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1.
Michael Elliott Alan K Whitfield Ian C Potter Stephen J M Blaber Digby P Cyrus Frank G Nordlie & Trevor D Harrison 《Fish and Fisheries》2007,8(3):241-268
Many studies have recently described and interpreted the community structure and function of fishes inhabiting estuaries and other transitional waters in terms of categories or guilds. The latter describe the main features of the fishes’ biology and the way in which they use an estuary. However, the approach has been developed by different workers in different geographical areas and with differing emphasis such that there is now a need to review the guilds proposed and used worldwide. The previous wide use of the guild approach has involved increasing overlap and/or confusion between different studies, which therefore increases the need for standardization while at the same time providing the opportunity to reconsider the types and their use worldwide. Against a conceptual model of the importance of the main features of fish use in estuaries and other transitional waters, this review further develops the guild approach to community classification of fish communities inhabiting those areas. The approach increases the understanding of the use of estuaries by fishes, their interactions and connectivity with adjacent areas (the open sea, coastal zone and freshwater catchments) and the estuarine resources required by fishes. This paper gives a global perspective on this categorization by presenting new or refined definitions for the categories, lists the synonyms from the literature and illustrates the concepts using examples from geographical areas covering north and central America, north and southern Europe, central and southern Africa, Australia and the Indo‐Pacific. 相似文献
2.
- 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.
3.
Lou Frotté Julien Ringelstein Dominique Monti Marie Robert Christophe Pécheyran Nadia Améziane Hélène Tabouret 《Ecology of Freshwater Fish》2020,29(1):132-144
All native fishes living in the Caribbean island rivers are considered diadromous but few species have been validated as diadromous. In Guadeloupe (Lesser Antilles) as well as in the other tropical islands, the riverine habitats are subject to strong anthropogenic pressure due to resource modifications or dams. The management of fish biodiversity requires knowledge concerning their life history traits and behaviour that are still unknown for most species at a local scale and at the whole distribution area of the species. In a Guadeloupe river, we inferred the migratory patterns of four freshwater fishes common to Caribbean rivers by the analysis of otolith microchemistry. We found two species Eleotris perniger (Eleotridae) and Sicydium plumieri (Gobiidae) to be completely amphidromous with a marine larval phase and a freshwater adult phase. Agonostomus monticola (Mugilidae) was also found to be amphidromous in this system. The fourth species Gobiesox cephalus (Gobiesocidae) showed elemental ratios suggesting an estuarine larval phase and was defined as “limited amphidromous”. The identification of such life history traits, with limited dispersion abilities, argues for specific management measures in tropical island rivers at a basin scale for the conservation of biodiversity. 相似文献
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A. K. WHITFIELD 《水产资源保护:海洋与淡水生态系统》1997,7(1):1-11
1. Habitat degradation, mainly through land use changes and excessive freshwater abstraction, has a major negative effect on southern African estuarine systems. Less important at present, but showing increasing signs towards becoming a major problem is environmental pollution, especially organic and inorganic wastes from industrial, agricultural and domestic sources. Although the major threats to estuarine-associated fishes are usually linked to environmental degradation, there is also evidence to suggest that certain fish species are declining in abundance primarily as a result of overfishing. 2. The viability of estuaries as nurseries and feeding grounds for fishes is directly related to the accessibility and productivity of these systems. Examples of the mismanagement of South African estuaries through excessive siltation, freshwater deprivation, poorly planned dredging activities, and artificial manipulation of estuary mouths, are discussed. 3. The need for conservation legislation based on a sound knowledge of the biology and ecology of threatened fish species, their communities and their habits is highlighted. Examples of possible ‘indicator’, ‘keystone’, ‘umbrella’ and ‘flagship’ species for South African estuaries are given. 4. Although estuaries on the subcontinent have long been recognized as nursery areas for a number of recreationally important marine fish species, these systems have not formed an integral component in the selection of marine reserves. The dependence of many marine teleosts on estuarine habitats necessitates the inclusion of these ecosystems in any aquatic reserve planning exercise. 5. The plight of endemic fish species is discussed, with the effects of both environmental degradation and overexploitation being highlighted. 6. It is concluded that the future health of South Africa's estuaries and their fishes depends on imaginative resource management and on the improved implementation of conservation measures in partnership with decision-makers, managers, scientists and estuarine users. © 1997 John Wiley & Sons, Ltd. 相似文献
6.
