bluuebunny/crossref_metadata_2025_split huggingface dataset:
The use of multivariate analytical techniques in conservation assessment of rocky seashores
Authors: Fuller I. A. , Telfer T. C. , Moore C. G. , Wilkinson M. 
Published: February 2007

Abstract1. This paper describes the use of multivariate analytical techniques as an aid to classifying and assessing the nature conservation value of rocky intertidal communities round the Northern Ireland coastline.2. Semiquantitative species abundance data from 128 rocky shore transects distributed round the coastline were subject to multivariate analysis in order to formulate a classification scheme for shore communities. Several different techniques were used on the grounds that a robust classification scheme should not be dependent upon the details of statistical methodology. Cluster analysis (three strategies) and TWINSPAN were used to produce hierarchical classification schemes, and ordination was used to assess the validity of suggested community boundaries.3. The resulting classification scheme of rocky shore communities is presented and discussed in terms of the six scientific/ecological criteria which Mitchell (1987) identified for the comparative evaluation of marine habitats and communities for nature conservation purposes.
Invertebrate assemblages of Essex salt marshes and their conservation importance
Authors: Mason C. F. , Heath D. J. , Gibbs D. J. 
Published: February 2007

Abstract1. Invertebrates were collected, using corers and sweep nets, from 25 salt marshes, and adjacent mudflats and strandlines, in Essex, eastern England, to describe assemblages and assess their conservation importance.2. Sweep net samples were more variable in taxon richness than core samples. Neither sampling method, nor samples from the three habitats (main marsh, mudflat, strandline) could be used as an indicator of taxon richness of the salt marsh as a whole.3. Core samples collected relatively few, but often abundant, marine species which were generally widespread and a large number of terrestrial species, which were generally restricted in distribution. The mudflat fauna was species poor. Sweep net samples of main marsh and strandline were markedly different in their species composition; many species, with generally patchy distributions, were recorded and Diptera predominated. There was no relationship between invertebrate taxon richness, plant species richness or measured environmental variables.4. TWINSPAN was used to classify sites and invertebrate species. On the entire data set, six groups of sites were identified, but there was no trend in taxonomic richness. Only 25% of species were restricted to a single group. Sweep nets provided a much higher discrimination of sites.5. The conservation value of salt marsh sites for invertebrates is discussed using four criteria: community distinctiveness, species richness, species rarity and community functioning. A holistic approach to the conservation of salt marshes within the region is recommended.
Reproduction, growth and diet of Gambusia holbrooki (Girard) in a temperate Australian river
Authors: Pen L. J. , Potter I. C. 
Published: February 2007

Abstract1. The biology of Gambusia holbrooki in the Collie River in southwestern Australia is described using data obtained from seine samples collected at 4–6 weekly intervals over two years.2. Females which had overwintered in the river bred between October and February (spring‐breeding group) and then died. Some of the large representatives of the resultant cohort of males and females bred between January and March (summer‐breeding group) and then also died. The offspring of these larger individuals and the smaller fish did not start breeding until the following spring, when they constituted the spring‐breeding group of the following breeding season. Breeding occurred when temperatures were above 15–16°C and day length exceeded 750–780 min. The increase in the mean length of the spring group of pregnant females from 33 mm in October to 52 mm in January was accompanied by a rise in mean fecundity from 33 to 131.3. In the Collie River, G. holbrooki is a generalist carnivore, feeding at the water surface and throughout the water column. Gut contents of a wide size range of G. holbrooki from each season contained neither the eggs, larvae, juveniles nor adults of any of the three indigenous fish species found in the system. Moreover, there was no evidence that G. holbrooki exhibited agonistic behaviour, such as fin clipping, towards these native fish.4. Coexistence of the three indigenous species with G. holbrooki, and thereby their conservation, is facilitated by the outcome of different spawning times and localities. Thus, the early life‐history stages of the indigenous species, which are most susceptible to predation, are typically produced in tributary creeks or flood waters between late winter and late spring, some time before the breeding of G. holbrooki results in a population explosion of this exotic species in the main channel of the river during summer.
Mitigating the impacts of stream and lake regulation in the flathead river catchment, Montana, USA: An ecosystem perspective
Authors: Stanford Jack A. , Richard Hauer F. 
Published: February 2007

