Phytoplankton species successions and their hydrological environment at a coastal station off Sydney

1986 ◽  
Vol 37 (3) ◽  
pp. 361 ◽  
Author(s):  
GM Hallegraeff ◽  
DD Reid
Keyword(s):  
Coastal Waters ◽  
Early Summer ◽  
Phytoplankton Species ◽  
Species Occurrence ◽  
Short Term ◽  
Coastal Station ◽  
Tropical Water ◽  
Diatom Blooms ◽  
Autumn And Winter ◽  
Water Species

Phytoplankton species occurrence was studied during 1978-1981 at a coastal station off Sydney and succession patterns were sought using polythetic agglomerative classification analysis. Three major phytoplankton categories were distinguished: (1) a large group of species (including most nanoplankton), which were present throughout the year; (2) a group of diatom species, which bloomed following episodic nutrient enrichments in spring, early summer, autumn and winter; (3) a group of warm-water species (e.g. Trichodesmium), which were associated with admixture of tropical water masses. Gross features of the phytoplankton cycle in these waters are related to the erratic flow pattern of the East Australian Current. However, clear short-term (4-14 weeks) species successions were evident within the spring and summer diatom blooms. These began with small diatoms (Asterionella, Leptocylindrus, Skeletonema, Thalassiosira) followed first by large diatoms (Detonula, Rhizosolenia, Stephanopyxis) and then by large dinoflagellates (Ceratium, Protoperidinium). This sequence is identical to that observed in coastal waters of other parts of the world. A phytoplankton checklist (280 species) for Sydney coastal waters is included as an appendix.

Population dynamics and reproduction ofHolothuria arenicola(Holothuroidea: Echinodermata) in coastal waters of Pakistan, North Arabian Sea

2015 ◽  
Vol 95 (6) ◽  
pp. 1245-1254 ◽  
Author(s):  
Saima Siddique ◽  
Zarrien Ayub
Keyword(s):  
Coastal Waters ◽  
Body Shape ◽  
Gonad Index ◽  
Significant Negative Correlation ◽  
Temporal Variations ◽  
Early Summer ◽  
Rocky Shores ◽  
Distribution Analysis ◽  
Autumn And Winter ◽  
Holothuria Arenicola

In Pakistan, although the sea cucumber fishery has not yet been developed,Holothuria arenicolais abundant on its coast. Nineteen months of sampling was carried out to study the population structure, allometric relationships and reproductive status ofH. arenicolastocks in Manora and Buleji rocky shores. All measured biometric characters showed significant temporal variations and width/length, weight/length, gutted weight/length and gutted weight/weight relationships followed negative allometry, indicating a change in body shape as the animal grows. Length-frequency distribution analysis was bimodal in both summer and autumn consisting of small-sized and medium-sized individuals while in winter and spring three modes were found at Manora. At Buleji, the population was unimodal in all seasons consisting of small-sized individuals. Sex inH. arenicolacannot be determined externally but can be identified on examination of gonad colour which is orange-like in females and creamy yellow in males. The sex was further confirmed on histological examination and maturation was divided into five stages, i.e. undetermined, early developing, late developing, mature and partially spawned. The sex ratio inH. arenicolawas approximately 1:1 and increase in gonad index was observed during spring and early summer, followed by a decrease in GI in autumn and winter, which showed the spawning followed by resting phase. The GI showed a significant negative correlation with salinity and non-significant correlation with temperature. There is a need to undertake more biological/ecological studies onH. arenicolain order to take effective measures for its management.

scholarly journals The impact of climate change induced alterations of streamflow and stream temperature on the distribution of riparian species

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0242682
Author(s):  
Jennifer B. Rogers ◽  
Eric D. Stein ◽  
Marcus W. Beck ◽  
Richard F. Ambrose
Keyword(s):  
Climate Change ◽  
Habitat Suitability ◽  
Species Distributions ◽  
Stream Temperature ◽  
Environmental Predictors ◽  
Species Occurrence ◽  
Short Term ◽  
Riparian Species ◽  
Water Species

