Consulta: subjectFacets:"Long-term changes"
Registros recuperados: 14
Data/hora: 16/06/2024 09:10:49

Comparative analysis of long-term alteration in structural organization of zoobenthos under permanent anthropogenic impact (Case study: Sevastopol Bay, Crimea).
Provedor de dados: 13
Autores: Revkov, N. K.; Petrov, A. N.; Kolesnikova, E. A.; Dobrotina, G. A.
The results of benthic survey of soft bottoms in the Sevastopol bay had been performed in 2001 are presented. This bay is under permanent technogenic impact and is being considered as one of the most polluted areas along the coastal part of Crimea. The peculiarities of quantitative development of macrobenthic assemblages were characterized, and taxa which define the structural organization of assemblages were distinguished. In spite of strong influence of technogenic pollution, Sevastopol bay can be attributed to faunistically rich areas of Crimean coast and the Black Sea at whole. Using the methods of multivariate statistical analysis, suites of 7 – 8 environmental variables (from the 32 ones considered in the analysis) that best explained the observed...
Tipo: Journal Contribution
Palavras-chave: Структура сообществ; Многолетние изменения; Черное море; Севастопольская бухта; Макрозообентос; Структура угруповань; Багаторічні зміни; Чорне море; Севастопольська бухта; Macrozoobenthos; Structure of assemblages; Long-term changes; The Black Sea; Sevastopol bay.
Ano: 2008
URL: http://repository.ibss.org.ua/dspace/handle/99011/820

Тенденции многолетних изменений фитоценозов «цистозирового пояса» Карадагского природного заповедника (Крым, Чёрное море).
Provedor de dados: 13
Autores: Костенко, Н. С.; Дикий, Е. А.; Заклецкий, А. А.
Трансформация цистозировых фитоценозов района Карадага за период 1970 – 2006 гг. может  быть охарактеризована преимущественно как аллогенная деградация. Факторами, угнетающе действующими на фитоценозы цистозиры, вероятнее всего, являются эвтрофирование акваторий и снижение прозрачности  водных масс. Результатом процессов трансформации является формирование на малых глубинах (1 – 2 м) устойчивых фитоценозов с доминированием бурых многолетников и значительной биомассой зелёных и красных мезосапробных водорослей, на глубинах от 3 м и более – формирование переходных растительных ассоциаций с cодоминированием бурых многолетников и сциофильных красных водорослей, а в дальнейшем – полная деградация цистозировых фитоценозов.
Tipo: Journal Contribution
Palavras-chave: Донная растительность; Цистозира; Трансформация сообществ; Эвтрофикация; Прозрачность; Освещённость; Крым; Чёрное море; Bottom vegetation; Macrophytobenthos; Cystoseira; Long-term changes; Eutrophication; Water transparency; Illumination; Crimea; Black Sea; Донна рослинність; Макрофітобентос; Цистозіра; Трансформації фітоценозів; Евтрофування; Прозорість; Освітленість; Крим; Чорне море.
Ano: 2008
URL: http://repository.ibss.org.ua/dspace/handle/99011/819

Многолетние изменения Gastropoda на талломе водоросли Cystoseira sp. в прибрежье Крыма (Черное море)
Provedor de dados: 13
Autores: Макаров, М. В.
Проведен анализ многолетних (с 1954 по 2005 гг.) изменений численности гастропод на талломе Cystoseira sp. Отмечено значительное (почти в 50 раз) уменьшение общей численности брюхоногих моллюсков, в основном за счет Rissoa splendida. Предполагается, что это является следствием увеличения общего уровня загрязнения акватории. Установлено, что в определенный период времени явно или незначительно преобладает один из трех массовых видов - R. splendida, Tricolia pullus, Bittium reticulatum. В настоящее время соотношение этих видов в эпифитоне цистозиры примерно одинаково.
Tipo: Journal Contribution
Palavras-chave: Брюхоногие моллюски; Rissoa splendida; Tricolia pullus; Bittium reticulatum; Эпифитон; Цистозира; Многолетние изменения; Черное море; Long-term changes; Epyphyton; Gastropods; Black Sea Long-term changes.
Ano: 2005
URL: http://repository.ibss.org.ua/dspace/handle/99011/233

