Northern range extension, abundance and distribution of Pacific coastal Bottlenose doplhins (Tursiops truncatus gilli) in Monterey Bay, California

Pacific coastal bottlenose dolphins (Tursiops truncatus gilli) have apparently moved to Monterey Bay as a result of a shift north of their known range. Between 1983 and 1993, 417 sightings were reported off central California. Eighty-four boat-based surveys, between October 1990 and November 1993, resulted in the photo-identification of 68 uniquely marked individuals. School size ranged between 2 and 35 animals (mean = 16.60, S.D. = 7.72). Forty-three (63%) of the dolphins identified were previously photographed in the Southern California Bight before 1989. Jolly-Seber population estimates indicated an increase in the Monterey Bay population from 1990 to 1993. At least 13 of the photo-identified dolphins were present in Monterey Bay throughout the study period. All but two of the calculated coefficients of association were 0.35, indicating a strong bond among resident animals. The occurrence of an El Niño from January 1992 to the end of 1993 may have affected the number of animals present in the bay: mean school size was significantly greater during El Niño.

Mollusks taken by Beam Trawl in the vicinity of Gray's Reef National Marine Sanctuary on the Continental Shelf off Georgia, Southeastern U.S.

Mollusks were sorted from samples of shell hash (obtained as bycatch during NOAA-sponsored studies of larval and juvenile fish distribution), and analyzed to gain qualitative insights on species composition, distribution and habitat affinities of the molluscan fauna on the continental shelf off Georgia. Samples came from beam trawls at 37 stations located in the immediate vicinity and offshore of the Gray’s Reef National Marine Sanctuary (GRNMS) at depths of 4.9 to 103 m. Two hundred sixty-three (263) taxa of mollusks (~58% as dead shells only) were collected, and nearly all (~99%) were identified to the species level. Ninety-seven of these taxa appeared in samples from one or more of the four stations established near the corners of the GRNMS. Samples were highly variable in terms of appearance, volume and species composition of mollusks, reflecting the extreme patchiness of benthic habitats within this region of the continental shelf. With very few exceptions, the mollusks were generally characteristic of either the Carolinian or Caribbean faunal provinces. The Georgia continental shelf, however, was outside the previously reported ranges for at least 16 of the species reported here. Most of these extralimital species were known previously from the East Coast of Florida, and represented northerly range extensions of 1-5° Latitude (110-560 km). One species represented a more significant range extension from the Bahamas and the southern Caribbean, and two represented southerly range extensions, known previously from only as close as off North Carolina. The high incidence of range extensions found in this study and the potential for discovery of additional species are discussed in the context of the diversity and patchiness of benthic habitats on the continental shelf of the region, and the sensitivity of species recruitment to variability in Gulf Stream patterns and global climate change. (PDF contains 52 pages)

Baseline aquatic faunal survey of Avon Park Air Force Range, Florida: fishes, mollusks, and crayfishes

This report presents results of the first systematic study of the diversity and distribution of fishes and mussels in Avon Park Air Force Range (APR). We also provide information on crayfishes and aquatic snails taken during our fish and mussel sampling activities. Our surveys documented the presence of 46 species of fishes (43 native and 3 nonindigenous), 9 species of mussels (including 8 native and 1 nonindigenous species), 5 species of aquatic snails, and two crayfish species. (347 page document)

Assessment of cobia, Rachycentron canadum, in the waters of the U.S. Gulf of Mexico