Pierre Feutry Philippe Keith Christophe Pécheyran Fanny Claverie Tony Robinet 《Ecology of Freshwater Fish》2011,20(4):636-645
Abstract – Strontium/Calcium (Sr/Ca) and Barium/Calcium (Ba/Ca) ratios were measured in 60 otoliths of the French Polynesian flagtail Kuhlia malo. Both elemental ratios were needed to correctly distinguish residence in marine, brackish and fresh water. High Sr/Ca and low Ba/Ca around the nucleus of all otoliths provided evidence of marine residency during the early life of all individuals. At about 0.5 mm from the core, Ba/Ca increased rapidly and remained high in all otoliths. High and unstable Sr/Ca ratios were attributed to estuarine residency, whereas low and stable Sr/Ca ratios were attributed to freshwater residency. These chemical signatures inferred that following recruitment to rivers, some fish remained in the estuary, while others moved upstream. Some individuals shared their time between fresh and brackish waters later in life. The findings of this study have important implications for the protection of nearshore, brackish and freshwater environments for the conservation of this French Polynesian diadromous species. 相似文献
7.
1. Recreational and subsistence angling in South African estuaries is a small, but relevant, sector of South Africa's diverse coastal fisheries. This paper reviews these fisheries and their effects in two estuaries. 2. The composition of angler's catches in two large Eastern Cape Province estuaries has hardly changed over a period of nearly 20 years. 3. Gill-net catches (in terms of CPUE) indicate a decline in the abundance of the most popular angling fish species, especially the spotted grunter Pomadasys commersonnii. 4. Regular freshwater inputs into estuaries are required to ensure a salinity gradient which is crucial for the maintenance of an abundant and diverse estuarine ichthyofaunal assemblage. 5. Present management and conservation policies are poorly defined, and the philosophy and principles of ecosystem preservation, rather than that of species preservation, should be seriously considered. © 1996 by John Wiley & Sons, Ltd. 相似文献
8.
Status of galaxiid fishes in Tasmania,Australia: conservation listings,threats and management issues
Scott A. Hardie Jean E. Jackson Leon A. Barmuta Robert W.G. White 《水产资源保护:海洋与淡水生态系统》2006,16(3):235-250
- 1. Fish of the family Galaxiidae are restricted to the southern hemisphere where they occupy a diverse array of habitats ranging from over 2000 m in elevation to sea level. Some species are diadromous and, hence, freshwater, estuarine and marine habitats are used during their life‐cycle; other species complete their entire life‐cycles in freshwater environments.
- 2. Tasmania has a diverse galaxiid fauna that accounts for 64% of native freshwater fish species found on the island. The Tasmanian galaxiid fauna is characterized by high species richness (5 genera and 16 species), endemism (11 species), restricted distributions, and non‐diadromous life histories (11 species).
- 3. The galaxiid fauna of Tasmania has significant conservation status with 69% of species considered ‘threatened’. The conservation status of the fauna is recognized at State, national and international levels.
- 4. The key threats to galaxiids in Tasmania are exotic species, hydrological manipulations, restricted distributions, general habitat degradation and exploitation of stocks.
- 5. Although work has recently been undertaken to conserve and manage Tasmanian galaxiid populations, the fauna is still thought to be imperilled. Knowledge gaps that need to be addressed include the biology and ecology of most species (e.g. reproductive biology, life histories, habitat use and requirements) and impacts of habitat manipulations, as well as mechanisms and impacts of interactions with exotic species. Techniques to monitor accurately the status of galaxiid species and their populations need to be developed and the coexistence of some galaxiids with introduced salmonids should also be examined.