Многолетние изменения в сообществах макрофитобентоса района Карадага (Крым, Черное море)
Provedor de dados: 13
Autores: Костенко, Н. С.; Дикий, Е. А.; Заклецкий, А. А.; Марченко, В. С.
Описаны изменения сообществ макрофитобентоса района Карадага (Крым, Черное море) за период 1970 -2005 гг.: смена видов-доминантов в фитоценозах, изменения общей биомассы растительности и биомассы ведущих видов. Приведены сукцессионные схемы. Проведена ординация растительных сообществ. Показаны отличия сукцессионных процессов в мелководной и глубоководной зонах шельфа.
Tipo: Journal Contribution
Palavras-chave: Макрофитобентос; Донная растительность; Сообщества; Сукцессии; Многолетние измене­ния; Фитоценозы. шельф; Карадаг; Черное море; Macrophytobentos; Bottom-dwelling vegetation; Communities; Successions; Long-term changes; Phyto-cenosis; Shelf; Karadag; Black Sea Long-term changes.
Ano: 2005
URL: http://repository.ibss.org.ua/dspace/handle/99011/230

Межгодовая изменчивость возрастной структуры популяции мидий Mytilus galloprovincialis в северо-западной части Черного моря
Provedor de dados: 13
Autores: Шурова, Н. М.
Проведен анализ многолетней изменчивости размерно-возрастной структуры поселений мидий в северо-западной части Черного моря. Выявленные межгодовые различия свидетельствуют о том, что в современных экологических условиях на северо-западном шельфе Черного моря продолжаются негативные процессы, которые увеличивают смертность моллюсков и приводят к неуклонному омоложению возрастной структуры их поселений. Это вызывает уменьшение продолжительности жизни черноморской мидии и снижение ее репродукционного потенциала.
Tipo: Journal Contribution
Palavras-chave: Population; Mussels; Long-term changes; The Black Sea; Популяция; Мидии; Черное море Population structure Population structure http://aims.fao.org/aos/agrovoc/c_6115.
Ano: 2003
URL: http://repository.ibss.org.ua/dspace/handle/99011/489

Spatiotemporal dynamics of submerged macrophyte status and watershed exploitation in a Mediterranean coastal lagoon: Understanding critical factors in ecosystem degradation and restoration
Provedor de dados: 5
Autores: Pasqualini, Vanina; Derolez, Valerie; Garrido, Marie; Orsoni, Valerie; Baldi, Yoann; Etourneau, Sabrina; Leoni, Vanina; Rebillout, Patrick; Laugier, Thierry; Souchu, Philippe; Malet, Nathalie.
Increases in the intensity of disturbances in coastal lagoons can lead to shifts in vegetation from aquatic angiosperms to macroalgal or phytoplankton communities. Such abrupt and discontinuous responses are facilitated by instability in the equilibrium controlling the trajectory of the community response. We hypothesized that the shift in macrophyte populations is reversible, and that this reversibility is dependent on changes in the pressures exerted on the watershed and lagoon functioning. Biguglia lagoon (Mediterranean Sea, Corsica) is an interesting case study for the evaluation of long-term coastal lagoon ecosystem functioning and the trajectory of submerged macrophyte responses to disturbances, to facilitate the appropriate restoration of...
Tipo: Text
Palavras-chave: Coastal lagoons; Human pressures; Long-term changes; Submerged macrophytes; Community shifts.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00372/48341/48564.pdf

