Important Feeding Ground Research Articles

The Black Sea Turtle (Chelonia mydas agassizii) at Lobos de Tierra Island, Northern Peru: High Densities in Small Areas

Abstract. Preliminary findings regarding black turtle (Chelonia mydas agassizii) occurrence in Lobos de Tierra Island, Northern Peru showed that 95% and 5% of turtles were juveniles and sub-adults, respectively, with an overall mean curved carapace length of 57.5 ± 7 cm (26.0–74.4 cm, n = 199). A total mean density of 180.4 turtles/km2 was found with highest densities found in bays and inlets located in the southeast. Inshore densities in shallow waters (< 1.5 m) were almost one order of magnitude greater than offshore at ∼ 1.5 km. In addition, based on structured qualitative interviews with fishermen, sea turtle capture and consumption still exists in the island, though occasional and sporadic. Jellyfish (Chrysaora plocamia) and green algae (Ulva sp.) consumption plays an important role in black turtle aggregations in the island, where densities are quite high compared to other feeding grounds elsewhere. We conclude that Lobos de Tierra constitutes an important Peruvian feeding ground, with high black tu...

Co-Occurrence and Habitat Use of Fin Whales, Striped Dolphins and Atlantic Bluefin Tuna in the Northwestern Mediterranean Sea.

Different dolphin and tuna species have frequently been reported to aggregate in areas of high frontal activity, sometimes developing close multi-species associations to increase feeding success. Aerial surveys are a common tool to monitor the density and abundance of marine mammals, and have recently become a focus in the search for methods to provide fisheries-independent abundance indicators for tuna stock assessment. In this study, we present first density estimates corrected for availability bias of fin whales (Balaenoptera physalus) and striped dolphins (Stenella coeruleoalba) from the Golf of Lions (GoL), compared with uncorrected estimates of Atlantic bluefin tuna (ABFT; Thunnus thynnus) densities from 8 years of line transect aerial surveys. The raw sighting data were further used to analyze patterns of spatial co-occurrence and density of these three top marine predators in this important feeding ground in the Northwestern Mediterranean Sea. These patterns were investigated regarding known species-specific feeding preferences and environmental characteristics (i. e. mesoscale activity) of the survey zone. ABFT was by far the most abundant species during the surveys in terms of schools and individuals, followed by striped dolphins and fin whales. However, when accounted for availability bias, schools of dolphins and fin whales were of equal density. Direct interactions of the species appeared to be the exception, but results indicate that densities, presence and core sighting locations of striped dolphins and ABFT were correlated. Core sighting areas of these species were located close to an area of high mesoscale activity (oceanic fronts and eddies). Fin whales did not show such a correlation. The results further highlight the feasibility to coordinate research efforts to explore the behaviour and abundance of the investigated species, as demanded by the Marine Strategy Framework Directive (MSFD).

Fishes of the river Padma, Bangladesh: Current trend and conservation status

The Padma River is one of the longest rivers and it is believed to be an important spawning and feeding ground for riverine fish species of Bangladesh. This study was conducted from February 2013 to January 2014 and with a view to revealing the diversity of fish fauna in the river. A total of 71 species were recorded belonging to 10 orders, 26 families and 54 genera. The most dominant fish order was Cypriniformes contributing 28 species in 16 genera. Cyprinidae was most dominant family contributing 23 species in 16 genera. Four alien species were found. Twenty eight species have been considered threatened by IUCN Bangladesh. These fishes were belonging to the following categories, Vulnerable (13%), Endangered (18%) and Critically Endangered (8%). Comparing the results with the previous findings, it was revealed that the species diversity have declined in the Padma River over time. Considering all the findings it is concluded that the Padma River could be considered a refuge for conservation of threatened freshwater fishes of Bangladesh. The conservation efforts should ensure minimization of anthropogenic impacts, especially the fishing pressure and introduction of alien invasive species.