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Fish assemblages of the northern Argentine coastal system: spatial patterns and their temporal variations 总被引：1，自引：1，他引：0
ANDRÉS J. JAUREGUIZAR ROBERTO MENNI CARLOS LASTA RAÚL GUERRERO 《Fisheries Oceanography》2006,15(4):326-344
The springtime spatial pattern of demersal fish assemblages in the northern Argentine coastal ecosystem (34°–41°S) and their relationships with environmental variables were investigated over 6 years (1981, 1983, 1994, 1995, 1998 and 1999). For each fish assemblage area for each year, we identified the most common species and those species that had the highest ability to discriminate it from adjacent assemblage areas. Within each area, species were considered as resident (common in all years) or facultative (contributing to less than 90% of similarity within any year). The analysis (detrended canonical correspondence analysis), conducted using species abundances (t nm?2) and environmental data, indicated that six fish assemblage areas are consistently distinguishable. The fish assemblage areas correspond to inner, central and middle regions of the Río de la Plata estuary, and inner, central and middle regions of the coastal shelf. Spatial differences in the composition among areas were primarily due to changes in species composition rather than changes in relative abundance, and were primarily related to water mass characteristics. Salinity in the estuary and temperature on the shelf were more relevant to the spatial structuring of the fish community in each environment. The assemblage areas showed a remarkable degree of temporal persistence in species composition and geographical location. The facultative species contributed more to the species composition temporal dynamics than resident species. El Niño (La Niña) condition, associated with increase (decrease) of the Río de la Plata freshwater discharge, produced a movement of the estuarine assemblage areas to the coastal shelf (upriver). Under normal freshwater discharge conditions, the boundaries of the fish assemblages were relatively more stable. 相似文献
10.
H. Verreycken C. Belpaire G. Van Thuyne J. Breine D. Buysse J. Coeck A. Mouton M. Stevens T. Van den Neucker L. De Bruyn D. Maes 《Fisheries Management and Ecology》2014,21(2):122-132
Red Lists are used to assess the extinction risk of species. Regional IUCN criteria were applied to categorise 42 indigenous freshwater fish species in Flanders into Red List categories. As such, three species are assessed as Regionally Extinct, eight as Critically Endangered, two as Endangered and eight as Vulnerable. A further five species are considered Near Threatened, 15 species as Least Concern and one species is Data Deficient. Five species disappeared from the Regionally Extinct category compared with the previous Red List (1988) as a consequence of improved water quality of estuaries and reintroduction programmes. In total, 62% of the freshwater fish species in Flanders was considered extinct or threatened. This is higher than neighbouring regions and Europe as a whole (44%). This new Red List of freshwater fishes in Flanders can be used to inform conservation actions. 相似文献
11.
DECLAN T. G. QUIGLEY 《水产资源保护:海洋与淡水生态系统》1996,6(4):313-318
1. Ireland's fish fauna comprises at least 31 species that could be classified as euryhaline. This group includes 12 diadromous species, 3 non-migratory species, and 16 essentially marine and/or estuarine species. Twenty-four species are regarded as indigenous, 6 as occasional vagrants from other biogeographical zones and one was introduced by man during the last century. Fourteen species are considered to be widespread, 11 local, and 6 rare. 2. The biology of euryhaline fish makes them particularly vulnerable to any degradation of the coastal and estuarine environments. However, relatively few studies have been carried out on the biology and distribution of most species of Irish euryhaline fish. This lack of basic information is of particular concern, considering that 35% (11) of our euryhaline species are considered to be threatened. 3. Although 8 of our euryhaline species are listed in the Red Data Book on Irish Vertebrates(Whilde, 1993) and in various annexes and appendices of the Bern Convention (Anon, 1982) and EU Habitats Directive(Anon, 1992), only one of these species (Atlantic salmon Salmo salar L.) is currently afforded protection by any specific national legislation in Ireland. It is recommended that research should be directed at assessing the current status of our euryhaline fish and that appropriate national protection should be afforded to threatened species. ©1996 by John Wiley & Sons, Ltd. 相似文献
12.
- 1. Ecological water reserves are part of the new water management philosophy in South Africa. The estuaries are threatened by excessive water abstraction from their rivers and the consequent reduction in freshwater input. This study was conducted to further improve our understanding of freshwater requirements in terms of nutrients for South African estuaries.
