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- 1. Ponds are a valuable resource for the conservation of freshwater biodiversity, but are often extremely numerous in a given area, making assessment of the conservation value of individual sites potentially time consuming.
- 2. The use of indicator taxa, the species richness of which is representative of total site species richness, may provide one way to improve the efficiency of survey work. However, such indicators are poorly developed for freshwater systems.
- 3. A data set was used describing the occurrence of macroinvertebrate taxa in ponds in Oxfordshire, UK, to assess the extent to which variation in the species richness of selected taxa most consistently represented variation in all other taxa.
- 4. Coenagriidae (Odonata) and Limnephilidae (Trichoptera) reflected the variation in species richness of other taxa most consistently, with Coenagriidae showing the best overall performance as an indicator taxon.
- 5. For both suggested indicator taxa, selection of sites based solely on the presence of at least one species of indicator would represent over 95% of all species recorded across all sites.
- 6. Further investigation in different geographical regions is necessary to establish whether these relationships are consistent over a wider area.
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Robert Nikolaus Malwina Schafft Andreas Maday Thomas Klefoth Christian Wolter Robert Arlinghaus 《水产资源保护:海洋与淡水生态系统》2021,31(1):153-172
- Humanity is facing a biodiversity crisis, with freshwater-associated biodiversity in a particularly dire state. Novel ecosystems created through human use of mineral resources, such as gravel pit lakes, can provide substitute habitats for the conservation of freshwater and riparian biodiversity. Many of these artificial ecosystems are subject to a high intensity of recreational use, however, which may limit their biodiversity potential.
- The species richness of several taxa (plants, amphibians, dragonflies, damselflies, waterfowl, and songbirds) was assessed and a range of taxonomic biodiversity metrics were compared between gravel pit lakes managed for recreational fisheries (n = 16) and unmanaged reference lakes (n = 10), controlling for non-fishing-related environmental variation.
- The average species richness of all the taxa examined was similar among lakes in both lake types and no substantial differences in species composition were found when examining the pooled species inventory. Similarly, there were no differences between lake types in the presence of rare species and in the Simpson diversity index across all of the taxa assessed.
- Variation in species richness among lakes was correlated with woody habitat, lake morphology (surface area and steepness), and land use, but was not correlated with the presence of recreational fisheries. Thus, non-fishing-related environmental variables had stronger effects on local species presence than recreational fisheries management or the presence of recreational anglers.
- Collectively, no evidence was found that anglers and recreational fisheries management constrain the development of aquatic and riparian biodiversity in gravel pit lakes in the study region; however, the conservation of species diversity in gravel pit lakes could benefit from an increasing reliance on habitat enhancement activities.
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- 1. The lack of information about marine biodiversity is problematic for the selection of conservation reserves that aim to protect representative samples of biodiversity. A number of surrogate measures for biodiversity have been suggested as a potential solution to this problem.
- 2. The present study tested the effectiveness of using higher taxa of macroinvertebrates as a surrogate for species‐level identification to depict spatial variation in species richness and assemblage variation and to select conservation reserves in one estuary in south‐east Australia.
- 3. Spatial patterns of richness and assemblage variation for species were significantly correlated with patterns defined from genera, families, orders, classes, and phyla with a decline in the magnitude of correlation coefficients from finer to coarser resolutions. A network of reserves selected to include representatives of all phyla, classes, orders, families and genera coincidentally included 54%, 61.7%, 75%, 92.6%, 98.8% species in 8.3%, 13.9%, 17.7%, 44.4% and 58.3% of grid cells, respectively. However, only reserves selected for genera, families and orders performed significantly better than random selection.
- 4. Percentage of species represented by orders, families and genera in a realistic level of available grid cells for conservation (i.e. 13.9%) were very close ranging between 70 and 73.5%. A factor diminishing the performance of order as surrogate for species richness was related to the difficulty of identifying many macroinvertebrates to the order level. Therefore, it is concluded that genus‐ and family‐level identification is an effective surrogate for species‐level identification for conservation planning in estuaries.
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- 1. Nine cetacean species have been reliably reported to occur in the shallow northern Adriatic Sea since the 17th century. However, only two species were considered regular there until the 1970s: the short‐beaked common dolphin (Delphinus delphis) and the common bottlenose dolphin (Tursiops truncatus).
- 2. Short‐beaked common dolphins have progressively disappeared from the northern Adriatic and are now rare in the region. The systematic culling campaigns and other takes that occurred between the second half of the 18th century and the 1960s, and habitat degradation in subsequent years are the most likely causes of their decline.
- 3. Today, common bottlenose dolphins are the only regular component of the northern Adriatic cetacean fauna; however, they now occur at low densities, and their fragmented groups are facing significant anthropogenic threats.