Long-term macrofaunal studies in a subtidal habitat off Norderney (East Frisia, Germany) from 1978 to 1994 .1. The late winter samples
Provedor de dados: 5
Autores: Zeiss, B; Kroncke, I.
Macrofaunal samples were collected regularly during springtime from 1978 to 1994 in the subtidal zone off Norderney, one of the East Frisian barrier islands. Sampling was carried out from a research vessel by means of a 0.2 m(2) van-Veen grab at five sites with water depths of 10-20 m. Abundances, biomasses and species composition were analysed by cluster analysis and multidimensional scaling. The resulting patterns are discussed in terms of anthropogenic impact and varying meteorological conditions. Species survival is severely impaired by cold winters, whereas storms and hot summers have a minor impact. There is evidence that mild meteorological conditions and eutrophication have resulted in an increase in total biomass since 1989. In addition to...
Tipo: Text
Palavras-chave: Macrofaunal; Fabulina fabula; Association; Long-term changes; Sublittoral; German bight; Climate.
Ano: 1997
URL: http://archimer.ifremer.fr/doc/00093/20401/18068.pdf

Long-term changes and coastal eutrophication. Examples from the Aland Islands and the Archipelago Sea, northern Baltic Sea
Provedor de dados: 5
Autores: Bonsdorff, E; Blomqvist, Em; Mattila, J; Norkko, A.
The coastal and archipelago waters of the northern Baltic Sea are influenced by increasing eutrophication (significantly increasing temporal trends in nutrient availability). Increased nutrient levels and pelagic primary production have led to decreased transparency in the water body, increased plankton biomass, and increased amounts of filamentous algae. Large-scale and long-term (15-30 years) comparisons have shown that zoobenthic communities have changed significantly (altered species diversity, increased total abundance and increased biomass). The stress in the ecosystem is also illustrated at the population level (Macoma balthica). An increasing trend is shown for a near-shore fish community, where the increase in biomass has been linear over the past...
Tipo: Text
Palavras-chave: Baltic Sea; Eutrophication; Long-term changes; Nutrient; Zoobenthos.
Ano: 1997
URL: http://archimer.ifremer.fr/doc/00093/20402/18069.pdf

Long-term time series in Calanus finmarchicus abundance - A question of space?
Provedor de dados: 5
Autores: Planque, Benjamin; Ibanez, F.
Year-to-year changes in abundance of the copepod Calanus finmarchicus in the North Atlantic are studied by means of the Continuous Plankton Recorder (CPR). Using data collected during the years 1962 to 1974, the spatial heterogeneity of long-term trends is studied by numerical analysis: Mantel test, Mantel correlogram, and spatio-temporal clustering. Results reveal that (1) interannual changes of C. finmarchicus abundance are spatially autocorrelated; (2) the spatial structures have a radius varying between 400 and 1100 km; and (3) there is a high variability in the annual changes observed between the different zones detected by clustering. These results show that observations made in the Northeast Atlantic cannot be extrapolated to the whole North...
Tipo: Text
Palavras-chave: North Atlantic; Calanus finmarchicus; Long-term changes; Space-time interactions; Continuous Plankton Recorder.
Ano: 1997
URL: http://archimer.ifremer.fr/doc/00093/20388/18055.pdf

Changements à long terme dans une communauté benthique d'un golfe méditerranéen (golfe de Fos)
Provedor de dados: 5
Autores: Salenpicard, C; Bellan, G; Bellansantini, D; Arlhac, D; Marquet, R.
Changes over a period of thirty years in a circalittoral mud community (% silt greater than or equal to 75) in the Gulf of Fos (French, Mediterranean coast) have been followed at three sites spaced along a transect NNW-SSE at depths of 15, 35 and 70 m. The results clearly show how the macrobenthic community at the three sites has been influenced by the construction of the port of Fos, notably as a consequence of sediment suspension during the dredging of the docks and the access channel, but also due to the dumping at sea of dredged material (more than 100 x 10(6) m(3) were dredged, about a quarter of which was dumped at sea, at depths of 30 to 60 m). The grouping of the samples taken before, during and after the development of the port (1963-1964, from...
Tipo: Text
Palavras-chave: Long-term changes; Benthos; Synecology; Parsimonious analysis.
Ano: 1997
URL: http://archimer.ifremer.fr/doc/00093/20400/18067.pdf