Fishes of the river Padma, Bangladesh: Current trend and conservation status

The Padma River is one of the longest rivers and it is believed to be an important spawning and feeding ground for riverine fish species of Bangladesh. This study was conducted from February 2013 to January 2014 and with a view to revealing the diversity of fish fauna in the river. A total of 71 species were recorded belonging to 10 orders, 26 families and 54 genera. The most dominant fish order was Cypriniformes contributing 28 species in 16 genera. Cyprinidae was most dominant family contributing 23 species in 16 genera. Four alien species were found. Twenty eight species have been considered threatened by IUCN Bangladesh. These fishes were belonging to the following categories, Vulnerable (13%), Endangered (18%) and Critically Endangered (8%). Comparing the results with the previous findings, it was revealed that the species diversity have declined in the Padma River over time. Considering all the findings it is concluded that the Padma River could be considered a refuge for conservation of threatened freshwater fishes of Bangladesh. The conservation efforts should ensure minimization of anthropogenic impacts, especially the fishing pressure and introduction of alien invasive species.

山东近海鱼类群落分类多样性

PDF HTML阅读 XML下载 导出引用 引用提醒 山东近海鱼类群落分类多样性 DOI: 10.5846/stxb201306101579 作者: 作者单位: 山东省海洋水产研究所,胶南市海洋与渔业局,烟台市水产研究所,山东省海洋水产研究所,山东省海洋水产研究所 作者简介: 通讯作者: 中图分类号: Q178.53 基金项目: 泰山学者岗位资助项目(TS200651036) Taxonomic diversity of fish assemblages in coastal waters off Shandong Author: Affiliation: Shandong Marine Fisheries Research Institute,,,,Shandong Marine Fisheries Research Institute Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:根据相关文献整理了山东近海鱼类名录,并根据1998-2009年山东近海鱼类调查名录,应用平均分类差异指数(Δ+)和分类差异变异指数(Δ+)研究了鱼类分类学多样性特征。结果表明,山东近海鱼类名录包括2纲28目91科169属225种,1998年调查仅2纲11目41科58属62种,2006年调查为1纲13目41科71属78种,2009年调查为1纲9目32科55属62种。1998年-2009年调查鱼类种类远远低于鱼类名录记录的种数,分类阶元包含指数较低,平均每属包含1.1种。根据山东近海鱼类名录计算鱼类平均分类差异指数为66.1,分类差异变异指数为141.7;1998-2009年历次调查鱼类平均分类差异指数在60.9-62.7之间,分类差异变异指数在65.4-92.3之间。将1998-2009年历次调查鱼类群落分类多样性指数计算值叠加到山东近海鱼类总名录的95%置信漏斗曲线图,结果表明大部分调查值在置信漏斗曲线之外,目前山东近海鱼类分类多样性已大幅下降。 Abstract:Maintaining biological diversity is one of the central goals of global biodiversity and ecosystem management. The coastal waters off Shandong, located in the Yellow and Bohai seas of northern China, are important spawning and feeding grounds for many fishery species, and so play an important role in biodiversity maintenance. Assessing taxonomic diversity provides a new method for measuring and interpreting community relationships in the form of inter-species differences. It can be carried out simultaneously in different regions, habitats or surveys and has been widely used in fish community studies. In this study, index and characters of taxonomic diversity of fishes in the coastal waters off Shandong were examined. First, a list of fish in the study area was established. This list was based on several studies from published literature and was established from surveys conducted during 1998 and 2009. Fish classification and nomenclature was adopted from the Nelson classification system and synonymous species were excluded. Then the taxonomic diversity, including the average taxonomic distinctness (Δ+) and variation in taxonomic distinctness (Δ+), of fish assemblages was calculated based on the list of fish species. Finally, the survey list of fishes was superpositioned into the total list of fishes in the coastal waters off Shandong and the 95% confidence funnel was calculated. Results show that there were 225 species belonging to 2 classes, 28 orders, 91 families and 169 genera in the checklist of fishes in coastal waters off Shandong. In 2006 there were only 2 classes, 11 orders, 41 families, 50 genera in 1998, 1 class, 13 orders, 41 families, 71 genera and 78 species; and in 2009 there were 1 class, 9 orders, 32 families, 55 genera and 62 species. These results show that the numbers of fish species in coastal waters off Shandong declined in surveys taken between 1998 and 2009. Inclusion index at the taxonomic level was low; with usually only a single species in each genus. The average taxonomic distinctness was 66.1 and variation in taxonomic distinctness was 141.7. In surveys taken between 2006 and 2009, the average taxonomic distinctness was between 60.9 and 62.7 and the variation in taxonomic distinctness was between 65.4 and 92.3. The analysis of 95% confidence funnels showed that almost all surveys were lower than the theoretical mean and was out of 95% confidence funnel, which suggests that the diversity of fishes in coastal waters off Shandong has significantly decreased. The inclusion index of fishes in coastal waters off Shandong was in line with the trend that the inclusion index was higher in tropical waters and lower in high-latitude waters. The average taxonomic distinctness value in coastal waters off Shandong was higher than in other continental shelf waters in China. Due to the large numbers of estuaries, bays, and diverse habitats, the coastal waters off Shandong maintain a fish community with many morphological different species and have a high taxonomic diversity. After decades of overfishing, polluting and habitat loss, the species composition has significantly changed and the taxonomic diversity has significantly declined. 参考文献 相似文献 引证文献