This assessment applies to cobia (Rachycentron canadum) located in the territorial waters of the U.S. Gulf of Mexico. Separation of the Gulf of Mexico and Atlantic Ocean is defined by the seaward extension of the Dade/Monroe county line in south Florida. Mixing of fish between the Atlantic and Gulf of Mexico occurs in the Florida Keys during winter months. Cobia annually migrate north in early spring in the Gulf to spawning grounds in the northern Gulf of Mexico, returning to the Florida Keys by winter. Catches of cobia in the Gulf of Mexico are dominated by recreational landings, accounting for nearly 90% of the total. Since 1980, the landings of cobia in the recreational fishery have remained fairly stable at around 400-600 mt with a slight peak of 1,014 mt in 1997. The recreational fishery was estimated to have landed 471 mt in 2000. The landings from the commercial fishery have shown a steady increase from 45 mt in 1980 to a peak of 120 mt in 1994, followed by a decline to 62 mt in 2000. The previous assessment of cobia occurred in 1996 using a virtual population analysis (VPA) model. For this analysis a surplus-production model (ASPIC) and a forward-projecting, age-structured population model programmed in the AD Model Builder (ADMB) software were applied to cobia data from the Gulf of Mexico. The primary data consisted of four catch-per-unit-effort (CPUE) indices derived from the Marine Recreational Fisheries Statistics Survey (MRFSS) (1981-1999), Southeast region headboat survey (1986-1999), Texas creel survey (1983-1999), and shrimp bycatch estimates (1980-1999). Length samples were available from the commercial (1983-2000) and recreational (1981-2000) fisheries. The ASPIC model applied to the cobia data provided unsatisfactory results. The ADMB model fit described the observed length composition data and fishery landings fairly well based on graphical examination of model residuals. The CPUE indices indicated some disagreement for various years, but the model fit an overall increasing trend from 1992-1997 for the MRFSS, headboat, and Texas creel indices. The shrimp bycatch CPUE was treated as a recruitment index in the model. The fit to these data followed an upward trend in recruitment from 1988-1997, but did not fit the 1994-1997 data points very well. This was likely the result of conflicting information from other data sources. Natural mortality (M) for cobia is unknown. As a result, a range of values for M from 0.2-0.4, based on longevity and growth parameters, were selected for use in the age-structured model. The choice of natural mortality appears to greatly influence the perceived status of the population. Population status as measured by spawning stock biomass in the last year relative to the value at maximum sustainable yield (SSB2000/SSBMSY), spawning stock biomass in the last year relative to virgin spawning stock biomass (SSB2000/S0), and static spawning stock biomass per recruit (SSBR) all indicate the population is either depleted, near MSY, or well above MSY depending on the choice of M. The variance estimates for these benchmarks are very large and in most cases ranges from depleted to very healthy status. The only statement that can be made with any degree of certainty about cobia in the Gulf of Mexico is that the population has increased since the 1980s. (PDF contains 61 pages)

Cruise Report 67-S-3 (Bottomfish Extension)

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A Comparison of the Range and Movements of Acmaea digitalis Eschscholtz, Acmaea scutum Eschscholtz, Acmaea limatula Carpenter and Lottia gigantea Sowerby

Ten limpets (4 Acmaea digitalis , 4 Acmaea scutum, 1 Acmaea limatula, and 1 Lottia gigantea) were marked and their movements observed over a thirteen day period. Recordings of positions were made on a map, and the path of each was drawn on the map from day to day. Acmaea digitalis showed the greatest range, mostly in a vertical direction, and moved usually at night during high tide. Acmaea scutum showed a more limited range in a horizontal direction, and moved both day and night during high tide. Acmaea limatula had a horizontal range similar to A. scutum,, but exhibited no movement during the day time. Lottia gigantea had the most restricted range of any limpet studied, and moved only at night during high tide. 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. Gene Haderlie went on to earn his Ph.D. from Berkeley and later became a Professor at the Naval Post Graduate School in Monterey. (PDF contains 23 pages)

Improved fisheries technologies and approaches for their dissemination: a case study of Niger State