- 4. The future of northern Adriatic dolphins will depend on precautionary action to prevent further decline and on intensified research effort aimed at identifying the most effective mitigation strategies.
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- Fish assemblages in estuaries have a much lower species richness (number of taxa) when compared with the combined numbers of freshwater and marine species from adjacent aquatic ecosystems. This is primarily because of the relatively harsh and fluctuating physico-chemical conditions in estuaries compared with the more stable freshwater and marine environments.
- A comprehensive fish survey of estuaries in South Africa is used as a basis to determine fish species richness in subtropical, warm temperate, and cool temperate systems along the coast, and to assess the degree of redundancy in the different biogeographic regions.
- In general, only one or two species belonging to each of the detritivorous, piscivorous, zoobenthivorous, and zooplanktivorous fish guilds are numerically well represented in the larger cool temperate estuaries, but between four and 10 species in each of these guilds are usually recorded in the larger subtropical estuaries.
- Although the overall low redundancy of fish species groups in estuaries has already been formally recognized in the literature, this short note highlights the sensitivity of certain trophic guilds in temperate South African estuaries to any form of redundancy, a characteristic that may be equally applicable, based on declining species richness with increasing latitude, to temperate estuaries in other parts of the world.
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- The Mediterranean common dolphin (Delphinus delphis), considered to have been very common in the past, had undergone a dramatic decline across most of the basin by the end of 1970s. In the northern Adriatic Sea, one of the regions with most available historical information, the common dolphin is thought to have been the most common and abundant cetacean throughout most of the 20th century. However, by the end of 1970s, it had virtually disappeared from the region and is now considered generally absent from the entire Adriatic Sea.
- This contribution summarizes the occurrence of common dolphins in the Gulf of Trieste and provides a brief review of published records in other parts of the Adriatic Sea.
- Systematic boat surveys in the wider area of the Gulf of Trieste between 2002 and 2019 confirmed that the common bottlenose dolphin (Tursiops truncatus) is the only regularly occurring cetacean species in this area. Despite this, several records of common dolphins were documented in the Gulf of Trieste between 2009 and 2012, through sightings of live animals or recovery of dead stranded animals.
- Dorsal fin markings allowed the photo-identification of some of these, suggesting that at least four different live individuals (three adults and one calf) occurred here in recent times. Most cases involved single adult individuals, but one included a mother-calf pair that was temporarily resident in a port for several months, a behaviour atypical for this species. Photo-identification showed that the presumed mother had previously been sighted in the Ionian Sea in Greece, over 1,000 km from the Gulf of Trieste, making this the longest documented movement for this species worldwide.
- At present, the common dolphin continues to be rare in the region.
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- 1. A basin approximation was used to analyse distribution patterns of different components of biodiversity (taxonomic richness, endemicity, taxonomic singularity, rarity) and conservation status of freshwater fish fauna in 27 Mediterranean Iberian rivers.
- 2. Basin area alone explained more than 80% of variation in native species richness. Larger basins featured not only a higher number of native species, but also more endemic and rare species and fewer diversified genera than smaller basins.
- 3. In contrast, smaller basins scored higher community conservation values, owing to their lower degree of invasion by introduced species.
- 4. The presence of dams was the most important factor determining the conservation status of fish communities, and it was also positively associated with the number of introduced species.
- 5. While the most important components of Iberian freshwater fish biodiversity are located in large basins, small unregulated basins feature better conserved fish communities.
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Population genetic structure of common bottlenose dolphins (Tursiops truncatus) in the Adriatic Sea and contiguous regions: implications for international conservation 
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下载免费PDF全文 Stefania Gaspari Draško Holcer Peter Mackelworth Caterina Fortuna Alexandros Frantzis Tilen Genov Morgana Vighi Chiara Natali Nikolina Rako Elisa Banchi Guido Chelazzi Claudio Ciofi 《水产资源保护:海洋与淡水生态系统》2015,25(2):212-222
- 相似文献
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James J. Bell 《水产资源保护:海洋与淡水生态系统》2007,17(2):133-145
- 1. Sponges are an important component of coral reef ecosystems, but even though they are widespread with the ability to significantly influence other benthic community members they rarely feature to any great extent in current monitoring or biodiversity assessment programmes conducted by volunteer and professional groups. This exclusion is usually because of the taxonomic problems associated with sponge identification.
- 2. A potential alternative to monitoring temporal or spatial change in sponge assemblages and assessing biodiversity levels is to characterize sponges using morphologies present rather than collecting species data. Quantifying sponge biodiversity (for monitoring and biodiversity assessments) at the morphological level is less time and resource consuming than collecting species data and more suited to groups with little training and experience of sponge taxonomy or in regions where detailed taxonomic information on sponges is sparse.