High recruitment associated with increased sea temperatures towards the southern range edge of a Western Australian endemic reef fish Choerodon rubescens (family Labridae)

Choerodon rubescens is a subtropical wrasse endemic to Western Australia which has recently recruited in high abundance into lagoonal habitats at the southern end of its distribution. Abundance, size structure and habitat associations of juvenile C. rubescens were assessed during summer and autumn 2013 (January–May) via underwater visual census across available shallow water habitats towards the southern range edge of their distribution (32°S, 115°E). High abundances of juveniles (up to 14 fish/40 m2) were found in areas where they were previously absent or in low abundance. Lagoonal habitats presented abundances three to eight times higher than seagrass beds or rocky reef, indicating preference of C. rubescens for mixed lagoonal habitats as settlement grounds. Such habitats contain open sandy areas with small rocks and rubble that are important feeding grounds for juveniles. Based on the size structure of populations encountered, recruitment was estimated to occur during summer 2011–12 and 2012–13. This coincides with water temperatures 1 to 2 °C higher than long-term averages in the region, making conditions more favourable for recruits to survive in greater numbers. We conclude that the high abundance of C. rubescens recruits towards the southern end of their distribution together with trends of increasing water temperature and the availability of suitable settlement habitat to the south of their present range, indicate a capacity for the species to shift its distribution southwards. Monitoring of future recruitment events will be crucial to determining range expansion capacity and guiding management efforts for this endemic and important fisheries species.

Distribution of sei whales (Balaenoptera borealis) in the subarctic–subtropical transition area of the western North Pacific in relation to oceanic fronts

The subarctic–subtropical transition area of the western North Pacific is an important summer feeding grounds of sei whales. The oceanographic structure and circulation of this area are largely determined by strong oceanic fronts and associated geostrophic currents, namely the Polar Front (PF), Subarctic Front (SAF) and Kuroshio Extension Front (KEF). The relationship between the distribution of sei whales and oceanographic fronts was investigated using a generalized additive model (GAM), and the cetacean sighting survey data and oceanographic observations in July from 2000 to 2007 were used in the analysis. The number of individual sei whales was used as the response variable while the distances from the PF, SAF, and KEF to the whales were used as explanatory variables along with the longitude values. Sei whales were concentrated north and south of the SAF and the areas from 250 to 300km north and from 100 to 200km south of the SAF were estimated as high-density areas of sei whales. The entire inter-frontal zone between the PF and SAF featured an elevated concentration of sei whales, and the area south of the PF and along the SAF was identified as an important feeding ground of sei whales in July from 2000 to 2007.