Technology generation and dissemination are important components of rural transformation programmes. Nigerian fisheries sub-sector is still hampered by low productivity (especially in aquaculture) and low output (capture fisheries and post-harvest technologies). Research institutions and the Universities have made efforts in developing improved technologies to find solution to these problems, yet the level of adoption of the technologies remain low. This is due to a combination of various factors among which are faulty agricultural policies; institutional framework and unfavourable socio-economic environment. Niger State plays an important role in production in Nigeria and host the only research institute with the mandate in inland fisheries. It is important therefore to know the effectiveness of various extension approaches used in disseminating the technologies developed and their impact on adopters. Forty fishers were randomly selected in Shiroro L.G.A. of the Niger State and interviewed. The study probed into their socio-economic characteristics, traditional practices, extent of awareness and adoption for fisheries technologies and the effectiveness and impact of various approaches used by the extension organizations to disseminate the technologies. The results show that the economically active age group of the fishers was in the range of 20-50 years (87.5%). Males (95%) dominate the fisher population. 47.5% of the respondents have average household size of 6-10 and 57.5% were below primary school in educational attainment. Only 57.5% belonged to cooperative societies, while 90.0% of the fishers have no access to credit other than personal finance. Majority of fish-farmers (60%) operate at homestead level with pond size less than 50 square meter, stock under polyculture fishing methods are at subsistence level, while 67.5% of processors use mud-oven to cure, by smoking, freshly caught fish. Disseminated aquaculture technologies have low level of awareness (5-20%) and adoption (2.5-22.5%). For capture fisheries and post-harvest technologies awareness levels of 47.5-72.5% and adoption levels of 27.5-50.0% were recorded. Method demonstration (87.5%), result demonstration (75.0%) and field days (47.5%) are the major approaches used by the ADP. Respondents were of the opinion that method demonstration (65%), result demonstration (57.5%) and field day (30.0%) are effective. 62.5% of respondents had enhanced income due impact of extension activities

Construction, extension and evaluation of the improved smoking kiln (Banda) in Kainji Lake area

Fish smoking, as a traditional occupation of fishermen and women in Kainji Lake Area (Nigeria) is done using simple traditional ovens called 'Banda', the fuel for the smoking being almost hundred percent dependent on wood. A simple modification was made to the traditional 'Banda' oven using a damper to prevent burning of the fish. A comparison of the improved and the traditional 'Banda' was made. The results indicate that fuel wood consumption was reduced 52 percent by using the improved 'Banda', which implied that 50 percent of fish processor's income could be saved through the adoption of this technology. The most important advantage of the improved kiln, fuel wood conservation, represents for fishers a problem of an economic importance. Whilst they are aware that it is becoming much more difficult to get the needed fuel wood, the children can still conveniently collect enough wood for both home use and processing activities. The cost of the components of the improved kiln, when compared with the traditional version may be considered quite significant, and hence the reluctance of the fish processors in constructing similar ones. Selected blacksmiths were trained to continue the fabrication of the kiln component. The training was carried out to assure that the improved kiln will be constructed even after the project will end to support the fabrication

The role of extension in fisheries development among rural communities

It is a common knowledge that there exists a wide gap between domestic fish production and demand in Nigeria. Government recognizes this situation and has in recent years encouraged fish production through fishing inputs subsidies, DFRRI assisted fingerlings production among others. Despite these efforts, impact at the grassroots has been low. One of the major reasons for the failure could be attributable to inadequate involvement of rural communities in fish production. This missing link appears to be ignorance of local communities in harnessing this potential to stimulate fish production. There is therefore the need to educate the rural dwellers through effective extension services. Strategies to achieve the required awareness have been discussed

Using climate extension to assist coastal decision-makers with climate adaptation

Coastal managers need accessible, trusted, tailored resources to help them interpret climate information, identify vulnerabilities, and apply climate information to decisions about adaptation on regional and local levels. For decades, climate scientists have studied the impacts that short term natural climate variability and long term climate change will have on coastal systems. For example, recent estimates based on Intergovernmental Panel on Climate Change (IPCC) warming scenarios suggest that global sea levels may rise 0.5 to 1.4 meters above 1990 levels by 2100 (Rahmstorf 2007; Grinsted, Moore, and Jevrejeva 2009). Many low-lying coastal ecosystems and communities will experience more frequent salt water intrusion events, more frequent coastal flooding, and accelerated erosion rates before they experience significant inundation. These changes will affect the ways coastal managers make decisions, such as timing surface and groundwater withdrawals, replacing infrastructure, and planning for changing land use on local and regional levels. Despite the advantages, managers’ use of scientific information about climate variability and change remains limited in environmental decision-making (Dow and Carbone 2007). Traditional methods scientists use to disseminate climate information, like peer-reviewed journal articles and presentations at conferences, are inappropriate to fill decision-makers’ needs for applying accessible, relevant climate information to decision-making. General guides that help managers scope out vulnerabilities and risks are becoming more common; for example, Snover et al. (2007) outlines a basic process for local and state governments to assess climate change vulnerability and preparedness. However, there are few tools available to support more specific decision-making needs. A recent survey of coastal managers in California suggests that boundary institutions can help to fill the gaps between climate science and coastal decision-making community (Tribbia and Moser 2008). The National Sea Grant College Program, the National Oceanic and Atmospheric Administration's (NOAA) university-based program for supporting research and outreach on coastal resource use and conservation, is one such institution working to bridge these gaps through outreach. Over 80% of Sea Grant’s 32 programs are addressing climate issues, and over 60% of programs increased their climate outreach programming between 2006 and 2008 (National Sea Grant Office 2008). One way that Sea Grant is working to assist coastal decision-makers with using climate information is by developing effective methods for coastal climate extension. The purpose of this paper is to discuss climate extension methodologies on regional scales, using the Carolinas Coastal Climate Outreach Initiative (CCCOI) as an example of Sea Grant’s growing capacities for climate outreach and extension. (PDF contains 3 pages)