- 3. This paper considers whether the same differences and similarities in sponge richness and assemblage composition can be identified using species and morphological data in response to environmental gradients at two coral reef ecosystems in south‐east Sulawesi, Indonesia, and whether volunteers can be used to reliably collect morphological information. Sponge morphologies were classified into 14 groups and different morphological assemblages were found by the author at the two sites and between depth intervals. Comparisons of sponge species and morphological composition data showed that common patterns in assemblage structuring and richness could be identified irrespective of whether morphological or species data were used. In addition, a positive linear relationship was found between sponge species and morphological richness.
- 4. The morphological data recorded by volunteer divers (n=10) were compared with that collected by the author. Although volunteers recorded fewer sponges than the author (approximately 15% less), missing mainly small encrusting specimens, similar assemblage structure could be identified from both the volunteers' and the author's data.
- 5. The results showed that the same differences in sponge assemblages between sites and depths could be identified from both species and morphological data. In addition, these morphological data could be reliably collected by volunteer divers.
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D.T. Bilton L.C. McAbendroth P. Nicolet A. Bedford S.D. Rundle A. Foggo P.M. Ramsay 《水产资源保护:海洋与淡水生态系统》2009,19(2):134-146
- 1. A high proportion of ponds are temporary in nature, although the biodiversity value of such sites is still poorly recognized. This work explores the plant and macroinvertebrate communities of 76 temporary and fluctuating water bodies in two regions of southern England (Lizard Peninsula, Cornwall and New Forest, Hampshire) that have retained high pond densities. The ecology and conservation status of sites is examined, and comparisons made with ponds elsewhere in England and Wales.
- 2. Lizard and New Forest ponds supported 119 plant and 165 macroinvertebrate species respectively. Patterns of community similarity for plants and macroinvertebrates were highly concordant, taxa being related in a similar manner to measured environmental variables including pond area, depth, pH and water chemistry.
- 3. Patterns of pond occupancy revealed that most species were locally rare, over half occurring in less than 10% of ponds, and less than 10% being recorded from more than 50% of sites. More than 50% of ponds supported at least one nationally rare plant and almost 75% at least one nationally rare macroinvertebrate. These taxa occupied a wide range of pond types in each region, and did not have predictably different ecologies from common species.
- 4. Comparisons with ponds elsewhere in England and Wales revealed that Lizard and New Forest communities are nationally distinct, being most similar to ponds in areas of low intensity agriculture elsewhere in western Britain. Individual ponds in both regions supported more nationally rare taxa, on average, than ponds sampled in the national survey.
- 5. Ponds in the two areas have high conservation value, both regionally and nationally, supporting almost 75% of the global species richness of temporary ponds sampled across England and Wales. Within each region, many taxa are found in relatively few sites, and effective conservation of pond biodiversity will require a regional management approach.
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Kieran A. Monaghan Ana L. Machado Frederick J. Wrona Amadeu M.V.M. Soares 《水产资源保护:海洋与淡水生态系统》2020,30(4):662-674
- The increasing risk of wildfire has focused attention on the timescale of the impact and recovery of river ecosystems and methods for their bioassessment.
- An 18‐year pseudo time‐series was exploited to document patterns in benthic macroinvertebrate impact and recovery and evaluate the efficacy of alternative metrics to assess fire damage. Macroinvertebrates were surveyed by kick‐sampling and data were collected on river habitats. Details of river catchments and wildfire were collated as a GIS database.
- Macroinvertebrate richness and abundance recovered rapidly, marked by a phase of dynamic increase, followed by relative stability (0–2 years and 3–18 years, respectively). Across sites, richness and abundance were best explained by time since fire.
- A biotic index of general river quality was ineffective as an indicator of fire damage. While a metric of K‐selected taxa (Odonata richness) was generally indicative of fire‐affected assemblages, a contrasting metric of r‐selected taxa (percentage of chironomids, baetids, and simuliids) was not.
- Ordination analysis revealed time as a significant determinant of community structure across sites; however, its overall statistical importance was eclipsed by habitat characteristics (water quality, shade, altitude, and latitude) that were associated with ecological variation across both recently affected sites and the putatively recovered communities.
- These results highlight the stochastic processes – environmental and ecological – that frame the macroinvertebrate response to wildfire. This probabilistic context emphasizes the difficulties of developing indicator taxa for wildfire bioassessment and reinforces the importance of standardized survey protocols and the use of contrasting metrics in the assessment of wildfire impact on the ecological quality of rivers.