Novel Coronavirus and Astrovirus in Delaware Bay Shorebirds

BackgroundWild birds are an important but to some extent under-studied reservoir for emerging pathogens. We used unbiased sequencing methods for virus discovery in shorebird samples from the Delaware Bay, USA; an important feeding ground for thousands of migratory birds.FindingsAnalysis of shorebird fecal samples indicated the presence of a novel astrovirus and coronavirus. A sanderling sample yielded sequences with distant homology to avian nephritis virus 1, an astrovirus associated with acute nephritis in poultry. A ruddy turnstone sample yielded sequences with homology to deltacoronaviruses.ConclusionsOur findings highlight shorebirds as a virus reservoir and the need to closely monitor wild bird populations for the emergence of novel virus variants.

Hawksbill × loggerhead sea turtle hybrids at Bahia, Brazil: where do their offspring go?

Hybridization between hawksbill (Eretmochelys imbricata) and loggerhead (Caretta caretta) breeding groups is unusually common in Bahia state, Brazil. Such hybridization is possible because hawksbill and loggerhead nesting activities overlap temporally and spatially along the coast of this state. Nevertheless, the destinations of their offspring are not yet known. This study is the first to identify immature hawksbill × loggerhead hybrids (n = 4) from this rookery by analyzing the mitochondrial DNA (mtDNA) of 157 immature turtles morphologically identified as hawksbills. We also compare for the first time modeled dispersal patterns of hawksbill, loggerhead, and hybrid offspring considering hatching season and oceanic phase duration of turtles. Particle movements varied according to season, with a higher proportion of particles dispersing southwards throughout loggerhead and hybrid hatching seasons, and northwards during hawksbill season. Hybrids from Bahia were not present in important hawksbill feeding grounds of Brazil, being detected only at areas more common for loggerheads. The genetic and oceanographic findings of this work indicate that these immature hybrids, which are morphologically similar to hawksbills, could be adopting behavioral traits typical of loggerheads, such as feeding in temperate waters of the western South Atlantic. Understanding the distribution, ecology, and migrations of these hybrids is essential for the development of adequate conservation and management plans.

Remote Antarctic feeding ground important for east Australian humpback whales

Understanding the dynamics of population recovery is particularly complex when an organism has multiple, remote breeding and feeding grounds separated by one of the longest known migration routes. This study reports on the most comprehensive assessment of humpback whale (Megaptera novaeangliae) movements between remote Antarctic waters south of New Zealand and east Australia (EA), and the migratory corridors and breeding grounds of Australia and Oceania. A total of 112 individual whales were identified; 57 from microsatellites and 61 by fluke with 23 % (n = 26) matched to sites outside Antarctica. Despite large datasets from other southern regions being included in the comparison, the whales were predominantly linked to EA (n = 24). Only two matches to the Oceania catalogues directly north was surprising; therefore the primary feeding grounds of these endangered whales still remain unknown. The confirmation of the Balleny Islands as an important feeding ground for EA whales could provide an insight into reasons behind the rapid recovery of this population. Determining the feeding grounds of Oceania’s whales may explain whether prey energetics or migration length are limiting factors to their recovery and will allow an understanding of future ecosystem changes in these whales.

Diversity and coverage of seagrass ecosystems in south-west Madagascar

Seagrass meadows provide important nursery and feeding grounds for many commercially valuable fish species. Here, we address the paucity of published information on the status of seagrasses in Madagascar by documenting the results from ecological surveys of 11 seagrass beds in Velondriake, a locally managed marine area (LMMA) in south-west Madagascar. The diversity and coverage of meadows was highest in the north of the LMMA with up to 51% coverage, and lowest in the south (26%). Overall, eight seagrass species were recorded: Cymodocea rotundata, C. serrulata, Halodule uninervis, Halophila ovalis, H. stipulacea, Syringodium isoetifolium, Thalassia hemprichii and Thalassodendron ciliatum. We discuss the natural and anthropogenic factors that may account for the observed low diversity of seagrasses in southern Velondriake, including overfishing, beach-seining, cyclones, siltation and mangrove deforestation. Based on these baseline surveys, as well as discussions with local communities, it is recommended that measures should be taken to reinforce efforts to ban beach-seines and that the role of seagrasses as carbon sinks and potential sustainable financing options through blue carbon initiatives should be investigated through further, more detailed surveys.