Abstract1. Seventy‐two per cent of the Flathead River catchment (22 241 km2) is federally designated and protected as wilderness or national park. Thus, the catchment remains one of the more pristine areas of its size in the temperate latitudes of the world.2. Discharge in the downstream reaches of the river system outside the protected areas is regulated by three dams for flood control and hydropower production. These dams have blocked natural migration of native fish from Flathead Lake (496 km2) and isolated populations in sub‐catchments. Temperature and erratic flow fluctuations have altered phenologies of river zoobenthos and fish, and in dam tailwaters aquatic biodiversity is drastically reduced in comparison to unregulated segments.3. Ecological problems caused by changing water quality conditions, altered land‐use patterns and introductions of non‐native biota are interactive with the impacts of stream and lake level regulation, thereby emphasizing the complexity of this river–lake ecosystem.4. Mitigation of the effects of regulation is compromised by differing management priorities and regulatory mandates of County, State, Tribal, and Federal agencies responsible for natural resource management within the catchment. Moreover, economic and ecological interests outside the Flathead influence the way flows are regulated within the catchment.5. The most pervasive influences of stream and lake regulation can be ameliorated by retrofitting the hypolimnial release dam with a selective depth outlet structure to allow temperature control, and by controlling changes in flow rates to create a more natural hydrograph in the tailwaters of the large dams. Allowing fish passage by construction of fish ladders is problematic because upstream passage will commingle native species that were isolated upstream by construction of the dams with non‐native species that were introduced subsequently below the dams. Cascading food web interactions elicited by invasions of non‐native biota may offset any advantage to native stocks gained by passage and/or augmentation with hatchery stocks.6. Mitigation must be adaptive in the sense that unanticipated effects and interactions with other management objectives can be documented and alternative action can be implemented.7. This case history of the effects of stream and lake level regulation, and the approaches to management reviewed in this paper, should serve as a lesson in river conservation.
The conservation status of the Nee Soon freshwater swamp forest of Singapore
Authors: Ng Peter K. L. , Lim Kelvin K. P. 
Published: February 2007

Abstract1. The most important area in Singapore for native aquatic fauna and flora is a relatively intact 5 km2 patch of freshwater swamp forest in Nee Soon.2. The Nee Soon Swamp Forest contains 48% of the primary freshwater fish, 71% of the amphibian, 28% of the reptile and 34% of the bird fauna of Singapore. The swamp also has the highest percentage of native and threatened freshwater fish and crustacean species on the island, as well as being the main (if not the only) habitat of the aquatic plant Hydrostemma. It is also the last refuge of two mammals, the Banded Leaf Monkey, Presbytis femoralis femoralis, and the Cream‐coloured Giant Squirrel, Ratufa affinis affinis.3. The threats to the swamp forest are discussed, and proposals are made to establish the swamp forest as Singapore's second major nature reserve.4. Study of the swamp forest is essentially still at a survey and discovery phase. The research priorities are to establish detailed species lists, the status of endangered species and the extent of buffer zones.5. The swamp forest is administered primarily by the newly established National Parks Board, but several other government organizations also have jurisdiction over the land, causing some problems in the management of the swamp. The roles of the university and non‐governmental organizations in conducting surveys, drafting recommendations and educating the general public are detailed.
Sea defence and nature conservation: Threat or opportunity
Authors: Doody J. P. 
Published: February 2007

Abstract1. New land has been ‘won’ from the sea by the process of embankment for centuries. It is perhaps not surprising, given the long term commitment to the protection of the land so created, that current works are concerned largely with reinforcing the existing line of sea defence.2. Those concerned with nature conservation have likewise in the past, expended considerable energy in trying to protect natural and semi‐natural habitat from destruction and exploitation by man. This has included land claim and associated sea defence works.3. This paper examines these two perceptions of ‘coastal protection’ and suggests a more enlightened approach which accepts change as an important part of coastal development, and provides a more positive way forward. Those concerned with sea defence and nature conservation may have to accept that protection of the current line of sea defence or existing coastal habitats, may not be the best option in all cases.
Strawberry creek on the University of California, Berkeley campus: A case history of urban stream restoration
Authors: Charbonneau Robert , Resh Vincent H. 
Published: February 2007

Abstract1. Strawberry Creek (37°52′ N; 122°15′ W) is the major focus of open space on the University of California, Berkeley (Alameda County, California, USA) campus; it provides visual amenity and variety, riparian and wildlife habitat, and educational and recreational opportunities.2. Since the beginning of this century, urbanization of the catchment, channel alteration and water quality degradation combined to cause deterioration of the creek's habitat and overall environmental quality; this was manifested by a marked absence of flora and fauna, obvious water pollution and severe erosion.3. In 1987 a restoration project was undertaken that focused on water‐pollution and erosion‐control measures. In 1989, native three‐spined sticklebacks (Gasterosteus aculeatus) were successfully reintroduced. Family Biotic Index scores for the macroinvertebrate community indicated a change from the ‘poor’ water quality conditions in 1986 to ‘good’ water quality in 1991.4. Environmental education programmes now involve over 1500 students who use the creek each year in laboratory exercises; a popular natural history and conservation walking‐tour guidebook has also been prepared.5. On‐going restoration efforts include additional reintroductions of other native species, further environmental education efforts and monitoring.6. Obstacles and key factors that led to the successful implementation of this project are presented to assist in implementing similar ecological restoration projects of urban streams.
An assessment of the ecological impacts of inter‐basin water transfers, and their threats to river basin integrity and conservation
Authors: Davies Bryan R. , Thoms Martin , Meador Michael 
Published: February 2007