- 2. The Gamtoos Estuary was sampled between November 1996 and November 1998 to determine its nutrient status and freshwater input rates. Furthermore, the possible existence of a distinct river‐estuarine interface (REI) in terms of nutrients has been investigated. Nutrients analysed included phosphate, nitrate, nitrite, ammonia, dissolved organic nitrogen (DON), dissolved organic carbon (DOC), particulate organic nitrogen (PON) as Kjieldahl nitrogen, total particulate phosphorus and total particulate carbon.
- 3. The Gamtoos River was found not to be the ultimate source of nutrients to the estuary, but non‐point sources such as the seepage of fertilisers from adjacent agricultural fields determined to a great extent the nutrient status of the estuary.
- 4. Results showed that it was not possible to identify a defined river‐estuarine interface region for all nutrients. Most were measured in higher concentrations in the lower salinity reaches (<17‰) where we observed the combined effect of inputs from the Gamtoos River, an agricultural drainage pipe, and fertilizer seepage from non‐point sources on nutrient concentration.
- 5. Prolonged water withdrawal for human use impacts the continuous renewal of the nutrient pool so important to other South African estuaries with relative pristine catchment areas. However, reduced fresh water inputs could enhance eutrophication in polluted estuaries due to a decreased flushing potential of the estuary. In this case the Gamtoos Estuary has a freshwater requirement for freshets and floods to “clean” the estuary of accumulated nutrients and other organic material.
- 6. This should be a consideration in further freshwater abstraction policies. Conservation issues arise since the Gamtoos Estuary is one of the few permanently open estuaries along the South African coast and serve in this study as an example and as a first attempt to relate freshwater requirements to nutrient dynamics in a South African context.
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Enhancing conservation of Australian freshwater ecosystems: identification of freshwater flagship fishes and relevant target audiences 
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下载免费PDF全文 Brendan C Ebner David L Morgan Adam Kerezsy Scott Hardie Stephen J Beatty Jamie E Seymour James A Donaldson Simon Linke Stirling Peverell David Roberts Thomas Espinoza Nadine Marshall Frederieke J Kroon Damien W Burrows Ryan R J McAllister 《Fish and Fisheries》2016,17(4):1134-1151
Flagship species, especially mammals and birds, are commonly used to increase awareness of conservation issues in marine and terrestrial ecosystems. However, flagship species oriented programs are often ad hoc with initiatives scarce in the freshwater context. Here, we aim to identify potential flagship candidates that would appeal to a broad cross section of society at a continental scale where freshwater ecosystems are under threat from human impacts. We identified 19 species from a list of 299 Australian freshwater fishes on the basis of body size, trophic guild and threatened species status assuming these characteristics of flagship species are transferable from previous work on terrestrial flagship species. We considered the potential of species to be of international appeal but focused mostly on eight relevant interest groups within Australia. This followed the rationale that public engagement with conservation issues in freshwater systems might be more effective if the link between fish species and the decisions people make were better understood, and we acknowledge the diverging interests of stakeholders. This scoping work contributes towards addressing the challenges of connecting societies to the principles of sharing water resources with ecosystems, and represents the first continental‐scale assessment of its kind. 相似文献
15.
Hilsa shad, Tenualosa ilisha (Hamilton), in Bangladesh is found in inland rivers, estuaries and the marine environment, throughout the year, but the peak catch period is during upstream migration. Tissue (white muscle, liver, brain) samples (total 640 specimens) were collected from three different localities, representing marine, brackish and fresh water, during the monsoon in the summer of the years 1993–1996 to identify genetic markers and study the population structure of this species. The samples were analysed by starch gel electrophoresis and isoelectric focusing, and stained for 15 enzymes and general muscle proteins. Only phosphoglucomutase, aspartate amino transferase, esterase and unidentified muscle proteins were found to be polymorphic. The allele frequencies for the samples collected in the marine environment deviated from corresponding samples from freshwater and estuarine localities, indicating that hilsa shad in Bangladesh waters comprise more than one gene pool. 相似文献
16.
