Remediation of upstream passage for migrating Galaxias (Family: Galaxiidae) through a pipe culvert

Movement through streams is critical for the maintenance of diadromous fish populations. Numerous fish passage improvement techniques exist, and knowledge of their effectiveness is required to conserve target species. An existing 70‐m pipe culvert was considered a barrier to the passage success of young‐of‐year (YOY) Galaxias spp. as a result of high water velocity (0.9 m/s). Water velocity in the pipe culvert was reduced by installing a concrete weir downstream of the culvert. A lateral ridge rock‐ramp fishway was installed to provide for the passage of fish over the weir, and baffles were installed in the upstream portion of the culvert to provide refuge from higher water velocity at this location. A BACI design was used to determine whether passage success, measured using a mark–recapture technique, improved as a result of the remediation works. The probability of successful passage of YOY Galaxias spp. through the culvert increased from 0.03 to 0.41 following remediation works and was similar to levels observed at a control site (0.33). The success of the fishway and baffles at this culvert provides an important case study for managers to adopt this technique to improve fish passage on a broader scale and range of other sites.     

Lateral movement of common carp (Cyprinus carpio L.) in a large lowland river and floodplain

Abstract –  Common carp ( Cyprinus carpio L.) are a major freshwater invader and knowledge of their movements is important for planning control efforts. To investigate the movement patterns of common carp, radio-tags were implanted into 46 adult fish; 37 near a large floodplain wetland, the Barmah-Millewa forest, and 9 in the Murray River approximately 175 km upstream. Tagged fish were located every second week between August 1999 and March 2001. Common carp occupied total linear ranges (TLR) between 0.4 and 238 km (mean 30 ± 61 km), with 25 fish (62.5%) occupying a TLR < 10 km. Two fish made large distance movements approximately 650 km downstream. Fish sex, the number of locations, time at large, or tagging location explained little variability ( P  > 0.05) in TLR. Monthly distance from release varied from 0.04 to 238 km (mean 15 ± 44 km), and was not significantly related to river discharge and water temperature, but 29 of 31 (93.5%) fish tagged at Barmah moved from the Murray River into adjacent floodplain habitats upon flooding. Five fish (12.5%) moved large distances (>127 km) upstream of the Barmah-Millewa forest. Fourteen fish (35%) showed site fidelity to within 20 m and usually occupied one or two home sites. Twenty-six fish (65%) showed site fidelity to within 100 m occupying up to five sites during the study period. Movement patterns of common carp were complex, and individuals exhibited different strategies, which is typical of invasive species. Efforts to control and potentially reduce common carp populations in regulated river-floodplain environments should target key floodplain access points and over-wintering habitats to reduce adult biomass, spawning and recruitment levels.     

Survey of mussel (Mytilus) species at Scottish shellfish farms

Mytilus trossulus and its hybrids with the native species Mytilus edulis and also Mytilus galloprovincialis have been recently detected in both farmed and natural populations of mussels in Scotland, adding complexity to the known M. edulis × M. galloprovincialis hybrid zone in Europe. Mytilus trossulus was first found in Scotland at aquaculture sites, where it was associated with significant losses in production and reductions in profitability. Mytilus trossulus and its hybrids have been identified at higher frequencies in farm stock than in natural intertidal populations, raising concerns about the potential wider impact of M. trossulus genotypes at mussel aquaculture sites in Scotland. The present study clarifies the composition of Mytilus species in cultivation at Scottish mussel aquaculture farms, by screening samples from 41 mussel aquaculture sites using a high-throughput real-time PCR methodology. Mytilus edulis alleles were detected at all sites. Mytilus galloprovincialis alleles were detected from samples collected at 39 sites, and M. trossulus alleles were found at five sites. Overall, M. trossulus genotypes were restricted in their geographical distribution. It is suggested that, in order to support the sustainability of the Scottish shellfish cultivation industry, the economic impact arising from the presence of M. trossulus could be limited through good management practice.     

蜜瓜和西瓜果汁的射频介电特性及其与糖度的关系

为了解果汁的介电特性与其主要内部品质──糖度之间的关系,该文利用末端开路的同轴探头和阻抗分析仪测量了10MHz～18GHI的频率范围内不同成熟度的3个品种密瓜汁和4个品种西瓜汁的介电特性,同时测量了反映果汁糖度的可溶性固形物含量和果肉的含水率,分析了介电特性和糖度间的关系.结果显示:密瓜和西瓜果汁的相对介电常数和介质损耗因数皆随频率的增大单调减小,品种间的差异对介电特性有影响;1.8GHz下密瓜汁的损耗角正切与糖度有较好的线性关系,其决定系数为0.784,但西瓜汁的介电特性与糖度的相关性较差;密瓜和西瓜果汁的糖度与果肉的含水率有很好的线性相关性,其决定系数分别为0.973和0.906.该研究将为基于介电特性的果汁糖度检测仪的开发提供了研究基础.     