Abstract1. Detailed research into the ecological impacts of inter‐basin water transfers (IBTs) is virtually nonexistent on a global scale. However, a growing awareness of the serious nature of such impacts—for example, the loss of biogeographical integrity, the loss of endemic biotas, the frequent introduction of alien and often invasive aquatic and terrestrial plants and animals, the genetic intermixing of once separated populations, the implications for water quality, the frequently drastic alteration of hydrological regimes, the implications for marine and estuarine processes, climatic effects, and the spread of disease vectors, amongst many others—demands a most urgent and world‐wide appraisal of all current planning and research strategies.2. This paper first defines the types of extant IBTs, and details some case studies for three widely separated regions of the world, namely: south‐eastern Australia, southern Africa, and the central and south‐western parts of the United States of America. In doing so, it highlights the chronic paucity of ecological data on their impacts, while simultaneously emphasising their extreme complexities.3. Finally, we call for an international meeting on such schemes, as a matter of priority and extreme urgency, in order to assess the extent of IBTs, their geographical distribution, and their ecological and sociological impacts and implications.
Particular problems for the conservation of diadromous fish
Authors: McDowall R. M. 
Published: February 2007

Abstract1. Known diadromous fish number <250 species, and <1.5% of fish species.2. They comprise ca. 3% of species regarded as ‘endangered’.3. Amongst them are species of great importance to fisheries, and out of proportion to their number.4. They occupy complexes of connected habitats between or through which passage is needed at two or more life history phases.5. They therefore pose special problems for conservation which relate to: a. diversity of habitats; b. huge areas occupied; c. the spatial separation of the various habitats used; d. need for fish passage; e. often heavy exploitation.6. These problems are often the opposite of those experienced with species that occupy local habitats and which are in danger of local extirpation.
Progress and opportunities for advancing marine nature conservation through coastal zone management in the United Kingdom
Authors: Gubbay S. 
Published: February 2007

Abstract1. The idea of ‘Coastal Zone Management’ (CZM) has received a great deal of attention in the UK in the past three years.2. There is no formally recognized CZM programme but recent significant developments are leading towards its implementation.3. This ‘Viewpoint’ describes the progress which is being made and discusses the potential benefits to marine nature conservation that could result from a programme of integrated CZM.
Vegetation succession in lakes in the coastal fringe of West Connemara, Ireland
Authors: Van Groenendael J. M. , Van Mansfeld M. J. M. , Roozen A. J. M. , Westhoff V. 
Published: February 2007

Abstract

It is hypothesized that the recent intensification of agricultural practice in the coastal fringe of West Connemara, Ireland, has affected the vegetation of vulnerable ecosystems like lakes and wetlands.
Lakes and wetlands, arranged in three transects running inland from the coast, were studied to detect an assumed decrease in the effects of eutrophication as a result of a decrease in the intensity in land use.
The data obtained from the vegetation survey in 1988 were compared with those collected at the same sites in 1975. The data were subjected to various multivariate statistics to detect changes in species composition and relationships between these changes and environmental variables such as pH and orthophosphate concentration in the surface waters.
Changes in species composition are accompanied by changes in environmental factors; notably a marked increase in orthophosphate level indicating an anthropogenic origin for most of the observed changes in vegetation.
Changes in species composition have also been used to construct a transition matrix for sites between 1975 and 1988. This has served as a basis for a prognosis on the state of the vegetation at these sites circa 2000. Data have also been grouped to indicate lake‐specific patterns in the changes.
The dynamics of all plant species have been established based on their frequency of disappearance from sites since 1975 and their rate of establishment in new sites in 1988. Special attention has been given to species from the red data list. It is concluded that over the past 13 years species diversity decreased in the whole area, and especially in coastal lakes. Red data list species appeared to be the more vulnerable ones.
Re‐establishment of Danish streams: Restoration and maintenance measures
Authors: Iversen Torben Moth , Kronvang Brian , Madsen Bent Lauge , Markmann Peter , Nielsen Mogens Bjørn 
Published: February 2007