Distributions of riparian species will likely shift due to climate change induced alterations in temperature and rainfall patterns, which alter stream habitat. Spatial forecasting of suitable habitat in projected climatic conditions will inform management interventions that support wildlife. Challenges in developing forecasts include the need to consider the large number of riparian species that might respond differently to changing conditions and the need to evaluate the many different characteristics of streamflow and stream temperature that drive species-specific habitat suitability. In particular, in dynamic environments like streams, the short-term temporal resolution of species occurrence and streamflow need to be considered to identify the types of conditions that support various species. To address these challenges, we cluster species based on habitat characteristics to select habitat representatives and we evaluate regional changes in habitat suitability using short-term, temporally explicit metrics that describe the streamflow and stream temperature regime. We use stream-specific environmental predictors rather than climatic variables. Unlike other studies, the stream-specific environmental predictors are generated from the time that species were observed in a particular reach, in addition to long term trends, to evaluate habitat preferences. With species occurrence data from local monitoring surveys and streamflow and stream temperature modeled from downscaled Coupled Model Intercomparison Project ‐ Phase 5 (CMIP5) climate projections, we predict change in habitat suitability at the end-of-century. The relative importance of hydrology and stream temperature varied by cluster. High altitudinal, cold water species’ distributions contracted, while lower elevation, warm water species distributions expanded. Modeling with short-term temporally explicit environmental metrics did produce different end-of-century projections than using long-term averages for some of the representative species. These findings can help wildlife managers prioritize conservation efforts, manage streamflow, initiate monitoring of species in vulnerable clusters, and address stressors, such as passage barriers, in areas projected to be suitable in future climate conditions.

scholarly journals Duration of Low Temperature Exposure Affects Egg Hatching of the Colorado Potato Beetle and Emergence of Overwintering Adults

Insects ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 609
Author(s):  
Jianghua Liao ◽  
Juan Liu ◽  
Zhijian Guan ◽  
Chao Li
Keyword(s):  
Low Temperature ◽  
Colorado Potato Beetle ◽  
Treatment Time ◽  
Early Summer ◽  
Short Term ◽  
Egg Survival ◽  
Egg Hatching ◽  
Potato Beetle ◽  
Temperature Exposure ◽  
Low Temperature Exposure

The Colorado potato beetle is a serious pest of Solanaceae in China. In early summer, cold spells in later spring may occur for brief periods in the field environmental conditions, and temperatures often deviate far below the normal temperature for short periods, such as sudden short-term low temperature, may affect the development of Colorado potato beetle eggs. This paper studies the effects of low temperature stress at 8 °C for 0 d, 1 d, 3 d, 5 d, 7 d, and 10 d on the development of Colorado potato beetle eggs. Our results show that egg survival is significantly affected by short-term low temperature exposure. The percentage of eggs hatched is significantly affected by different treatment times (p = 0.000)—the percentage of eggs hatched decreases with increased treatment time, and Colorado potato beetles will extend the wintering time of their soil to resist the effects of lower temperatures. Thus, exposure of Colorado potato beetles to a short-term low temperature affects their emergence and population growth; this study could provide information for the occurrence, monitoring, and early warning of Colorado potato beetle during short-term temperature.

scholarly journals Distribution and annual occurrence of Chaetognatha off Cananeia and Santos coast (São Paulo, Brazil)

1968 ◽  
Vol 17 (1) ◽  
pp. 33-55 ◽  
Author(s):  
M. S. de Almeida Prado
Keyword(s):  
Coastal Water ◽  
Annual Variation ◽  
Abundant Species ◽  
Breeding Period ◽  
Shelf Water ◽  
Vertical Movements ◽  
Tropical Water ◽  
The Vertical Distribution ◽  
Water Species ◽  
Different Levels