Improving aquaculture through increased fisheries extension research

The present study was conducted, as an attempt to disabuse minds of practicing fish farmers and also encourage prospective farmers who are of the opinion that fish culture is not as profitable as it is widely reported. The study was carried out in an abandoned concrete water fountain tank (20m super(2)) made primarily for recreational purposes. The tank was stocked initially with 125 post fingerlings (Heterobtranchus bidorsalis) bought at rate of N30 each. Cost of feeding was N3, 149.85. Gross and net profits for the passive 2- year culture stood at N27, 149.85 and N20, 000.00 respectively. The longest fish (L sub(max)) was 64.0 com TL while the smallest 41.5cm TL (64.8%L sub(max)) and weight 1.9kg (W sub(max)) and 0.5kg 26.3%W sub(max)). Weight and length data generated from the study were examined

Enhancement of fish production in Borno State with extension services

Borno State possesses great potentials for fish production both from inland fisheries and aquaculture. The socio-economic and environmental production factors are suitable for fish production. If the potential of the State were well harnessed, it would be playing significant roles in achieving self-sufficiency in fish production in Nigeria. But the situation at the moment is that its fisheries potentials are not being optimally utilized. While the inland waters of Lake Chad are currently being recklessly exploited, aquaculture development is given little or no attention. It is evident that there is a missing link between research results and the potential end users. Because information in fish production variables is a pre-requisite for fisheries development, the gap that exists between two poles must be bridged, fisheries Extension provides this important link between research result and the end users of research findings. The paper examines the importance of extension services as the key to unlock fish production information that are usually consigned to the pages of academic journals and research publications

The home range of the signal crayfish in a British lowland river

The signal crayfish Pacifastacus leniusculus (Dana), a native of north-western North America, is now a common resident in some British fresh waters following its introduction to England in 1976 (Lowery & Holdich 1988). In 1984, signal crayfish were introduced into the River Great Ouse, the major lowland river in southern central England, where they have established a large breeding population. This study examines two sites near Thornborough Weir. For the measurement and description of home range a new eletronic microchip system and a modified capture-mark-recapture method were employed. Signal crayfish were marked or tagged to see if they gradually moved away from their burrows. This method proved to be successful for estimating population densities when a section of river is divided into several equidistant linear ”locations”.

Home range and habitat use by Kemp's Ridley turtles in West-Central Florida

The Kemp's ridley turtle (Lepidochelys kempii) is an endangered species whose recovery depends in part on the identification and protection of required habitats. We used radio and sonic telemetry on subadult Kemp's ridley turtles to investigate home-range size and habitat use in the coastal waters of west-central Florida from 1994 to 1996. We tracked 9 turtles during May-August up to 70 days after release and fou.ld they occupied 5-30 km2 foraging ranges. Compositional analyses indicated that turtles used rock outcroppings in their foraging ranges at a significantly higher proportion than expected. based on availability within the study area. Additionally. turtles used live bottom (e.g .• sessile invertebrates) and green macroalgae habitats significantly more than seagrass habitat. Similar studies are needed through'mt the Kemp's ridley turtles' range to investigate regional and stage-specific differences in habitat use. which can then be used to conserve important foraging areas.

The marine extension - the great fire

From a special issue: A Brief History of the Charles Darwin Foundation for the Galapagos Islands 1959-1988