Abstract

Prior to 1983 the Danish legislation concerning streams gave priority to drainage of water. The revision of The Watercourse Act gave balanced priority to drainage of water and environmental quality, focusing on an ecologically more appropriate maintenance practice and giving special provisions for stream restoration activities.
Different measures of single structure restoration have been used, the most common being replacement of weirs, dams or other obstacles by rapids, establishment of salmonid spawning grounds, and installation of new or improved fish ladders.
The most common stream channel restoration method is integrated use of a number of single structure measures. Establishment of a two‐stage channel and re‐opening of small piped streams have also been used. Stream valley restoration includes restoration of old meanders or establishment of a new sinuous channel and involves the adjacent riparian areas.
The changed stream maintenance practice involves a new strategy for dredging and cutting of weeds and bank vegetation in order to minimize the ecological damage caused by keeping a reasonable discharge capacity. In 1990, environmentally acceptable weed‐cutting was performed in 37% of all municipal streams and the bank vegetation was left uncut in a third of the streams. Similarly, more than half of the county streams were maintained using hand scythes and in 74% of the streams the bank vegetation was left uncut.
Quantitatively, stream restoration has contributed little to the general improvement of Danish streams compared with changed maintenance practice. Stream restoration projects create public interest in the environmental quality of streams, but major improvements in the physical properties of Danish streams depend on future maintenance practice.
Due to major changes predicted in Danish agriculture many riparian areas and wetlands will reappear and the natural or semi‐natural physical properties of streams will be re‐established by natural processes or changed in maintenance practice. However, there will still be large areas with intensive agriculture, where environmental and agricultural interests must be balanced. The Danish experience has shown that this is possible.
Initial habitat response to incised channel rehabilitation
Authors: Douglas Shields F. , Cooper Charles M. , Knight Scott S. 
Published: February 2007

Abstract

Incised stream channel aquatic habitats typically are severely degraded. After the primary knickpoints or knickzones have passed, base flows are limited to shallow channels flanked by sandy berms within the enlarged high‐flow channel. Riparian vegetation, woody debris and pool habitat are in short supply, and stream systems become disengaged from their floodplains.
We hypothesized that habitat recovery might be accelerated in channels that have incised and are regaining equilibrium through deposition of sandy berms by placing rock spurs in the channel and by planting woody vegetation on the berms. On the basis of literature review and a pilot study, planting designs were developed for a large‐scale field experiment: 2550 1.5 m long cuttings of native willow (Salix spp.) 2–25 cm in diameter were planted 1–1.2 m deep along the base‐flow channel of an incised stream. A ridge of stone was placed on the water side of the plantings, and 17 rock spurs were constructed by extending existing spur dikes from the opposite bank.
Woody cover along the treated bank increased from 38% to 66% of bankline after one growing season. Survival of individual plantings was reduced from an estimated 60% to an observed 34% by competition from the exotic kudzu vine, Pueraria lobata. Mean depth and mean scour hole depth, corrected for stage variation, increased 44% and 82%, respectively. Mean scour hole width increased 130%. The mean length of fish and the number of fish species approximately doubled, while the total weight of fish captured by a unit of sampling effort increased by an order of magnitude.
Potential effects of incidental mortalities on the Hooker's sea lion (Phocarctos hookeri) population
Authors: Woodley Thomas H. , Lavigne David M. 
Published: February 2007

Abstract

Annual rate of increase (r) was estimated for the Hooker's sea lion (Phocarctos hookeri) using demographic models that incorporated age‐specific estimates of reproductive rate (mx) and survival (lx).
In the absence of empirical estimates of natural mortality (nx), survival schedules were derived by combining a range of incidental mortality rates (hx) in commercial fisheries with estimates of nx for two species that exhibit similar life histories to Hooker's sea lions: northern fur seals (Callorhinus ursinus), model A, and Himalayan thar (Hemitragus jemlahicus), model B. Model A represented a population that would have a limited capacity for population increase; incidental mortality rates of mature females above about lo would result in a population decline. Model B represented a population that, even in the absence of incidental mortalities, would just remain stable.
If either of these models accurately represents the population demography of Hooker's sea lions, then these animals have limited capacity for population increase. They are constrained by relatively delayed maturity, moderate reproductive rates and short life spans.
While absolute estimates of r from our models must be interpreted with caution, it is the responses of r to incidental mortalities and to increased natural mortality of pups that are most informative. Both models show r decreasing by 0.007–0.008 with a 0.01 increase in incidental mortalities of mature females. Both models also indicate that an increase in the natural mortality of pups by 0.027 will reduce r by 0.0055 or more.
Given the paucity of available empirical data, our results suggest that incidental mortalities of Hooker's sea lions in the trawl fishery for arrow squid (Nototodarus sloanii) should be minimized if a population decline is to be avoided.