Plankton samples were fortnightly taken at three fixed stations off Cananéia (1958, 1959, 1960) and off Santos (1960, 1961) by vertical hauling. They contained the following species: Sagitta enflata, S. friderici, S. hispida, S. minima, S. serratodentata, Krohnitta pacifica and Pterosagitta draco. S. frideriei is a typical coastal water species. S. enflata is a typical shelf water species. S. hispida and K. pacifica were present more frequently in shelf water but they were sometimes very abundant in coastal water. S. serratodentata, S. minima and P. draco occurred sparingly in tropical water, however, very few samples were taken in this water mass. Three different maturity stages were established (juvenile, intermediate and adult) in order to study the annual variation of the Chaetognatha. A special breeding period throughout the year was not observed as great swarms of juveniles and intermediates were found in spite of the very small number of adults. Two series of samples taken off Santos at a fixed station (Pt. III) during a period of 24 hours in three different levels were also counted to study the vertical distribution of the Chaetognatha in this area. The three most abundant species were: S. enflata, S. hispida and K. pacifica. S. enflata was more frequent at mid-water. S. hispida and K. pacifica seemed to prefer the surface layer. The thermocline did not affect their vertical migration except for S. hispida. There is indication that S. serratodentata performs vertical movements. S. minima seems to live below 25 m depth. K. subtilis occurred exceptionally in this vertical series of samples.

scholarly journals The holoplankton of the Santa Catarina coast, southern Brazil

2011 ◽  
Vol 83 (2) ◽  
pp. 575-588 ◽  
Author(s):  
Charrid Resgalla Jr
Keyword(s):  
Coastal Waters ◽  
Zooplankton Community ◽  
The State ◽  
Zooplankton Abundance ◽  
Santa Catarina ◽  
The North ◽  
Or Groups ◽  
Parvocalanus Crassirostris ◽  
Water Species ◽  
Potential Use

This paper presents information from different sampling surveys carried out along the Santa Catarina coast in order to outline the biogeographical characteristics of the zooplankton in this region and identify species or groups of species with potential use as bioindicators. Based on a checklist of species of the zooplankton community in the state, it was observed that, in the warmer months of the year, the fauna is similar to that of the states of Paraná and São Paulo (e.g. Creseis virgula f. virgula, Penilia avirostris; Acartia lilljeborgi and Oithona oswaldocruzi), while in the colder months there are coastal representatives of the fauna of Rio Grande do Sul (e.g. Acartia tonsa). However, the zooplankton consists predominantly of warm water species for most of the year, which is typical of Tropical Shelf Waters. Various species of zooplankton can be used as hydrological indicators, enabling a distinction to be made between coastal waters which are influenced by continental inputs (e.g. Paracalanus quasimodo and Parvocalanus crassirostris), common in the north of the state, and processes of upwelling (e.g. Podon intermedius) and the influence of the Subtropical Shelf Front (e.g. Pleopis polyphemoides), coming from the south. The different environments investigated present a zooplankton abundance that depends on the influence of continental inputs and the possibility of their retaining and contribution for the coastal enrichment, which varies seasonally

scholarly journals Spatial and temporal distribution of phytoplankton in Lake Skadar

2012 ◽  
Vol 64 (2) ◽  
pp. 585-595 ◽  
Author(s):  
Jelena Rakocevic
Keyword(s):  
Spatial Heterogeneity ◽  
Phytoplankton Community ◽  
General Pattern ◽  
Seasonal Succession ◽  
Temporal Distribution ◽  
Late Summer ◽  
Early Summer ◽  
Quantitative Composition ◽  
Autumn And Winter ◽  
Lake Skadar

Phytoplankton seasonal succession and spatial heterogeneity were studied in Lake Skadar from February to December 2004. A total of 167 taxa from 6 algal divisions were observed, with Bacillariophyta being best represented (52.8%). The general pattern of phytoplankton seasonal succession in Lake Skadar was: Bacillariophyta in the spring, Chlorophyta in early summer, Cyanobacteria and Chlorophyta in late summer and Bacillariophyta and Chlorophyta in autumn and winter. Distinct spatial heterogeneity was observed. The central, open part of the lake (pelagic zone) was characterized by dominant euplanktonic species, mostly diatoms, whereas the western and northwestern parts (more isolated and shallower) had higher abundance of greens and blue-greens and a higher percentage of resuspended benthic-epiphytic forms in the phytoplankton community. Comparison with former phytoplankton data showed distinct differences in terms of the qualitative and quantitative composition of the phytoplankton community of Lake Skadar, which indicates lake deterioration.