Parasites in subyearling Chinook salmon (Oncorhynchus tshawytscha) suggest increased habitat use in wetlands compared to sandy beach habitats in the Columbia River estuary

Many estuaries in the Pacific Northwest have been severely altered reducing wetlands habitat and resulting in an interest in their importance as rearing areas for juvenile salmon. To examine differences in habitat use during residency in the Columbia River estuary, we examined parasite communities acquired through food web interactions in subyearling Chinook salmon (Oncorhynchus tshawytscha) collected from four different habitat types in May and July of 2004 and 2005. Collections were made from two sandy bottom habitat types in the tidal freshwater and marine mixing areas of the estuary. These were compared to two wetlands types: one composed of scrub and shrub vegetation and another with emergent vegetation. Parasite assemblages differed among habitats suggesting differences in salmon feeding opportunities and rearing behaviors. In both years, the nematode, Hysterothylacium aduncum and the acanthocephalan, Echinorhynchus lageniformis, which use intermediate hosts found in the estuary, were more prevalent in lower wetlands suggesting increased feeding by salmon in these habitats. The differences in parasite assemblages among habitats suggests a variety of rearing and migration patterns through the Columbia River estuary and the increased prevalences of some parasites in the wetlands show that these habitats can be important feeding grounds for salmon.

Coral reef fish association with macroalgal beds on a tropical reef system in North-eastern Brazil

Macroalgal beds are recognised for their role as nursery and feeding grounds for several marine species. This study was conducted in the Tamandaré reef complex within the limits of the Costa dos Corais Marine Protected Area (MPA), North-eastern Brazil. The macroalgal bed studied is subjected to several disturbances, especially from tourism. The reef fish were assessed with free dives during the day and night using visual censuses within transects (20 × 2 m) and random swims. The percentage algal cover was estimated using quadrats (40 cm2). The behavioural traits of the fish also provided an understanding of their habitat use. In total, 68 fish species were recorded. The most abundant species were representatives of the families Labridae, Pomacentridae, Acanthuridae and Haemulidae. Sargassum polyceratium, Dictyopteris delicatula and Canistrocarpus cervicornis were the most abundant macroalgae. Because the most abundant fish trophic guild included primarily mobile invertebrate feeders (41.8%) and carnivores (28.4%), it is suggested that the high-canopy macroalgae harbour epiphytic invertebrates, which these fish use for food. Thereby, the study area would act as important nursery and feeding grounds. Tourism activity (e.g. laying chairs, trampling and anchoring) may disrupt fish behaviour and life- history traits and result in damage that would require mitigation through environmental awareness and law enforcement in the most affected areas.

Flying with the birds? Recent large‐area dispersal of four Australian Limnadopsis species (Crustacea: Branchiopoda: Spinicaudata)

Temporary water bodies are important freshwater habitats in the arid zone of Australia. They harbor a distinct fauna and provide important feeding and breeding grounds for water birds. This paper assesses, on the basis of haplotype networks, analyses of molecular variation and relaxed molecular clock divergence time estimates, the phylogeographic history, and population structure of four common temporary water species of the Australian endemic clam shrimp taxon Limnadopsis in eastern and central Australia (an area of >1,350,000 km2). Mitochondrial cytochrome c oxidase subunit I sequences of 413 individuals and a subset of 63 nuclear internal transcribed spacer 2 sequences were analyzed. Genetic differentiation was observed between populations inhabiting southeastern and central Australia and those inhabiting the northern Lake Eyre Basin and Western Australia. However, over large parts of the study area and across river drainage systems in southeastern and central Australia (the Murray–Darling Basin, Bulloo River, and southern Lake Eyre Basin), no evidence of population subdivision was observed in any of the four Limnadopsis species. This indicates recent gene flow across an area of ∼800,000 km2. This finding contrasts with patterns observed in other Australian arid zone taxa, particularly freshwater species, whose populations are often structured according to drainage systems. The lack of genetic differentiation within the area in question may be linked to the huge number of highly nomadic water birds that potentially disperse the resting eggs of Limnadopsis among temporary water bodies. Genetically undifferentiated populations on a large geographic scale contrast starkly with findings for many other large branchiopods in other parts of the world, where pronounced genetic structure is often observed even in populations inhabiting pools separated by a few kilometers. Due to its divergent genetic lineages (up to 5.6% uncorrected p-distance) and the relaxed molecular clock divergence time estimates obtained, Limnadopsis parvispinus is assumed to have inhabited the Murray–Darling Basin continuously since the mid-Pliocene (∼4 million years ago). This means that suitable temporary water bodies would have existed in this area throughout the wet–dry cycles of the Pleistocene.

