves as an indicator of habitat associations of the species and relative abundance of sites occupied, but it will also be useful as a comparative baseline for future monitoring efforts. In addition to sampling for amphibians, all encounters with reptiles were documented. The sampling methods used for detecting amphibians are also appropriate for many reptile species. These reptile locations are included in this report, but the number of reptile observations was not sufficient to estimate PAO for reptile species. We encountered 35 of the 46 species of reptiles believed to be present in Big Cypress National Preserve during this study, and evidence exists of the presence of four other reptile species in the Preserve. This study found no evidence of amphibian decline in Big Cypress National Preserve. Although no evidence of decline was observed, several threats to amphibians were identified. Introduced species, especially the Cuban treefrog (Osteopilus septentrionalis), are predators and competitors with several native frog species. The recreational use of off-road vehicles has the potential to affect some amphibian populations, and a study on those potential impacts is currently underway. Also, interference by humans with the natural hydrologic cycle of south Florida has the potential to alter the amphibian community. Continued monitoring of the amphibian species in Big Cypress National Preserve is recommended. The methods used in this study were adequate to produce reliable estimates of the proportion of sites occupied by most anuran species, and are a cost-effective means of determining the status of their populations.

Bathymetric surveys and lake deposits

A progress report on the bathymetric survey of Windereme undertaken in June 1937 by the Hydrographic Department of the Admiralty. The brief article outlines the background of the surveying process as well as the initial effectiveness of the survey work. There is a brief background to the geomorphological processes which were involved in shaping the Lake District topography, as well as some explanation of previous studies undertaken in the area. The report includes a figure showing the cross sections of lake beds and a figure detailing a core from the bottom deposits of Windermere.

Lune - 1992 surveys. Summary of results

This report summarises the routine monitoring surveys carried out in the River Lune and River Duddon estuaries during 1992. Data includes salinity, chloride, pH, nutrients and heavy metals.

Design and implementation of fishery modules in integrated household surveys in developing countries

Fish and other aquatic animals contribute to the food security of citizens of developing countries, both as a source of income and as a component of healthy diets, yet fishing is not currently captured in most integrated household surveys. This sourcebook provides essential technical guidance on the design of statistical modules and questionnaires aimed at collecting fishery data at the household level. Background on the main policies important to the fishery sector, information on the data needed to analyze issues of policy relevance, and methodology on the construction of survey questions to collect necessary data are also provided. The document is organized to provide essential technical guidance on how to design statistical modules and questionnaires aimed at collecting fishery data at the household level. It includes an overview of the main technical and statistical challenges related to sampling fishery-dependent households. The document starts with an introductory section identifying the potential reasons why fisheries and in particular small-scale fisheries have not been adequately included in national statistical systems in a large number of countries. The report then proposes a succinct review of what is known (and what remains unknown) about small-scale fisheries and their contribution to the livelihoods of households in sub-Saharan Africa. It also provides readers with background on the main policies that are important to the fishery sector, information on the data needed to analyze issues of policy relevance, and methodology on the construction of survey questions to collect necessary data.