scholarly journals Controls on short-term variations in Greenland glacier dynamics

2013 ◽  
Vol 59 (217) ◽  
pp. 883-892 ◽  
Author(s):  
A.V. Sundal ◽  
A. Shepherd ◽  
M. van den Broeke ◽  
J. Van Angelen ◽  
N. Gourmelen ◽  
...  
Keyword(s):  
Time Series ◽  
Radar Data ◽  
Early Summer ◽  
Short Term ◽  
Synthetic Aperture Radar Data ◽  
Velocity Fluctuations ◽  
Speed Up ◽  
Front Advance ◽  
Enhanced Surface ◽  
Front Dynamics

AbstractShort-term ice-dynamical processes at Greenland’s Jakobshavn and Kangerdlugssuaq glaciers were studied using a 3 day time series of synthetic aperture radar data acquired during the 2011 European Remote-sensing Satellite-2 (ERS-2) 3 day repeat campaign together with modelled meteorological parameters. The time series spans the period March–July 2011 and captures the first ∼30% of the summer melting season. In both study areas, we observe velocity fluctuations at the lower ∼10 km of the glacier. At Jakobshavn Isbræ, where our dataset covers the first part of the seasonal calving-front retreat, we identify ten calving episodes, with a mean calving-front area loss of 1.29 ± 0.4 km2. Significant glacier speed-up was observed in the near-terminus area following all calving episodes. We identify changes in calving-front geometry as the dominant control on velocity fluctuations on both glaciers, apart from a <15% early-summer speed-up at Kangerdlugssuaq Glacier during a period of calving-front advance, which we attribute to enhanced surface melt-induced basal lubrication. Our 3 day velocity maps show new spatial characteristics of the ice melange flow variability in the Jakobshavn and Kangerdlugssuaq fjord systems, which are primarily controlled by calving-front dynamics and fjord geometry.

Guide to Squid, Cuttlefish and Octopuses of Australasia

2000 ◽  
Author(s):  
Mark Norman ◽  
Amanda Reid
Keyword(s):  
Coastal Waters ◽  
Distribution Map ◽  
Marine Animals ◽  
Giant Squid ◽  
The World ◽  
Readable Form ◽  
Informative Text ◽  
Australasian Region ◽  
Water Species ◽  
Shallow Coastal Waters

The Australasian region is home to the greatest diversity of cephalopods — squid, cuttlefish, octopuses — in the world. Yet, we know very little about these fascinating marine animals. This book provides insights into the biology and behaviour of more than 60 species. From the Giant Squid to the deadly Blue-ringed Octopus, the secret lives of cephalopods are revealed in a highly readable form with outstanding colour images and informative text. For each species there is a distribution map and identification notes which summarise the main features to look for. While the book focuses on species found in relatively shallow coastal waters, a few of the more bizarre deeper-water species are included. Naturalists, divers, reef-walkers and anglers will find the book authoritative, yet very easy to use. A comprehensive section illustrating cuttlebones will enable beachcombers to identify most of the species they are likely to encounter.

Effect of the Leeuwin Current upon sea surface temperatures off south-western Australia

1984 ◽  
Vol 35 (4) ◽  
pp. 487 ◽  
Author(s):  
DJ Rochford
Keyword(s):  
Western Australia ◽  
Coastal Waters ◽  
Sea Surface ◽  
Sea Surface Temperatures ◽  
Leeuwin Current ◽  
South Eastern ◽  
Surface Temperatures ◽  
Autumn And Winter

Comparison of long-term mean monthly sea surface temperatures of coastal waters at comparable latitudes off south-eastern and south-westem Australia shows that, during the duration of the Leeuwin Current in autumn and winter, sea surface temperatures are 1-3�C higher off south-western Australia.

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