Study of Some Major Non-Biodegradable Solid Wastes Along Thane Creek of Mumbai

Thane creek is one of the most important ecosystems around Mumbai, and the mangroves surrounding the ecosystem form the vital green lung for the residents. It is also an important feeding and breeding ground for fishes. In re- cent past man has misused this ecosystem by way of releasing sewage, dumping solid waste, etc. and has succeeded in chocking the ecosystem. The results of present investigation indicates that plastics carry bags, milk/oil bags, plastic bottles and foot wares are some of the major NBDSW materials responsible for solid waste pollution. On the basis of the findings, it is suggested that accumulation of plastics and synthetic rubber can be controlled by recycling and incineration, while accumulation of glass can be controlled only by recycling. The objective of the present work is to throw light on deteri- orating condition of Thane creek, suggesting the need to prepare a well-planned waste management system. The wetland of Thane Creek, located at Thane, Mumbai, India, has attracted much attention of environmental biolo- gists over the last few decades, as this creek has been sub- jected to a lot of pollution from the Asia's biggest Thane- Belapur Industrial Complex located at the south of Mumbai harbor along the west coast of India. The creek area is one of the most important ecosystems around Mumbai and Thane, and the mangroves surrounding the ecosystem form the vital green lung for the residents. It is also an important feeding and breeding ground for fishes. Locals have been living in harmony amidst this ecosystem for ages, but in recent past man has misused this ecosystem by way of re- leasing sewage, dumping solid waste, etc. and has suc- ceeded in chocking the ecosystem. The creek is tidally in- fluenced with the dominance of neretic waters and negligi- ble fresh water flow except during the monsoon. The sub- stratum of the creek in the midstream is made up of con- solidated and unconsolidated boulders intermingled with lose rocks and rarely with sand and gravel. Extensive mud- flats are formed along both the banks of the creek which are characterized by the growth of mangroves. This area is also highly bio productive and yields about 2 to 3 thousand met- ric tones of fish annually. However, recent rapid urbaniza- tion and industrialization with improper environmental

First reports of deep-water hermit crabs Parapagurus Smith, 1879 (Decapoda, Parapaguridae) and coelenterate associates from the Mid-Atlantic Ridge and South Atlantic

Three species of deep water hermit crabs of the genus Parapagurus Smith, 1879, family Parapaguridae, were collected in the South Atlantic during studies of the fauna and ecology of the Mid-Atlantic Ridge, a seamount chain that is an important habitat, feeding ground, and site of reproduction for many open ocean and deep-sea species. The three species collected, P. abyssorum (Filhol, 1885), P. nudus (A. Milne-Edwards, 1891), and P. pilosimanus Smith, 1879, are known to range broadly in the Atlantic, but only one, P. pilosimanus, was previously reported from the South Atlantic. Thus, P. abyssorum and P. nudus are reported for the first time from the Mid-Atlantic Ridge and the South Atlantic. These three species live in association with zoanthids or actinians that produce carcinoecia and serve as housing. The carcinoecia found with the specimens are also reported.