Global consequences of land use

Land use has generally been considered a local environmental issue, but it is becoming a force of global importance. Worldwide changes to forests, farmlands, waterways, and air are being driven by the need to provide food, fiber, water, and shelter to more than six billion people. Global croplands, pastures, plantations, and urban areas have expanded in recent decades, accompanied by large increases in energy, water, and fertilizer consumption, along with considerable losses of biodiversity. Such changes in land use have enabled humans to appropriate an increasing share of the planet's resources, but they also potentially undermine the capacity of ecosystems to sustain food production, maintain freshwater and forest resources, regulate climate and air quality, and ameliorate infectious diseases. We face the challenge of managing trade-offs between immediate human needs and maintaining the capacity of the biosphere to provide goods and services in the long term.     

A nematicidal metabolite from Verticillium chlamydosporium

A bioassay‐directed fractionation of cultures of the fungus, Verticillium chlamydosporium, demonstrated nematicidal activity, due mainly to phomalactone. Compared with aldicarb, the lethal activity against Meloidogyne incognita was less, but its activity in suppressing root invasion was similar. The extract also contained monorden. © 2000 Society of Chemical Industry     

The Moray Firth Seal Management Plan: an adaptive framework for balancing the conservation of seals,salmon, fisheries and wildlife tourism in the UK

• 1. Within the Moray Firth, north‐east Scotland, there is a history of conflict between seals and salmon fisheries. Under the UK's Conservation of Seals Act 1970 (CoSA) seals are shot to protect fisheries. In 1999 six rivers in the Moray Firth were designated as Special Areas of Conservation (SACs) for Atlantic salmon under the EU Habitats Directive, and in 2000 an SAC for harbour seals was designated in the Dornoch Firth.
• 2. In the 1990s salmon stocks declined. Fisheries managers believed the decline was partly caused by seal predation and consequently increased shooting effort. In years 1993–2003 Moray Firth harbour seal numbers declined possibly due to shooting, posing a potential threat to the status of the Dornoch Firth SAC. Meanwhile wildlife tourism based on marine mammals has increased. The declines in salmon and harbour seals, and the implementation of the Habitats Directive forced a watershed in the approach of statutory authorities to managing seals, salmon and tourism.
• 3. In years 2002–2005 local District Salmon Fishery Boards, the Scottish Executive, Scottish Natural Heritage and stakeholders negotiated a pilot Moray Firth Seal Management Plan to restore the favourable conservation status of seal and salmon SACs, and to reduce shooting of harbour seals and seal predation on salmon.
• 4. Key facets of the plan are the management of the Moray Firth region under a CoSA Conservation Order; application of the Potential Biological Removal concept to identify a limit of seals to be killed; management areas where removal of seals is targeted to protect salmon, while avoiding seal pupping and tourism sites; a training and reporting system for marksmen; a research programme, and a framework allowing an annual review of the plan.
• 5. The plan was introduced in April 2005. A maximum limit of 60 harbour and 70 grey seals was set. Forty‐six harbour and 33 grey seals were killed in 2005 while in 2006 these figures were 16 and 42 respectively. Although the numbers killed were below the maximum limits in both years the returns raised questions about the plan's ability to manage seal shooting at netting stations. The plan provides a useful adaptive co‐management framework for balancing seal and salmon conservation with the protection of fisheries and/or fish farms and tourism for application in the UK and internationally.

Copyright © 2008 John Wiley & Sons, Ltd.     

Conservation of threatened species in the Galapagos Marine Reserve through identification and protection of marine key biodiversity areas

• 1. The Galapagos Marine Reserve provides refuge for numerous threatened marine species, including 16 mammals, birds, reptiles and fish currently recognized on the 2006 IUCN Red List of Threatened Species, plus an additional 25 endemic fish, mollusc, crustacean, echinoderm, coral and macroalgal species that comply with threatened species criteria because of declining extent of occurrence or highly‐localized ranges, and hence also qualify for inclusion on the Red List.
• 2. Threatened marine species with restricted ranges are not randomly distributed across the archipelago but tend to co‐occur at a limited number of sites that are predominantly located in the west. Sites at which threatened species are known to persist, particularly those with a large proportion of the global population, are here identified as sites of global conservation significance — key biodiversity areas.
• 3. The majority (27) of the 38 inshore key biodiversity areas identified are currently protected from fishing because they lie within the 17% of coastal waters that is zoned as ‘no‐take’ tourism or conservation zones. All key biodiversity areas should be protected from extractive exploitation if threatened species are to be safeguarded. This can be achieved, at the minimum, through a relatively minor amendment to the existing marine zoning scheme, whereby an additional 2% of the coastline is dedicated to conservation.

Copyright © 2008 John Wiley & Sons, Ltd.