Bruno O. David Matt Jarvis Deniz
zkundakci Kevin J. Collier Andy S. Hicks Malcolm Reid 《水产资源保护:海洋与淡水生态系统》2019,29(9):1409-1423
17.
- 1. During a study of five artificial brackish ponds situated in Doñana Natural Park and the Guadalquivir delta between July 2001 and June 2002, a total of six copepod species (two calanoids, three cyclopoids and one harpacticoid) were recorded. All of them are typical of brackish or estuarine habitats.
- 2. The estuarine calanoid copepod Acartia tonsa (originally from North America) was present in all the ponds studied. This exotic species has been found previously in European estuaries, but has not previously been recorded from artificial wetlands.
- 3. Both the relative and absolute abundance of the species varied significantly among months and ponds. A. tonsa was most abundant during autumn and spring, while Calanipeda aquae‐dulcis was most abundant in summer. This seasonal pattern of the copepod community composition was different from that reported in studies from other European estuaries or wetlands.
- 4. The invasion by and dominance of A. tonsa in the area of Doñana Natural Park has important implications for the conservation of the diverse native zooplankton fauna in the natural marshes of the adjacent Doñana National Park, which includes endemic species.
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JOACHIM MAES KARIN E. LIMBURG ANTON VAN DE PUTTE FRANS OLLEVIER 《Fisheries Oceanography》2005,14(1):17-31
Herring (Clupea harengus) enter and remain within North Sea estuaries during well‐defined periods of their early life history. The costs and benefits of the migrations between offshore spawning grounds and upper, low‐salinity zones of estuarine nurseries are identified using a dynamic state‐variable model, in which the fitness of an individual is maximized by selecting the most profitable habitat. Spatio‐temporal gradients in temperature, turbidity, food availability and predation risk simulate the environment. We modeled predation as a function of temperature, the optical properties of the ambient water, the time allocation of feeding and the abundance of whiting (Merlangius merlangus). Growth and metabolic costs were assessed using a bioenergetic model. Model runs using real input data for the Scheldt estuary (Belgium, The Netherlands) and the southern North Sea show that estuarine residence results in fitter individuals through a considerable increase in survival probability of age‐0 fish. Young herring pay for their migration into safer estuarine water by foregoing growth opportunities at sea. We suggest that temperature and, in particular, the time lag between estuarine and seawater temperatures, acts as a basic cue for herring to navigate in the heterogeneous space between the offshore spawning grounds at sea and the oligohaline nursery zone in estuaries. 相似文献
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1. The ampharetid polychaete Alkmaria romijni (protected under the Wildlife and Countryside Act 1981) is recorded from a survey of intertidal mudflats on the south bank of the Humber Estuary (UK) in an apparently unusual habitat for the species. 2. The records from the Humber are considered together with other records which have been collated recently as part of a review of rare and scarce marine benthic species in the UK. Some of these records are ‘new’. 3. An assessment of records from the Humber and elsewhere suggests that this tidal estuarine habitat is not atypical for A. romijni. Furthermore, it is not clear why the species shows such a restricted distribution within the Humber. 4. A. romijni can now be shown to not be confined to brackish lagoons in the UK, but rather is found in muddy sediments in sheltered to very sheltered conditions in both lagoons and certain estuaries. The majority of current records are now estuarine in the UK, suggesting that A. romijni can no longer be classed as a ‘lagoonal specialist’ species as previously considered. 5. Based on all UK records, the species should be considered ‘scarce’ rather than ‘rare’ using current assessment criteria. On balance, however, it is concluded that it is probably still appropriate to maintain the protected status of A. romijni. 6. Two other ‘lagoonal specialist’ species—the starlet sea anemone Nematostella vectensis and the lagoon sand shrimp Gammarus insensibilis—indicate, in the light of new records, that the reappraisal of lagoonal specialist status is restricted, for the present, to A. romijni rather than being common to other species. 7. The work highlights that there is a need for a re‐evaluation mechanism in the assessment of marine species considered to be of conservation importance. Copyright © 2000 John Wiley & Sons, Ltd. 相似文献