Physico-chemical analysis of the sediment samples collected from Thane Creek of Maharashtra, India

Thane Creek is one of the most important ecosystems around Mumbai and Thane, and the mangroves surrounding the ecosystem form the vital green lung for the residents. It is also an important feeding and breeding ground for fishes. Locals have been living in harmony amidst this ecosystem for ages, but in recent past, man has misused this ecosystem by way of releasing sewage, dumping solid waste, etc., and has succeeded in choking the ecosystem. This paper advocates habitat conservation and ecological studies with special reference to the physico-chemical characteristics of the sediment samples collected from six different sampling sites along the Thane Creek area. The constituents monitored included bulk density, moisture content, pH, EC, alkalinity, and chlorinity. The objective of the present work is to throw light on deteriorating condition of Thane Creek, suggesting the need for regular scientific studies, which will help to gauge the extent of pollution.

Artisanal salt production in Aveiro/Portugal - an ecofriendly process

Solar salinas are man-made systems exploited for the extraction of salt, by solar and wind evaporation of seawater. Salt production achieved by traditional methods is associated with landscapes and environmental and patrimonial values generated throughout history. Since the mid-twentieth century, this activity has been facing a marked decline in Portugal, with most salinas either abandoned or subjected to destruction, making it necessary to find a strategy to reverse this trend.It is, however, possible to generate revenue from salinas at several levels, not merely in terms of good quality salt production, but also by obtaining other products that can be commercialized, or by exploring their potential for tourism, and as research facilities, among others. Furthermore, with an adequate management, biodiversity can be restored to abandoned salinas, which constitute important feeding and breeding grounds for resident and migratory aquatic birds, many of which are protected by European Community Directives.The aims of this manuscript are to present a brief overview on the current state of sea salt exploitation in Portugal and to stress the importance of recovering these salinas for the conservation of this particular environment, for the regional economy, the scientific community and the general public. The Aveiro salina complex is presented in detail, to exemplify salina structure and functioning, as well as current problems and potential solutions for artisanal salinas.

Trophic interactions between preadult and adult Pomatoschistus minutus and Pomatoschistus microps and young Platichthys flesus occurring in inshore waters of the Gulf of Gdańsk (Southern Baltic)

Trophic interactions between preadult and adult Pomatoschistus minutus and Pomatoschistus microps and young Platichthys flesus occurring in inshore waters of the Gulf of Gdańsk (Southern Baltic) We intended to estimate if shallow inshore waters of the Gulf of Gdańsk can be considered important feeding grounds for the fishes under investigation. We also examined whether competition for food exists between the investigated fishes which co-exist. The study was carried out at Sopot and Chałupy stations from summer 2001 to autumn 2003. The results showed the high importance of Neomysis integer, which exclusively lives in coastal waters, in the diet of all three investigated fish species. It indicates that they utilize this zone as a feeding ground. The obtained dataset also led to the conclusion that fish trophic niches overlap by about 40%.

Size-related shifts in dietary composition ofCentropomus parallelus(Perciformes: Centropomidae) in an estuarine ecosystem of the southeastern coast of Brazil

Size-related and seasonal evaluation of the dietary composition of fat snook (Centropomus parallelus Poey 1860) in the upper sector of an estuary of the southeastern coast of Brazil were carried out based on stomach analyses of specimens ranging from 40 to 170 mm standard length. Results reveal that C. parallelus is a carnivorous species feeding mainly on benthic crustaceans. Relatively high stomach replenishment suggests that this environment is an important feeding ground for fat snook juveniles. Multivariate analyses indicated that predator size effect is significantly more important than seasonal variation in determining dietary composition. Predator length was associated with increased consumption of palaemonid shrimps (Macrobrachium spp.) and grapsid crabs, and decreased foraging on tanaids (Kalliapseudes schubarti), thus showing a preference shift from smaller to larger prey. Predator length was also positively associated with an increase in the stomach repletion index. Additionally, allometric growth of both gape and head were consistently correlated with this ontogenetic dietary transition, suggesting that such changes might be related to an individual’s ability to capture and consume larger, more elusive prey. The digestive tube is short and grows isometrically, which is in accordance with the carnivorous habit of this estuarine fish and its maintenance through ontogeny.