Eastern Atlantic bluefin tuna: what we learn from historical time-series of trap catches
Provedor de dados: 5
Autores: Ravier, Christelle; Fromentin, Jean-marc.
More than one hundred long-term time-series of bluefin tuna catches from the ancestral Mediterranean and Atlantic trap fisheries are used to (1) estimate historical range of BFT yields in the Mediterranean and adjacent Atlantic and (2) investigate spatial and temporal patterns of fluctuations in trap catches. Mean historical catches were around 110 000 tunas/year (± 50 000), i.e. 15 000 tons/year (∈[7 000;25 000]). Fluctuations in trap catches are of large magnitude, periods of high abundance being up to seven times higher than those of low abundance. More interesting was the occurrence of 100-year-long periodic fluctuations as well as 20-year cycles. These medium- to long-term fluctuations, representing more than 50% of the total variability in the...
Tipo: Text
Palavras-chave: Thunnus thynnus; Time series analyses; Abundance; Population dynamics; Long-term changes; Trapfishing.
Ano: 2002
URL: http://archimer.ifremer.fr/doc/00194/30497/28906.pdf

Analyse de l'évolution temporelle de communautés macrobenthiques à partir des probabilités de présence des espèces
Provedor de dados: 5
Autores: Mante, C; Durbec, Jp; Dauvin, Jc.
Statistical analysis of long-term changes in marine communities generally involves recourse to multivariate methods. Some of these, such as Correspondence Analysis (CA), are very sensitive to the presence of rare species in the data, whereas other methods, such as Principal Components analysis (PCA) or Multidimensional Scaling (MDS) are only sensitive to the dominant species. Thus, it is necessary to identify rare species. We used an original method of species determination, based on a multinomial scheme and permitting the generalization of the classical presence/absence coding from a probabilistic viewpoint. This selection method was applied to the identification of the different categories of species (rare, intermediate or dominant) that constitute the...
Tipo: Text
Palavras-chave: Statistical analysis; Probability; Long-term changes; Macrobenthic community.
Ano: 1997
URL: http://archimer.ifremer.fr/doc/00093/20428/18095.pdf

The ecological state of Lake Naivasha, Kenya, 2005: Turning 25 years research into an effective Ramsar monitoring programme
Provedor de dados: 20
Autores: Mavuti, K.M.; Harper, David.
The present paper summarises the state of ecological knowledge in the lake based upon the research of the teams of Harper &amp; Mavuti, funded by the Earthwatch Institute since 1987. It suggests how the research knowledge should drive the Ramsar monitoring programme that is now evolving.
Tipo: Proceedings Paper
Palavras-chave: Inland waters; Freshwater lakes; Tropical lakes; Ecological balance; Ecosystem management; Environment management; Environmental monitoring; Resource management; Baseline studies; Long-term changes; Environmental monitoring; Inland waters; Ecological balance; Resource management; Http://aims.fao.org/aos/agrovoc/c_37876; Http://aims.fao.org/aos/agrovoc/c_3876; Http://aims.fao.org/aos/agrovoc/c_34928; Http://aims.fao.org/aos/agrovoc/c_6524.
Ano: 2006
URL: http://hdl.handle.net/1834/2127

Asociación bentónicas en bancos de vieira patagónica (Zygochlamys patagonica) en el Mar Argentino
Provedor de dados: 20
Autores: Schejter, L.
The different aspects of the benthic assemblages at the Patagonian scallop beds in the Argentine Sea (SW Atlantic) were studied. The Patagonian scallop (Zygochlamys patagonica) is a commercial species distributed in the Magellanic Biogeographic Province, and has been commercially exploited since 1996. Temporal and spatial studies were performed in the community composition between 39°50'S and 36°15'S, and between 1998 and 2003, concluding that the species association was persistent after more than 7 years of trawling activities. Species composition in an exclusion area (closed to scallop fishing) did not differ from surrounding fished areas during the studied period, showing only a higher scallop biomass. ABC curves showed a pattern coincident with a non...
Tipo: Theses and Dissertations
Palavras-chave: Zoobenthos; Community composition; Long-term changes; Short-term changes; Species diversity; Fishing grounds; Epibionts; Scallop fisheries; Multivariate analysis; Multivariate analysis; Zoobenthos; Species diversity; Fishing grounds.
Ano: 2005
URL: http://hdl.handle.net/1834/3917